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Helmers, A. -K., Luebbing, I., Birkenfeld, F., Witt, K., Synowitz, M., Mehdorn, H. M., and Falk, D., Complications of Impulse Generator Exchange Surgery for Deep Brain Stimulation: A Single-Center, Retrospective Study, WORLD NEUROSURGERY, vol. 113. ELSEVIER SCIENCE INC, May-2018.
Abstract
BACKGROUND: Nonrechargeable deep brain stimulation impulse generators (IGs) with low or empty battery status require surgical IG exchange several years after initial implantation. The aim of this study was to investigate complication rates after IG exchange surgery and identify risk factors. METHODS: We retrospectively analyzed complications following IG exchange surgery from 2008 to 2015 in our department. Medical records of all patients who underwent IG exchange surgery were systematically reviewed. The shortest follow-up time was 19 months. RESULTS: From 2008 to 2015, 438 IGs were exchanged in 319 patients. Overall complication rate was 8.90\%. Infection developed in 12 patients (2.74\%). Six patients (1.37\%) experienced local wound erosions. Hardware malfunctions were present in 11 patients (2.51\%), and local hemorrhage was observed in 3 cases (0.68\%). Repeated fixation of the IG was required in 2 patients (0.46\%). Traction of the connecting cables necessitated surgical revision in 2 patients (0.46\%). In 2 cases (0.46\%), the IG was placed abdominally or exchanged for a smaller device owing to patient discomfort resulting from the initial positioning. One 80-year-old patient (0.23\%) had severely worsening heart failure and died 4 days after IG exchange surgery. CONCLUSIONS: IG exchange surgery, although often considered a minor surgery, was associated with a complication rate of approximately 9\% in our center. Patients and physicians should understand the complication rates associated with IG exchange surgery because this information might facilitate selection of a rechargeable IG.
Rothkirch, I., Wolff, S., Margraf, N. G., Pedersen, A., and Witt, K., Does Post-task Declarative Learning Have an Influence on Early Motor Memory Consolidation Over Day? An fMRI Study, FRONTIERS IN NEUROSCIENCE, vol. 12. FRONTIERS MEDIA SA, Apr.-2018.
Abstract
Previous studies demonstrated the influence of the post-learning period on procedural motor memory consolidation. In an early period after the acquisition, motor skills are vulnerable to modifications during wakefulness. Indeed, specific interventions such as world-list learning within this early phase of motor memory consolidation seem to enhance motor performance as an indicator for successful consolidation. This finding highlights the idea that manipulations of procedural and declarative memory systems during the early phase of memory consolidation over wakefulness may influence off-line consolidation. Using functional magnetic resonance imaging (fMRI) during initial motor sequence learning and motor sequence recall, we indirectly assess the influence of a secondary task taken place in the early phase of memory consolidation. All participants were scanned using fMRI during the learning phase of a serial reaction time task (SRTT) at 8 a.m.. Afterwards, they were randomly assigned to one of five conditions. One group performed a declarative verbal, one a declarative nonverbal learning task. Two groups worked on attention tasks. A control group passed a resting condition. Participants stayed awake the whole day and performed the SRTT in the MRI scanner 12h later at 8 p.m.. At the behavioral level, the analysis of the reaction times failed to show a significant group difference. The primary analysis assessing fMRI data based on the contrast (sequence - random) between learning and retrieval also did not show any significant group differences. Therefore, our main analysis do not support the hypothesis that a secondary task influences the retrieval of the SRTT. In a more liberal fMRI analysis, we compared only the sequence blocks of the SRTT from learning to recall. BOLD signal decreased in the ipsilateral cerebellum and the supplementary motor area solely in the verbal learning group. Although our primary analysis failed to show significant changes between our groups, results of the secondary analysis could be an indication for a beneficial effect of the verbal declarative task in the early post-learning phase. A nonverbal learning task did not affect the activation within the motor network. Further studies are needed to replicate this finding and to assess the usefulness of this manipulation.
Lhommee, E., Wojtecki, L., Czernecki, V., Witt, K., Maier, F., Tonder, L., Timmermann, L., Haelbig, T. D., Pineau, F., Durif, F., Witjas, T., Pinsker, M., Mehdorn, M., Sixel-Doering, F., Kupsch, A., Krueger, R., Elben, S., Chabardes, S., Thobois, S., Brefel-Courbon, C., Ory-Magne, F., Regis, J. -M., Maltete, D., Sauvaget, A., Rau, J., Schnitzler, A., Schupbach, M., Schade-Brittinger, C., Deuschl, G., Houeto, J. -L., Krack, P., and Grp, E. A. R. L. Y. S. T. I. M. S., Behavioural outcomes of subthalamic stimulation and medical therapy versus medical therapy alone for Parkinson's disease with early motor complications (EARLYSTIM trial): secondary analysis of an open-label randomised trial, LANCET NEUROLOGY, vol. 17, no. 3. ELSEVIER SCIENCE INC, Mar.-2018.
Abstract
Background Although subthalamic stimulation is a recognised treatment for motor complications in Parkinson's disease, reports on behavioural outcomes are controversial, which represents a major challenge when counselling candidates for subthalamic stimulation. We aimed to assess changes in behaviour in patients with Parkinson's disease receiving combined treatment with subthalamic stimulation and medical therapy over a 2-year follow-up period as compared with the behavioural evolution under medical therapy alone. Methods We did a parallel, open-label study (EARLYSTIM) at 17 surgical centres in France (n=8) and Germany (n=9). We recruited patients with Parkinson's disease who were disabled by early motor complications. Participants were randomly allocated (1: 1) to either medical therapy alone or bilateral subthalamic stimulation plus medical therapy. The primary outcome was mean change in quality of life from baseline to 2 years. A secondary analysis was also done to assess behavioural outcomes. We used the Ardouin Scale of Behavior in Parkinson's Disease to assess changes in behaviour between baseline and 2-year follow-up. Apathy was also measured using the Starkstein Apathy Scale, and depression was assessed with the Beck Depression Inventory. The secondary analysis was done in all patients recruited. We used a generalised estimating equations (GEE) regression model for individual items and mixed model regression for subscores of the Ardouin scale and the apathy and depression scales. This trial is registered with ClinicalTrials.gov, number NCT00354133. The primary analysis has been reported elsewhere; this report presents the secondary analysis only. Findings Between July, 2006, and November, 2009, 251 participants were recruited, of whom 127 were allocated medical therapy alone and 124 were assigned bilateral subthalamic stimulation plus medical therapy. At 2-year follow-up, the levodopa-equivalent dose was reduced by 39\% (-363.3 mg/day {[}SE 41.8]) in individuals allocated bilateral subthalamic stimulation plus medical therapy and was increased by 21\% (245.8 mg/day {[}40.4]) in those assigned medical therapy alone (p<0.0001). Neuropsychiatric fluctuations decreased with bilateral subthalamic stimulation plus medical therapy during 2-year follow-up (mean change -0.65 points {[}SE 0.15]) and did not change with medical therapy alone (-0.02 points {[}0.15]); the between-group difference in change from baseline was significant (p=0.0028). At 2 years, the Ardouin scale subscore for hyperdopaminergic behavioural disorders had decreased with bilateral subthalamic stimulation plus medical therapy (mean change -1.26 points {[}SE 0.35]) and had increased with medical therapy alone (1.12 points {[}0.35]); the between-group difference was significant (p<0.0001). Mean change from baseline at 2 years in the Ardouin scale subscore for hypodopaminergic behavioural disorders, the Starkstein Apathy Scale score, and the Beck Depression Inventory score did not differ between treatment groups. Antidepressants were stopped in 12 patients assigned bilateral subthalamic stimulation plus medical therapy versus four patients allocated medical therapy alone. Neuroleptics were started in nine patients assigned medical therapy alone versus one patient allocated bilateral subthalamic stimulation plus medical therapy. During the 2-year follow-up, two individuals assigned bilateral subthalamic stimulation plus medical therapy and one patient allocated medical therapy alone died by suicide. Interpretation In a large cohort with Parkinson's disease and early motor complications, better overall behavioural outcomes were noted with bilateral subthalamic stimulation plus medical therapy compared with medical therapy alone. The presence of hyperdopaminergic behaviours and neuropsychiatric fluctuations can be judged additional arguments in favour of subthalamic stimulation if surgery is considered for disabling motor complications.
Baldewig, M., Goldbaum, O., Richter-Landsberg, C., Weyland, A., and Bantel, C., Short-term incubation of gabapentin or pregabalin does not affect chemically induced injury in neuronal cell models in vitro, JOURNAL OF PAIN RESEARCH, vol. 11. DOVE MEDICAL PRESS LTD, 2018.
Abstract
Purpose: Gabapentinoids are currently the mainstay of pharmacological treatments for patients with neuropathic pain. Little is known about the effects of this therapy on the integrity of neuronal networks, especially in patients with an already-damaged nervous system. Since gabapentinoids can worsen cognitive functions and recent studies have shown alterations in the brains of patients with neuropathic pain, it may be possible that these drugs have neurotoxic effects. Methods: Rat clonal PC12 pheochromocytoma (autonomic) and primary sensory dorsal-root ganglion (DRG) neurons from newborn Wistar rats were employed for this study. To mimic neuronal damage, cells were exposed to cytotoxins using either hydrogen peroxide (H2O2) or vincristine. Results: No direct cytotoxic effects were observed after incubating PC12 cells for 24 hours with increasing concentrations of gabapentin or pregabalin using MTT cytotoxicity assays. Even a 7-day incubation did not cause cellular damage. Furthermore, in preinjured PC12 and DRG neurons, neither gabapentin nor pregabalin prevented or enhanced the cytotoxic effects of H2O2 or vincristine after incubation for 24 hours and 7 days, respectively. Cell morphology and integrity of the cytoskeleton assessed by employing immunostaining of cytoskeletal proteins (alpha-tubulin, neurofilament L) remained intact and were not altered by gabapentinoids. Conclusion: Based on these results, gabapentinoids are unlikely to be neurotoxic in cultured autonomic (PC12) and sensory DRG cells, even when cells are preinjured. These results are of high clinical relevance, as it seems unlikely that the morphological changes recently observed in the brains of neuropathic pain patients are caused or worsened by gabapentinoids.
Moritz, N., Adiloglu, K., Anemueller, J., Goetze, S., and Kollmeier, B., Multi-Channel Speech Enhancement and Amplitude Modulation Analysis for Noise Robust Automatic Speech Recognition, COMPUTER SPEECH AND LANGUAGE, vol. 46. ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, Nov.-2017.
Abstract
The paper describes a system for automatic speech recognition (ASR) that is benchmarked with data of the 3rd CHiME challenge, a dataset comprising distant microphone recordings of noisy acoustic scenes in public environments. The proposed ASR system employs various methods to increase recognition accuracy and noise robustness. Two different multi-channel speech enhancement techniques are used to eliminate interfering sounds in the audio stream. One speech enhancement method aims at separating the target speaker's voice from background sources based on non-negative matrix factorization (NMF) using variational Bayesian (VB) inference to estimate NMF parameters. The second technique is based on a time-varying minimum variance distortionless response (MVDR) beamformer that uses spatial information to suppress sound signals not arriving from a desired direction. Prior to speech enhancement, a microphone channel failure detector is applied that is based on cross-comparing channels using a modulation-spectral representation of the speech signal. ASR feature extraction employs the amplitude modulation filter bank (AMFB) that implicates prior information of speech to analyze its temporal dynamics. AMFBs outperform the commonly used frame splicing technique of filter bank features in conjunction with a deep neural network (DNN) based ASR system, which denotes an equivalent data-driven approach to extract modulation-spectral information. In addition, features are speaker adapted, a recurrent neural network (RNN) is employed for language modeling, and hypotheses of different ASR systems are combined to further enhance the recognition accuracy. The proposed ASR system achieves an absolute word error rate (WER) of 5.67\% on the real evaluation test data, which is 0.16\% lower compared to the best score reported within the 3rd CHiME challenge. (C) 2017 Elsevier Ltd. All rights reserved.
Schroeder, J., Moritz, N., Anemueller, J., Goetze, S., and Kollmeier, B., Classifier Architectures for Acoustic Scenes and Events: Implications for DNNs, TDNNs, and Perceptual Features from DCASE 2016, IEEE-ACM TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING, vol. 25, no. 6, SI. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Jun.-2017.
Abstract
This paper evaluates neural network (NN) based systems and compares them to Gaussian mixture model (GMM) and hidden Markov model (HMM) approaches for acoustic scene classification (SC) and polyphonic acoustic event detection (AED) that are applied to data of the ``Detection and Classification of Acoustic Scenes and Events 2016{''} (DCASE' 16) challenge, task 1 and task 3, respectively. For both tasks, the use of deep neural networks (DNNs) and features based on an amplitude modulation filterbank and a Gabor filterbank (GFB) are evaluated and compared to standard approaches. For SC, additionally a time-delay NN approach is proposed that enables analysis of long contextual information similar to recurrent NNs but with training efforts comparable to conventional DNNs. The SC system proposed for task 1 of the DCASE' 16 challenge attains a recognition accuracy of 77.5\%, which is 5.6\% higher compared to the DCASE' 16 baseline system. For the AED task, DNNs are adopted in tandem and hybrid approaches, i.e., as part of HMM-based systems. These systems are evaluated for the polyphonic data of task 3 from the DCASE' 16 challenge. Several strategies to address the issue of polyphony are considered. It is shown that DNN-based systems perform less accurate than the traditional systems for this task. Best results are achieved using GFB features in combination with a multiclass GMM-HMM back end.
Bach, J. -H., Kollmeier, B., and Anemueller, J., Matching Pursuit Analysis of Auditory Receptive Fields' Spectro-Temporal Properties, FRONTIERS IN SYSTEMS NEUROSCIENCE, vol. 11. FRONTIERS MEDIA SA, Feb.-2017.
Abstract
Gabor filters have long been proposed as models for spectro-temporal receptive fields (STRFs), with their specific spectral and temporal rate of modulation qualitatively replicating characteristics of STRF filters estimated from responses to auditory stimuli in physiological data. The present study builds on the Gabor-STRF model by proposing a methodology to quantitatively decompose STRFs into a set of optimally matched Gabor filters through matching pursuit, and by quantitatively evaluating spectral and temporal characteristics of STRFs in terms of the derived optimal Gabor-parameters. To summarize a neuron's spectro-temporal characteristics, we introduce a measure for the ``diagonality,{''} i.e., the extent to which an STRF exhibits spectro-temporal transients which cannot be factorized into a product of a spectral and a temporal modulation. With this methodology, it is shown that approximately half of 52 analyzed zebra finch STRFs can each be well approximated by a single Gabor or a linear combination of two Gabor filters. Moreover, the dominant Gabor functions tend to be oriented either in the spectral or in the temporal direction, with truly ``diagonal{''} Gabor functions rarely being necessary for reconstruction of an STRF's main characteristics. As a toy example for the applicability of STRF and Gabor-STRF filters to auditory detection tasks, we use STRF filters as features in an automatic event detection task and compare them to idealized Gabor filters and mel-frequency cepstral coefficients (MFCCs). STRFs classify a set of six everyday sounds with an accuracy similar to reference Gabor features (94\% recognition rate). Spectro-temporal STRF and Gabor features outperform reference spectral MFCCs in quiet and in low noise conditions (down to 0 dB signal to noise ratio).
Merola, A., Fasano, A., Hassan, A., Ostrem, J. L., Contarino, M. F., Lyons, M., Krauss, J. K., Wolf, M. E., Klassen, B. T., van Rootselaar, A. -F., Regidor, I., Duker, A. P., Ondo, W., Guridi, J., Volkmann, J., Shukla, A. W., Mandybur, G. T., Okun, M. S., Witt, K., Starr, P. A., Deuschl, G., and Espay, A. J., Thalamic Deep Brain Stimulation for Orthostatic Tremor: A Multicenter International Registry, MOVEMENT DISORDERS, vol. 32, no. 8. WILEY, Aug.-2017.
Abstract
Background: We report the accumulated experience with ventral intermediate nucleus deep brain stimulation for medically refractory orthostatic tremor. Methods: Data from 17 patients were reviewed, comparing presurgical, short-term (0-48 months), and long-term (>= 48 months) follow-up. The primary end point was the composite activities of daily living/instrumental activities of daily living score. Secondary end points included latency of symptoms on standing and treatment-related complications. Results: There was a 21.6\% improvement (P = 0.004) in the composite activities of daily living/instrumental activities of daily living score, which gradually attenuated (12.5\%) in the subgroup of patients with an additional long-term follow-up (8 of 17). The latency of symptoms on standing significantly improved, both in the shortterm (P = 0.001) and in the long-term (P = 0.018). Three patients obtained no/minimal benefit from the procedure. Conclusions: Deep brain stimulation of the ventral intermediate nucleus was, in general, safe and well tolerated, yielding sustained benefit in selected patients with medically refractory orthostatic tremor. (C) 2017 International
Nydahl, P., Bartoszek, G., Binder, A., Paschen, L., Margraf, N. G., Witt, K., and Ewers, A., Prevalence for delirium in stroke patients: A prospective controlled study, BRAIN AND BEHAVIOR, vol. 7, no. 8. WILEY, Aug.-2017.
Abstract
Background and Purpose: This study investigates the prevalence of delirium in acute stroke patients on a primary stroke unit (SU) analyzing associated risk factors and clinical outcomes. Method: Prospective, 4-month observational study from 2015 to 2016 on patients aged >= 18years with stroke at a German university hospital's SU. The presence of delirium as first outcome was rated at three times daily using the Confusion Assessment Method (CAM). Secondary outcome measures were duration of delirium, rehabilitation in SU, length of stay in SU and hospital, complications, and mortality. Significant risk factors were used to conduct a confounder-matched case-control analysis. Results: 309 patients were included. The overall prevalence of delirium was 10.7\% (33 patients) mostly on the first and second hospital day. Duration of delirium on SU was in median 1.0 day (Interquartile range: 0.3-2days). In 39.4\% of patients delirium was present in a short time interval (<= 8 hr) and in 24\% of patients delirium was diagnosed during nightshifts exclusively. Significant risk factors for delirium were dementia, age >= 72 years, severe neurological disability on admission, and increased C-reactive protein on admission. The case-control analysis showed that delirious patients had more complications and a trend toward a worse rehabilitation. Conclusions: These results underline the importance of delirium screening in stroke patients specifically during the night. Since even short delirious episodes are associated with more complications and increased disability, future studies are needed to find delirium prevention strategies.
Doehring, J., Stoldt, A., Witt, K., Schoenfeld, R., Deuschl, G., Born, J., and Bartsch, T., Motor skill learning and offline-changes in TGA patients with acute hippocampal CA1 lesions, CORTEX, vol. 89. ELSEVIER MASSON, Apr.-2017.
Abstract
Learning and the formation of memory are reflected in various memory systems in the human brain such as the hippocampus based declarative memory system and the striatum-cortex based system involved in motor sequence learning. It is a matter of debate how both memory systems interact in humans during learning and consolidation and how this interaction is influenced by sleep. We studied the effect of an acute dysfunction of hippocampal CA1 neurons on the acquisition (on-line condition) and off-line changes of a motor skill in patients with a transient global amnesia (TGA). Sixteen patients (68 +/- 4.4 yrs) were studied in the acute phase and during follow-up using a declarative and procedural test, and were compared to controls. Acute TGA patients displayed profound deficits in all declarative memory functions. During the acute amnestic phase, patients were able to acquire the motor skill task reflected by increasing finger tapping speed across the on-line condition, albeit to a lesser degree than during follow-up or compared to controls. Retrieval two days later indicated a greater off-line gain in motor speed in patients than controls. Moreover, this gain in motor skill performance was negatively correlated to the declarative learning deficit. Our results suggest a differential interaction between procedural and declarative memory systems during acquisition and consolidation of motor sequences in older humans. During acquisition, hippocampal dysfunction attenuates fast learning and thus unmasks the slow and rigid learning curve of striatum-based procedural learning. The stronger gains in the post-consolidation condition in motor skill in CA1 lesioned patients indicate a facilitated consolidation process probably occurring during sleep, and suggest a competitive interaction between the memory systems. These findings might be a reflection of network reorganization and plasticity in older humans and in the presence of CA1 hippocampal pathology. (C) 2016 Elsevier Ltd. All rights reserved.
Dinkelbach, L., Moeller, B., Witt, K., Schnitzler, A., and Suedmeyer, M., How to improve patient education on deep brain stimulation in Parkinson's disease: the CARE Monitor study, BMC NEUROLOGY, vol. 17. BIOMED CENTRAL LTD, Feb.-2017.
Abstract
Background: The introduction of deep brain stimulation (DBS) about 25 years ago provided one of the major breakthroughs in the treatment of Parkinson's disease (PD). However, a high percentage of patients are reluctant to undergo DBS. Previous research revealed that the critical step on the patient's path to DBS is the decision whether to undergo further diagnostic assessment for surgery at a specialized DBS-center. The aims of the current study were to evaluate how effective the combination of an outpatient DBS screening tool, STIMULUS, with specially developed educational material was to enhance patient education on DBS and to identify motivational aspects which influenced the patients' willingness to undergo further assessment. Methods: In total, 264 patients were identified as appropriate candidates for DBS by general neurologists using the electronic preselection tool STIMULUS. Patient-centered information material was designed and handed out to support education on DBS. Further, several clinical characteristics and details of the patient counseling were documented. Refusal or consent to show up at a DBS center was registered over the following 16 months. Results: 114 (43.2\%) patients preselected as eligible for DBS (STIMULUS Score >= 6) agreed to show up at a specialized DBS center to undergo further diagnostic assessment. The patients' ages, PD classification as an akinetic-rigid type and the talks' topics side-effects of dopaminergic medication and the optimal time frame had a significant influence on the patients' decisions. Conclusions: The combination of preselection tools as STIMULUS with comprehensive information material is effective to increase DBS-acceptance rate in PD patients. Important topics of the information about DBS cover the optimal time frame for DBS surgery, the side-effects of dopaminergic medication as well as side-effects and complications of DBS surgery.
Schmidt, N., Paschen, L., Deuschl, G., and Witt, K., Reduced Empathy Scores in Patients with Parkinson's Disease: A Non-Motor Symptom Associated with Advanced Disease Stages, JOURNAL OF PARKINSONS DISEASE, vol. 7, no. 4. IOS PRESS, 2017.
Abstract
Background: Empathy describes the ability to infer and share emotional experiences of other people and is a central component of normal social functioning. Impaired empathy might be a non-motor symptom in Parkinson's disease (PD). Objective: To examine empathic abilities and their relationship to clinical and cognitive functioning in PD patients. Methods: Empathy was measured in 75 non-demented PD patients and 34 age-matched healthy controls using a German version of the Interpersonal Reactivity Index. Moreover, we collected demographic and clinical data and conducted a comprehensive neuropsychological test battery. Results: PD patients had a significant lower global empathy score than healthy controls. Furthermore, we found significant group differences for the cognitive empathy scales but not for the scales which are sensitive for affective empathy components. The empathy decrease was significantly higher in advanced Hoehn \& Yahr stages. There were only sporadic significant correlations between empathy scores and cognitive variables. Conclusions: PD patients show a stage dependent empathy score decrease which is driven mainly by cognitive aspects of empathy. However, emotional empathy aspects are not reduced.
Pottek, M., Knop, G. C., Weiler, R., and Dedek, K., Electrophysiological Characterization of GFP-Expressing Cell Populations in the Intact Retina, JoVE, no. 57. MyJove Corporation, 2016.
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Dedek, K. and Waldegger, S., Colocalization of KCNQ1/KCNE channel subunits in the mouse gastrointestinal tract, Pflügers Archiv European Journal of Physiology, vol. 442, no. 6. Springer Science + Business Media, pp. 896-902, 2016.
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Kurtz, L., Janssen-Bienhold, U., Kurtz, A., and Wagner, C., Connexin Expression in Renin-Producing Cells, Journal of the American Society of Nephrology, vol. 20, no. 3. American Society of Nephrology (ASN), pp. 506-512, 2016.
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Mouritsen, H., Janssen-Bienhold, U., Liedvogel, M., Feenders, G., Stalleicken, J., Dirks, P., and Weiler, R., Cryptochromes and neuronal-activity markers colocalize in the retina of migratory birds during magnetic orientation, Proceedings of the National Academy of Sciences, vol. 101, no. 39. Proceedings of the National Academy of Sciences, pp. 14294-14299, 2016.
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Farkas, D., Denham, S. L., Bendixen, A., and Winkler, I., Assessing the validity of subjective reports in the auditory streaming paradigm, The Journal of the Acoustical Society of America, vol. 139, no. 4. p. 1762, Apr.-2016.
Abstract DOI
While subjective reports provide a direct measure of perception, their validity is not self-evident. Here, the authors tested three possible biasing effects on perceptual reports in the auditory streaming paradigm: errors due to imperfect understanding of the instructions, voluntary perceptual biasing, and susceptibility to implicit expectations. (1) Analysis of the responses to catch trials separately promoting each of the possible percepts allowed the authors to exclude participants who likely have not fully understood the instructions. (2) Explicit biasing instructions led to markedly different behavior than the conventional neutral-instruction condition, suggesting that listeners did not voluntarily bias their perception in a systematic way under the neutral instructions. Comparison with a random response condition further supported this conclusion. (3) No significant relationship was found between social desirability, a scale-based measure of susceptibility to implicit social expectations, and any of the perceptual measures extracted from the subjective reports. This suggests that listeners did not significantly bias their perceptual reports due to possible implicit expectations present in the experimental context. In sum, these results suggest that valid perceptual data can be obtained from subjective reports in the auditory streaming paradigm
Farkas, D., Denham, S. L., Bendixen, A., Tóth, D., Kondo, H. M., and Winkler, I., Auditory Multi-Stability: Idiosyncratic Perceptual Switching Patterns, Executive Functions and Personality Traits, PloS one, vol. 11, no. 5. p. e0154810, 2016.
Abstract DOI
Multi-stability refers to the phenomenon of perception stochastically switching between possible interpretations of an unchanging stimulus. Despite considerable variability, individuals show stable idiosyncratic patterns of switching between alternative perceptions in the auditory streaming paradigm. We explored correlates of the individual switching patterns with executive functions, personality traits, and creativity. The main dimensions on which individual switching patterns differed from each other were identified using multidimensional scaling. Individuals with high scores on the dimension explaining the largest portion of the inter-individual variance switched more often between the alternative perceptions than those with low scores. They also perceived the most unusual interpretation more often, and experienced all perceptual alternatives with a shorter delay from stimulus onset. The ego-resiliency personality trait, which reflects a tendency for adaptive flexibility and experience seeking, was significantly positively related to this dimension. Taking these results together we suggest that this dimension may reflect the individual's tendency for exploring the auditory environment. Executive functions were significantly related to some of the variables describing global properties of the switching patterns, such as the average number of switches. Thus individual patterns of perceptual switching in the auditory streaming paradigm are related to some personality traits and executive functions
Lamers, M. and Ruigendijk, E., Case in Aphasia, Oxford Handbooks Online. Oxford University Press, 2016.
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Carroll, R. and Ruigendijk, E., ERP responses to processing prosodic phrasing of sentences in amplitude modulated noise, Neuropsychologia, vol. 82. Elsevier BV, pp. 91-103, Feb.-2016.
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Mohammadiha, N., Doclo, S., Vos, M. D., Bleichner, M., and Debener, S., Track L: Miscellaneous, Biomedical Engineering / Biomedizinische Technik, vol. 59, no. s1. Walter de Gruyter GmbH, 2016.
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Chen, L. -C., Sandmann, P., Thorne, J. D., Bleichner, M. G., and Debener, S., Cross-Modal Functional Reorganization of Visual and Auditory Cortex in Adult Cochlear Implant Users Identified with fNIRS, Neural plasticity, vol. 2016. p. 4382656, 2016.
Abstract DOI
Cochlear implant (CI) users show higher auditory-evoked activations in visual cortex and higher visual-evoked activation in auditory cortex compared to normal hearing (NH) controls, reflecting functional reorganization of both visual and auditory modalities. Visual-evoked activation in auditory cortex is a maladaptive functional reorganization whereas auditory-evoked activation in visual cortex is beneficial for speech recognition in CI users. We investigated their joint influence on CI users' speech recognition, by testing 20 postlingually deafened CI users and 20 NH controls with functional near-infrared spectroscopy (fNIRS). Optodes were placed over occipital and temporal areas to measure visual and auditory responses when presenting visual checkerboard and auditory word stimuli. Higher cross-modal activations were confirmed in both auditory and visual cortex for CI users compared to NH controls, demonstrating that functional reorganization of both auditory and visual cortex can be identified with fNIRS. Additionally, the combined reorganization of auditory and visual cortex was found to be associated with speech recognition performance. Speech performance was good as long as the beneficial auditory-evoked activation in visual cortex was higher than the visual-evoked activation in the auditory cortex. These results indicate the importance of considering cross-modal activations in both visual and auditory cortex for potential clinical outcome estimation
Langemann, U. and Klump, G. M., Detecting modulated signals in modulated noise: (I) behavioural auditory thresholds in a songbird, European Journal of Neuroscience, vol. 26, no. 7. Wiley-Blackwell, pp. 1969-1978, 2016.
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Janson, J. and Kranczioch, C., Good vibrations, bad vibrations: Oscillatory brain activity in the attentional blink, Advances in Cognitive Psychology, vol. 7, no. -1. University of Finance and Management in Warsaw, pp. 92-107, 2016.
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Götz, T., Baumbach, P., Reuken, P., Huonker, R., Kranczioch, C., Debener, S., Brunkhorst, F. M., Witte, O. W., Klingner, C., and Günther, A., The loss of neural synchrony in the post septic brain, Clinical Neurophysiology, vol. 127, no. 5. Elsevier BV, pp. 2200-2207, May-2016.
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Götz, T., Baumbach, P., Huonker, R., Kranczioch, C., Witte, O. W., Debener, S., Klingner, C., Brunkhorst, F. M., and Günther, A., Slowed peak resting frequency and MEG overactivation in survivors of severe sepsis and septic shock, Clinical Neurophysiology, vol. 127, no. 2. Elsevier BV, pp. 1247-1253, Feb.-2016.
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Aisenbrey, S., Iris Pigment Epithelial Translocation in the Treatment of Exudative Macular Degeneration, Arch Ophthalmol, vol. 124, no. 2. American Medical Association (AMA), p. 183, 2016.
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Süsskind, D., Neuhann, I., Hilgers, R. -D., Hagemann, U., Szurman, P., Bartz-Schmidt, K. U., and Aisenbrey, S., Primary vitrectomy for rhegmatogenous retinal detachment in pseudophakic eyes: 20-gauge versus 25-gauge vitrectomy, Acta Ophthalmol. Wiley-Blackwell, Jun.-2016.
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Süsskind, D., Hagemann, U., Schrader, M., Januschowski, K., Schnichels, S., and Aisenbrey, S., Toxic effects of melphalan, topotecan and carboplatin on retinal pigment epithelial cells, Acta Ophthalmol, vol. 94, no. 5. Wiley-Blackwell, pp. 471-478, 19-Feb.-2016.
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Aisenbrey, S., Zhang, M., Bacher, D., Yee, J., Brunken, W. J., and Hunter, D. D., Retinal Pigment Epithelial Cells Synthesize Laminins, Including Laminin 5, and Adhere to Them through α3- and α6-Containing Integrins, Invest. Ophthalmol. Vis. Sci., vol. 47, no. 12. Association for Research in Vision and Ophthalmology (ARVO), p. 5537, 1-Dec.-2016.
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Walz, J. M., Bemme, S., Pielen, A., Aisenbrey, S., Breuß, H., Alex, A. F., Wagenfeld, L., Schiedel, S., Krohne, T. U., and Stahl, A., The German ROP Registry: data from 90 infants treated for retinopathy of prematurity, Acta Ophthalmol. Wiley-Blackwell, May-2016.
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Laycock, H. and Bantel, C., Objective Assessment of Acute Pain, General Anesthesia and Sleep, vol. 7, no. 6. OMICS Publishing Group, 2016.
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Groß, S., Lam, A. P., Matthies, S., and Philipsen, A., Therapie der ADHS unter Berücksichtigung psychotherapeutischer Studien, InFo Neurologie & Psychiatrie, vol. 18, no. 3. Springer Science + Business Media, pp. 32-39, Mar.-2016.
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Bachmann, K., Lam, A. P., and Philipsen, A., Mindfulness-Based Cognitive Therapy and the Adult ADHD Brain: A Neuropsychotherapeutic Perspective, Front. Psychiatry, vol. 7. Frontiers Media SA, 27-Jun.-2016.
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Matthies, S. and Philipsen, A., Comorbidity of Personality Disorders and Adult Attention Deficit Hyperactivity Disorder (ADHD)—Review of Recent Findings, Curr Psychiatry Rep, vol. 18, no. 4. Springer Science + Business Media, 18-Feb.-2016.
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Philipsen, A., Tebartz van Elst, L., and Graf, E., Quality of Life of Adult Patients With Attention-Deficit/Hyperactivity Disorder Taking Methylphenidate—Reply, JAMA Psychiatry, vol. 73, no. 5. American Medical Association (AMA), p. 534, 1-May-2016.
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Hinz, J., Mansur, A., Hanekop, G. G., Weyland, A., Popov, A. F., Schmitto, J. D., Grüne, F. F. G., Bauer, M., and Kazmaier, S., Influence of isoflurane on the diastolic pressure-flow relationship and critical occlusion pressure during arterial CABG surgery: a randomized controlled trial, PeerJ, vol. 4. PeerJ, p. e1619, 26-Jan.-2016.
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Bloos, F., Trips, E., Nierhaus, A., Briegel, J., Heyland, D. K., Jaschinski, U., Moerer, O., Weyland, A., Marx, G., Gründling, M., Kluge, S., Kaufmann, I., Ott, K., Quintel, M., Jelschen, F., Meybohm, P., Rademacher, S., Meier-Hellmann, A., Utzolino, S., Kaisers, U. X., Putensen, C., Elke, G., Ragaller, M., Gerlach, H., Ludewig, K., Kiehntopf, M., Bogatsch, H., Engel, C., Brunkhorst, F. M., Loeffler, M., and Reinhart, K., Effect of Sodium Selenite Administration and Procalcitonin-Guided Therapy on Mortality in Patients With Severe Sepsis or Septic Shock: A Randomized Clinical Trial, JAMA internal medicine. Jul.-2016.
Abstract DOI
High-dose intravenous administration of sodium selenite has been proposed to improve outcome in sepsis by attenuating oxidative stress. Procalcitonin-guided antimicrobial therapy may hasten the diagnosis of sepsis, but effect on outcome is unclear.To determine whether high-dose intravenous sodium selenite treatment and procalcitonin-guided anti-infectious therapy in patients with severe sepsis affect mortality.The Placebo-Controlled Trial of Sodium Selenite and Procalcitonin Guided Antimicrobial Therapy in Severe Sepsis (SISPCT), a multicenter, randomized, clinical, 2 × 2 factorial trial performed in 33 intensive care units in Germany, was conducted from November 6, 2009, to June 6, 2013, including a 90-day follow-up period.Patients were randomly assigned to receive an initial intravenous loading dose of sodium selenite, 1000 µg, followed by a continuous intravenous infusion of sodium selenite, 1000 µg, daily until discharge from the intensive care unit, but not longer than 21 days, or placebo. Patients also were randomized to receive anti-infectious therapy guided by a procalcitonin algorithm or without procalcitonin guidance.The primary end point was 28-day mortality. Secondary outcomes included 90-day all-cause mortality, intervention-free days, antimicrobial costs, antimicrobial-free days, and secondary infections.Of 8174 eligible patients, 1089 patients (13.3%) with severe sepsis or septic shock were included in an intention-to-treat analysis comparing sodium selenite (543 patients [49.9%]) with placebo (546 [50.1%]) and procalcitonin guidance (552 [50.7%]) vs no procalcitonin guidance (537 [49.3%]). The 28-day mortality rate was 28.3% (95% CI, 24.5%-32.3%) in the sodium selenite group and 25.5% (95% CI, 21.8%-29.4%) (P = .30) in the placebo group. There was no significant difference in 28-day mortality between patients assigned to procalcitonin guidance (25.6% [95% CI, 22.0%-29.5%]) vs no procalcitonin guidance (28.2% [95% CI, 24.4%-32.2%]) (P = .34). Procalcitonin guidance did not affect frequency of diagnostic or therapeutic procedures but did result in a 4.5% reduction of antimicrobial exposure.Neither high-dose intravenous administration of sodium selenite nor anti-infectious therapy guided by a procalcitonin algorithm was associated with an improved outcome in patients with severe sepsis. These findings do not support administration of high-dose sodium selenite in these patients; the application of a procalcitonin-guided algorithm needs further evaluation.clinicaltrials.gov Identifier: NCT00832039
Dell'Orco, D. and Koch, K. -W., Fingerprints of calcium-binding protein conformational dynamics monitored by surface plasmon resonance, ACS chemical biology. Jul.-2016.
Abstract
Surface plasmon resonance (SPR) spectroscopy is widely used to probe interactions involving biological macromolecules by detecting changes in the refractive index in a metal/dielectric interface following the dynamic formation of a molecular complex. In the last years SPR-based experimental approaches were developed to monitor conformational changes induced by the binding of small analytes to proteins coupled to the surface of commercially available sensor chips. A significant contribution to our understanding of the phenomenon came from the study of several Ca2+-sensor proteins operating in diverse cellular scenarios, in which the conformational switch is triggered by specific Ca2+ signals. Structural and physicochemical analyses demonstrated that the SPR signal not only depends on the change in protein size upon Ca2+-binding but likely originates from variations in the hydration shell structure. The resulting changes in the dielectric properties of water or of the protein-water interface eventually reflect different crowding conditions on the SPR sensor chip, which mimic the cellular environment. SPR could hence be used to monitor conformational transitions in proteins, especially when a significant variation in the hydrophobicity of the solvent-exposed protein surface occurs, thus leading to changes in the dielectric milieu of the whole sensor chip surface. We review recent work in which SPR has been successfully employed to provide a fingerprint of the conformational change dynamics in proteins under native and altered conditions, which include posttranslational modifications, co-presence of competing analytes and point mutations of single amino acids associated to genetic diseases
Sulmann, S., Wallisch, M., Scholten, A., Christoffers, J., and Koch, K. -W., Mapping Calcium-Sensitive Regions in the Neuronal Calcium Sensor GCAP2 by Site-Specific Fluorescence Labeling, Biochemistry, vol. 55, no. 18. pp. 2567-2577, May-2016.
Abstract DOI
Myristoylation of most neuronal calcium sensor proteins, a group of EF-hand calcium-binding proteins mainly expressed in neuronal tissue, can have a strong impact on protein dynamics and functional properties. Intracellular oscillations of the free Ca(2+) concentration can trigger conformational changes in Ca(2+) sensors. The position and possible movements of the myristoyl group in the photoreceptor cell-specific Ca(2+) sensor GCAP2 are not well-defined but appear to be different from those of the highly homologous cognate GCAP1. We designed and applied a new group of diaminoterephthalate-derived fluorescent probes to label GCAP2 at a covalently attached 12-azido-dodecanoic acid (a myristoyl substitute) and at cysteine residues in critical positions. Fluorescence emission of dye-labeled GCAP2 decreased when going from low (10(-9) M) to high [Ca(2+)] (10(-3) M), reaching a half-maximal effect of fluorescence emission at 0.44 ± 0.07 μM. The modified acyl group can therefore monitor changes in the protein conformation during binding and dissociation of Ca(2+) in the physiological range of free [Ca(2+)]. However, fluorescence quenching studies showed that the dye-acyl chain was shielded from the quencher by an adjacent polypeptide region. Further probing three cysteine positions (C35, C111, and C131) by dye labeling revealed that all positions were also sensitive to a change in [Ca(2+)], but only one (C131) was sensitive to a change in [Mg(2+)]. We suggest a scenario during illumination of the photoreceptor cell in which Ca(2+) dissociates first from low and medium affinity binding sites. These steps are sensed by dyes in cysteines at positions 35 and 111. Release of Ca(2+) from high affinity sites is sensed by regions adjacent to the dye-labeled fatty acid and involves the critical conformational change leading to activating guanylate cyclase
Richter-Landsberg, C., Protein aggregate formation in oligodendrocytes: tau and the cytoskeleton at the intersection of neuroprotection and neurodegeneration, Biological Chemistry, vol. 397, no. 3. Walter de Gruyter GmbH, 1-Jan.-2016.
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Wichmann, H., Brinkhoff, T., Simon, M., and Richter-Landsberg, C., Dimethylsulfoniopropionate Promotes Process Outgrowth in Neural Cells and Exerts Protective Effects against Tropodithietic Acid, Marine drugs, vol. 14, no. 5. 2016.
Abstract DOI
The marine environment harbors a plethora of bioactive substances, including drug candidates of potential value in the field of neuroscience. The present study was undertaken to investigate the effects of dimethylsulfoniopropionate (DMSP), produced by several algae, corals and higher plants, on cells of the mammalian nervous system, i.e., neuronal N2a and OLN-93 cells as model system for nerve cells and glia, respectively. Additionally, the protective capabilities of DMSP were assessed in cells treated with tropodithietic acid (TDA), a marine metabolite produced by several Roseobacter clade bacteria. Both cell lines, N2a and OLN-93, have previously been shown to be a sensitive target for the action of TDA, and cytotoxic effects of TDA have been connected to the induction of oxidative stress. Our data shows that DMSP promotes process outgrowth and microtubule reorganization and bundling, accompanied by an increase in alpha-tubulin acetylation. Furthermore, DMSP was able to prevent the cytotoxic effects exerted by TDA, including the breakdown of the mitochondrial membrane potential, upregulation of heat shock protein Hsp32 and activation of the extracellular signal-regulated kinases 1/2 (ERK1/2). Our study points to the conclusion that DMSP provides an antioxidant defense, not only in algae but also in mammalian neural cells
Dongmo, S., Leyk, J., Dosche, C., Richter-Landsberg, C., Wollenberger, U., and Wittstock, G., Electrogeneration of O2.−and H2O2Using Polymer-modified Microelectrodes in the Environment of Living Cells, Electroanalysis. Wiley-Blackwell, 2016.
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Laumen, G., Tollin, D. J., Beutelmann, R., and Klump, G. M., Aging effects on the binaural interaction component of the auditory brainstem response in the Mongolian gerbil: Effects of interaural time and level differences, Hearing Research, vol. 337. Elsevier BV, pp. 46-58, Jul.-2016.
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Kortlang, S., Mauermann, M., and Ewert, S. D., Suprathreshold auditory processing deficits in noise: Effects of hearing loss and age, Hearing Research, vol. 331. Elsevier BV, pp. 27-40, Jan.-2016.
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Abdullaeva, O. S., Schulz, M., Balzer, F., Parisi, J., Luetzen, A., Dedek, K., and Schiek, M., Photoelectrical Stimulation of Neuronal Cells by an Organic Semiconductor-Electrolyte Interface, Langmuir : the ACS journal of surfaces and colloids. Aug.-2016.
Abstract
As a step towards the realization of neuro-prosthetics for vision restoration, we follow an electrophysiological patch-clamp approach to study the fundamental photoelectrical stimulation mechanism of neuronal model cells by an organic semiconductor-electrolyte interface. Our photoactive layer consisting of an anilino-squaraine donor blended with a fullerene acceptor is supporting the growth of the neuronal model cell line (N2A cells) without an adhesion layer on it, and is not impairing cell viability. The transient photocurrent signal upon illumination from the semiconductor-electrolyte layer is able to trigger a passive response of the neuronal cells under physiological conditions via a capacitive coupling mechanism. We study the dynamics of the capacitive transmembrane currents by patch-clamp recordings and compare them to the dynamics of the photocurrent signal and its spectral responsivity. Furthermore, we characterize the morphology of the semiconductor-electrolyte interface by atomic force microscopy, and study the stability of the interface in dark and under illuminated conditions
Scheunemann, D., Wilken, S., Parisi, J., and Borchert, H., Charge carrier loss mechanisms in CuInS2/ZnO nanocrystal solar cells, Physical chemistry chemical physics : PCCP, vol. 18, no. 24. pp. 16258-16265, Jun.-2016.
Abstract DOI
Heterojunction solar cells based on colloidal nanocrystals (NCs) have shown remarkable improvements in performance in the last decade, but this progress is limited to merely two materials, PbS and PbSe. However, solar cells based on other material systems such as copper-based compounds show lower power conversion efficiencies and much less effort has been made to develop a better understanding of factors limiting their performance. Here, we study charge carrier loss mechanisms in solution-processed CuInS2/ZnO NC solar cells by combining steady-state measurements with transient photocurrent and photovoltage measurements. We demonstrate the presence of an extraction barrier at the CuInS2/ZnO interface, which can be reduced upon illumination with UV light. However, trap-assisted recombination in the CuInS2 layer is shown to be the dominant decay process in these devices
Yi, J. -M., Smirnov, V., Piao, X., Hong, J., Kollmann, H., Silies, M., Wang, W., Groß, P., Vogelgesang, R., Park, N., and Lienau, C., Suppression of Radiative Damping and Enhancement of Second Harmonic Generation in Bull's Eye Nanoresonators, ACS nano, vol. 10, no. 1. pp. 475-483, Jan.-2016.
Abstract DOI
We report a drastic increase of the damping time of plasmonic eigenmodes in resonant bull's eye (BE) nanoresonators to more than 35 fs. This is achieved by tailoring the groove depth of the resonator and by coupling the confined plasmonic field in the aperture to an extended resonator mode such that spatial coherence is preserved over distances of more than 10 μm. Experimentally, this is demonstrated by probing the plasmon dynamics at the field level using broadband spectral interferometry. The nanoresonator allows us to efficiently concentrate the incident field inside the central aperture of the BE and to tailor its local optical nonlinearity by varying the aperture geometry. By replacing the central circular hole with an annular ring structure, we obtain 50-times higher second harmonic generation efficiency, allowing us to demonstrate the efficient concentration of long-lived plasmonic modes inside nanoapertures by interferometric frequency-resolved autocorrelation. Such a light concentration in a nanoresonator with high quality factor has high potential for sensing and coherent control of light-matter interactions on the nanoscale
Diederich, A., Colonius, H., and Kandil, F. I., Prior knowledge of spatiotemporal configuration facilitates crossmodal saccadic response : A TWIN analysis, Experimental brain research, vol. 234, no. 7. pp. 2059-2076, Jul.-2016.
Abstract DOI
Saccadic reaction times from a focused-attention task with a visual target and an acoustic nontarget support the hypothesis that the amount of saccadic facilitation in the presence of a nontarget increases with the prior knowledge of alignment with the target across different blocks of trials. The time-window-of-integration model can account for the size of the effect by having window size depend on the prior knowledge of alignment. Some efforts to identify the neural correlates of the effect are discussed
Alavash, M., Thiel, C. M., and Gießing, C., Dynamic coupling of complex brain networks and dual-task behavior, NeuroImage, vol. 129. Elsevier BV, pp. 233-246, Apr.-2016.
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Greschner, M., Heitman, A. K., Field, G. D., Li, P. H., Ahn, D., Sher, A., Litke, A. M., and Chichilnisky, E. J., Identification of a Retinal Circuit for Recurrent Suppression Using Indirect Electrical Imaging, Current biology : CB, vol. 26, no. 15. pp. 1935-1942, Aug.-2016.
Abstract DOI
Understanding the function of modulatory interneuron networks is a major challenge, because such networks typically operate over long spatial scales and involve many neurons of different types. Here, we use an indirect electrical imaging method to reveal the function of a spatially extended, recurrent retinal circuit composed of two cell types. This recurrent circuit produces peripheral response suppression of early visual signals in the primate magnocellular visual pathway. We identify a type of polyaxonal amacrine cell physiologically via its distinctive electrical signature, revealed by electrical coupling with ON parasol retinal ganglion cells recorded using a large-scale multi-electrode array. Coupling causes the amacrine cells to fire spikes that propagate radially over long distances, producing GABA-ergic inhibition of other ON parasol cells recorded near the amacrine cell axonal projections. We propose and test a model for the function of this amacrine cell type, in which the extra-classical receptive field of ON parasol cells is formed by reciprocal inhibition from other ON parasol cells in the periphery, via the electrically coupled amacrine cell network
Koepcke, L., Ashida, G., and Kretzberg, J., Single and Multiple Change Point Detection in Spike Trains: Comparison of Different CUSUM Methods, Frontiers in systems neuroscience, vol. 10. p. 51, 2016.
Abstract DOI
In a natural environment, sensory systems are faced with ever-changing stimuli that can occur, disappear or change their properties at any time. For the animal to react adequately the sensory systems must be able to detect changes in external stimuli based on its neuronal responses. Since the nervous system has no prior knowledge of the stimulus timing, changes in stimulus need to be inferred from the changes in neuronal activity, in particular increase or decrease of the spike rate, its variability, and shifted response latencies. From a mathematical point of view, this problem can be rephrased as detecting changes of statistical properties in a time series. In neuroscience, the CUSUM (cumulative sum) method has been applied to recorded neuronal responses for detecting a single stimulus change. Here, we investigate the applicability of the CUSUM approach for detecting single as well as multiple stimulus changes that induce increases or decreases in neuronal activity. Like the nervous system, our algorithm relies exclusively on previous neuronal population activities, without using knowledge about the timing or number of external stimulus changes. We apply our change point detection methods to experimental data obtained by multi-electrode recordings from turtle retinal ganglion cells, which react to changes in light stimulation with a range of typical neuronal activity patterns. We systematically examine how variations of mathematical assumptions (Poisson, Gaussian, and Gamma distributions) used for the algorithms may affect the detection of an unknown number of stimulus changes in our data and compare these CUSUM methods with the standard Rate Change method. Our results suggest which versions of the CUSUM algorithm could be useful for different types of specific data sets
Mathes, B., Schmiedt-Fehr, C., Kedilaya, S., Strüber, D., Brand, A., and Basar-Eroglu, C., Theta response in schizophrenia is indifferent to perceptual illusion, Clinical Neurophysiology, vol. 127, no. 1. Elsevier BV, pp. 419-430, Jan.-2016.
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Ehlers, J., Strüber, D., and Basar-Eroglu, C., Multistable perception in children: Prefrontal delta oscillations in the developing brain, International Journal of Psychophysiology, vol. 103. Elsevier BV, pp. 129-134, May-2016.
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Herrmann, C. S., Strüber, D., Helfrich, R. F., and Engel, A. K., EEG oscillations: From correlation to causality, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 103. pp. 12-21, May-2016.
Abstract DOI
Already in his first report on the discovery of the human EEG in 1929, Berger showed great interest in further elucidating the functional roles of the alpha and beta waves for normal mental activities. Meanwhile, most cognitive processes have been linked to at least one of the traditional frequency bands in the delta, theta, alpha, beta, and gamma range. Although the existing wealth of high-quality correlative EEG data led many researchers to the conviction that brain oscillations subserve various sensory and cognitive processes, a causal role can only be demonstrated by directly modulating such oscillatory signals. In this review, we highlight several methods to selectively modulate neuronal oscillations, including EEG-neurofeedback, rhythmic sensory stimulation, repetitive transcranial magnetic stimulation (rTMS), and transcranial alternating current stimulation (tACS). In particular, we discuss tACS as the most recent technique to directly modulate oscillatory brain activity. Such studies demonstrating the effectiveness of tACS comprise reports on purely behavioral or purely electrophysiological effects, on combination of behavioral effects with offline EEG measurements or on simultaneous (online) tACS-EEG recordings. Whereas most tACS studies are designed to modulate ongoing rhythmic brain activity at a specific frequency, recent evidence suggests that tACS may also modulate cross-frequency interactions. Taken together, the modulation of neuronal oscillations allows to demonstrate causal links between brain oscillations and cognitive processes and to obtain important insights into human brain function
Kasten, F. H., Dowsett, J., and Herrmann, C. S., Sustained Aftereffect of α-tACS Lasts Up to 70 min after Stimulation, Frontiers in human neuroscience, vol. 10. p. 245, 2016.
Abstract DOI
Transcranial alternating current stimulation (tACS) has been repeatedly demonstrated to increase power of endogenous brain oscillations in the range of the stimulated frequency after stimulation. In the alpha band this aftereffect has been shown to persist for at least 30 min. However, in most experiments the aftereffect exceeded the duration of the measurement. Thus, it remains unclear how the effect develops beyond these 30 min and when it decays. The current study aimed to extend existing findings by monitoring the physiological aftereffect of tACS in the alpha range for an extended period of 90 min post-stimulation. To this end participants received either 20 min of tACS or sham stimulation with intensities below their individual sensation threshold at the individual alpha frequency (IAF). Electroencephalogram (EEG) was acquired during 3 min before and 90 min after stimulation. Subjects performed a visual vigilance task during the whole measurement. While the enhanced power in the individual alpha band did not return back to pre-stimulation baseline in the stimulation group, the difference between stimulation and sham diminishes after 70 min due to a natural alpha increase of the sham group
Pikovsky, A. S., Zaks, M. A., Feudel, U., and Kurths, J., Singular continuous spectra in dissipative dynamics, Phys. Rev. E, vol. 52, no. 1. American Physical Society (APS), pp. 285-296, 2016.
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Wahl, B., Feudel, U., Hlinka, J., Wächter, M., Peinke, J., and Freund, J. A., Granger-causality maps of diffusion processes, Physical review. E, vol. 93, no. 2. p. 022213, Feb.-2016.
Abstract DOI
Granger causality is a statistical concept devised to reconstruct and quantify predictive information flow between stochastic processes. Although the general concept can be formulated model-free it is often considered in the framework of linear stochastic processes. Here we show how local linear model descriptions can be employed to extend Granger causality into the realm of nonlinear systems. This novel treatment results in maps that resolve Granger causality in regions of state space. Through examples we provide a proof of concept and illustrate the utility of these maps. Moreover, by integration we convert the local Granger causality into a global measure that yields a consistent picture for a global Ornstein-Uhlenbeck process. Finally, we recover invariance transformations known from the theory of autoregressive processes
Drey, M., Sieber, C. C., Bertsch, T., Bauer, J. M., Schmidmaier, R., and , Osteosarcopenia is more than sarcopenia and osteopenia alone, Aging clinical and experimental research, vol. 28, no. 5. pp. 895-899, Oct.-2016.
Abstract DOI
Sarcopenia and osteopenia/osteoporosis show a high prevalence in old age and incur a high risk for falls, fractures, and further functional decline. Physical performance and bone metabolism in patients suffering from the so-called osteosarcopenia-the combination of sarcopenia and osteopenia-are currently still unknown.This study investigates physical performance and bone metabolism in osteosarcopenic, prefrail, community-dwelling older adults.68 prefrail adults between 65 and 94 years were assigned to four groups according to mean DXA results: osteosarcopenic [low T-score and low appendicular lean mass (aLM)], sarcopenic (low aLM), osteopenic (low T-score), and controls. Multiple linear regression analysis, adjusted for age, gender, physical activity, and 25-OH-vitamin D3 serum level, was used to identify the influence of being osteosarcopenic, sarcopenic, or osteopenic on physical performance (hand grip, chair rise test, sit-to-stand power, gait speed, SPPB) and serum markers for increased bone turnover [osteocalcin, β-crosslaps and procollagen type 1 amino-terminal propeptide (P1NP)].Only osteosarcopenic participants showed significantly reduced hand grip strength, increased chair rising time, and STS power time as well as significantly increased bone turnover markers.Due to low physical performance and high bone turnover, older adults with osteosarcopenia have to be regarded as the most at-risk population for fractures and further functional decline.Up-to-date osteoporosis and post-fracture management of older persons should aim at both, bone and muscle
Biechl, D., Tietje, K., Gerlach, G., and Wullimann, M. F., Crypt cells are involved in kin recognition in larval zebrafish, Scientific Reports, vol. 6. Nature Publishing Group, p. 24590, 18-Apr.-2016.
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Bender, M., Mouritsen, H., and Christoffers, J., A robust synthesis of 7,8-didemethyl-8-hydroxy-5-deazariboflavin, Beilstein journal of organic chemistry, vol. 12. pp. 912-917, 2016.
Abstract DOI
The biosynthetic precursor of redox cofactor F420, 7,8-didemethyl-8-hydroxy-5-deazariboflavin, was prepared in four steps from 6-chlorouracil, 2-chloro-4-hydroxybenzaldehyde and bis-isopropylidene protected D-ribose. The latter aldehyde was transformed to the corresponding protected ribitylamine via the oxime, which was submitted to reduction with LiAlH4. Key advantage compared to previous syntheses is the utilization of a polyol-protective group which allowed the chromatographic purification of a key-intermediate product providing the target compound with high purity
Warrant, E., Frost, B., Green, K., Mouritsen, H., Dreyer, D., Adden, A., Brauburger, K., and Heinze, S., The Australian Bogong Moth Agrotis infusa: A Long-Distance Nocturnal Navigator, Frontiers in behavioral neuroscience, vol. 10. p. 77, 2016.
Abstract DOI
The nocturnal Bogong moth (Agrotis infusa) is an iconic and well-known Australian insect that is also a remarkable nocturnal navigator. Like the Monarch butterflies of North America, Bogong moths make a yearly migration over enormous distances, from southern Queensland, western and northwestern New South Wales (NSW) and western Victoria, to the alpine regions of NSW and Victoria. After emerging from their pupae in early spring, adult Bogong moths embark on a long nocturnal journey towards the Australian Alps, a journey that can take many days or even weeks and cover over 1000 km. Once in the Alps (from the end of September), Bogong moths seek out the shelter of selected and isolated high ridge-top caves and rock crevices (typically at elevations above 1800 m). In hundreds of thousands, moths line the interior walls of these cool alpine caves where they "hibernate" over the summer months (referred to as "estivation"). Towards the end of the summer (February and March), the same individuals that arrived months earlier leave the caves and begin their long return trip to their breeding grounds. Once there, moths mate, lay eggs and die. The moths that hatch in the following spring then repeat the migratory cycle afresh. Despite having had no previous experience of the migratory route, these moths find their way to the Alps and locate their estivation caves that are dotted along the high alpine ridges of southeastern Australia. How naïve moths manage this remarkable migratory feat still remains a mystery, although there are many potential sensory cues along the migratory route that moths might rely on during their journey, including visual, olfactory, mechanical and magnetic cues. Here we review our current knowledge of the Bogong moth, including its natural history, its ecology, its cultural importance to the Australian Aborigines and what we understand about the sensory basis of its long-distance nocturnal migration. From this analysis it becomes clear that the Bogong moth represents a new and very promising model organism for understanding the sensory basis of nocturnal migration in insects
Schwarze, S., Schneider, N. -L., Reichl, T., Dreyer, D., Lefeldt, N., Engels, S., Baker, N., Hore, P. J., and Mouritsen, H., Weak Broadband Electromagnetic Fields are More Disruptive to Magnetic Compass Orientation in a Night-Migratory Songbird (Erithacus rubecula) than Strong Narrow-Band Fields, Frontiers in behavioral neuroscience, vol. 10. p. 55, 2016.
Abstract DOI
Magnetic compass orientation in night-migratory songbirds is embedded in the visual system and seems to be based on a light-dependent radical pair mechanism. Recent findings suggest that both broadband electromagnetic fields ranging from ~2 kHz to ~9 MHz and narrow-band fields at the so-called Larmor frequency for a free electron in the Earth's magnetic field can disrupt this mechanism. However, due to local magnetic fields generated by nuclear spins, effects specific to the Larmor frequency are difficult to understand considering that the primary sensory molecule should be organic and probably a protein. We therefore constructed a purpose-built laboratory and tested the orientation capabilities of European robins in an electromagnetically silent environment, under the specific influence of four different oscillating narrow-band electromagnetic fields, at the Larmor frequency, double the Larmor frequency, 1.315 MHz or 50 Hz, and in the presence of broadband electromagnetic noise covering the range from ~2 kHz to ~9 MHz. Our results indicated that the magnetic compass orientation of European robins could not be disrupted by any of the relatively strong narrow-band electromagnetic fields employed here, but that the weak broadband field very efficiently disrupted their orientation
Hore, P. J. and Mouritsen, H., The Radical-Pair Mechanism of Magnetoreception, Annual review of biophysics, vol. 45. pp. 299-344, Jul.-2016.
Abstract DOI
Although it has been known for almost half a century that migratory birds can detect the direction of the Earth's magnetic field, the primary sensory mechanism behind this remarkable feat is still unclear. The leading hypothesis centers on radical pairs-magnetically sensitive chemical intermediates formed by photoexcitation of cryptochrome proteins in the retina. Our primary aim here is to explain the chemical and physical aspects of the radical-pair mechanism to biologists and the biological and chemical aspects to physicists. In doing so, we review the current state of knowledge on magnetoreception mechanisms. We dare to hope that this tutorial will stimulate new interdisciplinary experimental and theoretical work that will shed much-needed additional light on this fascinating problem in sensory biology
Hiscock, H. G., Worster, S., Kattnig, D. R., Steers, C., Jin, Y., Manolopoulos, D. E., Mouritsen, H., and Hore, P. J., The quantum needle of the avian magnetic compass, Proceedings of the National Academy of Sciences of the United States of America, vol. 113, no. 17. pp. 4634-4639, Apr.-2016.
Abstract DOI
Migratory birds have a light-dependent magnetic compass, the mechanism of which is thought to involve radical pairs formed photochemically in cryptochrome proteins in the retina. Theoretical descriptions of this compass have thus far been unable to account for the high precision with which birds are able to detect the direction of the Earth's magnetic field. Here we use coherent spin dynamics simulations to explore the behavior of realistic models of cryptochrome-based radical pairs. We show that when the spin coherence persists for longer than a few microseconds, the output of the sensor contains a sharp feature, referred to as a spike. The spike arises from avoided crossings of the quantum mechanical spin energy-levels of radicals formed in cryptochromes. Such a feature could deliver a heading precision sufficient to explain the navigational behavior of migratory birds in the wild. Our results (i) afford new insights into radical pair magnetoreception, (ii) suggest ways in which the performance of the compass could have been optimized by evolution, (iii) may provide the beginnings of an explanation for the magnetic disorientation of migratory birds exposed to anthropogenic electromagnetic noise, and (iv) suggest that radical pair magnetoreception may be more of a quantum biology phenomenon than previously realized
Mouritsen, H., Heyers, D., and Güntürkün, O., The Neural Basis of Long-Distance Navigation in Birds, Annual review of physiology, vol. 78. pp. 133-154, 2016.
Abstract DOI
Migratory birds can navigate over tens of thousands of kilometers with an accuracy unobtainable for human navigators. To do so, they use their brains. In this review, we address how birds sense navigation- and orientation-relevant cues and where in their brains each individual cue is processed. When little is currently known, we make educated predictions as to which brain regions could be involved. We ask where and how multisensory navigational information is integrated and suggest that the hippocampus could interact with structures that represent maps and compass information to compute and constantly control navigational goals and directions. We also suggest that the caudolateral nidopallium could be involved in weighing conflicting pieces of information against each other, making decisions, and helping the animal respond to unexpected situations. Considering the gaps in current knowledge, some of our suggestions may be wrong. However, our main aim is to stimulate further research in this fascinating field
Schoenfeld, A. A., Wieker, S., Harder, D., and Poppe, B., Changes of the optical characteristics of radiochromic films in the transition from EBT3 to EBT-XD films, Physics in medicine and biology, vol. 61, no. 14. pp. 5426-5442, Jul.-2016.
Abstract
A new type of radiochromic film, the EBT-XD film, has been introduced with the aim to reduce the orientation effect and the lateral response artifact occurring in the use of radiochromic films together with flatbed scanners. The task of the present study is to quantify the changes of optical characteristics involved with the transition from the well-known EBT3 films to the new EBT-XD films, using the optical bench arrangement already applied by Schoenfeld et al (2014 Phys. Med. Biol. 59 3575-97). Largely reduced polarization effects and the almost complete loss of the anisotropy of the scattered light produced in a radiation-exposed film have been observed. The Rayleigh-Debye-Gans theory is used to understand these optical changes as arising from the reduced length-to-width ratio of the LiPCDA polymer crystals in the active layer of the EBT-XD film. The effect of these changes on the flatbed scanning artifacts will be shortly addressed, but treated in more detail in a further paper
Ranzi, P., Thiel, C. M., Herrmann, C. S., and Freund, J. A., EEG source reconstruction in male nonsmokers after nicotine administration during the resting state, Neuropsychobiology, vol. 73, no. 4. 21-Apr.-2016.
Abstract DOI
Modern psychopharmacological research in humans focuses on how specific psychoactive molecules modulate oscillatory brain activity. We present state-of-the-art EEG methods applied in a resting-state drug study. Thirty healthy male nonsmokers were randomly allocated either to a nicotine group (14 subjects, 7 mg transdermal nicotine) or a placebo group (16 subjects). EEG activity was recorded in eyes-open (EO) and eyes-closed (EC) conditions before and after drug administration. A source reconstruction (minimum norm algorithm) analysis was conducted within a frequency range of 8.5-18.4 Hz subdivided into three different frequency bands. During EO, nicotine reduced the power of oscillatory activity in the 12.5- to 18.4-Hz frequency band in the left middle frontal gyrus. In contrast, in the EC condition, nicotine reduced the power in the 8.5- to 10.4-Hz frequency band in the superior frontal gyri and in the 10.5- to 12.4-Hz and 12.5- to 18.4-Hz frequency bands in the supplementary motor areas. In summary, nicotine reduced the power of the 12.5- to 18.4-Hz band in the left middle frontal gyrus during EO, and it reduced power from 8.5 to 18.4 Hz in a brain area spanning from the superior frontal gyri to the supplementary motor areas during EC. In conclusion, the results suggest that nicotine counteracts the phenomenon of anteriorization of α activity, hence potentially increasing the level of vigilance.
Puschmann, S., Huster, R. J., and Thiel, C. M., Mapping the spatiotemporal dynamics of processing task-relevant and task-irrelevant sound feature changes using concurrent EEG-fMRI, Human Brain Mapping, vol. 37, no. 10. 2016.
Abstract
The cortical processing of changes in auditory input involves auditory sensory regions as well as different frontoparietal brain networks. The spatiotemporal dynamics of the activation spread across these networks has, however, not been investigated in detail so far. We here approached this issue using concurrent functional magnetic resonance imaging (fMRI) and electroencephalography (EEG), providing us with simultaneous information on both the spatial and temporal patterns of change-related activity. We applied an auditory stimulus categorization task with switching categorization rules, allowing to analyze change-related responses as a function of the changing sound feature (pitch or duration) and the task relevance of the change. Our data show the successive progression of change-related activity from regions involved in early change detection to the ventral and dorsal attention networks, and finally the central executive network. While early change detection was found to recruit feature-specific networks involving auditory sensory but also frontal and parietal brain regions, the later spread of activity across the frontoparietal attention and executive networks was largely independent of the changing sound feature, suggesting the existence of a general feature-independent processing pathway of change-related information. Task relevance did not modulate early auditory sensory processing, but was mainly found to affect processing in frontal brain regions.
Bunzeck, N. and Thiel, C. M., Neurochemical modulation of repetition suppression and novelty signals in the human brain, Cortex, vol. 80. 2016.
Abstract DOI
The repeated processing of a sensory stimulus, such as a picture or sound, leads to a decrement in response in neurons that fired to the initial presentation. These effects are well known from single cell recordings in the inferior temporal cortex in monkeys, and functional neuroimaging in humans on large-scale neural activity could show similar effects in extrastriate, frontal and medial temporal lobe regions. The role of specific neurotransmitters in repeated processing of information is, however, less clear. In the first part of this article, we will introduce the two concepts of repetition suppression and novelty signals, which is followed by a brief overview of pharmacological neuroimaging in humans. We will then summarize human studies suggesting that gamma-aminobutyric-acid (GABA) and acetylcholine play an important role in modulating behavioral priming and associated repetition suppression in extrastriate and frontal brain regions. Finally, we review studies on neural novelty signals in the dopaminergic mesolimbic system, and conclude that dopamine regulates the temporal aspects of novelty processing and closely relates to long-term memory encoding rather than behavioral priming. As such, this review describes differential roles of GABA, acetylcholine and dopamine in repeated stimulus processing, and further suggests that repetition suppression and neural novelty signals may not be two sides of the same coin but rather independent processes.
Daubenbüchel, A. M. M., Hoffmann, A., Eveslage, M., Özyurt, J., Lohle, K., Reichel, J., Thiel, C. M., Martens, H., Geenen, V., and Müller, H. L., Oxytocin in survivors of childhood-onset craniopharyngioma, Endocrine, vol. (in press). 2016.
Abstract
Quality of survival of childhood-onset craniopharyngioma patients is frequently impaired by hypothalamic involvement or surgical lesions sequelae such as obesity and neuropsychological deficits. Oxytocin, a peptide hormone produced in the hypothalamus and secreted by posterior pituitary gland, plays a major role in regulation of behavior and body composition. In a cross-sectional study, oxytocin saliva concentrations were analyzed in 34 long-term craniopharyngioma survivors with and without hypothalamic involvement or treatment-related damage, recruited in the German Childhood Craniopharyngioma Registry, and in 73 healthy controls, attending the Craniopharyngioma Support Group Meeting 2014. Oxytocin was measured in saliva of craniopharyngioma patients and controls before and after standardized breakfast and associations with gender, body mass index, hypothalamic involvement, diabetes insipidus, and irradiation were analyzed. Patients with preoperative hypothalamic involvement showed similar oxytocin levels compared to patients without hypothalamic involvement and controls. However, patients with surgical hypothalamic lesions grade 1 (anterior hypothalamic area) presented with lower levels (p = 0.017) of oxytocin under fasting condition compared to patients with surgical lesion of posterior hypothalamic areas (grade 2) and patients without hypothalamic lesions (grade 0). Craniopharyngioma patients’ changes in oxytocin levels before and after breakfast correlated (p = 0.02) with their body mass index. Craniopharyngioma patients continue to secrete oxytocin, especially when anterior hypothalamic areas are not involved or damaged, but oxytocin shows less variation due to nutrition. Oxytocin supplementation should be explored as a therapeutic option in craniopharyngioma patients with hypothalamic obesity and/or behavioral pathologies due to lesions of specific anterior hypothalamic areas. Clinical trial number: KRANIOPHARYNGEOM 2000/2007(NCT00258453; NCT01272622).
Baum, S. H., Colonius, H., Thelen, A., Micheli, C., and Wallace, M. T., Above the mean: examining variability in hehavioral and neural responses to multisensory stimuli, Multisensory Research, vol. 29, no. 6-7. 2016.
Abstract
Even when experimental conditions are kept constant, a robust and consistent finding in both behavioral and neural experiments designed to examine multisensory processing is striking variability. Although this variability has often been considered uninteresting noise (a term that is laden with strong connotations), emerging work suggests that differences in variability may be an important aspect in describing differences in performance between individuals and groups. In the current review, derived from a symposium at the 2015 International Multisensory Research Forum in Pisa, Italy, we focus on several aspects of variability as it relates to multisensory function. This effort seeks to expand our understanding of variability at levels of coding and analysis ranging from the single neuron through large networks and on to behavioral processes, and encompasses a number of the multimodal approaches that are used to evaluate and characterize multisensory processing including single-unit neurophysiology, electroencephalography (EEG), functional magnetic resonance imaging (fMRI), and electrocorticography (ECoG).
Colonius, H., An invitation to coupling and copulas: with applications to multisensory modeling, Journal of Mathematical Psychology, vol. (in press). 2016.
Abstract
Stropahl, M., Chen, L. -C., and Debener, S., Cortical reorganization in postlingually deaf cochlear implant users: Intra-modal and cross-modal considerations, Hear. Res., vol. (in press). 2016.
Abstract
With the advances of cochlear implant (CI) technology, many deaf individuals can partially regain their hearing ability. However, there is a large variation in the level of recovery. Cortical changes induced by hearing deprivation and restoration with CIs have been thought to contribute to this variation. The current review aims to identify these cortical changes in postlingually deaf CI users and discusses their maladaptive or adaptive relationship to the CI outcome. Overall, intra-modal and cross-modal reorganization patterns have been identified in postlingually deaf CI users in visual and in auditory cortex. Even though cross-modal activation in auditory cortex is considered as maladaptive for speech recovery in CI users, a similar activation relates positively to lip reading skills. Furthermore, cross-modal activation of the visual cortex seems to be adaptive for speech recognition. Currently available evidence points to an involvement of further brain areas and suggests that a focus on the reversal of visual take-over of the auditory cortex may be too limited. Future investigations should consider expanded cortical as well as multi-sensory processing and capture different hierarchical processing steps. Furthermore, prospective longitudinal designs are needed to track the dynamics of cortical plasticity that takes place before and after implantation.
Mirkovic, B., Bleichner, M. G., De Vos, M., and Debener, S., Target speaker detection with concealed EEG around the ear, Front. Neurosci., vol. 10:349. 2016.
Abstract
Target speaker identification is essential for speech enhancement algorithms in assistive devices aimed toward helping the hearing impaired. Several recent studies have reported that target speaker identification is possible through electroencephalography (EEG) recordings. If the EEG system could be reduced to acceptable size while retaining the signal quality, hearing aids could benefit from the integration with concealed EEG. To compare the performance of a multichannel around-the-ear EEG system with high-density cap EEG recordings an envelope tracking algorithm was applied in a competitive speaker paradigm. The data from 20 normal hearing listeners were concurrently collected from the traditional state-of-the-art laboratory wired EEG system and a wireless mobile EEG system with two bilaterally-placed around-the-ear electrode arrays (cEEGrids). The results show that the cEEGrid ear-EEG technology captured neural signals that allowed the identification of the attended speaker above chance-level, with 69.3% accuracy, while cap-EEG signals resulted in the accuracy of 84.8%. Further analyses investigated the influence of ear-EEG signal quality and revealed that the envelope tracking procedure was unaffected by variability in channel impedances. We conclude that the quality of concealed ear-EEG recordings as acquired with the cEEGrid array has potential to be used in the brain-computer interface steering of hearing aids.
Chen, L. -C., Stropahl, M., Schoenwiesner, M., and Debener, S., Enhanced visual adaptation in cochlear implant users revealed by concurrent EEG-fNIRS, NeuroImage, vol. (in press). 2016.
Abstract
Previous studies have observed lower visual cortex activation for visual processing in cochlear implant (CI) users compared to normal hearing controls, while others reported enhanced visual speechreading abilities in CI users. The present work investigated whether lower visual cortical activation for visual processing can be explained by a more efficient visual sensory encoding in CI users. Specifically, we investigated whether CI users show enhanced stimulus-specific adaptation for visual stimuli compared to controls. Auditory sensory adaptation was also investigated to explore the sensory specificity of the predicted effect. Twenty post-lingually deafened adult CI users and twenty age-matched controls were presented with repeated visual and auditory stimuli during simultaneous acquisition of electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS). By integrating EEG and fNIRS signals we found significantly enhanced visual adaptation and lower visual cortex activation in CI users compared to controls. That is, responses to repeated visual stimuli decreased more prominently in CI users than in controls. The results suggest that CI users process visual stimuli more efficiently than controls.
Antal, A. and Herrmann, C. S., Transcranial alternating current and random noise stimulation: Possible mechanisms, Neural Plasticity, vol. 2016:3616807. 2016.
Abstract
Background. Transcranial alternating current stimulation (tACS) is a relatively recent method suited to noninvasively modulate brain oscillations. Technically the method is similar but not identical to transcranial direct current stimulation (tDCS). While decades of research in animals and humans has revealed the main physiological mechanisms of tDCS, less is known about the physiological mechanisms of tACS. Method. Here, we review recent interdisciplinary research that has furthered our understanding of how tACS affects brain oscillations and by what means transcranial random noise stimulation (tRNS) that is a special form of tACS can modulate cortical functions. Results. Animal experiments have demonstrated in what way neurons react to invasively and transcranially applied alternating currents. Such findings are further supported by neural network simulations and knowledge from physics on entraining physical oscillators in the human brain. As a result, fine-grained models of the human skull and brain allow the prediction of the exact pattern of current flow during tDCS and tACS. Finally, recent studies on human physiology and behavior complete the picture of noninvasive modulation of brain oscillations. Conclusion. In future, the methods may be applicable in therapy of neurological and psychiatric disorders that are due to malfunctioning brain oscillations.
Dowsett, J. and Herrmann, C. S., Transcranial alternating current stimulation with sawtooth waves: simultaneous stimulation and EEG recording, Front. Hum. Neurosci., vol. 10:135. 2016.
Abstract
Transcranial alternating current stimulation (tACS) has until now mostly been administered as an alternating sinusoidal wave. Despite modern tACS stimulators being able to deliver alternating current with any arbitrary shape there has been no systematic exploration into the relative benefits of different waveforms. As tACS is a relatively new technique there is a huge parameter space of unexplored possibilities which may prove superior or complimentary to the traditional sinusoidal waveform. Here, we begin to address this with an investigation into the effects of sawtooth wave tACS on individual alpha power. Evidence from animal models suggests that the gradient and direction of an electric current should be important factors for the subsequent neural firing rate; we compared positive and negative ramp sawtooth waves to test this. An additional advantage of sawtooth waves is that the resulting artifact in the electroencephalogram (EEG) recording is significantly simpler to remove than a sine wave; accordingly we were able to observe alpha oscillations both during and after stimulation. We found that positive ramp sawtooth, but not negative ramp sawtooth, significantly enhanced alpha power during stimulation relative to sham (p < 0.01). In addition we tested for an after-effect of both sawtooth and sinusoidal stimulation on alpha power but in this case did not find any significant effect. This preliminary study paves the way for further investigations into the effect of the gradient and direction of the current in tACS which could significantly improve the usefulness of this technique.
Herrmann, C. S., Murray, M. M., Ionta, S., Hutt, A., and Lefebvre, J., Shaping intrinsic neural oscillations with periodic stimulation, J. Neurosci., vol. 36, no. 19. 2016.
Abstract
Rhythmic brain activity plays an important role in neural processing and behavior. Features of these oscillations, including amplitude, phase, and spectrum, can be influenced by internal states (e.g., shifts in arousal, attention or cognitive ability) or external stimulation. Electromagnetic stimulation techniques such as transcranial magnetic stimulation, transcranial direct current stimulation, and trans- cranial alternating current stimulation are used increasingly in both research and clinical settings. Currently, the mechanisms whereby time-dependent external stimuli influence population-scale oscillations remain poorly understood. Here, we provide computational insights regarding the mapping between periodic pulsatile stimulation parameters such as amplitude and frequency and the response dynamics of recurrent, nonlinear spiking neural networks. Using a cortical model built of excitatory and inhibitory neurons, we explored a wide range of stimulation intensities and frequencies systematically. Our results suggest that rhythmic stimulation can form the basis of a control paradigm in which one can manipulate the intrinsic oscillatory properties of driven networks via a plurality of input-driven mechanisms. Our results show that, in addition to resonance and entrainment, nonlinear acceleration is involved in shaping the rhythmic response of our modeled network. Such nonlinear acceleration of spontaneous and synchronous oscillatory activity in a neural network occurs in regimes of intense, high-frequency rhythmic stimulation. These results open new perspectives on the manipulation of synchro- nous neural activity for basic and clinical research.
Ruhnau, P., Neuling, T., Fuscá, M., Herrmann, C. S., Demarchi, G., and Weisz, N., Eyes wide shut: Transcranial alternating current stimulation drives alpha rhythm in a state dependent manner, Scientific Reports, vol. 6:27138. 2016.
Abstract
Transcranial alternating current stimulation (tACS) is used to modulate brain oscillations to measure changes in cognitive function. It is only since recently that brain activity in human subjects during tACS can be investigated. The present study aims to investigate the phase relationship between the external tACS signal and concurrent brain activity. Subjects were stimulated with tACS at individual alpha frequency during eyes open and eyes closed resting states. Electrodes were placed at Cz and Oz, which should affect parieto-occipital areas most strongly. Source space magnetoencephalography (MEG) data were used to estimate phase coherence between tACS and brain activity. Phase coherence was significantly increased in areas in the occipital pole in eyes open resting state only. The lag between tACS and brain responses showed considerable inter-individual variability. In conclusion, tACS at individual alpha frequency entrains brain activity in visual cortices. Interestingly, this effect is state dependent and is clearly observed with eyes open but only to a lesser extent with eyes closed.
Veniero, D., Strüber, D., Thut, G., and Herrmann, C. S., Noninvasive Brain Stimulation Techniques Can Modulate Cognitive Processing, Organizational Research Methods, vol. (in press). 2016.
Abstract DOI
Recent methods that allow a noninvasive modulation of brain activity are able to modulate human cognitive behavior. Among these methods are transcranial electric stimulation and transcranial magnetic stimulation that both come in multiple variants. A property of both types of brain stimulation is that they modulate brain activity and in turn modulate cognitive behavior. Here, we describe the methods with their assumed neural mechanisms for readers from the economic and social sciences and little prior knowledge of these techniques. Our emphasis is on available protocols and experimental parameters to choose from when designing a study. We also review a selection of recent studies that have successfully applied them in the respective field. We provide short pointers to limitations that need to be considered and refer to the relevant papers where appropriate.
Finke, M., Büchner, A., Ruigendijk, E., Meyer, M., and Sandmann, P., On the relationship between auditory cognition and speech intelligibility in cochlear implant users: An ERP study, Neuropsychologia, vol. 87. 2016.
Abstract
Carroll, R., Warzybok, A., Kollmeier, B., and Ruigendijk, E., Age-related differences in lexical access relate to speech recognition in noise, Front. Psychol., vol. 7:990. 2016.
Abstract
Vocabulary size has been suggested as a useful measure of “verbal abilities“ that correlates with speech recognition scores. Knowing more words is linked to better speech recognition. How vocabulary knowledge translates to general speech recognition mechanisms, how these mechanisms relate to offline speech recognition scores, and how they may be modulated by acoustical distortion or age, is less clear. Age-related differences in linguistic measures may predict age-related differences in speech recognition in noise performance. We hypothesized that speech recognition performance can be predicted by the efficiency of lexical access, which refers to the speed with which a given word can be searched and accessed relative to the size of the mental lexicon. We tested speech recognition in a clinical German sentence-in-noise test at two signal-to-noise ratios (SNRs), in 22 younger (18-35 yrs.) and 22 older (60-78 yrs.) listeners with normal hearing. We also assessed receptive vocabulary, lexical access time, verbal working memory, and hearing thresholds as measures of individual differences. Age group, SNR level, vocabulary size and lexical access time were significant predictors of individual speech recognition scores, but working memory and hearing threshold were not. Interestingly, longer accessing times were correlated with better speech recognition scores. Hierarchical regression models for each subset of age group and SNR showed very similar patterns: The combination of vocabulary size and lexical access time contributed most to speech recognition performance; only for the younger group at the better SNR (yielding about 85% correct speech recognition) did vocabulary size alone predict performance. Our data suggest that successful speech recognition in noise is mainly modulated by the efficiency of lexical access. This suggests that older adults’ poorer performance in the speech recognition task may have arisen from reduced efficiency in lexical access; with an average vocabulary size similar to that of younger adults, they were still slower in lexical access.
Feinkohl, A., Borzeszkowski, K. M., and Klump, G. M., Azimuthal sound localization in the European starling (Sturnus vulgaris): III. Comparison of sound localization measures, Hear. Res., vol. 332. 2016.
Abstract DOI
Sound localization studies have typically employed two types of tasks: absolute tasks that measured the localization of the angular location of a single sound and relative tasks that measured the localization of the angular location of a sound relative to the angular location of another sound from a different source (e.g., in the Minimum Audible Angle task). The present study investigates the localization of single sounds in the European starling (Sturnus vulgaris) with a left/right discrimination paradigm. Localization thresholds of 8–12° determined in starlings using this paradigm were much lower than the minimum audible angle thresholds determined in a previous study with the same individuals. The traditional concept of sound localization classifies the present experiment as an absolute localization task. However, we propose that the experiment presenting single sounds measured localization of the angular location of the sound relative to a non-acoustic spatial frame of reference. We discuss how the properties of the setup can determine if presentation of single sounds in a left/right discrimination paradigm comprises an absolute localization task rather than a localization task relative to a non-acoustic reference. Furthermore, the analysis methods employed may lead to quite different threshold estimates for the same data, especially in case of a response bias in left/right discrimination. We propose using an analysis method precluding effects of response bias on the threshold estimate.
Behrens, D. and Klump, G. M., Comparison of mouse minimum audible angle determined in prepulse inhibition and operant conditioning procedures, Hear. Res., vol. 333. 2016.
Abstract DOI
Both reward based operant conditioning (OC) and reflex-based prepulse inhibition (PPI) procedures are used in sound localisation studies in mice. Since the results of both procedures are compared in the literature, it is important to assess whether they provide similar results if the same stimulus paradigm is applied. Here, we compare the sensitivity of C57BL/6 mice in OC and PPI procedures for detecting a switch in speaker location using broadband and narrowband noise stimuli and determined their minimum audible angle (MAA). In the OC procedure, we calculated d' values from the hit and false alarm rates. In the PPI procedure, we calculated the area under ROC curves from the startle response amplitudes and derived da values to obtain a sensitivity measure that corresponds to d'. For both procedures, the mean sensitivity to the speaker switch increased with an increase in angular separation. For broadband noise stimuli, a d' of up to 3.3 (OC) and a da of up to 1.1 (PPI) were observed at large speaker separations. Narrowband noise stimuli resulted in lower sensitivities in both procedures, resulting in a maximum d' of 2.0 (OC) and a maximum da of 0.3 (PPI). Using a sensitivity of 1.0 as the threshold criterion, broadband noise MAAs in the range from 32° to 46° were observed in the OC procedure whereas a broadband noise MAAs of 108° or higher were observed in the PPI procedure. In the OC procedure, narrowband noise MAAs in the range from 37° to 62° were observed. In the PPI procedure, no narrowband noise MAA could be determined since none of the subjects reached the threshold. Thus, OC procedures result in a better performance of the subjects in the sound localization task than PPI procedures, challenging the view that both procedures can be used interchangeably.
Laumen, G., Ferber, A. T., Klump, G. M., and Tollin, D. J., The physiological basis and clinical use of the binaural interaction component of the auditory brainstem response, Ear Hear, vol. 37, no. 5. 2016.
Abstract DOI
The auditory brainstem response (ABR) is a sound-evoked noninvasively measured electrical potential representing the sum of neuronal activity in the auditory brainstem and midbrain. ABR peak amplitudes and latencies are widely used in human and animal auditory research and for clinical screening. The binaural interaction component (BIC) of the ABR stands for the difference between the sum of the monaural ABRs and the ABR obtained with binaural stimulation. The BIC comprises a series of distinct waves, the largest of which (DN1) has been used for evaluating binaural hearing in both normal hearing and hearing-impaired listeners. Based on data from animal and human studies, the authors discuss the possible anatomical and physiological bases of the BIC (DN1 in particular). The effects of electrode placement and stimulus characteristics on the binaurally evoked ABR are evaluated. The authors review how interaural time and intensity differences affect the BIC and, analyzing these dependencies, draw conclusion about the mechanism underlying the generation of the BIC. Finally, the utility of the BIC for clinical diagnoses are summarized.
Schepker, H. and Doclo, S., A Semidefinite Programming Approach to Min-max Estimation of the Common Part of Acoustic Feedback Paths in Hearing Aids, IEEE Trans. Aud. Sp. Lang. Proc., vol. 24, no. 2. 2016.
Abstract
Thiemann, J., Müller, M., Marquardt, D., Doclo, S., and van de Par, S., Speech enhancement for multimicrophone binaural hearing aids aiming to preserve the spatial auditory scene, EURASIP J. Adv. Signal Process., vol. 2016:12. 2016.
Abstract
Kodrasi, I. and Doclo, S., Joint Dereverberation and Noise Reduction Based on Acoustic Multi-Channel Equalization, IEEE Trans. Aud. Sp. Lang. Proc., vol. 24, no. 4. 2016.
Abstract
Schepker, H. and Doclo, S., Least-squares estimation of the common pole-zero filter of acoustic feedback paths in hearing aids, IEEE Trans. Aud. Sp. Lang. Proc., vol. (in press), no. 99. 2016.
Abstract
In adaptive feedback cancellation both the convergence speed and the computational complexity depend on the number of adaptive parameters used to model the acoustic feedback paths. To reduce the number of adaptive parameters it has been proposed to model the acoustic feedback paths as the convolution of a time-invariant common pole-zero filter and time-varying all-zero filters, enabling to track fast changes. In this paper a novel procedure to estimate the common pole-zero filter of acoustic feedback paths is presented. In contrast to previous approaches which minimize the so-called equation-error, we propose to approximate the desired output-error minimization by employing a weighted least-squares procedure motivated by the Steiglitz-McBride iteration. The estimation of the common pole-zero filter is formulated as a semidefinite programming problem, to which a constraint based on Lyapunov theory is added in order to guarantee the stability of the estimated polezero filter. Experimental results using measured acoustic feedback paths from a two-microphone behind-the-ear hearing aid show that the proposed optimization procedure using the Lyapunov constraint outperforms existing optimization procedures in terms of modelling accuracy and added stable gain.
Kuklasinski, A., Doclo, S., Jensen, S., and Jensen, J., Maximum Likelihood PSD Estimation for Speech Enhancement in Reverberation and Noise, IEEE Trans. Aud. Sp. Lang. Proc., vol. 24, no. 9. 2016.
Abstract
In this contribution we focus on the problem of power spectral density (PSD) estimation from multiple microphone signals in reverberant and noisy environments. The PSD estimation method proposed in this paper is based on the maximum likelihood (ML) methodology. In particular, we derive a novel ML PSD estimation scheme that is suitable for sound scenes which besides speech and reverberation consist of an additional noise component whose second-order statistics are known. The proposed algorithm is shown to outperform an existing similar algorithm in terms of PSD estimation accuracy. Moreover, it is shown numerically that the mean squared estimation error achieved by the proposed method is near the limit set by the corresponding Cram´er-Rao lower bound. The speech dereverberation performance of a multi-channel Wiener filter (MWF) based on the proposed PSD estimators is measured using several instrumental measures and is shown to be higher than when the competing estimator is used. Moreover, we perform a speech intelligibility test where we demonstrate that both the proposed and the competing PSD estimators lead to similar intelligibility improvements.
Grimm, S., Lawin-Ore, T. C., Doclo, S., and Freudenberger, J., Phase reference for the generalized multichannel Wiener filter, EURASIP J. Adv. Signal Process., vol. 2016:78. 2016.
Abstract
The multichannel Wiener filter (MWF) is a well-established noise reduction technique for speech processing. Most commonly, the speech component in a selected reference microphone is estimated. The choice of this reference microphone influences the broadband output signal-to-noise ratio (SNR) as well as the speech distortion. Recently, a generalized formulation for the MWF (G-MWF) was proposed that uses a weighted sum of the individual transfer functions from the speaker to the microphones to form a better speech reference resulting in an improved broadband output SNR. For the MWF, the influence of the phase reference is often neglected, because it has no impact on the narrow-band output SNR. The G-MWF allows an arbitrary choice of the phase reference especially in the context of spatially distributed microphones. In this work, we demonstrate that the phase reference determines the overall transfer function and hence has an impact on both the speech distortion and the broadband output SNR. We propose two speech references that achieve a better signal-to-reverberation ratio (SRR) and an improvement in the broadband output SNR. Both proposed references are based on the phase of a delay-and-sum beamformer. Hence, the time-difference-of-arrival (TDOA) of the speech source is required to align the signals. The different techniques are compared in terms of SRR and SNR performance.
Krawczyk-Becker, M. and Gerkmann, T., Fundamental Frequency Informed Speech Enhancement in a Flexible Statistical Framework, IEEE Trans. Aud. Sp. Lang. Proc., vol. 24, no. 5. 2016.
Abstract
Conventional statistical clean speech estimators, like the Wiener filter, are frequently used for the spectro-temporal enhancement of noise corrupted speech. Most of these approaches estimate the clean speech independently for each time-frequency point, neglecting the structure of the underlying speech sound. In this work, we derive a statistical estimator that explicitly takes into account information about the characteristic structure of voiced speech by means of a harmonic signal model. To this end, we also present a way to estimate a harmonic model-based clean speech representation and the corresponding error variance directly in the short-time Fourier transform domain. The resulting estimator is optimal in the minimum-mean-squared error sense and can conveniently be formulated in terms of a multichannel Wiener filter. The proposed estimator outperforms several reference algorithms in terms of speech quality and intelligibility as predicted by instrumental measures.
Josupeit, A., Kopčo, N., and Hohmann, V., Modeling of speech localization in a multi-talker mixture using periodicity and energy-based auditory features, J. Acoust. Soc. Am., vol. 139, no. 5. 2016.
Abstract
Jürgens, T., Clark, N., Lecluyse, W., and Meddis, R., Exploration of a physiologically-inspired hearing-aid algorithm using a computer model mimicking impaired hearing, Int. J. Audiol., vol. 55, no. 6. 2016.
Abstract
Objective: To use a computer model of impaired hearing to explore the effects of a physiologically-inspired hearing-aid algorithm on a range of psychoacoustic measures. Design: A computer model of a hypothetical impaired listener’s hearing was constructed by adjusting parameters of a computer model of normal hearing. Absolute thresholds, estimates of compression, and frequency selectivity (summarized to a hearing profile) were assessed using this model with and without pre-processing the stimuli by a hearing-aid algorithm. The influence of different settings of the algorithm on the impaired profile was investigated. To validate the model predictions, the effect of the algorithm on hearing profiles of human impaired listeners was measured. Study sample: A computer model simulating impaired hearing (total absence of basilar membrane compression) was used, and three hearing-impaired listeners participated. Results: The hearing profiles of the model and the listeners showed substantial changes when the test stimuli were pre-processed by the hearing-aid algorithm. These changes consisted of lower absolute thresholds, steeper temporal masking curves, and sharper psychophysical tuning curves. Conclusion: The hearing-aid algorithm affected the impaired hearing profile of the model to approximate a normal hearing profile. Qualitatively similar results were found with the impaired listeners’ hearing profiles.
Patterson, R. D., Andermann, M., Uppenkamp, S., and Rupp, A., Locating Melody Processing Activity in Auditory Cortex with Magnetoencephalography, Advances in Experimental Medicine and Biology, vol. 894. 2016.
Abstract
This paper describes a technique for isolating the brain activity associated with melodic pitch processing. The magnetoencephalograhic (MEG) response to a four note, diatonic melody built of French horn notes, is contrasted with the response to a control sequence containing four identical, “tonic” notes. The transient response (TR) to the first note of each bar is dominated by energy-onset activity; the melody processing is observed by contrasting the TRs to the remaining melodic and tonic notes of the bar (2–4). They have uniform shape within a tonic or melodic sequence which makes it possible to fit a 4-dipole model and show that there are two sources in each hemisphere—a melody source in the anterior part of Heschl’s gyrus (HG) and an onset source about 10 mm posterior to it, in planum temporale (PT). The N1m to the initial note has a short latency and the same magnitude for the tonic and the melodic sequences. The melody activity is distinguished by the relative sizes of the N1m and P2m components of the TRs to notes 2–4. In the anterior source a given note elicits a much larger N1m-P2m complex with a shorter latency when it is part of a melodic sequence. This study shows how to isolate the N1m, energy-onset response in PT, and produce a clean melody response in the anterior part of auditory cortex (HG).
Behler, O. and Uppenkamp, S., Auditory fMRI of Sound Intensity and Loudness for Unilateral Stimulation, Advances in Experimental Medicine and Biology, vol. 894. 2016.
Abstract
We report a systematic exploration of the interrelation of sound intensity, ear of entry, individual loudness judgments, and brain activity across hemispheres, using auditory functional magnetic resonance imaging (fMRI). The stimuli employed were 4 kHz-bandpass filtered noise stimuli, presented monaurally to each ear at levels from 37 to 97 dB SPL. One diotic condition and a silence condition were included as control conditions. Normal hearing listeners completed a categorical loudness scaling procedure with similar stimuli before auditory fMRI was performed. The relationship between brain activity, as inferred from blood oxygenation level dependent (BOLD) contrasts, and both sound intensity and loudness estimates were analyzed by means of linear mixed effects models for various anatomically defined regions of interest in the ascending auditory pathway and in the cortex. The results indicate distinct functional differences between midbrain and cortical areas as well as between specific regions within auditory cortex, suggesting a systematic hierarchy in terms of lateralization and the representation of sensory stimulation and perception.
Behler, O. and Uppenkamp, S., The representation of level and loudness in the central auditory system for unilateral stimulation, NeuroImage, vol. 139. 2016.
Abstract
Loudness is the perceptual correlate of the physical intensity of a sound. However, loudness judgments depend on a variety of other variables and can vary considerably between individual listeners. While functional magnetic resonance imaging (fMRI) has been extensively used to characterize the neural representation of physical sound intensity in the human auditory system, only few studies have also investigated brain activity in relation to individual loudness. The physiological correlate of loudness perception is not yet fully understood. The present study systematically explored the interrelation of sound pressure level, ear of entry, individual loudness judgments, and fMRI activation along different stages of the central auditory system and across hemispheres for a group of normal hearing listeners. 4-kHz-bandpass filtered noise stimuli were presented monaurally to each ear at levels from 37 to 97 dB SPL. One diotic condition and a silence condition were included as control conditions. The participants completed a categorical loudness scaling procedure with similar stimuli before auditory fMRI was performed. The relationship between brain activity, as inferred from blood oxygenation level dependent (BOLD) contrasts, and both sound level and loudness estimates were analyzed by means of functional activation maps and linear mixed effects models for various anatomically defined regions of interest in the ascending auditory pathway and in the cortex. Our findings are overall in line with the notion that fMRI activation in several regions within auditory cortex as well as in certain stages of the ascending auditory pathway might be more a direct linear reflection of perceived loudness rather than of sound pressure level. The results indicate distinct functional differences between midbrain and cortical areas as well as between specific regions within auditory cortex, suggesting a systematic hierarchy in terms of lateralization and the representation of level and loudness.
Reed, D. K., Dietz, M., Josupeit, A., and van de Par, S., Lateralization of stimuli with alternating interaural time differences: The role of monaural envelope cues, J. Acoust. Soc. Am., vol. 139. 2016.
Abstract
A temporally acute binaural system can help to resolve inherent fluctuations in binaural information that are often present in complex auditory scenes. Using a broadband noise stimulus that rapidly alternates between two different values of interaural time difference(ITD), the ability of the binaural system to hear the lateral position resulting from one of the ITD values was investigated. Results show that listeners are able to accurately lateralize brief noise tokens of only 3–7 ms in duration. In two subsequent experiments, the role of an amplitude modulation (AM) imposed on the ITD-switching stimulus used in the first experiment was tested. For wideband stimuli, the temporal position of the ITD target relative to the phase of the AM did not influence absolute lateralization or detection performance. When the stimuli were narrowband, however, detection of the ITD target was best when temporally positioned in the rising portion of the AM. These experiments illustrate that the auditory system is capable of making accurate lateral estimates of very brief moments of ITD information. Furthermore, for these instantaneous changes in ITD information, the stimulus bandwidth can influence the role of envelope cues for the readout of binaural information.
Schoenmaker, E. and van de Par, S., Intelligibility for Binaural Speech with Discarded Low-SNR Speech Components, Advances in Experimental Medicine and Biology, vol. 894. 2016.
Abstract
Speech intelligibility in multitalker settings improves when the target speaker is spatially separated from the interfering speakers. A factor that may contribute to this improvement is the improved detectability of target-speech components due to binaural interaction in analogy to the Binaural Masking Level Difference (BMLD). This would allow listeners to hear target speech components within specific time-frequency intervals that have a negative SNR, similar to the improvement in the detectability of a tone in noise when these contain disparate interaural difference cues. To investigate whether these negative-SNR target-speech components indeed contribute to speech intelligibility, a stimulus manipulation was performed where all target components were removed when local SNRs were smaller than a certain criterion value. It can be expected that for sufficiently high criterion values target speech components will be removed that do contribute to speech intelligibility. For spatially separated speakers, assuming that a BMLD-like detection advantage contributes to intelligibility, degradation in intelligibility is expected already at criterion values below 0 dB SNR. However, for collocated speakers it is expected that higher criterion values can be applied without impairing speech intelligibility. Results show that degradation of intelligibility for separated speakers is only seen for criterion values of 0 dB and above, indicating a negligible contribution of a BMLD-like detection advantage in multitalker settings. These results show that the spatial benefit is related to a spatial separation of speech components at positive local SNRs rather than to a BMLD-like detection improvement for speech components at negative local SNRs.
Schoenmaker, E., Brand, T., and van de Par, S., The multiple contributions of interaural differences to improved speech intelligibility in multitalker scenarios, J. Acoust. Soc. Am., vol. 139, no. 5. 2016.
Abstract
Buschermöhle, M., Wagener, K. C., and Kollmeier, B., Sprachaudiometrische Messungen mit dem verkürzten Oldenburger Satztest OLKISA bei Erwachsenen, Z. Audiol., vol. 55, no. 1. 2016.
Abstract
Abstract | The Oldenburg Sentence Test for Children (OLKISA) has been used for speech audiometry with children for several years. In principle, the test procedure is also applicable for adults. The necessary evaluation and corresponding values for comparison are described here. The results of measurements with 40 normal hearing adults show that the OLKISA can be conducted with adults in quiet as well as in noise. For the group of test subjects under examination and after eliminating the training effect, a range of speech reception thresholds for 50 % intelligibility of 18.8 ± 2.2 dB SPL was found in quiet and a range of -7.2 ± 1.2 dB SNR was found in noise (Oldenburg noise) for adaptive measurements. The slope of the psychometric function of the OLKISA for the examined population of test subjects was 12.8 ± 0.8 %/dB in quiet and 13.7 ± 1.3 %/dB in noise. ### Zusammenfassung | Der Oldenburger Kinder-Satztest (OLKISA) wird seit Jahren in der Sprachaudiometrie mit Kindern eingesetzt. Grundsätzlich ist das Verfahren auch mit Erwachsenen durchführbar. Die dafür notwendige Evaluation und entsprechende Vergleichswerte werden hier vorgestellt. Die Ergebnisse der Messungen mit 40 normalhörenden erwachsenen Probanden zeigen, dass der OLKISA sowohl in Ruhe als auch im Störgeräusch mit Erwachsenen verwendet werden kann. Bei adaptiv durchgeführten Messungen der Sprachverständlichkeitsschwelle für 50 % Verständlichkeit ergaben sich mit der untersuchten Probandengruppe nach Ausschluss des Trainingseffekts Bereiche von 18,8 ± 2,2 dB SPL in Ruhe und -7,2 ± 1,2 dB SNR im Störgeräusch (Oldenburger Rauschen). Die Steigung der psychometrischen Funktion des OLKISA für die untersuchte Probandengruppe lag bei 12,8 ± 0,8 %/dB in Ruhe und 13,7 ± 1,3 %/dB im Störgeräusch.
Lüddemann, H., Kollmeier, B., and Riedel, H., Electrophysiological and psychophysical asymmetries in sensitivity to interaural correlation gaps and implications for binaural integration time, Hear. Res., vol. 332. 2016.
Abstract
Brief deviations of interaural correlation (IAC) can provide valuable cues for detection, segregation and localization of acoustic signals. This study investigated the processing of such “binaural gaps” in continuously running noise (100-2000 Hz), in comparison to silent “monaural gaps”, by measuring late auditory evoked potentials (LAEPs) and perceptual thresholds with novel, iteratively optimized stimuli. Mean perceptual binaural gap duration thresholds exhibited a major asymmetry: they were substantially shorter for uncorrelated gaps in correlated and anticorrelated reference noise (1.75 ms and 4.1 ms) than for correlated and anticorrelated gaps in uncorrelated reference noise (26.5 ms and 39.0 ms). The thresholds also showed a minor asymmetry: they were shorter in the positive than in the negative IAC range. The mean behavioral threshold for monaural gaps was 5.5 ms. For all five gap types, the amplitude of LAEP components N1 and P2 increased linearly with the logarithm of gap duration. While perceptual and electrophysiological thresholds matched for monaural gaps, LAEP thresholds were about twice as long as perceptual thresholds for uncorrelated gaps, but half as long for correlated and anticorrelated gaps. Nevertheless, LAEP thresholds showed the same asymmetries as perceptual thresholds. For gap durations below 30 ms, LAEPs were dominated by the processing of the leading edge of a gap. For longer gap durations, in contrast, both the leading and the lagging edge of a gap contributed to the evoked response. Formulae for the equivalent rectangular duration (ERD) of the binaural system’s temporal window were derived for three common window shapes. The psychophysical ERD was 68 ms for diotic and about 40 ms for anti- and uncorrelated noise. After a nonlinear Z-transform of the stimulus IAC prior to temporal integration, ERDs were about 10 ms for reference correlations of ±1 and 80 ms for uncorrelated reference. Hence, a physiologically motivated peripheral nonlinearity changed the rank order of ERDs across experimental conditions in a plausible manner.
Schubotz, W., Brand, T., Kollmeier, B., and Ewert, S. D., The influence of high-frequency envelope information on low-frequency vowel identification in noise, PLOS ONE, vol. 11, no. 1 (e0145610). 2016.
Abstract DOIFull Text
Vowel identification in noise using consonant-vowel-consonant (CVC) logatomes was used to investigate a possible interplay of speech information from different frequency regions. It was hypothesized that the periodicity conveyed by the temporal envelope of a high frequency stimulus can enhance the use of the information carried by auditory channels in the low-frequency region that share the same periodicity. It was further hypothesized that this acts as a strobe-like mechanism and would increase the signal-to-noise ratio for the voiced parts of the CVCs. In a first experiment, different high-frequency cues were provided to test this hypothesis, whereas a second experiment examined more closely the role of amplitude modulations and intact phase information within the high-frequency region (4-8 kHz). CVCs were either natural or vocoded speech (both limited to a low-pass cutoff-frequency of 2.5 kHz) and were presented in stationary 3-kHz low-pass filtered masking noise. The experimental results did not support the hypothesized use of periodicity information for aiding low-frequency perception.
Oetting, D., Hohmann, V., Appell, J. -E., Kollmeier, B., and Ewert, S. D., Spectral and binaural loudness summation for hearing-impaired listeners, Hear. Res., vol. 335. 2016.
Abstract
Sensorineural hearing loss typically results in a steepened loudness function and a reduced dynamic range from elevated thresholds to uncomfortably loud levels for narrowband and broadband signals. Restoring narrowband loudness perception for hearing-impaired (HI) listeners can lead to overly loud perception of broadband signals and it is unclear how binaural presentation affects loudness perception in this case. Here, loudness perception quantified by categorical loudness scaling for nine normal-hearing (NH) and ten HI listeners was compared for signals with different bandwidth and different spectral shape in monaural and in binaural conditions. For the HI listeners, frequency- and level-dependent amplification was used to match the narrowband monaural loudness functions of the NH listeners. The loudness functions for NH and HI listeners showed good agreement for monaural broadband signals. However, HI listeners showed substantially greater loudness for binaural broadband signals than for the NH listeners: on average a 14.1 dB lower level was required to reach “very loud” (range 30.8 to -3.7 dB). Overall, with narrowband loudness compensation, a given binaural loudness for broadband signals above “medium loud” was reached at systematically lower levels for HI than for NH listeners. Such increased binaural loudness summation was not found for loudness categories below “medium loud” or for narrowband signals. Large individual variations in the increased loudness summation were observed and could not be explained by the audiogram or the narrowband loudness functions.
Kollmeier, B., Akeroyd, M. A., Arlinger, S., Bentler, R. A., Boothroyd, A., Dillier, N., Dreschler, W. A., Gagne, J. -P., Lutman, M. E., Wouters, J., and , Reply to the Comment on 'International Collegium of Rehabilitative Audiology (ICRA) recommendations for the constructor of multilingual speech test by Akeroyd et al' by Cas Smits, Int. J. Audiol., vol. 55, no. 4. 2016.
Abstract
Willberg, T., Buschermöhle, M., Sivonen, V., Aarnisalo, A. A., Löppönen, H., Kollmeier, B., and Dietz, A., The development and evaluation of the Finnish digit triplet test, Acta Otolaryngol., vol. 136, no. 10. 2016.
Abstract
Schädler, M. R., Warzybok, A., Ewert, S. D., and Kollmeier, B., A simulation framework for auditory discrimination experiments: Revealing the importance of across-frequency processing in speech perception, J. Acoust. Soc. Am., vol. 139, no. 5. 2016.
Abstract
A framework for simulating auditory discrimination experiments, based on an approach from Schädler, Warzybok, Hochmuth, and Kollmeier [(2015). Int. J. Audiol. 54, 100–107] which was originally designed to predict speech recognition thresholds, is extended to also predict psychoacoustic thresholds. The proposed framework is used to assess the suitability of different auditory-inspired feature sets for a range of auditory discrimination experiments that included psychoacoustic as well as speech recognitionexperiments in noise. The considered experiments were 2 kHz tone-in-broadband-noise simultaneous masking depending on the tone length, spectral masking with simultaneously presented tone signals and narrow-band noise maskers, and German Matrix sentence test reception threshold in stationary and modulated noise. The employed feature sets included spectro-temporal Gabor filter bank features, Mel-frequency cepstral coefficients, logarithmically scaled Mel-spectrograms, and the internal representation of the Perception Model from Dau, Kollmeier, and Kohlrausch [(1997). J. Acoust. Soc. Am. 102(5), 2892–2905]. The proposed framework was successfully employed to simulate all experiments with a common parameter set and obtain objective thresholds with less assumptions compared to traditional modeling approaches. Depending on the feature set, the simulated reference-free thresholds were found to agree with—and hence to predict—empirical data from the literature. Across-frequency processing was found to be crucial to accurately model the lower speech reception threshold in modulated noise conditions than in stationary noise conditions.
Pieper, I., Mauermann, M., Kollmeier, B., and Ewert, S. D., Physiological motivated transmission-lines as front end for loudness models, J. Acoust. Soc. Am., vol. 139, no. 5. 2016.
Abstract
Kortlang, S., Grimm, G., Hohmann, V., and Kollmeier, B., Auditory Model-Based Dynamic Compression Controlled by Subband Instantaneous Frequency and Speech Presence Probability Estimates, IEEE Trans. Aud. Sp. Lang. Proc., vol. 24, no. 10. 2016.
Abstract
Schubotz, W., Brand, T., Kollmeier, B., and Ewert, S. D., Monaural speech intelligibility and detection in maskers with varying amounts of spectro-temporal speech features, J. Acoust. Soc. Am., vol. 140. 2016.
Abstract
Speech intelligibility is strongly affected by the presence of maskers. Depending on the spectro-temporal structure of the masker and its similarity to the target speech, different masking aspects can occur which are typically referred to as energetic, amplitude modulation, and informational masking. In this study speech intelligibility and speech detection was measured in maskers that vary systematically in the time-frequency domain from steady-state noise to a single interfering talker. Male and female target speech was used in combination with maskers based on speech for the same or different gender. Observed data were compared to predictions of the speech intelligibility index, extended speech intelligibility index, multi-resolution speech-based envelope-power-spectrum model, and the short-time objective intelligibility measure. The different models served as analysis tool to help distinguish between the different masking aspects. Comparison shows that overall masking can to a large extent be explained by short-term energetic masking. However, the other masking aspects (amplitude modulation an informational masking) influence speech intelligibility as well. Additionally, it was obvious that all models showed considerable deviations from the data. Therefore, the current study provides a benchmark for further evaluation of speech prediction models.
Grimm, G., Kollmeier, B., and Hohmann, V., Spatial acoustic scenarios in multichannel loudspeaker systems for hearing aid evaluation, J. Am. Acad. Audiol., vol. 27, no. 7. 2016.
Abstract
Background: Field tests and guided walks in real environments show that the benefit from hearing aid (HA) signal processing in real-life situations is typically lower than the predicted benefit found in laboratory studies. This suggests that laboratory test outcome measures are poor predictors of real-life HA benefits. However, a systematic evaluation of algorithms in the field is difficult due to the lack of reproducibility and control of the test conditions. Virtual acoustic environments that simulate real-life situations may allow for a systematic and reproducible evaluation of HAs under more realistic conditions, thus providing a better estimate of real-life benefit than established laboratory tests. Purpose: To quantify the difference in HA performance between a laboratory condition and more realistic conditions based on technical performance measures using virtual acoustic environments, and to identify the factors affecting HA performance across the tested environments. Research Design: A set of typical HA beamformer algorithms was evaluated in virtual acoustic environments of different complexity. Performance was assessed based on established technical performance measures, including perceptual model predictions of speech quality and speech intelligibility. Virtual acoustic environments ranged from a simple static reference condition to more realistic complex scenes with dynamically moving sound objects. Results: HA benefit, as predicted by signal-to-noise ratio (SNR) and speech intelligibility measures, differs between the reference condition and more realistic conditions for the tested beamformer algorithms. Other performance measures, such as speech quality or binaural degree of diffusiveness, do not show pronounced differences. However, a decreased speech quality was found in specific conditions. A correlation analysis showed a significant correlation between room acoustic parameters of the sound field and HA performance. The SNR improvement in the reference condition was found to be a poor predictor of HA performance in terms of speech intelligibility improvement in the more realistic conditions. Conclusions: Using several virtual acoustic environments of different complexity, a systematic difference in HA performance between a simple reference condition and more realistic environments was found, which may be related to the discrepancy between laboratory and real-life HA performance reported previously.
Warzybok, A., Zokoll, M. A., and Kollmeier, B., Development and evaluation of the Russian digit triplet test, Acta Acust united Ac, vol. 102, no. 4. 2016.
Abstract
The purpose of this study was to develop, optimize, and evaluate the Russian digit triplet test for hearing screening in noise. The speech material consists of sequences of three digits like 3-2-8. A closed-set test format enables its automated administration. The speech material was optimized and evaluated for headphone and landline telephone presentation. Results were compared to digit triplet tests in other languages. First, the speech material was recorded and optimized with respect to intelligibility by applying level corrections on the basis of digit-specific speech reception thresholds (SRT) defined as signal-to-noise ratio yielding 50% intelligibility. In the following, evaluation measurements were conducted to verify test list equivalency and to obtain reference data for listeners with normal hearing. Evaluation measurements showed small differences across the six test lists. Mean slopes of the list-specific recognition functions were 14.8 %/dB and 14.4 %/dB for the headphone and the landline telephone version, respectively. The reference SRT with corresponding standard deviation for the headphone and the landline telephone version were – 11.7 ± 0.9 dB and – 8.5 ± 0.6 dB, respectively. The difference of 3.2 dB in SRT between the two test versions could be explained by the limited frequency bandwidth for the transmission over landline telephone. Both versions were shown to be reliable tests for screening speech recognition in noise and to be comparable with other languages.
Kollmeier, B., Schädler, M. R., Warzybok, A., Meyer, B. T., and Brand, T., Sentence Recognition Prediction for Hearing-impaired Listeners in Stationary and Fluctuation Noise With FADE Empowering the Attenuation and Distortion Concept by Plomp With a Quantitative Processing Model, Trends Hear, vol. 20. 2016.
Abstract
To characterize the individual patient’s hearing impairment as obtained with the matrix sentence recognition test, a simulation Framework for Auditory Discrimination Experiments (FADE) is extended here using the Attenuation and Distortion (A+D) approach by Plomp as a blueprint for setting the individual processing parameters. FADE has been shown to predict the outcome of both speech recognition tests and psychoacoustic experiments based on simulations using an automatic speech recognition system requiring only few assumptions. It builds on the closed-set matrix sentence recognition test which is advantageous for testing individual speech recognition in a way comparable across languages. Individual predictions of speech recognition thresholds in stationary and in fluctuating noise were derived using the audiogram and an estimate of the internal level uncertainty for modeling the individual Plomp curves fitted to the data with the Attenuation (A-) and Distortion (D-) parameters of the Plomp approach. The “typical” audiogram shapes from Bisgaard et al with or without a “typical” level uncertainty and the individual data were used for individual predictions. As a result, the individualization of the level uncertainty was found to be more important than the exact shape of the individual audiogram to accurately model the outcome of the German Matrix test in stationary or fluctuating noise for listeners with hearing impairment. The prediction accuracy of the individualized approach also outperforms the (modified) Speech Intelligibility Index approach which is based on the individual threshold data only.
Palanca-Castan, N., Laumen, G., Reed, D., and Köppl, C., The Binaural Interaction Component in Barn Owl (Tyto alba) Presents few Differences to Mammalian Data , JARO, vol. (in press). 2016.
Abstract
The auditory brainstem response (ABR) is an evoked potential that reflects the responses to sound by brainstem neural centers. The binaural interaction component (BIC) is obtained by subtracting the sum of the monaural ABR responses from the binaural response. Its latency and amplitude change in response to variations in binaural cues. The BIC is thus thought to reflect the activity of binaural nuclei and is used to non-invasively test binaural processing. However, any conclusions are limited by a lack of knowledge of the relevant processes at the level of individual neurons. The aim of this study was to characterize the ABR and BIC in the barn owl, an animal where the ITD-processing neural circuits are known in great detail. We recorded ABR responses to chirps and to 1 and 4 kHz tones from anesthetized barn owls. General characteristics of the barn owl ABR were similar to those observed in other bird species. The most prominent peak of the BIC was associated with nucleus laminaris and is thus likely to reflect the known processes of ITD computation in this nucleus. However, the properties of the BIC were very similar to previously published mammalian data and did not reveal any specific diagnostic features. For example, the polarity of the BIC was negative, which indicates a smaller response to binaural stimulation than predicted by the sum of monaural responses. This is contrary to previous predictions for an excitatory-excitatory system such as nucleus laminaris. Similarly, the change in BIC latency with varying ITD was not distinguishable from mammalian data. Contrary to previous predictions, this behavior appears unrelated to the known underlying neural delay-line circuitry. In conclusion, the generation of the BIC is currently inadequately understood and common assumptions about the BIC need to be reconsidered when interpreting such measurements.
Pirschel, F. and Kretzberg, J., Multiplexed Population Coding of Stimulus Properties by Leech Mechanosensory Cells, J Neurosci, vol. 36, no. 13. 2016.
Abstract
Sensory coding has long been discussed in terms of a dichotomy between spike timing and rate coding. However, recent studies found that in primate mechanoperception and other sensory systems, spike rates and timing of cell populations complement each other. They simultaneously carry information about different stimulus properties in a multiplexed way. Here, we present evidence for multiplexed encoding of tactile skin stimulation in the tiny population of leech mechanoreceptors, consisting of only 10 cells of two types with overlapping receptive fields. Each mechanoreceptor neuron of the leech varies spike count and response latency to both touch intensity and location, leading to ambiguous responses to different stimuli. Nevertheless, three different stimulus estimation techniques consistently reveal that the neuronal population allows reliable decoding of both stimulus properties. For the two mechanoreceptor types, the transient responses of T (touch) cells and the sustained responses of P (pressure) cells, the relative timing of the first spikes of two mechanoreceptors encodes stimulus location, whereas summed spike counts represent touch intensity. Differences between the cell types become evident in responses to combined stimulus properties. The best estimation performance for stimulus location is obtained from the relative first spike timing of the faster and temporally more precise T cells. Simultaneously, the sustained responses of P cells indicate touch intensity by summed spike counts and stimulus duration by the duration of spike responses. The striking similarities of these results with previous findings on primate mechanosensory afferents suggest multiplexed population coding as a general principle of somatosensation. SIGNIFICANCE STATEMENT Multiplexing, the simultaneous encoding of different stimulus properties by distinct neuronal response features, has recently been suggested as a mechanism used in several sensory systems, including primate somatosensation. While a rigorous experimental verification of the multiplexing hypothesis is difficult to accomplish in a complex vertebrate system, it is feasible for a small population of individually characterized leech neurons. Monitoring the responses of all four mechanoreceptors innervating a patch of skin revealed striking similarities between touch encoding in the primate and the leech: summed spike counts represent stimulus intensity, whereas relative timing of first spikes encodes stimulus location. These findings suggest that multiplexed population coding is a general mechanism of touch encoding common to species as different as man and worm.
Ashida, G., Kretzberg, J., and Tollin, D. J., Roles for Coincidence Detection in Coding Amplitude-Modulated Sounds, PLOS Computational Biology, vol. 12(6):e1004997. 2016.
Abstract
Many sensory neurons encode temporal information by detecting coincident arrivals of synaptic inputs. In the mammalian auditory brainstem, binaural neurons of the medial superior olive (MSO) are known to act as coincidence detectors, whereas in the lateral superior olive (LSO) roles of coincidence detection have remained unclear. LSO neurons receive excitatory and inhibitory inputs driven by ipsilateral and contralateral acoustic stimuli, respectively, and vary their output spike rates according to interaural level differences. In addition, LSO neurons are also sensitive to binaural phase differences of low-frequency tones and envelopes of amplitude-modulated (AM) sounds. Previous physiological recordings in vivo found considerable variations in monaural AM-tuning across neurons. To investigate the underlying mechanisms of the observed temporal tuning properties of LSO and their sources of variability, we used a simple coincidence counting model and examined how specific parameters of coincidence detection affect monaural and binaural AM coding. Spike rates and phase-locking of evoked excitatory and spontaneous inhibitory inputs had only minor effects on LSO output to monaural AM inputs. In contrast, the coincidence threshold of the model neuron affected both the overall spike rates and the half-peak positions of the AM-tuning curve, whereas the width of the coincidence window merely influenced the output spike rates. The duration of the refractory period affected only the low-frequency portion of the monaural AM-tuning curve. Unlike monaural AM coding, temporal factors, such as the coincidence window and the effective duration of inhibition, played a major role in determining the trough positions of simulated binaural phase-response curves. In addition, empirically-observed level-dependence of binaural phase-coding was reproduced in the framework of our minimalistic coincidence counting model. These modeling results suggest that coincidence detection of excitatory and inhibitory synaptic inputs is essential for LSO neurons to encode both monaural and binaural AM sounds.
Mehraei, G., Hickox, A. E., Bharadwaj, H. M., Goldberg, H., Verhulst, S., Liberman, M. C., and Shinn-Cunningham, B. G., Auditory brainstem response latency in noise as a marker of cochlear synaptopathy, J. Neurosci., vol. 36, no. 13. 2016.
Abstract
Evidence from animal and human studies suggests that moderate acoustic exposure, causing only transient threshold elevation, can nonetheless cause “hidden hearing loss” that interferes with coding of suprathreshold sound. Such noise exposure destroys synaptic connections between cochlear hair cells and auditory nerve fibers; however, there is no clinical test of this synaptopathy in humans. In animals, synaptopathy reduces the amplitude of auditory brainstem response (ABR) wave-I. Unfortunately, ABR wave-I is difficult to measure in humans, limiting its clinical use. Here, using analogous measurements in humans and mice, we show that the effect of masking noise on the latency of the more robust ABR wave-V mirrors changes in ABR wave-I amplitude. Furthermore, in our human cohort, the effect of noise on wave-V latency predicts perceptual temporal sensitivity. Our results suggest that measures of the effects of noise on ABR wave-V latency can be used to diagnose cochlear synaptopathy in humans. SIGNIFICANCE STATEMENT Although there are suspicions that cochlear synaptopathy affects humans with normal hearing thresholds, no one has yet reported a clinical measure that is a reliable marker of such loss. By combining human and animal data, we demonstrate that the latency of auditory brainstem response wave-V in noise reflects auditory nerve loss. This is the first study of human listeners with normal hearing thresholds that links individual differences observed in behavior and auditory brainstem response timing to cochlear synaptopathy. These results can guide development of a clinical test to reveal this previously unknown form of noise-induced hearing loss in humans
Nothwang, H. G., Evolution of mammalian sound localization circuits: A developmental perspective, Progress in Neurobiology, vol. 141. 2016.
Abstract
Ebbers, L., Runge, K., and Nothwang, H. G., Differential patterns of histone methylase EHMT2 and its catalyzed histone modifications H3K9me1 and H3K9me2 during maturation of central auditory system, Cell Tissue Res, vol. 365, no. 2. 2016.
Abstract
Histone methylation is an important epigenetic mark leading to changes in DNA accessibility and transcription. Here, we investigate immunoreactivity against the euchromatic histone-lysine N-methyltransferase EHMT2 and its catalyzed mono- and dimethylation marks at histone 3 lysine 9 (H3K9me1 and H3K9me2) during postnatal differentiation of the mouse central auditory system. In the brainstem, expression of EHMT2 was high in the first postnatal week and down-regulated thereafter. In contrast, immunoreactivity in the auditory cortex (AC) remained high during the first year of life. This difference might be related to distinct demands for adult plasticity. Analyses of two deaf mouse models, namely Cldn14 −/− and Cacna1d −/−, demonstrated that sound-driven or spontaneous activity had no influence on EHMT2 immunoreactivity. The methylation marks H3K9me1 and H3K9me2 were high throughout the auditory system up to 1 year. Young auditory neurons showed immunoreactivity against both methylations at similar intensities, whereas many mature neurons showed stronger labeling for either H3K9me1 or H3K9me2. These differences were only poorly correlated with cell types. To identify methyltransferases contributing to the persistent H3K9me1 and H3K9me2 marks in the adult brainstem, EHMT1 and the retinoblastoma-interacting zinc-finger protein RIZ1 were analyzed. Both were down-regulated during brainstem development, similar to EHMT2. Contrary to EHMT2, EHMT1 was also down-regulated in adult cortical areas. Together, our data reveal a marked difference in EHMT2 levels between mature brainstem and cortical areas and a decoupling between EHMT2 abundance and histone 3 lysine 9 methylations during brainstem differentiation. Furthermore, EHMT1 and EHMT2 are differentially expressed in cortical areas.
Hartwich, H., Rosengauer, E., Rüttiger, L., Wilms, V., Waterholter, S. -K., and Nothwang, H. G., Functional Role of γ-Crystallin N in the Auditory Hindbrain, PLOS ONE, vol. 11(8):e0161140. 2016.
Abstract
γ-crystallins are major components of the vertebrate lens but show expression in other tissues as well. Their extralenticular functions remain so far unclear. Here, we explored such roles in the rodent superior olivary complex in which previous analysis demonstrated developmentally regulated expression of Crygd, Cryge and Crygn. Immunohistochemistry with novel antibodies against Crygd/e and Crygn indicate that expression of Crygd/e was moderate and varied between the perinatal superior olivary complex of mice, rats, and gerbils. Crygn-immunoreactivity was more robust and consistently highest in the medial nucleus of the trapezoid body, but also present in other nuclei of the superior olivary complex. To analyze the function of Crygn in the auditory hindbrain, we used a Crygn allele with a floxed exon 2. Upon pairing with Egr2::Cre mice, exon 2, encoding the first two greek key motifs of Crygn, was deleted in the developing auditory hindbrain. Anatomical analysis of these mice revealed a 20% volume reduction in the medial nucleus of the trapezoid body and a 7% reduction in the lateral superior olive at postnatal day 25. This was due to cell loss between postnatal days 4 and 25, whereas cell size was unaffected. Auditory brainstem responses showed normal threshold but a significant increase in the amplitude of wave IV. Crygn is hence required for postmigratory survival and proper function of auditory hindbrain neurons. These results ascertain for the first time an essential extralenticular role for γ-crystallins in vivo.
Klump, G. M., Noise matters: The evolution of communication, Animal Behaviour, vol. 119. Elsevier BV, p. 17, Sep.-2016.
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Friedl, T. W. P. and Klump, G. M., Extrapair paternity in the red bishop (Euplectes orix): is there evidence for the good-genes hypothesis?, Behaviour, vol. 139, no. 6. Brill Academic Publishers, pp. 777-800, 2016.
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Baltus, A. and Herrmann, C. S., The importance of individual frequencies of endogenous brain oscillations for auditory cognition - A short review, Brain research, vol. 1640, no. Pt B. pp. 243-250, Jun.-2016.
Abstract DOI
Oscillatory EEG activity in the human brain with frequencies in the gamma range (approx. 30-80Hz) is known to be relevant for a large number of cognitive processes. Interestingly, each subject reveals an individual frequency of the auditory gamma-band response (GBR) that coincides with the peak in the auditory steady state response (ASSR). A common resonance frequency of auditory cortex seems to underlie both the individual frequency of the GBR and the peak of the ASSR. This review sheds light on the functional role of oscillatory gamma activity for auditory processing. For successful processing, the auditory system has to track changes in auditory input over time and store information about past events in memory which allows the construction of auditory objects. Recent findings support the idea of gamma oscillations being involved in the partitioning of auditory input into discrete samples to facilitate higher order processing. We review experiments that seem to suggest that inter-individual differences in the resonance frequency are behaviorally relevant for gap detection and speech processing. A possible application of these resonance frequencies for brain computer interfaces is illustrated with regard to optimized individual presentation rates for auditory input to correspond with endogenous oscillatory activity. This article is part of a Special Issue entitled SI: Auditory working memory
Volkening, N., Unni, A., Löffler, B. S., Fudickar, S., Rieger, J. W., and Hein, A., Characterizing the Influence of Muscle Activity in fNIRS Brain Activation Measurements, IFAC-PapersOnLine, vol. 49, no. 11. Elsevier BV, pp. 84-88, 2016.
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Fonken, Y. M., Rieger, J. W., Tzvi, E., Crone, N. E., Chang, E., Parvizi, J., Knight, R. T., and Krämer, U. M., Frontal and motor cortex contributions to response inhibition: evidence from electrocorticography, J Neurophysiol, vol. 115, no. 4. American Physiological Society, pp. 2224-2236, 10-Feb.-2016.
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Notbohm, A., Kurths, J., and Herrmann, C. S., Modification of Brain Oscillations via Rhythmic Light Stimulation Provides Evidence for Entrainment but Not for Superposition of Event-Related Responses, Frontiers in human neuroscience, vol. 10. p. 10, 2016.
Abstract DOI
The functional relevance of brain oscillations in the alpha frequency range (8-13 Hz) has been repeatedly investigated through the use of rhythmic visual stimulation. The underlying mechanism of the steady-state visual evoked potential (SSVEP) measured in EEG during rhythmic stimulation, however, is not known. There are two hypotheses on the origin of SSVEPs: entrainment of brain oscillations and superposition of event-related responses (ERPs). The entrainment but not the superposition hypothesis justifies rhythmic visual stimulation as a means to manipulate brain oscillations, because superposition assumes a linear summation of single responses, independent from ongoing brain oscillations. Here, we stimulated participants with a rhythmic flickering light of different frequencies and intensities. We measured entrainment by comparing the phase coupling of brain oscillations stimulated by rhythmic visual flicker with the oscillations induced by arrhythmic jittered stimulation, varying the time, stimulation frequency, and intensity conditions. In line with a theoretical concept of entrainment (the so called Arnold tongue), we found the phase coupling to be more pronounced with increasing stimulation intensity as well as at stimulation frequencies closer to each participant's intrinsic frequency. Only inside the Arnold tongue did the conditions significantly differ from the jittered stimulation. Furthermore, even in a single sequence of an SSVEP, we found non-linear features (intermittency of phase locking) that contradict the linear summation of single responses, as assumed by the superposition hypothesis. Our findings provide unequivocal evidence that visual rhythmic stimulation entrains brain oscillations, thus validating the approach of rhythmic stimulation as a manipulation of brain oscillations
Vosskuhl, J., Huster, R. J., and Herrmann, C. S., BOLD signal effects of transcranial alternating current stimulation (tACS) in the alpha range: A concurrent tACS-fMRI study, NeuroImage, vol. 140. pp. 118-125, Oct.-2016.
Abstract DOI
Many studies have proven transcranial alternating current stimulation (tACS) to manipulate brain activity. Until now it is not known, however, how these manipulations in brain activity are represented in brain metabolism or how spatially specific these changes are. Alpha-tACS has been shown to enhance the amplitude of the individual alpha frequency (IAF) and a negative correlation between alpha amplitude and occipital BOLD signal was reported in numerous EEG/fMRI experiments. Thus, alpha-tACS was chosen to test the effects of tACS on the BOLD signal. A reduction thereof was expected during alpha-tACS which shows the spatial extent of tACS effects beyond modeling studies. Three groups of subjects were measured in an MRI scanner, receiving tACS at either their IAF (N=11), 1Hz (control; N=12) or sham (i.e., no stimulation - a second control; N=11) while responding to a visual vigilance task. Stimulation was administered in an interleaved pattern of tACS-on runs and tACS-free baseline periods. The BOLD signal was analyzed in response to tACS-onset during resting state and in response to seldom target stimuli. Alpha-tACS at 1.0mA reduced the task-related BOLD response to visual targets in the occipital cortex as compared to tACS-free baseline periods. The deactivation was strongest in an area where the BOLD signal was shown to correlate negatively with alpha amplitude. A direct effect of tACS on resting state BOLD signal levels could not be shown. Our findings suggest that tACS-related changes in BOLD activity occur only as a modulation of an existing BOLD response
Helfrich, R. F., Herrmann, C. S., Engel, A. K., and Schneider, T. R., Different coupling modes mediate cortical cross-frequency interactions, NeuroImage, vol. 140. pp. 76-82, Oct.-2016.
Abstract DOI
Cross-frequency coupling (CFC) has been suggested to constitute a highly flexible mechanism for cortical information gating and processing, giving rise to conscious perception and various higher cognitive functions in humans. In particular, it might provide an elegant tool for information integration across several spatiotemporal scales within nested or coupled neuronal networks. However, it is currently unknown whether low-frequency (theta/alpha) or high-frequency gamma oscillations orchestrate cross-frequency interactions, raising the question of who is master and who is slave. While correlative evidence suggested that at least two distinct CFC modes exist, namely, phase-amplitude-coupling (PAC) and amplitude-envelope correlations (AEC), it is currently unknown whether they subserve distinct cortical functions. Novel non-invasive brain stimulation tools, such as transcranial alternating current stimulation (tACS), now provide the unique opportunity to selectively entrain the low- or high-frequency component and study subsequent effects on CFC. Here, we demonstrate the differential modulation of CFC during selective entrainment of alpha or gamma oscillations. Our results reveal that entrainment of the low-frequency component increased PAC, where gamma power became preferentially locked to the trough of the alpha oscillation, while gamma-band entrainment enhanced AECs and reduced alpha power. These results provide causal evidence for the functional role of coupled alpha and gamma oscillations for visual processing
Wilms, V., Köppl, C., Söffgen, C., Hartmann, A. -M., and Nothwang, H. G., Molecular bases of K+ secretory cells in the inner ear: shared and distinct features between birds and mammals, Scientific Reports, vol. 6. Springer Nature, p. 34203, 29-Sep.-2016.
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Bolte, P., Bleibaum, F., Einwich, A., Guenther, A., Liedvogel, M., Heyers, D., Depping, A., Woehlbrand, L., Rabus, R., Janssen-Bienhold, U., and Mouritsen, H., Localisation of the Putative Magnetoreceptive Protein Cryptochrome 1b in the Retinae of Migratory Birds and Homing Pigeons, PLOS ONE, vol. 11, no. 3. PUBLIC LIBRARY SCIENCE, Mar.-2016.
Abstract DOI
Cryptochromes are ubiquitously expressed in various animal tissues including the retina. Some cryptochromes are involved in regulating circadian activity. Cryptochrome proteins have also been suggested to mediate the primary mechanism in light-dependent magnetic compass orientation in birds. Cryptochrome 1b (Cry1b) exhibits a unique carboxy terminus exclusively found in birds so far, which might be indicative for a specialised function. Cryptochrome 1a (Cry1a) is so far the only cryptochrome protein that has been localised to specific cell types within the retina of migratory birds. Here we show that Cry1b, an alternative splice variant of Cry1a, is also expressed in the retina of migratory birds, but it is primarily located in other cell types than Cry1a. This could suggest different functions for the two splice products. Using diagnostic bird-specific antibodies (that allow for a precise discrimination between both proteins), we show that Cry1b protein is found in the retinae of migratory European robins (Erithacus rubecula), migratory Northern Wheatears (Oenanthe oenanthe) and pigeons (Columba livia). In all three species, retinal Cry1b is localised in cell types which have been discussed as potentially well suited locations for magnetoreception: Cry1b is observed in the cytosol of ganglion cells, displaced ganglion cells, and in photoreceptor inner segments. The cytosolic rather than nucleic location of Cry1b in the retina reported here speaks against a circadian clock regulatory function of Cry1b and it allows for the possible involvement of Cry1b in a radical-pair-based magnetoreception mechanism.
Moritz, N., Kollmeier, B., and Anemueller, J., Integration of Optimized Modulation Filter Sets Into Deep Neural Networks for Automatic Speech Recognition, IEEE-ACM TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING, vol. 24, no. 12. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Dec.-2016.
Abstract
Inspired by physiological studies on the human auditory system and by results from psychoacoustics, an amplitude modulation filter bank (AMFB) has been developed and successfully applied to feature extraction for automatic speech recognition (ASR) in earlier work. Here, we address the question as to which amplitude modulation (AM) frequency decomposition leads to optimal ASR performance by proposing a parameterized functional relationship between modulation center frequency and modulation bandwidth. Word error rates (WERs) of ASR experiments with 1551 different AMFBs are systematically evaluated and compared, resulting in the identification of a comparatively narrow range of optimal modulation frequency to modulation bandwidth characteristics. To integrate modulation processing with deep neural network (DNN) acoustic modeling, we propose merging of modulation filter coefficients with DNN weights prior to a final training step and an improved mean-variance normalization scheme for AMFBs. These modifications are shown to result in further reduction of WERs and are indicative of the proposed system's improved generalization ability, when compared across corpora of 100-960 h of data with mismatched training and test conditions. Analysis of DNN-learned temporal AM filtering properties is carried out and implications for the relevance of different modulation regions as well as the relation to psychoacoustic findings are discussed. ASR experiments with the proposed system demonstrate a high degree of robustness against extrinsic acoustic distortions, resulting in, e.g., an average WER of 9.79\% on the Aurora-4 task.
Kalbe, E., Rehberg, S. P., Heber, I., Kronenbuerger, M., Schulz, J. B., Storch, A., Linse, K., Schneider, C., Graeber, S., Liepelt-Scarfone, I., Berg, D., Dams, J., Balzer-Geldsetzer, M., Hilker, R., Oberschmidt, C., Witt, K., Schmidt, N., Mollenhauer, B., Trenkwalder, C., Spottke, A., Roeske, S., Wittchen, H. -U., Riedel, O., and Dodel, R., Subtypes of mild cognitive impairment in patients with Parkinson's disease: evidence from the LANDSCAPE study, JOURNAL OF NEUROLOGY NEUROSURGERY AND PSYCHIATRY, vol. 87, no. 10. BMJ PUBLISHING GROUP, Oct.-2016.
Abstract
Objective Inconsistent results exist regarding the cognitive profile in patients with Parkinson's disease with mild cognitive impairment (PD-MCI). We aimed at providing data on this topic from a large cohort of patients with PD-MCI. Methods Sociodemographic, clinical and neuropsychological baseline data from patients with PD-MCI recruited in the multicentre, prospective, observational DEMPARK/LANDSCAPE study were analysed. Results 269 patients with PD-MCI (age 67.8 +/- 7.4, Unified Parkinson's Disease Rating Scale (UPDRS-III) scores 23.2 +/- 11.6) were included. PD-MCI subtypes were 39.4\% non-amnestic single domain, 30.5\% amnestic multiple domain, 23.4\% non-amnestic multiple domain and 6.7\% amnestic single domain. Executive functions were most frequently impaired. The most sensitive tests to detect cognitive dysfunctions were the Modified Card Sorting Test, digit span backwards and word list learning direct recall. Multiple stepwise regression analyses showed that global cognition, gender and age, but not education or disease-related parameters predicted PD-MCI subtypes. Conclusions This study with the so far largest number of prospectively recruited patients with PD-MCI indicates that non-amnestic PD-MCI is more frequent than amnestic PD-MCI; executive dysfunctions are the most typical cognitive symptom in PD-MCI; and age, gender and global cognition predict the PD-MCI subtype. Longitudinal data are needed to test the hypothesis that patients with PD-MCI with specific cognitive profiles have different risks to develop dementia.
Mengel, D., Dams, J., Ziemek, J., Becker, J., Balzer-Geldsetzer, M., Hilker, R., Baudrexel, S., Kalbe, E., Schmidt, N., Witt, K., Liepelt-Scarfone, I., Graeber, S., Petrelli, A., Neuser, P., Schulte, C., Linse, K., Storch, A., Wittchen, H. -U., Riedel, O., Mollenhauer, B., Ebentheuer, J., Treniwalder, C., Klockgether, T., Spottke, A., Wuellner, U., Schulz, J. B., Reetz, K., Heber, I. A., Ramirez, A., and Dodel, R., Apolipoprotein E epsilon 4 does not affect cognitive performance in patients with Parkinson's disease, PARKINSONISM \& RELATED DISORDERS, vol. 29. ELSEVIER SCI LTD, Aug.-2016.
Abstract
Introduction: Cognitive impairment is a common and disabling non-motor symptom in Parkinson's disease (PD). The apolipoprotein E (APOE) allele epsilon 4 is a known risk factor for Alzheimer's disease and has also been suggested to be a risk factor for dementia in PD and even a predictor of impairment in certain cognitive domains. Methods: A total of 447 PD patients (PD patients without cognitive impairment: n = 187; PD patients with mild cognitive impairment: n = 188; PD patients with dementia: n = 72) were included from an ongoing observational German multicenter cohort study (LANDSCAPE study). All patients underwent an extensive neuropsychological test battery, including assessments of memory, visuospatial functioning, attention, language, and executive function. APOE genotype was determined by an allelic discrimination assay. Linear regression analysis was used to explore the associations between APOE-epsilon 4 and cognitive performance. Results: The APOE-epsilon 4 allele was not associated with a diagnosis of cognitive impairment in PD (PD with mild cognitive impairment and PD with dementia) or with deficits in specific neuropsychological domains in our study cohort. Conclusion: Our data question the relevance of the APOE-epsilon 4 allele as a predictor of cognitive impairment in PD. (C) 2016 Elsevier Ltd. All rights reserved.
Schlenstedt, C., Muthuraman, M., Witt, K., Weisser, B., Fasano, A., and Deuschl, G., Postural control and freezing of gait in Parkinson's disease, PARKINSONISM \& RELATED DISORDERS, vol. 24. ELSEVIER SCI LTD, Mar.-2016.
Abstract
Introduction: The relationship between freezing of gait (FOG) and postural instability in Parkinson's disease (PD) is unclear. We analyzed the impact of FOG on postural control. Methods: 31 PD patients with FOG (PD+FOG), 27 PD patients without FOG (PD-FOG) and 22 healthy control (HC) were assessed in the ON state. Postural control was measured with the Fullerton Advanced Balance (FAB) scale and with center of pressure (COP) analysis during quiet stance and maximal voluntary forward backward leaning. Results: The groups were balanced concerning age, disease duration and disease severity. PD+FOG performed significantly worse in the FAB scale (21.8 +/- 5.8) compared to PD-FOG (25.6 +/- 5.0) and HC (34.9 +/- 2.4) (mean +/- SD, p < 0.01). PD+FOG had impaired ability to voluntary lean forward, difficulties to stand on foam with eyes closed and reduced limits of stability compared to PD-FOG (p < 0.05). During quiet stance the average anterior posterior COP position was significantly displaced towards posterior in PD+FOG in comparison to PD-FOG and HC (p < 0.05). The COP position correlated with severity of FOG (p < 0.01). PD+FOG and PD-FOG did not differ in average COP sway excursion, sway velocity, sway regularity and postural control asymmetry. Conclusions: PD+FOG have reduced postural control compared to PD-FOG and HC. Our results show a relationship between the anterior posterior COP position during quiet stance and FOG. The COP shift towards posterior in PD+FOG leads to a restricted precondition to generate forward progression during gait initiation. This may contribute to the occurrence of FOG or might be a compensatory strategy to avoid forward falls. (C) 2015 Elsevier Ltd. All rights reserved.
Zeuner, K. E., Acewicz, A., Knutzen, A., Dressler, D., Lohmann, K., and Witt, K., Dopamine DRD2 polymorphism (DRD2/ANNK1-Taq1A) is not a significant risk factor in writer's cramp, JOURNAL OF NEUROGENETICS, vol. 30, no. 3-4. TAYLOR \& FRANCIS LTD, 2016.
Abstract
Writers' cramp is a movement disorder with dystonic co-contraction of fingers and hand during writing and is part of the clinical spectrum of focal dystonias. Previous studies showed reduced striatal dopamine receptor D2 (DRD2) availability in dystonia. The expression of D2 receptors is modulated by a DRD2/ANKK1-Taq1A polymorphism (rs1800497). This study addresses the question of whether the DRD2/ANKK1-Taq1A polymorphism is a risk factor for writer's cramp. We determined the DRD2/ANKK1-Taq1A polymorphism 34 patients with writer's cramp compared to 67 age matched controls. 35.3\% of the patients and 31.3\% of our controls were assigned to the A1 genotype status (p = .7). Therefore DRD2/ANKK1-Taq1A gene is not a significant risk factor in the evolution of writer's cramp.
Baauw, S., Zuckerman, S., Ruigendijk, E., and Avrutin, S., Principle B delays as a processing problem: Evidence from task effects, Production-Comprehension Asymmetries in Child Language. Walter de Gruyter GmbH, 2016.
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Langemann, U. and Klump, G. M., Perception and acoustic communication networks, Animal Communication Networks. Cambridge University Press (CUP), pp. 451-480, 2016.
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Langemann, U., Krumm, B., Liebner, K., Beutelmann, R., and Klump, G. M., Moving Objects in the Barn Owl’s Auditory World, Physiology, Psychoacoustics and Cognition in Normal and Impaired Hearing. Springer Science + Business Media, pp. 219-227, 2016.
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Isken, M. and Hein, A., Continuous Geriatric Assessments Supported by a Mobile Service Robot: Movement Analysis, Advanced Technologies and Societal Change. Springer Science + Business Media, pp. 37-46, 2016.
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Müller, S. M., Steen, E. -E., and Hein, A., Inferring Multi-person Presence in Home Sensor Networks, Advanced Technologies and Societal Change. Springer Science + Business Media, pp. 47-56, 2016.
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Lins, C., Frenken, M., Halder, L., and Hein, A., Designing and Introducing an Activity Motivating Mobile Web App Platform for Seniors, Advanced Technologies and Societal Change. Springer Science + Business Media, pp. 15-24, 2016.
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Verhulst, S., Piktel, P., Jagadeesh, A., and Mauermann, M., On the Interplay Between Cochlear Gain Loss and Temporal Envelope Coding Deficits, Physiology, Psychoacoustics and Cognition in Normal and Impaired Hearing. Springer Science + Business Media, pp. 467-475, 2016.
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Diederich, A., Age and Personal Responsibility as Prioritization Criteria? The View of the Public and of Physicians, Prioritization in Medicine. Springer Science + Business Media, pp. 241-257, 2016.
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Pöschel, T. and Freund, J. A., Cluster statistics and traffic on a lattice, Lecture Notes in Physics. Springer Science + Business Media, pp. 220-231, 2016.
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Freund, J. A., Symbolic dynamics approach to stochastic processes, Lecture Notes in Physics. Springer Science + Business Media, pp. 179-192, 2016.
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Atema, J., Gerlach, G., and Paris, C. B., Sensory biology and navigation behavior of reef fish larvae, Ecology of Fishes on Coral Reefs. Cambridge University Press (CUP), pp. 3-15, 2016.
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Colonius, H., Stochastic orders of variability, Mathematical Models of Perception and Cognition Volume I: A Festschrift for James T. Townsend. p. (in press), 2016.
Abstract
Frye, M., Micheli, C., Schepers, I. M., Schalk, G., Rieger, J. W., and Meyer, B. T., Neural responses to speech-specific modulations derived from a spectro-temporal filter bank," in Proc Interspeech., Conf. Int. Speech Comm. Assoc. (Interspeech). 2016.
Behrens, D. and Klump, G. M., Comparison of Sensitivity in Prepulse Inhibition and Operant Conditioning Procedures measuring Sound Localization Acuity in the Mouse, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
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Background In an intensity difference limen paradigm in C57BL/6 mice, the sensitivity observed in an operant conditioning procedure was much larger than the sensitivity observed with a prepulse inhibition (PPI) procedure (Behrens & Klump 2015). Here, we compare the sensitivity of both procedures in a sound localization paradigm investigating, whether the sensitivity difference observed in an intensity difference limen paradigm may also be found in other paradigms. Methods The mice were presented with an acoustic background of repeated 100 ms noise stimuli broadcast from a reference speaker. At random times, one of the stimuli in the sequence was replaced by a stimulus that was broadcast from a test speaker located 12.5° to 180° apart from the reference speaker. Broadband (20 kHz bandwidth, 20 kHz center frequency) and narrowband (500 Hz bandwidth, 25 kHz center frequency) noise stimuli were presented in separate sessions. In the operant procedure, a Go/No-Go paradigm with food rewards was used and hit- and false-alarm rates served to calculate the sensitivity measure d’. In the PPI procedure, the movement of the mouse elicited by a 110 dB SPL startle stimulus (35 ms, 2-50 kHz) was measured using a piezo-electric pressure transducer. We applied an ROC analysis by comparing the distribution of startle amplitudes with a change in speaker location to that without such a change and calculated d(a) values, a sensitivity measure that corresponds to d’. Results For both procedures, the mean sensitivity measure increased with an increase of the angle between test and reference speaker. In the operant conditioning procedure, the sensitivity for large speaker separations reached d’-values of around 3.0 (broadband noise) and 2.0 (narrowband noise). The results obtained by the PPI procedure showed a much lower sensitivity, reaching da-values of 1.0 (broadband noise) and only 0.3 (narrowband noise). Conclusions The higher sensitivity observed in the operant procedure results in lower thresholds for localizing broadband noise than in the PPI procedure in which the subjects showed a lower sensitivity. The operant procedure also revealed a large sensitivity of C57BL/6 mice to localize narrowband noise stimuli, whereas in the PPI procedure the sensitivity was so low that no threshold could be determined. Thus, the operant procedure will allow obtaining measures of localization acuity when the PPI procedure fails. The observation of a higher sensitivity in operant conditioning procedures compared to PPI procedures appears to be a more general effect. Funding This study was funded by the DFG (TRR 31 and Cluster of Excellence “Hearing4all”)
Tolnai, S., Beutelmann, R., Lammers, M., Hillenbrand, J., and Klump, G. M., Behavioral Sensitivity to Interaural Level and Time Differences in the Mongolian Gerbil tested using Virtual Headphones, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
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Gerbils’ sound localization ability has extensively been tested under free-field stimulation (e.g., Heffner & Heffner, 1988; Maier & Klump, 2006; Carney et al., 2011; Lingner et al., 2012). While many neurophysiological studies use closedfield or near-field stimulation to present signals with interaural time and level differences (ITD and ILD, respectively), the gerbil’s behavioral sensitivity to ITD and ILD has so far only been derived from acoustic measurements (Maki & Furukawa, 2005) and free-field stimuli that favor the use of one or the other interaural cue (Lesica et al., 2012). Here we investigate the behavioral sensitivity of gerbils to ITD and ILD using freefield loudspeakers to mimic stimulation via headphones. Six Mongolian gerbils were trained in a left/right discrimination task using broadband noise stimuli presented from a loudspeaker array (-90° to +90°, minimum angle between loudspeakers 12°). Data collection under the so-called virtualheadphone stimulation started when animals reliably reached >95% correct responses for the outermost loudspeaker positions. Two loudspeakers in the array presented virtualheadphone stimuli using cross-talk cancellation in order to eliminate the undesired signal paths between the speakers and their respective contralateral ears. The cross-talk cancellation filters were based on head-related transfer functions measured prior to the experiments from a gerbil carcass. Stimuli were narrow-band noise bursts (bandwidth: 200 Hz, centre frequency: 0.75, 1, 2, 4, or 6 kHz, 60 dB SPL) to which either ITD (up to ±500 μs) or ILD (up to ±20 dB) were applied. Psychometric functions were derived from the animals’ responses and thresholds calculated at a sensitivity level corresponding to a d’ of 1. We found that all gerbils tested were able to lateralize sounds depending on the applied ITD or ILD. For stimuli with an ILD, reliable responses could be obtained for narrow-band noises with center frequencies ≥2 kHz. For stimuli with an ITD, reliable responses could be collected for center frequencies up to 2 kHz. Responses to stimuli with an ITD were cyclic indicating the use of phase information by the animals. The data will be discussed in terms of its applicability by comparing thresholds collected under virtual-headphone stimulation with data from free-field stimulation. Funding This study was funded by the DFG (TRR 31 and Cluster of Excellence “Hearing4all”).
Kato, Y. and Klump, G. M., Effects of Masker Bandwidth, Mistuning and Binaural Cues on the Representation of Components in a Harmonic Tone Complex in the Gerbil Inferior Colliculus, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
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Harmonicity is an important cue to group components of sounds from a specific source in the acoustic environment. If a component of a harmonic sound is slightly shifted in frequency, that tone becomes distinct from other harmonics components in a complex with a specific fundamental frequency. In a human psychophysical study, Klein-Hennig and colleagues (2012) determined masked thresholds for detecting a single component of a tone complex in relation to its mistuning and binaural phase by asking the subjects to report the presence of the target component presented at different sound levels. Unexpectedly, when adding masker harmonics outside the auditory filter tuned to the target frequency the masked threshold increased. This is in contrast to the expectation, that a higher number of components would make it easier to separate the complex from the target. To investigate the mechanisms underlying this observation, we recorded single- and multi-unit responses from inferior colliculus neurons of anesthetized gerbils that have been demonstrated to have a high sensitivity for detecting mistuning of components in a harmonic complex (e.g., Klinge-Strahl et al. 2013). Complex tone maskers were centered at the target frequency and either had 8 or 32 harmonic components equally distributed to both sides of the target. Maskers with two different phase relation between components were applied: random phase and sine phase maskers. Target tones were either tuned or mistuned with respect to the masker fundamental. Maskers were always played with the same phase to both ears. Targets of different levels were played either with the same phase or with a phase difference of 180 degrees between the two ears. Spike rate and temporal patterns of spike sequences (analysis with van Rossum [2001] metrics) were used to determine neuronal response thresholds. Neuronal sensitivity (da) was determined by subjecting the response measures to an ROC analysis comparing responses to masker plus target and masker alone. In general, an increased target level resulted in a higher da for both the rate response and the temporal spike pattern. Similar to the human psychophysical data (Klein-Hennig et al. 2012), the sensitivity for both response measures was considerably reduced in a fraction of the neurons if the bandwidth of the harmonic complex masker was increased. Also the phase relation of the masker components affected the response. However, the impact of mistuning and target phase was only small. The relation between the neurophysiological and the psychophysical data will be discussed. Funding This study was funded by the DFG (TRR 31 and Cluster of Excellence “Hearing4all”)
Kodrasi, I. and Doclo, S., Incorporating the Noise Statistics in Acoustic Multichannel Equalization, AES Conference: 60th International Conference (DREAMS). 2016.
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Acoustic multi-channel equalization techniques, such as the regularized partial multi-channel equalization technique based on the multiple-input/output inverse theorem (RP-MINT), are able to achieve a high dereverberation performance in the presence of room impulse response perturbations but may lead to additive noise amplification. This paper proposes to directly extend the RP-MINT technique by incorporating the noise statistics in the reshaping filter design, such that joint dereverberation and noise reduction is achieved. In addition to the regularization parameter used in the RP-MINT technique, a weighting parameter is introduced to trade off between dereverberation and noise reduction. To automatically determine the regularization and weighting parameters, a novel non-intrusive procedure based on the L-hypersurface is proposed. Simulation results using instrumental performance measures show that the proposed technique maintains the high dereverberation performance of the RP-MINT technique, while improving the noise reduction performance.
Jukic, A., van Waterschoot, T., Gerkmann, T., and Doclo, S., A General Framework for Multichannel Speech Dereverberation Exploiting Sparsity, AES Conference: 60th International Conference (DREAMS), no. Session 9. AES E-Library, 2016.
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We consider the problem of blind multi-channel speech dereverberation without the knowledge of room acoustics. The dereverberated speech component is estimated by subtracting the undesired component, estimated using multi-channel linear prediction (MCLP), from the reference microphone signal. In this paper we present a framework for MCLP-based speech dereverberation by exploiting sparsity in the time-frequency domain. The presented framework uses a wideband or a narrowband signal model and a sparse analysis or synthesis model for the desired speech component. The proposed problems involving a reweighted $\ell_1$-norm, are solved in a flexible optimization framework. The obtained results are comparable to the state of the art, motivating further extensions exploiting sparsity and speech structure.
Desiraju, N. K., Doclo, S., Buck, M., Gerkmann, T., and Wolff, T., On Determining Optimal Reverberation Parameters for Late Residual Echo Suppression, AES Conference: 60th International Conference (DREAMS), no. Session 8. AES E-Library, 2016.
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When deploying acoustic echo cancellation systems in large rooms, using short filters may result in significant amount of residual echo caused by room reverberation. In this paper, we model the late residual echo as exponentially decaying and use a parametric IIR filter to estimate its power in the subband domain for application in residual echo suppression. Working in an offline system identification setup, the problem of finding the optimal parameters of the IIR filter is addressed, with an analysis conducted on the performance of two parameter estimation methods: output error and equation error. The late residual echo power estimates obtained using the two methods are furthermore judged using the mean squared error and the mean squared log error cost functions. Results indicate that minimizing the mean squared log error for the output error method provides accurate estimates for the late residual echo power and the reverberation decay parameter.
Kuklasinski, A., Doclo, S., Jensen, S. H., and Jensen, J., Multichannel Wiener Filter for Speech Dereverberation in Hearing Aids —Sensitivity to DoA Errors, AES Conference: 60th International Conference (DREAMS), no. Sesion 2. 2016.
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In this paper we study the robustness of a recently proposed Multi-channel Wiener Filter-based speech dereverberation algorithm to errors in the assumed direction of arrival (DoA) of the target speech. Different subsets of microphones of a pair of behind-the-ear hearing aids are used to construct various monaural and binaural configurations of the algorithm. Via a simulation experiment with frontally positioned target it is shown, that when correct DoA is assumed binaural configurations of the algorithm almost double the improvement of PESQ measure over monaural configurations. However, in conditions where the assumed DoA is increasingly incorrect, the performance of the binaural configurations is shown to deteriorate more quickly than that of the monaural configurations. In effect, for large DoA errors it is the simpler, monaural configurations that perform better.
Hu, M., Sharma, D., Doclo, S., Brookes, M., and Naylor, P. A., Blind Adaptive SIMO Acoustic System Identification Using a Locally Optimal Step-Size, AES Conference:60th International Conference (DREAMS), no. Session 6. 2016.
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Blind adaptive identification of a Single-Input Multiple-Output (SIMO) acoustic system has useful applications including acoustic environment sensing, source localization and, in combination with multichannel equalization, dereverberation. An empirically chosen step-size is usually employed in blind system identification algorithms based on cross-relation error minimization. Although some adaptive step-size approaches have been proposed in the literature, the derivations rely, in some cases, on coarse approximations. In this paper, a locally optimal adaptive-step size exploiting the algebraic nature of the problem is derived. Experimental results using simulated room impulse responses show that the proposed algorithm has higher initial convergence rate.
Schepker, H., Tran, L. T. T., Nordholm, S., and Doclo, S., Improving adaptive feedback cancellation in hearing aids using an affine combination of filters, IEEE Int. Conf. Acoust. Speech Sig. Process. (ICASSP). 2016.
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Fischer, D., Doclo, S., Habets, E. A. P., and Gerkmann, T., Combined Single-Microphone Wiener and MVDR Filtering based on Speech Interframe Correlations and Speech Presence Probability, ITG Fachtagung Sprachkummunikation. 2016.
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Marquardt, D., Kayser, H., and Doclo, S., Evaluation of MVDR-based noise reduction algorithms for binaural hearing aids in the presence of DOA estimation errors, Int. Hear. Aid Res. Conf. (IHCON). 2016.
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Schepker, H. and Doclo, S., Acoustic feedback cancellation for a multimicrophone earpiece using a null-steering beamformer, Int. Hear. Aid Res. Conf. (IHCON). 2016.
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Fischer, D. and Gerkmann, T., Single-Microphone Speech Enhancement Using MVDR Filtering And Wiener Post-Filtering, IEEE Int. Conf. Acoust. Speech Sig. Process. (ICASSP). 2016.
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Grimm, G., Hendrikse, M., Josupeit, A., Buschermöhle, M., and Hohmann, V., Hearing aid evaluation using complex acoustic scenarios, Int. Hear. Aid Res. Conf. (IHCON). 2016.
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With increasing complexity of hearing aids, the use of realistic and complex acoustic environments in the laboratory for hearing aid evaluation gains more and more attention. This contribution presents several listening scenarios relevant to hearing aid research that were defined for this purpose and rendered with a suitable virtual acoustics method. The scenarios vary in acoustic complexity and comprise in-door communication scenarios, in-door passive listening scenarios, and out-door environments, including public transport. Case studies using subsets of these scenarios are presented: Estimates of aided performance of different classes of hearing-aid algorithms using a virtual hearing aid, influence of source and receiver movement on beamformer performance, speech intelligibility measures using an international matrix test and evaluation of an auditory-based scene analysis algorithm. [Work funded by DFG FOR1732, SFB/TR31 and EXC 107
Lundbeck, M., Grimm, G., Hohmann, V., Bramsløw, L., and Neher, T., Influence of multi-microphone hearing aid algorithms on source movement perception, Int. Hear. Aid Res. Conf. (IHCON). 2016.
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Zamaninezhad, L., Hohmann, V., Büchner, A., Jürgens, T., and , Speech Intelligibility Benefits in a Model of Cochlear Implant Listeners with Ipsilateral Residual Acoustic Hearing, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
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Introduction Speech perception in users of conventional cochlear implants (CI) degrades considerably in the presence of noise. Due to advances in surgical techniques, for a subgroup of CI candidates whose apical auditory nerves can still be stimulated acoustically, there is the possibility to preserve acoustic hearing even after implantation. Several clinical and vocoder studies reported on speech intelligibility benefits for electro-acoustic (EA-) listening condition in comparison with electric-only or acoustic-only conditions (termed EA-benefit) in these listeners. Goals of the study The goal of this study is to introduce an auditory model of speech intelligibility that can predict the EA-benefit. The model is used to assess the effect of different physiological factors on speech perception of electro-acoustic listeners. Methods Two different physiologically inspired auditory models are used to simulate the auditory nerve spiking pattern in response to electric and acoustic stimulation. The auditory model of Fredelake and Hohmann (2012) produces auditory nerve spikes in response to electric stimulation while the Meddis (2006) model simulates auditory nerve spikes in response to acoustic stimulation. Both spiking patterns were further processed by the central stage of the model of Fredelake and Hohmann (2012) to obtain internal representations of the stimuli, which may be present in the central part of the auditory system. The back-end of the proposed model consists of a standard GMM/ HMM speech recognition system. The internal representations were fed into the classifier and the recognition rate determined the predicted speech reception thresholds (SRTs) for sentences in stationary speech-shaped noise. Predicted SRTs were compared to SRTs measured in 22 patients equipped with Nucleus Hybrid-L device. Results The model predicted EA-benefit (SRT-difference between electric-only and electro-acoustic listening condition) of up to 3 dB, which agrees with the EA-benefit observed in most of the patients. Changing the amount of residual acoustic hearing in the model resulted in an EA-benefit even if the speech intelligibility with acoustic-only stimulation was close to chance, which is in line with the results of some of the patients. Increasing the amount of electric field spatial spread in the model increased SRTs both in electric-only and electroacoustic listening condition. Conclusion The model of speech intelligibility for electro-acoustic listeners can predict the EA-benefit that is observed in actual patients. The model has been used to assess the influence of different physiological parameters on speech reception thresholds and EA-benefit. Funding This work is supported by DFG cluster of excellence EXC 1077/1 "Hearing4All".
Neher, T., Lundbeck, M., Grimm, G., and Hohmann, V., Einfluss der akustischen Komplexität auf die Bewegungswahrnehmung bei Normal- und Schwerhörenden, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Die auditorische Bewegungswahrnehmung ist relativ unerforscht, insbesondere in akustisch sehr komplexen Situationen. In diesem Beitrag zeigen wir Ergebnisse aus ersten Studien zum Einfluss von Nachhall und Quellenanzahl auf die Bewegungswahrnehmung von normal- und schwerhörenden Probanden. Virtuelle Hörumgebungen wurden mittels eines Ambisonics-basierten Systems, das Simulationenmit hoher physikalischer Genauigkeit ermöglicht, erzeugt. Sowohl radiale (nah-fern) als auch laterale (links-rechts) Quellenbewegungenwurden untersucht. Natürliche Umgebungsgeräusche dienten als Testsignale. Die akustische Komplexität wurde durch Beifügen von stationären Quellen als auch Nachhall variiert. Zum Ausgleich der Hörbarkeit kam eine lineare Verstärkung zum Einsatz. Erwartungskonform zeigten die Analysen, dass Schwerhörende Quellenbewegungen schlechter wahrnehmen können als Normalhörende, jedoch nur unter akustisch komplexeren Bedingungen. Des Weiteren führte die Erhöhung der Quellenanzahl zu einer verminderten Detektierbarkeit von sowohl radialen als auch lateralen Bewegungen. Nachhall hatte lediglich einen Einfluss auf die Detektierbarkeit radialer Bewegungen, für die erhöhte Schwellen gemessen wurden. Zusammenfassend konnte mittels dieser Ergebnisse der Grundstein für Folgestudien gelegt werden, die sich mit dem Einfluss von Hörgerätesignalverarbeitung auf die auditorische Bewegungswahrnehmung befassen.
Heeren, J., Grimm, G., and Hohmann, V., The Influence of Dynamic Binaural Cues on Speech Intelligibility at Low and High Frequencies, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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The amount of spatial release from masking is mainly determined by the change in interaural time difference (ITD) of the noise relative to the ITD of the signal. Accordingly, speech-in-noise with frontal speech presentation and noise from the front or back (S0N0 and S0N180 conditions) lead to similar detection and speech intelligibility thresholds. However, head movements can introduce dynamic binaural cues that may lead to a release from masking (RFM). In this study the effect of dynamic binaural cues on speech intelligibility was investigated for lowpass and highpass filtered signals to assess the influence of ITDs and interaural level differences (ILD). Movements were implemented as modulations of the nominal azimuths of the sound sources (S0N180, S0N0). These modulations were either in-phase or anti-phase for S and N. The stimuli were rendered using 11. order ambisonics with ’basic’ decoding, and presented via loudspeakers. Speech and noise signals were filtered at 1000 Hz (lowpass), 1500 Hz (highpass) or unfiltered. Results show a significant RFM with dynamic binaural cues for S0N0 in all filter conditions. For S0N180 only the unfiltered condition shows a significant RFM (funded by DFG FOR1732).
Ernst, S. M. A., Hohmann, V., Kollmeier, B., and Grimm, G., Virtuelle Umgebungen zur Erfassung des Real-World Benefits eines akustisch transparenten Hörsystems, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Die zunehmend komplexere Signalverarbeitung moderner digitaler Hörgeräte bietet zwar große Chancen für eine optimierte Versorgung, aber auch eine größer werdende Herausforderung für die effiziente individuelle Anpassung. Da bereits Patienten mit nur geringfügiger Schwerhörigkeit oder sogar Normalhörende von aktueller Hörgerätetechnologie profitieren können, spielt die effektive Wiedergabequalität eine immer größere Rolle. Sie kann nur über eine umfassende Evaluation neuer Hörsysteme mit einer Bewertung des erreichbaren Nutzens insbesondere in möglichst realitätsnahen Hörsituationen abgeschätzt werden. In dieser Studie werden dazu Methoden der virtuellen Akustik und ihr Einsatz in der Entwicklung und Bewertung eines akustisch transparenten Hörsystemprototyps vorgestellt. Dazu wurde eine Methode zum direkten virtuellen Vergleich von verschiedenen Kombinationen von Hardware- Bauformen und Signaloptimierung entwickelt. Für die virtuellen Testkonditionenwurden verschiedene alltagsrelevanteKonversationsszenen konzipiert und umgesetzt, die ein breites Spektrum verschiedener Signalqualitäten abdecken. Es konnte gezeigt werden, dass das neue transparente Hörsystem einen hohen Grad der Signalsteuerung ermöglicht und somit deutliche Vorteile gegenüber der klassischen Hörgerätesystemtechnik bietet. Das vorgestellte Hörsystem schafft so die Voraussetzungen für einen transparenten Klang, d.h. eine hohe individuelle Wiedergabequalität als Basis für neue Signalverarbeitungsstrategien.
Grimm, G., Heeren, J., and Hohmann, V., Vergleich von Distanzwahrnehmung in simulierten und realen Räumen, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Distanzwahrnehmung wird in der Regel mit dem Hallmaß (direct-toreverberant ratio, DRR) in Verbindung gebracht. Daher ist eine Interaktion von raumakustischen Simulationsmethoden und Distanzwahrnehmung zu erwarten. In dieser Studie wurde die Distanzwahrnehmung in einem realen Raum mit der Distanzwahrnehmung in einer einfachen Simulation desselben Raums verglichen. Dazu wurde ein Identifikations- Test verwendet, in dem die Versuchsteilnehmer fünf akustische Stimuli einer visuellen Darstellung von fünf Lautsprechern in unterschiedlichen Entfernungen zuordnen sollten. Die Stimuli unterschieden sich nur in der Aufnahmeposition. Die ”realen” Teststimuli wurden mit aufgenommenen kopfbezogenen Impulsantworten (HRIR) aus dem zu testenden Raum generiert. Die simulierten Stimuli wurdenmit reflexionsarmen HRIR und einer Raumakustiksimulation erzeugt. Für die Raumakustiksimulation wurde ein Werkzeug genutzt, welches auf zeitvariante Simulationen für Anwendungen in der Audiologie optimiert ist. Frühe Reflexionen werden mit einem geometrischen Spiegelschallquellenmodell nachgebildet, später Nachhall wird über positionsunabhängigen Faltungshall hinzugefügt. Unterschiedliche Einstellungen des Spiegelschallquellenmodells und des Übergangs von frühen Reflexionen zu spätem Hall wurden untersucht. Die subjektiven Ergebnisse wurden mit etablierten Raumakustikmaßen wie DRR, IACC und T60 verglichen. Die Ergebnisse zeigen, dass die verwendete effiziente Simulationsmethode bei geeigneter Parametrisierung eine natürliche Distanzwahrnehmung ähnlich wie in realen Räumen erreichen kann.
Schmidt, F., Kollmeier, B., and Uppenkamp, S., Stärken und Schwächen von Pegelmaßen und Lautheitsmodellen bei der Bewertung von Musik, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Die Lautheit von Musik wird von vielen Menschen ganz unterschiedlich wahrgenommen. Neben der physikalischen Komplexität des vielfältigen Klangszenarios von Musik ist vor allem die Verwechselung zwischen Lautheit und Präferenz eine Ursache für die Schwankung in der Beurteilung. Diese Schwierigkeit führt dazu, dass in der Anwendung bspw. bei Fernsehen und Rundfunk immer noch Pegelmaße Lautheitsmodellen vorgezogen werden, und weiter dass diese physiologisch motivierten, jedoch nur an Rauschen und Sinuston entwickelten Lautheitsmodelle nur schwerlich für diese Herausforderung modifiziert werden können. Der Paarvergleich ist eine geeignete Methode, um die Schwierigkeit der Beurteilung zu reduzieren, da den Versuchspersonen die Einordnung der wahrgenommenen Lautheit in einer absoluten Skala erspart bleibt. Mithilfe des Bradley-Terry-Luce Verfahrens für die Paarvergleichsauswertung lassen sich dann nicht nur Aussagen über die Rangfolge der verglichenen Musikstücke treffen, sondern auch quantitativ über Lautheitsverhältnisse. Wie gut können die Modelle einen Pool an Musikstücken nach Lautheit sortieren und wie gut deren Lautheitsverhältnisse zueinander schätzen? So können nun verschiedene Lautheitsmodelle qualitativ bewertet und darüber hinaus Stärken, Schwächen und Modifizierungen aufgezeigt werden. Die bisherigen Ergebnisse zeigen, dass sich in der Qualität der Darstellung der Rangfolge Pegelmaße und Lautheitsmodelle kaum unterscheiden. Dagegen treten bei der Darstellung der Verhältniswerte interessante Unterschiede auf, welche Ansätze zu Modifizierungen von Lautheitsmodellen liefern.
Thiemann, J. and van de Par, S., Probabilistic 2D localization of sound sources using a multichannel bilateral hearing aid, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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In the context of localization for Computational Auditory Scene Analysis (CASA), probabilistic localization is a technique where a probability that a sound source is present is computed for each possible direction. This approach has been shown to work well with artificial head signals provided the location of the sources to be localized is in front of the user and approximately on the same plane as the ears. Modern hearing aids use multiple microphones to perform array processing, and in a bilateral configuration, the extra microphones can be used by localization algorithms to not only estimate the horizontal direction (azimuth), but vertical direction (elevation) as well, thereby also resolving the front-back confusion. In this work, we present three different approaches to use Gaussian Mixture Model classifiers to localize sounds relative to a multi-microphone bilateral hearing aid. One approach is to divide a unit sphere into a nonuniform grid and assign a class to each grid point; the other two approaches estimate elevation and azimuth separately, using either a verticalpolar coordinate system or an ear-polar coordinate system. The benefits and drawbacks in terms of performance, computational complexity and memory requirements are discussed for each of these approaches.
Oetjen, A., Letens, U., Maiberger, D., van de Par, S., Schiller, J., and Strasser, E., Wahrnehmung und Beurteilung von Fahrzeuggeräuschen unter Berücksichtigung psychoakustischer Messgrößen, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Bei der Beurteilung der Güte eines Fahrzeuggeräuschs durch psychoakustische Laien bzw. NutzerInnen wird in der Regel Bezug auf Attribute wie z.B. ”sportlich” oder ”komfortabel” und die An- oder Abwesenheit von störenden Geräuschelementen genommen. Im Prozess der Geräuschanalyse und des Sounddesigns stellen jedoch geräuschbeschreibende, psychoakustische Messgrößen wie z.B. Lautheit, Tonhaltigkeit, Rauigkeit und Impulshaftigkeit ein wichtiges Analysetool zur Geräuschcharakterisierung dar. Die Optimierung eines Fahrzeuggeräuschs zur adäquaten Positionierung des Fahrzeugs auf dem Markt profitiert stark von Kenntnissen über die Verbindung zwischen diesen psychoakustischen Geräuschcharakteristika und den dem Geräusch zugeordneten Attributen. Durch gezielte Variation verschiedener Geräuschcharakteristika mit Geräuschsynthesesystemen direkt im Fahrversuch und bei Hörexperimenten im Labor werden Geräuscheigenschaften mit subjektiv wahrgenommenen Eindrücken verknüpft. Hierbei kann die subjektive Bewertung einer Größe jedoch , bedingt z.B. durch für Fahrzeuggeräusche typische Eigenschaften wie stochastische Modulationen oder sich zeitlich schnell verändernde Geräuschkomponenten, stark von der Berechnung der Messgröße durch Analysealgorithmen abweichen. Es werden Ergebnisse aus Fahr- und Laborversuchen sowie neu entwickelte Methoden zur Berechnung psychoakustischer Messgrößen vorgestellt. Durch deren erhöhte Berechnungssicherheit können nun belastbarere Aussagen über Zusammenhänge zwischen Subjektivurteilen und modellhaft berechneten Geräuschattributen gemacht werden.
Imbery, C., van de Par, S., and Bitzer, J., Einfluss der Rotationsachse auf die wahrgenommene Ausrichtung einer Schallquelle, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Das binaurale Hören ermöglicht dem Menschen neben der Lokalisation auch die Ausrichtung einer direktiven Schallquelle anzugeben. In einem Hörversuch wurde die wahrgenommene Ausrichtung eines Lautsprechers in einem Raum experimentell bestimmt. Der Lautsprecher drehte sich einmal um die Mittelachse am physikalischen Schwerpunkt und einmal um das akustische Zentrum nahe der Membran. Bei der Rotation um das akustische Zentrum sollte die Quellposition gleich bleiben. Bei einer Rotation um die Mittelachse ist eine stabile Quellposition nicht gegeben. In diesem Beitrag soll gezeigt werden, dass die Wahl der Rotationsachse der direktiven Schallquelle die wahrgenommeneQuellausrichtung beeinflusst. Besonders für Lautsprecherausrichtungen im vorderen Bereich (±90◦), bei dem der Lautsprecher dem Zuhörer zugewandt ist, unterscheiden sich die Probandenurteile zwischen den beiden Rotationsachsen. Bei einer Rotation um die Mittelachse ist der Winkel der wahrgenommenen Ausrichtung größer als der ermittelte Winkel bei einer Drehung um das akustische Zentrum. Eine mögliche Ursache könnte die zusätzliche Information einer Quellpositionsverschiebung, verursacht durch interaurale Pegel- und Laufzeitunterschiede beim Hörenden, sein.
Grosse, J., van de Par, S., and Trahiotis, C., Stimulus coherence influences sound-field localization and fusion/segregation of leading and lagging sounds, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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The ability to localize sound sources in reverberant environments is dependent upon first-arriving information, an outcome commonly termed ”the precedence effect”. For example, in laboratory experiments, the combination of a leading (direct) sound followed by a lagging (reflected) sound is localized in the direction of the leading sound. This study was designed to measure the degree to which the interaural coherence of leading and lagging sounds, respectively, affected performance. The coherence of leading or lagging sounds was varied by either presenting a sound from a single loudspeaker or by presenting mutually uncorrelated versions of sounds from 5 adjacent loudspeakers. The listener’s task was to point to the perceived location of leading and lagging sources of sounds which were 10-ms long, low-pass filtered white noises, or 2- second long tokens of speech. The leading and lagging stimuli were presented either from speakers located directly in front of them or from speakers located +/- 45◦ to the right or left. The results indicate that leading coherent sounds influence perceived location more so than do leading incoherent sounds. This was true independent of whether sounds were Gaußian noises or tokens of speech.
Haeussler, A., Georganti, E., and van de Par, S., Limits of binaural decoloration investigated over ERB-based spectral manipulation, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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When sound is reproduced inside a room, both ears receive different spectral content. It can be assumed that the brain uses this different spectral information arriving at each ear to balance spectral deviations over the frequencies associated with coloration. This effect is known as binaural decoloration. To investigate this effect more closely, simplified spectral shapes can be used to get insight into the underling process. In this contribution spectral shapes are designed to fluctuate with a constant rate on the ERB rate scale. To get a dichotic presentation, both ears receive the contrary spectral shape. While the energy increases in one ear, it decreases at the other ear and vice versa in a frequencydependentmanner. A listening test is conducted in order to measure the threshold for these spectral modifications to result in an unnatural sound. It is discussed whether the effect of binaural decoloration depends on the rate of this spectral manipulation.
Janßen, N. A., Oetjen, A., Weber, R., and van de Par, S., Temporal Build-Up of Psychoacoustic Roughness, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Psychoacoustic roughness, which can occur for example in sounds of rotating machinery and speech, can have influence on different sound quality aspects such as the perceived pleasantness. Therefore, roughness has relevance in the context of product sound design, e.g. for vehicle interior sounds. Roughness arises from amplitude modulations within the frequency range of about 15 to 150 Hz. Due to variations of such modulations over time, roughness can vary over time, for example when a car is accelerating. So far, roughness perception has rarely been studied with a focus on such temporal changes. One may question whether there exists a temporal build-up for the strength of perceived subjective roughness. In the present study, a roughness matching experiment for stimuli containing amplitude modulated parts with different lengths was conducted. It was found that the amount of perceived overall roughness seems to increase with increasing duration of the rough portion inside a sound with fixed overall length. From this, a general trend for changes in roughness perceptionwith such time-changes has been found and a model describing these changes will be presented.
Jacobsen, A., Grosse, J., and van de Par, S., Upmixing Stereo Signals and Perceptive Optimization for Multichannel Audio Reproduction, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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In multichannel audio reproduction it is usually desired to create a listening experience that is as authentic as possible with respect to the spatial impression. Recently, a newmultichannel audio reproduction system and optimization method was introduced by Grosse and van de Par [IEEE, (2015)], that is used for a perceptual accurate reproduction of recorded sound fields. Basis for this are separately recorded signals that represent the direct and diffuse sound field. In order to minimize the perceptual relevant influences in the reproduction room, the optimization method takes care of the spectral aspects of those signals. To generalize the proposed method, existing stereo recordings are processed in such a way that they can be used for the above-mentioned reproduction system. For this purpose an algorithm for signal separation that has been presented by Breebaart and Schuijers [IEEE, (2008)] is used to decompose a stereo signal into a direct and diffuse signal. These signals are used in the perceptually motivated optimization method as well. A subjective evaluation is conducted to show the improvement of the perceived quality of such an approach.
Wendt, T., van de Par, S., Ewert, S. D., and , Efficient Synthesis of Coupled-Rooms BRIRs using Image Sources and Feedback Delay Networks, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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The simulation of room acoustics for auralization can have numerous applications in interactive evaluation environments (e.g., for hearing aid development), psychoacoustic studies with adaptively changing roomreverberation, or simulation, rehabilitation, and computer games. A fast and perceptually plausible method for synthesizing binaural room impulse responses (BRIR) [Wendt et al., J. Audio Eng. Soc., 62, 11 (2014)] has been extended to simulate the acoustics of multiple coupled rooms, that are acoustically connected by doors or wall openings. As for the single-room simulation method, computational efficiency is achieved by using a hybrid approach, where the early reflections are calculated as image sources up to a low order and the reverberation is generated by efficient feedback delay networks [FDN; Jot and Chaigne, Proc. 90th AES Conv. (1991)]. The binaurally extended FDNs are designed to account for the reverberation properties of coupled rooms, as well as for the spatial distribution of reverberation in the respective rooms, including the vicinity of the room connections. The suggested BRIR synthesis method was evaluated by comparing measured and synthesized BRIRs for connected rooms differing in size and reverberation time using technical measures and subjective listening tests.
Buhl, M., van de Par, S., and Ernst, S. M. A., Technische und perzeptive Evaluation eines räumlichkeitsbewahrenden Beamformers, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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In der sogenannten Cocktail-Party-Situation sprechen meistens mehrere Personen durcheinander, aber als Zuhörer verfolgt man in der Regel zu jedem Zeitpunkt nur einen dieser Sprecher. Für die Wahrung einer angenehmen und natürlichen Hörsituation unter solchen Umständen ist neben guter Sprachverständlichkeit des Zielsprechers auch der korrekte räumliche Eindruck der gesamten akustischen Szene wichtig. Ein den Hörer unterstützender Hörgerätealgorithmus sollte daher sowohl den Signal-Rausch-Abstand (SNR) zwischen Zielsprecher und dem Störgeräusch verbessern als auch möglichst die binaurale Information vollständig erhalten. Der von Hadad et al. (2012) vorgeschlagene Binaural Linearly ConstrainedMinimum Variance (BLCMV) Beamformer verspricht, beide Ziele zu einem hohen Maße zu erreichen. In dieser Studie wurde das Verhalten des BLCMV-Beamformers für verschiedene Optimierungen des Algorithmus instrumentell untersucht. Basierend auf den gefundenenVeränderungen der binauralen Signaleigenschaften wurden künstliche Signale generiert und zusammen mit den vom Beamformer direkt verarbeiteten Signalen von 10 Probanden evaluiert. Hierbei wurden Sprachverständlichkeit, Lokalisation und Höranstrengung bewertet. Es zeigt sich, dass der SNR der dominierende Faktor für Sprachverständlichkeit und Höranstrengung ist. In den Experimenten zur Lokalisation zeigte sich allerdings, dass die Optimierung mit der stärksten SNR-Verbesserung zu einer deutlichen Verfälschung des räumlichen Eindrucks führte. Diese Ergebnisse zusammenfassend wird eine Kompromisseinstellung vorgeschlagen, die bei geringfügig kleinerer SNR-Verbesserung eine möglichst große Räumlichkeit bewahrt.
Dollack, F., Imbery, C., van de Par, S., and Bitzer, J., Einfluss von visueller Stimulation auf Distanzwahrnehmung und Externalisierung, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Bei der Darbietung von Kopfhörersignalen kann es wünschenswert sein, eine möglichst realistische Hörsituation eines Schallereignisses zu simulieren. Neben einer bestimmten Einfallsrichtung und Distanz sollte das Schallereignis außerhalb des Kopfes wahrgenommen werden. Jedoch ist es nicht immermöglich bei der Generierung der Kopfhörersignale die dafür notwendigen individuellenAußenohrübertragungsfunktionen zu berücksichtigen und das Kopfhörersignal individuell zu entzerren. Für diesen Beitrag wurden in psychoakustischen Experimenten untersucht, welchen Einfluss ein zusätzlicher visueller Stimulus auf die Wahrnehmung eines Schallereignisses hat. Dafür wurde die wahrgenommeneDistanz von sechs Entfernungen zwischen 0.9 m bis 4.9 m variiert und der Grad der Externalisierung für 24 Einfallsrichtungen in 15 Grad Schritten bei einer Entfernung von 1.4 m ermittelt. Die visuelle Darbietung erfolgte auf einem 3D-Monitor mit aktivierter und deaktivierter 3D-Funktion und mit der Virtual Reality Brille Oculus Rift. Eine weitere Kondition, ohne visuelle Darbietung, diente als Referenz. Die akustischen Stimuli wurden durch Binauralsynthese mit binauralen Raumimpulsantworten eines Kunstkopfes generiert. Die zusätzliche visuelle Darbietung zeigt keinen signifikanten Einfluss auf den Grad der Externalisierung. Allerdings scheinen die Ergebnisse des Distanzexperiments durch die visuelle Darbietung beeinflusst zu werden. Im Vergleich zur Referenzkondition ohne visueller Darbietung zeigt sich eine systematische Überschätzung der Distanz.
Maiberger, D., Letens, U., Tischler, M., Weber, R., and van de Par, S., Eine Typisierung von Fahrzeugkunden nach Geräuschvorlieben, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Wie in vielen Bereichen unseres Alltags wachsen auch im Pkw-Bereich die Ansprüche der Nutzer. Neben Fahreigenschaften und finanziellen Aspekten rücken zunehmend auch Umweltaspekte wie z.B. Lärmbelastung in den Fokus. Neben der Belastung durch Lärm haben die Fahrgeräusche für viele Menschen aber eine viel weitreichendere Bedeutung: sie sind Träger von Informationen, sie sind die ”Sprache” des Fahrzeugs, sie können sogar Emotionen auslösen. Die Wirkung der Fahrgeräusche eines Fahrzeugs auf eine Person kann aber ganz unterschiedlich ausfallen, je nachdem in welchem Kontext das Gehörte steht, so z.B. die Beziehung der Person zum Fahrzeug, die Situation, in der sie die Geräusche erlebt, aber sicherlich auch ihre individuelle Einstellung zu Fahrgeräuschen: persönliche Vorlieben und damit verbundene Erwartungen und Ansprüche an das Fahrgeräusch sind moderierende Faktoren bei der Beurteilung von Fahrgeräuschen. In diesem Beitrag werden die Ergebnisse einer Befragung dargestellt, in der die Einstellung der Teilnehmer zum Thema Fahrzeuggeräusche sowie ihre Beurteilung der bzw. Wünsche an die Geräusche des eigenen Fahrzeugs erfasst wurden. Anhand der Ergebnisse einer großen Stichprobe von Fahrzeugkunden aus dem Premium-Segment wurde eine Typisierung vorgenommen, um damit einen Ansatzpunkt für weitere Analysen der individuellen Einflüsse auf die Beurteilung von Fahrgeräuschen zu schaffen. Die Ergebnisse deuten auf drei unterschiedliche ”Fahrzeugsound”-Typen hin.
Strasser, E., Maiberger, D., Weber, R., Letens, U., and van de Par, S., Untersuchung der Kontextvariablen bei der Bewertung von Fahrzeuggeräuschen, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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In diesem Beitrag behandeln wir die Fragewelchen Klangcharakter ein Fahrzeug aufweisen muss um positiv wahrgenommen zu werden. Dabei ist ein zentraler Aspekt, ob es interindividuelle Unterschiede in der Wahrnehmung des Fahrgeräusches gibt, und wie die Reaktion des Fahrers ausfällt wenn der Klangcharakter des Fahrzeuges nicht mit seiner Erwartung übereinstimmt. In der hier vorgestellten Studie wurden diese Fragen in holistischerWeise betrachtet. Bei der als Feldexperiment ausgelegten Blindstudie fuhren 20 Probanden eine Limousine der oberen Mittelklasse jeweils dreimal zur Probe, wobei bei zwei Fahrten der Fahrzeugklang durch einen elektroakustischen Soundgenerator modifiziert wurde. Die Probanden wurden instruiert während der Fahrt all ihre Gedanken zum Fahrgeräusch laut zu äußern. Die Probanden wurden im weiteren Verlauf gebeten eine globale bzw. auf die Faktoren Komfort und Sportlichkeit bezogene Bewertung des Fahrgeräusches abzugeben. Durch die Gestaltung als Leitfadeninterview wurden auch qualitative Aspekte der Wahrnehmung des Fahrgeräusches miterfasst. Am Ende der Testfahrt wurden die Probanden gebeten einen Fragebogen zu Persönlichkeitsfaktoren, ihrer Einstellung zu Lärm sowie ihrer Einstellung zu Fahrzeugen auszufüllen. Darüber hinaus wurde die implizite Einstellung der Probanden zu Statussymbolen abgefragt. Die vorliegende Publikation präsentiert die zentralen Ergebnisse dieser Studie und diskutiert deren Implikationen.
Klockgether, S. and van de Par, S., Perception of spatiousness in rooms in dependence of the strength of absorption at the side walls in real and simulated rooms, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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The Perception of spaciousness in rooms is depending on the reflections of the sound at the walls. Especially the strength of the reflections at the side walls are often assumed to be important for the perception of source width and envelopment. This study shows the results of a psychoacoustic experiment, where the perception of source width and envelopment had to be rated by subjects. The stimuli were anechoic music signals convolved with binaural room impulse responses (BRIR) and were presented with headphones. The BRIRs were either recordings of real rooms or simulated with a mirror image model. The simulation of BRIRs allowed to alter the absorption coefficients of the side walls separately from the other surfaces of the room. By systematically varying the strength of the side reflections within the room, the dependency of the perception of spaciousness on lateral fraction was investigated. The resulting subjective ratings of the stimuli are compared to subjective ratings of stimuli gained by direct manipulations of the interaural crosscorrelation of BRIRs. In this way we can compare the influence of side reflections on the perception of source width and envelopment to the influence of interaural cross-correlation.
Hu, H., Kollmeier, B., and Dietz, M., Suitability of the binaural interaction component for interaural electrode pairing of bilateral cochlear implants, Advances in Experimental Medicine and Biology, vol. 894. Springer, 2016.
Abstract
Denk, F., Kollmeier, B., and Ernst, S. M. A., High-Fidelity Hearing Instruments: Evaluating Listening Quality of a New Prototype Using a Method for Evaluating Modified Listening (MEML), Audio Engineering Society Conference: 2016 AES International Conference on Headphone Technology. 2016.
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Moritz, N., Schröder, J., Goetze, S., Anemüller, J., and Kollmeier, B., Acoustic Scene Classification using Time-Delay Neural Networks and Amplitude Modulation Filter Bank Features, Detection and Classification of Acoustic Scenes and Events. 2016.
Abstract
This paper presents a system for acoustic scene classification (SC) that is applied to data of the SC task of the DCASE’16 challenge (Task 1). The proposed method is based on extracting acoustic features that employ a relatively long temporal context, i.e., amplitude modulation filer bank (AMFB) features, prior to detection of acoustic scenes using a neural network (NN) based classification approach. Recurrent neural networks (RNN) are well suited to model long-term acoustic dependencies that are known to encode important information for SC tasks. However, RNNs require a relatively large amount of training data in comparison to feed-forward deep neural networks (DNNs). Hence, the time-delay neural network (TDNN) approach is used in the present work that enables analysis of long contextual information similar to RNNs but with training efforts comparable to conventional DNNs. The proposed SC system attains a recognition accuracy of 76.5 %, which is 4.0 % higher compared to the DCASE’16 baseline system.
Kollmeier, B., Lenarz, T., Warzybok, A., Schädler, M., Haumann, S., Brand, T., and Lücke, J., Auditory Profile and Common Audiological Functional Parameters (CAFPAs): From Diagnostics to Machine-Learning-based Evidence, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
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# Introduction # How well should the various audiological findings best be represented and how can this information be used to characterize the individual hearing problem of each patient – preferably in a way which is independent from his or her native language? This contribution reviews the approach and models developed in the Cluster of Excellence Hearing4All (Oldenburg/Hannover) to unite the diverse audiological databases, e.g. from the hearing research and clinical institutions in Oldenburg and in Hannover in a more abstract, comprehensive way than the previously defined “auditory profiles”. # Method # A set of “common audiological functional parameters” (CAFPAs) has been defined that serves as an abstract representation of the most important audiological characteristics of each patient. The CAFPAs include, e.g., sensitivity loss in different frequency regions, distortion component and compression loss at low and high frequencies, central and binaural loss, cognitive and socio-economic component of the hearing loss. These CAFPAs have been defined in order to make non-consistent and non-complete audiological data accessible for methods of machine learning, such as, e.g. Bayesian nets. Since speech recognition tests in noise are the most crucial outcome parameter, the multilingual matrix test (Kollmeier et al., 2015 Int. J. Audiol. online first) is used which is suitable not only for comparisons across different clinics but also across languages. The individual Speech Recognition Thresholds (SRT) in stationary and in fluctuating noise were predicted using the audiogram and an estimate of the internal level uncertainty as parameters following the Automatic Speech Recognition (ASR) approach by Schädler et al. (2015, Int. J. Audiol. Online first) # Results # Using such statistical methods, a data-driven audiological classification for different classes of hearing loss becomes possible. Estimates of the “typical” hearing loss and suprathreshold distortion components in combination with ASR-based speech recognition prediction allow to predict the individual performance for the closed-set Matrix sentence recognition test in different languages. # Conclusions # A consistency check across the different audiological input and outcome measures becomes possible by using auditory models adapted to the individual hearing impairment. The concept of a more abstract representation of audiological diagnostical information in combination with speech recognition prediction methods and other machine learning approaches appears to be promising for further research in diagnostical and rehabilitative audiology. # Funding# DFG, EXC 1077 Hearing4All
Dietz, M., Baumgaertel, R., Hu, H., Williges, B., and Kollmeier, B., Extent of Lateralization with Large Interaural Time Differences in Normal Hearing Listeners and Bilateral Cochlear Implant Users, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
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For normal hearing listeners, sound localization in the frontal azimuthal half-plane is primarily achieved by neural processing of interaural differences in level and arrival time. While interaural level differences are to some extent also used by bilateral cochlear implant (CI) subjects, encoding of perceptually exploitable interaural time differences (ITDs) by pulse timing is still a topic of ongoing research. The current study is motivated by the fact that CI subjects are able to exploit ITDs when presented with fully synchronized low-rate pulse trains. In the first part of the study, extent of lateralization for fixed ITDs of up to 3 ms was measured in normal-hearing subjects. Stimuli were either unfiltered or 3-5 kHz band pass filtered click trains, the latter mimicking the perception of CI users, i.e. the absence of any low-frequency temporal fine-structure information. Results indicate that, while unfiltered click trains of 600 μs ITD (corresponding to almost 90° in free-field listening) were lateralized at the ear, filtered click-trains required approximately 1.0-1.4 ms ITD for equally strong lateralization, at least in some subjects. In the second part of this study, lateralization of low-rate pulse trains was measured using single electrode stimulation in bilateral CI subjects. For the subjects tested so far with the constant rate and constant level pulse trains, a change in lateralization percept with changing ITD could only be measured at rates lower than 200 pulses per second (pps). On average, an ITD of 1.0 ms was required to lateralize the pulse train at the ear. The results indicate that, if the speech coding allows for sufficiently low pulse rates, ITD enhancement may be beneficial in future binaural CIs to provide improved localization performance. The rate limit of 100-200 pps is, however, even lower than for ITD detection. The results have inspired the development of a signal processing algorithm specific for binaural CIs. Ongoing research is evaluating sound localization performance and speech intelligibility with this new algorithm. # Funding # This work was funded by European Union under the Advancing Binaural Cochlear Implant Technology (ABCIT) grant agreement (No. 304912) and by the DFG Cluster of Excellence Hearing4all.
Oetting, D., Hohmann, V., Appell, J. -E., Kollmeier, B., and Ewert, S. D., Binaural bandwidth-adaptive dynamic compression, Int. Hear. Aid Res. Conf. (IHCON). 2016.
Abstract
Kollmeier, B., Zokoll, M. A., Buschermöhle, M., Warzybok, A., and Wagener, K. C., Unaided and aided speech recognition performance evaluation across languages with hearing impaired patients using multilingual matrix sentence tests, Int. Hear. Aid Res. Conf. (IHCON). 2016.
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Kollmeier, B., Warzybok, A., Ernst, S., Schädler, M. R., and , Objective, individualized benefit prediction for hearing aid algorithms using automatic speech recognition: How far do we get with FADE?, Int. Hear. Aid Res. Conf. (IHCON). 2016.
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Habicht, J., Kollmeier, B., and Neher, T., Can hearing aids speed up speech comprehension in noise? Insights from eye-tracking measurements, Int. Hear. Aid Res. Conf. (IHCON). 2016.
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Schädler, M. R., Warzybok, A., Brand, T., and Kollmeier, B., Simulating Speech Recognition of Listeners with Impaired Hearing using an Automatic Speech Recognition System: Modelling Suprathreshold Deficiencies with Level Uncertainty, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
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Introduction Which information is needed to complement the pure tone audiogram in order to accurately predict speech reception thresholds (SRTs) in noise for listeners with impaired hearing? To answer this question, a framework which is able to simulate speech recognition in noise of listeners with normal hearing and accurately predict reference-free SRTs in several noise conditions (Schädler et al., in press) was enhanced to perform simulations for listeners with impaired hearing. Method Reference-free, i.e. not depending on any reference measurement, SRTs were predicted by simulating the German matrix sentence test (Wagener et al. 1999) with an individually adapted automatic speech recognition (ASR) system. In a first experiment, the effect of the absolute hearing thresholds, determined from 200 individual audiograms, was implemented into the feature extraction stage of the ASR system. The recognition results were compared to empirical data and speech intelligibility index (SII) based predictions form the literature. For a second experiment, in extension to the pure tone audiogram based simulations, a suprathreshold deficiency, modelled by a level uncertainty uL in the feature extraction stage of the ASR system, is postulated. The values for the individual supra-threshold deficiency uL were determined from the respective other noise condition by choosing uL to match the empirical and predicted SRTs. Results The results show that the loss of sensitivity described by the individual pure tone threshold explains only 40% of the empirically observed variance in a stationary and 50% in a fluctuating noise condition. Taking into account pure tone threshold and individual supra-threshold hearing deficiency, 67% and 76% of the empirically observed variance can be explained in the stationary and the fluctuating noise condition, respectively. Conclusions The study concludes that the individual audiogram describes the impaired hearing incompletely and should be complemented with a description of individual supra-threshold hearing deficiencies to improve the prediction accuracy. The accurate simulation of human speech recognition, using suboptimal signal processing in order to model impaired hearing, could enable simulations under aided conditions. The suitability of this approach for aided performance prediction should be assessed in future work. Funding This work was supported by the Deutsche Forschungsgemeinschaft SFB/TRR 31 “The active auditory system” and the Cluster of Excellence Grant “Hearing4all”.
Kollmeier, B., Warzybok, A., Hochmuth, S., Boboshko, M., Bentler, R., and Zokoll, M., Multilingual Matrix Sentence Recognition Tests: Providing a common Ground for Multi-Center Audiological Studies, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
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Introduction The difficulty of understanding speech in noisy environments is not very well reflected by pure tone audiogram findings. To better understand a patient’s problem, it is necessary to assess his or her communication ability in noisy environments. This might also help to assess possible supra-threshold distortions that occur in the auditory system as a result of hearing impairment, independent from the sensitivity loss assessed by the tone audiogram or speech audiometry in quiet. Hence, speech recognition tests in noise have become more and more important in audiological diagnostics in recent years. So-called ‘matrix sentence tests’ use a closedset format and comprise syntactically fixed, semantically unpredictable sentences (e.g. “Peter kept two green toys”). Providing a vocabulary of only 50 words (10 alternatives for each position in the sentence), matrix sentence tests are suitable for speech perception testing without losing the usability for repeated speech perception testing with the same patient. In a multilingual society where each patient should be tested with her or his native language, experimenters that do not understand the test language may still supervise the test if its closed-set response format is used. Meanwhile matrix sentences tests developed according to common minimum quality standards for speech intelligibility tests are available for 15 different languages (i.e., in Swedish, German, Danish, Dutch, American English, British English, French, Polish, Turkish, Spanish, Italian, Persian, Arabian, Finnish, and Russian) together with a varying degree of supportive data. The common quality standards result in a high homogeneity of the speech materials and test lists employed what yields steep test-specific intelligibility functions and high test efficiency. Methods This contribution presents matrix sentence test data of two multi-center studies in the USA and Russia investigating the different influence of hearing ability on the SRT in quiet and noise. Data include adaptively estimated speech reception thresholds (SRTs), i.e. the sound pressure levels or signal-tonoise ratios (SNR) yielding 50% speech intelligibility, as well as correlations between hearing ability and SRT. Results The common quality standards applied during their development resulted in efficient and reliable tests with high comparability across the languages. Data emphasize the high potential of matrix sentence tests to disentangle the contribution of possible supra-threshold distortions to a certain hearing loss from that of the pure loss in sensitivity. Conclusions The Matrix test format has been shown as a sensitive diagnostic tool suitable for multilingual comparisons. Funding DFG, Cluster of Excellence 1077 Hearing4All
Kollmeier, B., Carroll, R., Warzybok, A., Uslar, V., Brand, T., and Ruigendijk, E., Sentence recognition in noise: How well do we understand sensory and cognitive factors?, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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The relative contribution of sensory, bottom-up processing and cognitive, top-down processing in speech comprehension is influenced by external factors (like linguistic complexity, interfering noise, and reverberation) and internal factors (like age, hearing loss, and cognitive abilities of the listener). A review is given on joint studies from audiology and linguistics to characterize these factors. The studies to be presented in more detail obtained speech recognition in noise and/or reverberation in younger (YNH) and older listeners (ONH) with normal hearing, and in older hearing-impaired listeners (OHI). For YNH and ONH, a combination of age, SNR, vocabulary size, and lexical access time predicted speech recognition scores. OHI required more favorable SNR to reach the same performance than the age-matched ONH even when speech was presented with NAL-R amplification to (partially) compensate for their sensory deficits. Whereas vocabulary size was unchanged and lexical access time was increased both for ONH and OHI, working memory slightly decreased only for OHI. This provides evidence for the importance of non-auditory cognitive measures (like a specific combination of vocabulary size, lexical access time, and working memory) in explaining the comparatively poorer speech recognition scores that are observed for older vs. younger listeners and for OHI vs. ONH.
Warzybok, A., Rennies-Hochmuth, J., and Kollmeier, B., Masking versus Cognition during Speech Recognition in noise and reverberation: Can different sentence tests provide a quantitative estimate?, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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This study investigates the effect of noise and reverberation on speech recognition for an open- and a closed-set sentence test. While both tests yield approximately the same recognition threshold in trained normalhearing listeners, their performance may differ due to cognitive factors, i.e., the closed-set test is more sensitive to training effects while the open-set test is more affected by language familiarity. The experimental data were compared to predictions of the speech transmission index as a measure of pure acoustic effects. The largest differences between the open- and closed-set speech tests were measured in reverberation indicating a considerable influence of non-acoustic, cognitive factors. The recognition scores were on average 50% higher for the closed-set test with syntactically fixed and semantically unpredictable sentences than for the open-set test consisting of everyday sentences. To examine the underlying reasons, the closed-set test was presented to naïve listeners, with no training prior the measurements and no information about the test’s structure. Removing this information, the differences between the tests were not present indicating that the degree of familiarity with the speech material has a major impact on speech recognition. This indicates a strong cognitive factor which cannot be predicted by the speech transmission index.
Kubiak, A., Rennies-Hochmuth, J., and Kollmeier, B., Towards individual audio consumer profiles, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Project aims at providing an audio signal presentationwhich is optimized to the individual preference and any hearing impairment in a situation and presentation-material-aware way. Previous studies have shown that individual listening preferences, although quite stable within subjects, differed markedly across the group. Therefore, in the present study, to find out possible sources of variability, subjects with normal or slightly impaired hearing are selected according to three factors: age, speech intelligibility performance and audiogram, and assigned to test groups so that - within each group - subjects differ in only one of the factors. Each person performs a battery of tests using speech stimuli in noise and quiet. In the first set of experiments, the reaction to very basic signal modifications such as broadband gain, equalization, allowed amount of artifacts due to dynamic range compression or clipping is assessed to optimize the presentation mode to each individual. The second part assesses preferred processing schemes of a complex speech enhancement algorithm together with the benefit of such enhancement. This systematic data base will be used to investigate if basic individual factors are related to listening preferences and if preferences with respect to simple signal modifications generalize to more complex processing schemes.
Schell-Majoor, L., Rennies-Hochmuth, J., Ewert, S. D., and Kollmeier, B., Validierung einer Methode zur gleichzeitigen Bewertung von Rauigkeit, Schärfe, Tonhaltigkeit, Lautheit und Lästigkeit, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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In der Psychoakustik sind Rauigkeit, Schärfe, Tonhaltigkeit und Lautheit gängige Maße zur Bewertung von Geräuschen. In Studien mit Probanden wird in der Regel immer nur eines der Maße bewertet, z.B. um eine Berechnungsvorschrift für das jeweilige Maß abzuleiten. Eine Methode für die Vorhersage der Klangqualität von Geräuschen ist die Kombination dieser Maße zu einem Gesamturteil, z.B. Lästigkeit. Hierfür wird meist nur das Gesamturteil mit Probanden subjektiv gemessen und die zu kombinierenden Maße werden berechnet. Es fehlen somit subjektive Daten, die sowohl die verschiedenen psychoakustischen Maße als auch das Gesamturteil für eine Auswahl von Geräuschen beinhalten. In diesem Beitrag wird eine Methode vorgestellt und validiert, in der die psychoakustischen Maße Rauigkeit, Schärfe, Tonhaltigkeit und Lautheit gleichzeitig mit Lästigkeit als Gesamturteil subjektiv bewertet werden. Für eine einfache Anwendung soll die Methode eine Bewertung von vielen Geräuschen in kurzer Zeit mit untrainierten Probanden ermöglichen. Die Ergebnisse zeigen, dass die Probanden in Test/Re-Test-Messungen zu gut reproduzierbaren Ergebnissen kommen. Die absoluten Bewertungen werden vom experimentellen Kontext, insbesondere der Geräuschauswahl, beeinflusst. Die relativen Bewertungen sind jedoch gut reproduzierbar.
Ernst, S. M. A., Hohmann, V., Kollmeier, B., and Grimm, G., Virtuelle Umgebungen zur Erfassung des Real-World Benefits eines akustisch transparenten Hörsystems, Proc. German Annual Conf. Acoust. (DAGA). 2016.
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Die zunehmend komplexere Signalverarbeitung moderner digitaler Hörgeräte bietet zwar große Chancen für eine optimierte Versorgung, aber auch eine größer werdende Herausforderung für die effiziente individuelle Anpassung. Da bereits Patienten mit nur geringfügiger Schwerhörigkeit oder sogar Normalhörende von aktueller Hörgerätetechnologie profitieren können, spielt die effektive Wiedergabequalität eine immer größere Rolle. Sie kann nur über eine umfassende Evaluation neuer Hörsysteme mit einer Bewertung des erreichbaren Nutzens insbesondere in möglichst realitätsnahen Hörsituationen abgeschätzt werden. In dieser Studie werden dazu Methoden der virtuellen Akustik und ihr Einsatz in der Entwicklung und Bewertung eines akustisch transparenten Hörsystemprototyps vorgestellt. Dazu wurde eine Methode zum direkten virtuellen Vergleich von verschiedenen Kombinationen von Hardware- Bauformen und Signaloptimierung entwickelt. Für die virtuellen Testkonditionenwurden verschiedene alltagsrelevanteKonversationsszenen konzipiert und umgesetzt, die ein breites Spektrum verschiedener Signalqualitäten abdecken. Es konnte gezeigt werden, dass das neue transparente Hörsystem einen hohen Grad der Signalsteuerung ermöglicht und somit deutliche Vorteile gegenüber der klassischen Hörgerätesystemtechnik bietet. Das vorgestellte Hörsystem schafft so die Voraussetzungen für einen transparenten Klang, d.h. eine hohe individuelle Wiedergabequalität als Basis für neue Signalverarbeitungsstrategien.
Palanca-Castan, N., Laumen, G., Reed, D., and Köppl, C., Characterization of the Binaural Interaction Component in Barn Owl (Tyto alba), Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
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Background The auditory brainstem response (ABR) is an evoked potential that reflects the responses to sound by the brainstem neural centers. The binaural interaction component (BIC) is obtained by subtracting the sum of the monaural ABR responses from the binaural response. It is assumed to represent the activity of binaural nuclei (Jewett, 1970, Electroencephalogr. Clin. Neurophysiol. 28: 609–618). The amplitude and latency of the BIC are dependent on the binaural cues presented (Furst et al., 1990, Hear. Res. 187: 63–72). The BIC can be used to non-invasively test binaural processing. However, any conclusions are limited by the lack of knowledge of the relevant processes at the level of individual neurons. The aim of this study is to characterize the ABR and BIC in the barn owl, an animal where the ITD-processing neural circuits have been extensively studied. Methods ABRs were measured in 9 adult barn owls. Responses to chirps at different levels and ITDs were recorded, and the BIC was derived as a function of ITD. To determine the extent of the crosstalk caused by the presence of the interaural canal, compound action potential (CAP) recordings were collected for two other adult barn owls. All BIC measurements were taken below the level of crosstalk. Results The ABR in barn owl showed 2-3 waves in the first 10 ms of recording. Wave I only appeared consistently at high levels. Wave II and III increased in amplitude and decreased in latency with increasing stimulus level. The most salient component of the BIC was a negative deflection (DN1) that corresponded to wave III. The latency of DN1 closely corresponded to the latency of local neurophonic potentials recorded in nucleus laminaris (Carr et al. 2015, J. Neurophysiol., in press). Both the amplitude and latency of DN1 varied with changing ITD. Conclusion The most visible component of the BIC (DN1) was associated with nucleus laminaris and is thus likely to reflect the known processes of ITD computation in this nucleus. DN1 was a negative deflection, which indicates a smaller response to binaural stimulation than predicted by the sum of monaural responses. This negative polarity is not consistent with previous predictions (Wada and Starr, 1989, Electroencephalogr. Clin. Neurophysiol. 56, 340–351) for an excitatory-excitatory system such as the one present in barn owl, and alternative models like the one by Gaumond and Psaltikidou (1991, J. Acoust. Soc. Am. 89: 454:456) need to be considered. Funding NPC, GL, CK funded by the DFG (TRR31) and the cluster of excellent “Hearing4all”. DK supported by the program “Function and pathophysiology of the auditory system” funded by the state of Lower Saxony, Germany.
Zhang, L., Stachowiak, R., and Köppl, C., Loss of inner hair cell afferent synapses in aging gerbils, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
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Background Age-related hearing loss is well documented in gerbils more than 2 years old. Outer hair cell (OHC) loss, mostly used as an indicator of age-dependent hearing loss, is scattered and mainly found in apical and basal half-turns. However, loss of OHC is not well correlated with hearing loss, as assessed by CAP thresholds. In addition, inner hair cells (IHC) are rarely missing. A reduction in the number of synapses between afferent neurons and IHC has been reported in ageing mice (Sergeyenko, et al., J Neurosci., 2013, 33:13686-13694). In gerbils, few studies have focused on synapses, mainly due to technical difficulties with labeling (Meyer AC, et al. Nat Neurosci, 2009, 12:444-453). In this study, we present reliable pre- and postsynaptic immunoloabeling of afferent synapses in gerbils of different ages. We followed changes in the synapses with ageing, to investigate a potential mechanism for age-related hearing loss. Methods Quiet-aged gerbils, 2 to 43 months old, were perfused transcardially with 4% paraformaldehyde under deep anesthesia with sodium pentobarbital. Cochleae were harvested immediately after perfusion and decalcified in 0.5 M EGTA for 2 days at 4°C. An anti-CTBP2 antibody (BD Biosciences, No. 612044) and an anti-GluR2 (Millipore MAB 397) were used to label presynaptic ribbons and postsynaptic receptors, respectively. An anti-Myosin VIIa antibody (Proteus Biosciences 25-6790) labeled hair cells. Four different regions, located at 3.8, 5.19, 6.64, and 8.13 mm from the apex, corresponding to 2, 4, 8 and 16 kHz respectively (Müller M, Hear Res, 1996, 94:148–156) were examined with confocal microscopy. At each location, structures co-labeled with anti-CtBP2 and anti-GluA2 were defined as functional afferent synapses and quantified. Results The staining methods for both pre- and post-synaptic markers were reliable and repeatable at all ages. The total length of 6 cochleae analyzed to date was 11.6 ±0.45 mm. Preliminary data showed that both the pre- and post- synaptic markers decreased with age. At the 2 kHz region, afferent synapse numbers changed from 21/IHC in gerbils between 2 and 17 months of age, to 10.6/IHC in 43 months old animals. At the regions corresponding to 4, 8, and 16 kHz, synapse numbers decreased more gradually with age. Discussion In conclusion, synapse loss occurs much earlier than OHC loss in ageing gerbils and therefore could be a more reliable indicator of age-related hearing loss. However, the relation between synapse loss and age-related hearing loss still needs clarification. Funding This research is supported by the program of Cluster of Excellence “Hear4all”.
Ashida, G., Kretzberg, J., and Tollin, D., Coding Amplitude-Modulated Sounds by Coincidence Detection in the Lateral Superior Olive, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
AbstractFull Text
Background Neurons in the mammalian lateral superior olive (LSO) detect interaural level differences by comparing excitatory inputs from the ipsilateral cochlear nucleus with inhibitory inputs driven by contralateral sounds. LSO neurons also show sensitivity to binaural phase-differences of amplitude-modulated (AM) sounds. Although binaural coding by LSO has been extensively studied both theoretically and experimentally, monaural response characteristics of LSO to AM sounds are only marginally understood. Previous in vivo recordings in cat LSO showed that spiking rates of LSO neurons generally decrease with increasing modulation frequency, but that variations of modulation-frequency dependence across neurons were considerably large (Joris and Yin, 1998, J. Neurophysiol.). In this study, we aim to reveal the underlying mechanisms for this monaural AM coding using a simple computational model of LSO. Methods Phase-locked excitatory inputs to LSO were modeled as an inhomogeneous Poisson process with a periodic intensity function, while spontaneous inhibition was modeled as homogeneous Poisson process. Similar to a previous modeling study (Franken et al., 2014, Front. Neural Circuits), the LSO neuron was modeled as a counter of coincident inputs. Namely, if the number of excitatory inputs within a preset coincidence window reached or exceeded the threshold, an output spike was generated. Then the model is in the refractory period, in which no more spikes are generated. Effects of inhibition were modeled as a transient increase in threshold. We systematically varied parameters of the model and examined how they affect AM-tuning of the model neuron. Results By changing the model parameters, most variations of AMtuning curves observed in vivo were reproduced. Frequencydependence of input parameters (spike rates, degrees of phase-locking, and spontaneous inhibition) had only minor effects on LSO output spike rates. In contrast, increasing coincidence threshold or shortening the coincidence window resulted in lower output spike rates. Moreover, lower coincidence thresholds led to higher half-peak positions of AM-tuning curves. The duration of the refractory period affected the AM-tuning curve only below 300 Hz. Conclusion Our modeling results suggest that coincidence detection is one of the most fundamental operations in LSO and that variations of coincidence parameters may explain the empirical neuronto- neuron variations in AM coding. Investigating the relations between the abstract parameters of our coincidence counting model and underlying biophysical factors (such as membrane and synaptic properties) would be an important subject of future study. Funding Supported by the Cluster of Excellence “Hearing4all” (GA, JK), by the NIH Grant DC011555 (DJT), and by a Hanse-Wissenschaftskolleg (HWK) Fellowship (DJT).
Altoé, A., Pulkki, V., and Verhulst, S., The two functions of the reticular lamina, International Congress on Sound & Vibration. 2016.
AbstractFull Text
The cell body of the outer hair cells connects the reticular lamina and the basilar membrane through supporting cells. According to the predominant view of cochlear mechanics, the outer hair cells enhance wave propagation in the scala media by dynamically expanding and contracting their body, thus providing an active driving force to the basilar membrane. In order to maximize the efficiency of such mechanism, the reticular lamina should behave like a rigid anchor; in this way the force associated with the length change of the outer hair cells body is efficiently transmitted to the basilar membrane. On the other hand, the motion of the reticular lamina provides a direct drive to the inner-hair cells through a fluid-cilia coupling mechanism. Therefore a free-to-move reticular lamina would be highly responsive to the activity of outer hair cells, thus locally enhancing the sensitivity of inner hair cells. Within this view, the reticular lamina should trade-off between the two conflicting requirements of 1) providing a firm attachment to the outer hair cells and 2) being sensitive to outer hair cells motility. A different thesis, partially supported by recent recordings of the intact organ of Corti, is that a longitudinal coupling of motion in the scala media (similar as in feed-forward cochlear models) allows for a simultaneous enhancement of basilar membrane and stereocilia vibrations without imposing contradicting requirements for the functioning of the reticular lamina. In this study, we discuss the recent experimental and theoretical findings under this perspective.
Altoe’, A., Verhulst, S., and Pulkki, V., Resolving the Discrepancies between Basilar Membrane, Reticular Lamina and Inner Hair Cell Tuning, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
AbstractFull Text
Classical recordings from the basal region of the chinchilla cochlea (~8 kHz) show that neural tuning curves lie about halfway between basilar-membrane (BM) constant-velocity and constant-displacement tuning curves. This suggests that inner-hair cells (IHCs) respond to a combination of BM velocity and displacement; a statement that finds support in classical guinea-pig IHC recordings. In this study, we offer an explanation for the well-documented relationship between neural and mechanical tuning that relies on a proportionality between IHCs stereocilia deflection amplitude and BM velocity up to the units’ best frequency. By assuming well-established features of IHC processing, i.e. a Boltzmann type transduction nonlinearity followed by the low-pass filtering action of the IHC basolateral membrane, we derive the theoretical background for this work. We then validate our hypothesis using numerical simulations in a computational model of the inner hair cell/auditory nerve complex. Unfortunately, the demonstrated proportionality between BM velocity and stereocilia deflection seems in contrast with recent in-vivo recordings from the ~18 kHz region of the guinea-pig cochlea that show a level-dependent sharper tuning of the reticular lamina (RL) compared to BM tuning. To resolve this discrepancy, we propose the existence of a mode of RL vibration that reflects the motion of the BM in a more basal cochlear region at a fixed distance. This mode of vibration can account for sharper RL than BM tuning in the 18 kHz region through a phase cancellation mechanism and we show this numerically using a linear nonlocal model that relates RL and BM vibrations. The suggested phase cancellation mechanism results in a mode that enhances RL vibrations at high-frequencies (above 10 kHz), but that leaves lower-frequency responses unaffected in agreement with the differences observed in the high (~18 kHz; guinea pig) vs lower (~8 kHz; chinchilla) frequency cochlear mechanics. Additionally, the proposed linear model is capable of capturing the apparent nonlinear relationship between RL and BM motion. We propose a description of BM-RL-IHC transduction that is based on previous BM and IHC models, combined with (i) frequency dependent stereocilia low-pass filtering and (ii) a feedforward model of RL motion, and demonstrate that it can account for well-documented relationships between mechanical and neural tuning. We lastly point out that established functional models of the IHC/auditory-nerve complex tend to overestimate the neural response to lowfrequency stimuli, resulting from an excessive low-pass filtering in the IHC stage. Funding Work supported by Aalto ELEC doctoral school and DFG Cluster of Excellence EXC 1077/1 "Hearing4all".
Verhulst, S., Jagadeesh, A., Mauermann, M., and Ernst, F., Amplitude-Modulation Detection in Noise: Relation to Subcomponents of Peripheral Hearing Loss, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
AbstractFull Text
and aging can reduce the number and types of auditorynerve fibers responsible for a robust coding of sound to the auditory brainstem. Even though a temporal coding deficit associated with auditory-nerve and brainstem processing has been linked to degraded amplitude-modulation detection in listeners with normal audiometric thresholds, it is not clear how these supra-threshold hearing deficits interact with the outer-hair-cell-loss component of hearing loss. As listeners with elevated audiometric thresholds likely suffer from a mixture of peripheral pathologies, it is important to understand which of the hearing deficits is perceptually more dominant in specific listening conditions. The present study separated cochlear mechanical hearing deficits derived from DPOAE growth functions from brainstem coding fidelity measures (ABR and EFR) in listeners with normal and mildly-sloping audiograms, and compared these metrics to psychoacoustic amplitude-modulation (AM) detection performance. Specifically, we adopted a differential paradigm in which we tested how badly various types of masking noises impact AM detection performance. The fixedlevel wideband noise masker condition was designed to inform about how auditory filter widening and coding fidelity impact AM detection performance. In the second, narrowband masker (40Hz), condition, we expected performance to be limited by temporal coding fidelity within a single auditory filter. AM detection thresholds to 65 and 70 dB SPL, 100-Hzmodulated 4-kHz pure tones were measured in 18 listeners in the quiet and two masker conditions. Two stimulus configurations were considered for the elevated-threshold group: in the first, stimulus levels were adjusted according to equal sensation level (SL); in the second, stimulus levels were kept constant. AM detection performance in quiet was similar for both the elevated-threshold and normal-threshold group when stimuli were presented at equal SL. For that same condition, AM thresholds were significantly more robust against the broadband noise in the elevated-threshold group. However, for the fixed level condition, AM detection was significantly worse in the elevated-threshold group and the broadband noise degraded AM detection more in the normal-hearing group. The narrowband masker impacted both groups similarly in the equal SL condition, but had nearly no effect on the elevated-threshold group when stimuli were presented at fixed levels. We are currently further relating the psychoacoustic results to the recorded physiological metrics to elucidate which subcomponents of peripheral hearing loss are responsible for AM detection performance in the different masker conditions. Funding DFG Cluster of Excellence EXC 1077/1 "Hearing4all"
Savin, C., Monk, T., and Lücke, J., Intrinsic plasticity for optimal learning of variable stimulus intensities, Int. Conf. Computational Systems Neuroscience (COSYNE). 2016.
Abstract
In many situations the meaning of a stimulus is the same despite fluctuations in its overall strength. A visual scene’s content does not depend on light intensity, or a word utterance should be recognised irrespective of its loudness. Nonetheless, gain fluctuations are an integral part of the input statistics and they can help differentiate between stimuli. In the visual domain, for instance objects of the same class are likely to have similar surface properties, resulting in a distinct distribution of light intensities. Light intensities can therefore help identify objects. The neural underpinnings of such computation are unclear. Existing models discard gain information by ad hoc preprocessing (Nessler, 2009; Keck, 2012) or by divisive normalisation (Schwarz, 2001) before learning the input statistics from normalized data. Overall, it is unknown how neural circuits can robustly extract statistical regularities in their inputs when the overall intensity of stimuli is variable. Here we develop a principled account of unsupervised learning in the face of gain variations. We introduce a novel generative mixture model (Product- Poisson-Gamma) that explicitly models the statistics of stimulus intensity, and we derive a biologically-plausible neural circuit implementation for inference and learning in this model. We find that explicitly taking into account gain variations improves the robustness of unsupervised learning, as differences in input strength help distinguish between classes with similar features but different gain statistics. From a biological perspective, the derived neural circuit, in which feature-sensitive neurons are equipped with a specific form of intrinsic plasticity (IP), provides novel insights into the interaction between Hebbian and IP during learning. Furthermore, our results imply that neural excitability reflects nontrivial input statistics, in particular the intensity of the features to which a neuron is sensitive.
Schulze, J., Nolte, L., Lyutenski, S., Tinne, N., Ripken, T., Willaredt, M., Nothwang, H. G., Lenarz, T., and Warnecke, A., Combination of SLOT and Immunohistochemistry to Define Complex Morphological Phenotype Changes in Cochlear Structures, Exemplary Shown on Cav1.3 Knock-Out Mice, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2016.
AbstractFull Text
Overview The present study focuses on the identification of morphological differences of Cav1.3 knock-out mice in comparison to wild type mice by application of different methods. Cav1.3 knock-out mice lack the voltage-gated L-type Ca2+ channels Cav1.3. This channel controls vesicle fusion and subsequent neurotransmitter release from cochlear inner hair cells to afferent auditory nerve fibers. Cav1.3 knock-out mice display a developmental failure of cochlear structures. This study aimed at the characterization of early and late stage of the degenerative process in the inner ear in order to identify suitable time-point for therapeutic interventions concerning preservation of hair cell function and regeneration of the auditory nerve. Methods Wild type mice and knock-out mice were used for the isolation of the cochleae and fixed by immersion of PFA (4%). For immunocytochemistry, the cochleae were dissected into basal, medial and apical sections and these were stained with CtBP2, Otoferlin and DAPI for counting the number of synaptic ribbons per inner hair cell. For scanning laser optical tomography (SLOT), decalcification, dehydration, optical clearing and antibody staining of the whole cochlea were performed. For visualization of myelinated nerve fibers, the cochleae were stained with osmium. Results Coupling of SLOT and immunocytochemistry allowed the overview of whole cochleae to show specific anatomical structures and selective mapping of cellular structures (hair cells and afferent nerve fibers respectively). Accordingly, the number of synaptic ribbons in the Cav1.3 knock-out mice is decreased along the different cochlear turns compared to wild type mice as shown previously. The decrease starts around postnatal day (P) 9 in the basal and medial turn of the cochlea and around P20 in the apical turn. A slightly reduced myelination and density of afferent auditory fibers was shown by osmium staining of the cochlea at P18 Conclusions This study reveals that SLOT is a suitable tool in the field of otology for in toto visualization of the internal structure of the cochlea. By means of the different methods, we showed that the degenerative processes start as early as P9 in the basal and medial turn of the cochleae of Cav1.3 knock-out mice and proceed to the apical turn at about P20. Funding Cluster of Excellence “Hearing4all”
Schulze, J., Nolte, L., Lyutenski, S., Tinne, N., Ripken, T., Willaredt, M., Nothwang, H. G., , T., and , Molekulare und morphologische Veränderungen in den Cochleae von Cav1.3 Knockout-Mäusen, Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohrenheilkunde. 2016.
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Schlüter, T., Rosengauer, E., Steel, K., and Nothwang, H. G., Essential role of miR-96, Forum of Neuroscience (FENS). 2016.
Abstract
Wortelen, B., Unni, A., Rieger, J. W., and Lüdtke, A., Towards the Integration and evaluation of online workload measures in a cognitive architecture, 7th IEEE Conference on Cognitive Infocommunications. 2016.
Noack, M. and Richter-Landsberg, C., Activation of autophagy by rapamycin does not protect oligodendrocytes against protein aggregate formation and cell death induced by proteasomal inhibition, Journal of molecular neuroscience : JMN online, vol. 55.2015, no. 1. 2015.
Abstract DOIFull Text
Rod outer segment guanylate cyclase 1 (ROS-GC1) is a pivotal enzyme for vertebrate phototransduction and the systematically growing evidence point to its connection with processes other than phototransduction within and outside the retina. ROS-GC1 activity is regulated by Ca2+ in two opposite modes. This regulation is indirect and occurs through Ca2+-binding proteins. At nanomolar Ca2+ concentrations, ROS-GC1 is activated by GCAPs and at micromolar Ca2+-concentrations, by S100β and neurocalcin. The former mode operates in phototransduction and the latter was proposed to play a role in synaptic activity. The last possibility was supported by findings of ROS-GC1 expression not only in various retinal layers other than photoreceptor outer segments but also outside the retina, in pineal gland and olfactory bulb. If ROS-GC1 indeed is to play a role in neurotransmission its expression must be colocalized with its Ca2+-dependent regulators and with possible targets of an increased cyclic GMP concentration, cyclic nucleotide-gated channels or cyclic GMP-dependent protein kinase, in synaptic regions. In this review these aspects of ROS-GC1 expression in retina, pineal gland and olfactory bulb are discussed.
Leyk, J., Goldbaum, O., Noack, M., and Richter-Landsberg, C., Inhibition of HDAC6 modifies tau inclusion body formation and impairs autophagic clearance, Journal of molecular neuroscience : JMN online, vol. 55.2015, no. 4. 2015.
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Wilken, S., Wilkens, V., Scheunemann, D., Nowak, R. -E., Maydell, K. von, Parisi, J., and Borchert, H., Semitransparent polymer-based solar cells with aluminum-doped zinc oxide electrodes, ACS applied materials & interfaces / American Chemical Society, vol. 7.2015, no. 1. 2015.
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Noack, M. and Richter-Landsberg, C., Activation of autophagy by rapamycin does not protect oligodendrocytes against protein aggregate formation and cell death induced by proteasomal inhibition, Journal of molecular neuroscience : JMN online, vol. 55.2015, no. 1. 2015.
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Leyk, J., Goldbaum, O., Noack, M., and Richter-Landsberg, C., Inhibition of HDAC6 modifies tau inclusion body formation and impairs autophagic clearance, Journal of molecular neuroscience : JMN online, vol. 55.2015, no. 4. 2015.
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Wilken, S., Wilkens, V., Scheunemann, D., Nowak, R. -E., Maydell, K. von, Parisi, J., and Borchert, H., Semitransparent polymer-based solar cells with aluminum-doped zinc oxide electrodes, ACS applied materials & interfaces / American Chemical Society, vol. 7.2015, no. 1. 2015.
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Dell'Orco, D. and Koch, K. -W., Transient complexes between dark rhodopsin and transducin: circumstantial evidence or physiological necessity?, Biophysical journal, vol. 108, no. 3. Feb.-2015.
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Marino, V., Scholten, A., Koch, K. -W., and Dell'Orco, D., Two retinal dystrophy-associated missense mutations in GUCA1A with distinct molecular properties result in a similar aberrant regulation of the retinal guanylate cyclase, Human molecular genetics. Sep.-2015.
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Sulmann, S., Vocke, F., Scholten, A., and Koch, K. -W., Retina specific GCAPs in zebrafish acquire functional selectivity in Ca2+-sensing by myristoylation and Mg2+-binding, Scientific reports, vol. 5. 2015.
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Marino, V., Sulmann, S., Koch, K. -W., and Dell'Orco, D., Structural effects of Mg²⁺ on the regulatory states of three neuronal calcium sensors operating in vertebrate phototransduction, Biochimica et biophysica acta, vol. 1853, no. 9. Sep.-2015.
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Robin, J., Brauer, J., Sulmann, S., Marino, V., Dell'Orco, D., Lienau, C., and Koch, K. -W., Differential Nanosecond Protein Dynamics in Homologous Calcium Sensors, ACS chemical biology, vol. 10, no. 10. Oct.-2015.
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Tena-Campos, M., Ramon, E., Lupala, C. S., Pérez, J. J., Koch, K. -W., and Garriga, P., Zinc Is Involved in Depression by Modulating G Protein-Coupled Receptor Heterodimerization, Molecular neurobiology. Apr.-2015.
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Sulmann, S., Vocke, F., Scholten, A., and Koch, K. -W., Erratum: Retina specific GCAPs in zebrafish acquire functional selectivity in Ca(2+)-sensing by myristoylation and Mg(2+)-binding, Scientific reports, vol. 5. 2015.
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Zernii, E. Y., Grigoriev, I. I., Nazipova, A. A., Scholten, A., Kolpakova, T. V., Zinchenko, D. V., Kazakov, A. S., Senin, I. I., Permyakov, S. E., Dell'Orco, D., Philippov, P. P., and Koch, K. -W., Regulatory function of the C-terminal segment of guanylate cyclase-activating protein 2, Biochimica et biophysica acta, vol. 1854, no. 10 Pt A. Oct.-2015.
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Tulli, D., Hart, S. D., Mazumder, P., Carrilero, A., Tian, L., Koch, K. -W., Yongsunthon, R., Piech, G. A., and Pruneri, V., Correction to Monolithically integrated micro- and nanostructured glass surface with antiglare, antireflection, and superhydrophobic properties, ACS applied materials & interfaces, vol. 7, no. 18. May-2015.
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Lee, S. C. S., Meyer, A., Schubert, T., Hüser, L., Dedek, K., and Haverkamp, S., Morphology and connectivity of the small bistratified A8 amacrine cell in the mouse retina, J. Comp. Neurol., vol. 523, no. 10. Wiley-Blackwell, pp. 1529-1547, 10-Mar.-2015.
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Bolte, P., Herrling, R., Dorgau, B., Schultz, K., Feigenspan, A., Weiler, R., Dedek, K., and Janssen-Bienhold, U., Expression and Localization of Connexins in the Outer Retina of the Mouse, J Mol Neurosci, vol. 58, no. 2. Springer Science + Business Media, pp. 178-192, 9-Oct.-2015.
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Dorgau, B., Herrling, R., Schultz, K., Greb, H., Segelken, J., Ströh, S., Bolte, P., Weiler, R., Dedek, K., and Janssen-Bienhold, U., Connexin50 couples axon terminals of mouse horizontal cells by homotypic gap junctions, J. Comp. Neurol., vol. 523, no. 14. Wiley-Blackwell, pp. 2062-2081, 14-May-2015.
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Sienknecht, U. J., Current concepts of hair cell differentiation and planar cell polarity in inner ear sensory organs, Cell and Tissue Research, vol. 361, no. 1. Springer Science + Business Media, pp. 25-32, 12-May-2015.
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Bendixen, A., Duwe, S., and Reiche, M., Noise occlusion in discrete tone sequences as a tool towards auditory predictive processing?, Brain research, vol. 1626. pp. 97-107, Nov.-2015.
Abstract DOI
The notion of predictive coding is a common feature of many theories of auditory information processing. Experimental demonstrations of predictive auditory processing often rest on omitting predictable input in order to uncover the prediction made by the brain. Findings show that auditory cortical activity elicited by the omission of a predictable tone resembles the activity elicited by the actual tone. Here we attempted to extend this approach towards using noises instead of omissions in order to capture a more prevalent case of degraded sensory input. By applying a subtraction approach to remove ERP effects of the noise itself, auditory cortical activity elicited "behind" the noise was uncovered. We hypothesized that ERPs elicited behind noise stimuli covering predictable tones should be more similar to ERPs elicited by the actual tones than when the same comparison is made for unpredictable tones. ERP results during passive listening partly confirm this hypothesis, but also point towards some methodological caveats in this particular approach towards studying neural correlates of predictive auditory processing due to contributions from predictability-unrelated factors. A follow-up active listening condition indicated that participants were not more likely to perceive the tone sequence as continuous when a predictable tone was covered with noise than when this pertained to an unpredictable tone. Overall, the noise-based paradigm in its present form was not shown to be successful in revealing predictive processing in perceptual judgments or early neural correlates of sound processing. We discuss these findings in the contexts of predictive processing and illusory auditory continuity. This article is part of a Special Issue entitled SI: Prediction and Attention
Bauer, A. -K. R., Jaeger, M., Thorne, J. D., Bendixen, A., and Debener, S., The auditory dynamic attending theory revisited: A closer look at the pitch comparison task, Brain research, vol. 1626. pp. 198-210, Nov.-2015.
Abstract DOI
The dynamic attending theory as originally proposed by Jones, 1976. Psychol. Rev. 83(5), 323-355 posits that tone sequences presented at a regular rhythm entrain attentional oscillations and thereby facilitate the processing of sounds presented in phase with this rhythm. The increased interest in neural correlates of dynamic attending requires robust behavioral indicators of the phenomenon. Here we aimed to replicate and complement the most prominent experimental implementation of dynamic attending (Jones et al., 2002. Psychol. Sci. 13(4), 313-319). The paradigm uses a pitch comparison task in which two tones, the initial and the last of a longer series, have to be compared. In-between the two, distractor tones with variable pitch are presented, at a regular pace. A comparison tone presented in phase with the entrained rhythm is hypothesized to lead to better behavioral performance. Aiming for a conceptual replication, four different variations of the original paradigm were created which were followed by an exact replication attempt. Across all five experiments, only 40 of the 140 tested participants showed the hypothesized pattern of an inverted U-shaped profile in task accuracy, and the group average effects did not replicate the pattern reported by Jones et al., 2002. Psychol. Sci. 13(4), 313-319 in any of the five experiments. However, clear evidence for a relationship between musicality and overall behavioral performance was found. This study casts doubt on the suitability of the pitch comparison task for demonstrating auditory dynamic attending. We discuss alternative tasks that have been shown to support dynamic attending theory, thus lending themselves more readily to studying its neural correlates. This article is part of a Special Issue entitled SI: Prediction and Attention
Bendixen, A., Háden, G. P., Németh, R., Farkas, D., Török, M., and Winkler, I., Newborn infants detect cues of concurrent sound segregation, Developmental neuroscience, vol. 37, no. 2. pp. 172-181, 2015.
Abstract DOI
Separating concurrent sounds is fundamental for a veridical perception of one's auditory surroundings. Sound components that are harmonically related and start at the same time are usually grouped into a common perceptual object, whereas components that are not in harmonic relation or have different onset times are more likely to be perceived in terms of separate objects. Here we tested whether neonates are able to pick up the cues supporting this sound organization principle. We presented newborn infants with a series of complex tones with their harmonics in tune (creating the percept of a unitary sound object) and with manipulated variants, which gave the impression of two concurrently active sound sources. The manipulated variant had either one mistuned partial (single-cue condition) or the onset of this mistuned partial was also delayed (double-cue condition). Tuned and manipulated sounds were presented in random order with equal probabilities. Recording the neonates' electroencephalographic responses allowed us to evaluate their processing of the sounds. Results show that, in both conditions, mistuned sounds elicited a negative displacement of the event-related potential (ERP) relative to tuned sounds from 360 to 400 ms after sound onset. The mistuning-related ERP component resembles the object-related negativity (ORN) component in adults, which is associated with concurrent sound segregation. Delayed onset additionally led to a negative displacement from 160 to 200 ms, which was probably more related to the physical parameters of the sounds than to their perceptual segregation. The elicitation of an ORN-like response in newborn infants suggests that neonates possess the basic capabilities of segregating concurrent sounds by detecting inharmonic relations between the co-occurring sounds
Biran, M. and Ruigendijk, E., Do case and gender information assist sentence comprehension and repetition for German- and Hebrew-speaking children?, Lingua, vol. 164. Elsevier BV, pp. 215-238, Sep.-2015.
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Wendt, D., Kollmeier, B., and Brand, T., How hearing impairment affects sentence comprehension: using eye fixations to investigate the duration of speech processing, Trends in hearing, vol. 19. 2015.
Abstract DOI
The main objective of this study was to investigate the extent to which hearing impairment influences the duration of sentence processing. An eye-tracking paradigm is introduced that provides an online measure of how hearing impairment prolongs processing of linguistically complex sentences; this measure uses eye fixations recorded while the participant listens to a sentence. Eye fixations toward a target picture (which matches the aurally presented sentence) were measured in the presence of a competitor picture. Based on the recorded eye fixations, the single target detection amplitude, which reflects the tendency of the participant to fixate the target picture, was used as a metric to estimate the duration of sentence processing. The single target detection amplitude was calculated for sentence structures with different levels of linguistic complexity and for different listening conditions: in quiet and in two different noise conditions. Participants with hearing impairment spent more time processing sentences, even at high levels of speech intelligibility. In addition, the relationship between the proposed online measure and listener-specific factors, such as hearing aid use and cognitive abilities, was investigated. Longer processing durations were measured for participants with hearing impairment who were not accustomed to using a hearing aid. Moreover, significant correlations were found between sentence processing duration and individual cognitive abilities (such as working memory capacity or susceptibility to interference). These findings are discussed with respect to audiological applications
Debener, S., Emkes, R., De Vos, M., and Bleichner, M., Unobtrusive ambulatory EEG using a smartphone and flexible printed electrodes around the ear, Scientific reports, vol. 5. p. 16743, 2015.
Abstract DOI
This study presents first evidence that reliable EEG data can be recorded with a new cEEGrid electrode array, which consists of ten electrodes printed on flexible sheet and arranged in a c-shape to fit around the ear. Ten participants wore two cEEGrid systems for at least seven hours. Using a smartphone for stimulus delivery and signal acquisition, resting EEG and auditory oddball data were collected in the morning and in the afternoon six to seven hours apart. Analysis of resting EEG data confirmed well-known spectral differences between eyes open and eyes closed conditions. The ERP results confirmed the predicted condition effects with significantly larger P300 amplitudes for target compared to standard tones, and a high test-retest reliability of the P300 amplitude (r > = .74). Moreover, a linear classifier trained on data from the morning session revealed similar performance in classification accuracy for the morning and the afternoon sessions (both > 70%). These findings demonstrate the feasibility of concealed and comfortable brain activity acquisition over many hours
Pohl, N. U., Klump, G. M., and Langemann, U., Effects of signal features and background noise on distance cue discrimination by a songbird, The Journal of experimental biology, vol. 218, no. Pt 7. pp. 1006-1015, Apr.-2015.
Abstract DOI
During the transmission of acoustic signals, the spectral and temporal properties of the original signal are degraded, and with increasing distance more and more echo patterns are imposed. It is well known that these physical alterations provide useful cues to assess the distance of a sound source. Previous studies in birds have shown that birds employ the degree of degradation of a signal to estimate the distance of another singing male (referred to as ranging). Little is known about how acoustic masking by background noise interferes with ranging, and if the number of song elements and stimulus familiarity affect the ability to discriminate between degraded and undegraded signals. In this study we trained great tits (Parus major L.) to discriminate between signal variants in two background types, a silent condition and a condition consisting of a natural dawn chorus. We manipulated great tit song types to simulate patterns of reverberation and degradation equivalent to transmission distances of between 5 and 160 m. The birds' responses were significantly affected by the differences between the signal variants and by background type. In contrast, stimulus familiarity or their element number had no significant effect on signal discrimination. Although background type was a significant main effect with respect to the response latencies, the great tits' overall performance in the noisy dawn chorus was similar to the performance in silence
Kranczioch, C. and Thorne, J. D., The beneficial effects of sounds on attentional blink performance: An ERP study, NeuroImage, vol. 117. Elsevier BV, pp. 429-438, Aug.-2015.
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Zich, C., Debener, S., Kranczioch, C., Bleichner, M. G., Gutberlet, I., and De Vos, M., Real-time EEG feedback during simultaneous EEG–fMRI identifies the cortical signature of motor imagery, NeuroImage, vol. 114. Elsevier BV, pp. 438-447, Jul.-2015.
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Zich, C., De Vos, M., Kranczioch, C., and Debener, S., Wireless EEG with individualized channel layout enables efficient motor imagery training, Clinical Neurophysiology, vol. 126, no. 4. Elsevier BV, pp. 698-710, Apr.-2015.
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Braun, N., Debener, S., Sölle, A., Kranczioch, C., and Hildebrandt, H., Biofeedback-based self-alert training reduces alpha activity and stabilizes accuracy in the Sustained Attention to Response Task, Journal of Clinical and Experimental Neuropsychology, vol. 37, no. 1. Informa UK Limited, pp. 16-26, 2-Jan.-2015.
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Zich, C., Debener, S., De Vos, M., Frerichs, S., Maurer, S., and Kranczioch, C., Lateralization patterns of covert but not overt movements change with age: An EEG neurofeedback study, NeuroImage, vol. 116. Elsevier BV, pp. 80-91, Aug.-2015.
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Januschowski, K., Krupp, C., Mueller, S., Hofmann, K., Schnichels, S., Hagemann, U., Spitzer, M. S., Bartz-Schmidt, K. -U., and Aisenbrey, S., Investigating short-term toxicity of melphalan in a model of an isolated and superfused bovine retina, Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 254, no. 1. Springer Science + Business Media, pp. 91-96, 3-Sep.-2015.
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Shah, S., Bantel, C., Ho, A., Kuehler, B., Childs, S., Towlerton, G., and Goodall, I., Different measures, different outcomes? Survey into the effectiveness of chronic pain clinics in a London tertiary referral center, Journal of Pain Research. Dove Medical Press Ltd., p. 477, Aug.-2015.
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Giuliano Heinen, C. P., Schmidt, T., and Kretschmer, T., Endoscopically Assisted Piriformis-to-Knee Surgery of Sciatic, Peroneal, and Tibial Nerves, Neurosurgery. Ovid Technologies (Wolters Kluwer Health), p. 1, Jan.-2015.
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Groß, S. and Philipsen, A., Konzeptualisierung der Psychotherapie bei ADHS und Sucht, SUCHT, vol. 61, no. 5. Hogrefe & Huber, pp. 311-318, Oct.-2015.
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Hoxhaj, E. and Philipsen, A., Psychotherapie bei ADHS im Erwachsenenalter: Eine Bestandsaufnahme, Zeitschrift für Psychiatrie, Psychologie und Psychotherapie, vol. 63, no. 1. Hogrefe & Huber, pp. 25-31, Jan.-2015.
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Bubl, E., Dörr, M., Riedel, A., Ebert, D., Philipsen, A., Bach, M., and Tebartz van Elst, L., Elevated Background Noise in Adult Attention Deficit Hyperactivity Disorder Is Associated with Inattention, PLoS ONE, vol. 10, no. 2. Public Library of Science (PLoS), p. e0118271, 18-Feb.-2015.
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Endres, D., Perlov, E., Maier, S., Feige, B., Nickel, K., Goll, P., Bubl, E., Lange, T., Glauche, V., Graf, E., Ebert, D., Sobanski, E., Philipsen, A., and Elst, L., Normal Neurochemistry in the Prefrontal and Cerebellar Brain of Adults with Attention-Deficit Hyperactivity Disorder, Frontiers in behavioral neuroscience, vol. 9. p. 242, 2015.
Abstract DOI
Attention-deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. In an attempt to extend earlier neurochemical findings, we organized a magnetic resonance spectroscopy (MRS) study as part of a large, government-funded, prospective, randomized, multicenter clinical trial comparing the effectiveness of specific psychotherapy with counseling and stimulant treatment with placebo treatment (Comparison of Methylphenidate and Psychotherapy Study). We report the baseline neurochemical data for the anterior cingulate cortex (ACC) and the cerebellum in a case-control setting. For the trial, 1,480 adult patients were contacted for participation, 518 were assessed for eligibility, 433 were randomized, and 187 were potentially eligible for neuroimaging. The control group included 119 healthy volunteers. Single-voxel proton MRS was performed. In the patient group, 113 ACC and 104 cerebellar spectra fulfilled all quality criteria for inclusion in statistical calculations, as did 82 ACC and 78 cerebellar spectra in the control group. We did not find any significant neurometabolic differences between the ADHD and control group in the ACC (Wilks' lambda test: p = 0.97) or in the cerebellum (p = 0.62). Thus, we were unable to replicate earlier findings in this methodologically sophisticated study. We discuss our findings in the context of a comprehensive review of other MRS studies on ADHD and a somewhat skeptical neuropsychiatric research perspective. As in other neuropsychiatric disorders, the unclear nosological status of ADHD might be an explanation for false-negative findings
Stropahl, M., Plotz, K., Schönfeld, R., Lenarz, T., Sandmann, P., Yovel, G., De Vos, M., and Debener, S., Cross-modal reorganization in cochlear implant users: Auditory cortex contributes to visual face processing, NeuroImage, vol. 121. Elsevier BV, pp. 159-170, Nov.-2015.
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Sandmann, P., Plotz, K., Hauthal, N., de Vos, M., Schönfeld, R., and Debener, S., Rapid bilateral improvement in auditory cortex activity in postlingually deafened adults following cochlear implantation, Clinical Neurophysiology, vol. 126, no. 3. Elsevier BV, pp. 594-607, Mar.-2015.
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Grüne, F., Kazmaier, S., Stolker, R. J., Visser, G. H., and Weyland, A., Carbon dioxide induced changes in cerebral blood flow and flow velocity: role of cerebrovascular resistance and effective cerebral perfusion pressure, J Cereb Blood Flow Metab, vol. 35, no. 9. SAGE Publications, pp. 1470-1477, 15-Apr.-2015.
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Thomas-Rueddel, D. O., Poidinger, B., Weiss, M., Bach, F., Dey, K., Häberle, H., Kaisers, U., Rüddel, H., Schädler, D., Scheer, C., Schreiber, T., Schürholz, T., Simon, P., Sommerer, A., Schwarzkopf, D., Weyland, A., Wöbker, G., Reinhart, K., and Bloos, F., Hyperlactatemia is an independent predictor of mortality and denotes distinct subtypes of severe sepsis and septic shock, Journal of Critical Care, vol. 30, no. 2. Elsevier BV, pp. 439.e1-439.e6, Apr.-2015.
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Koch, K. -W. and Dell’Orco, D., Protein and Signaling Networks in Vertebrate Photoreceptor Cells, Frontiers in Molecular Neuroscience, vol. 8. Frontiers Media SA, 17-Nov.-2015.
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Pukaß, K., Goldbaum, O., and Richter-Landsberg, C., Mitochondrial impairment and oxidative stress compromise autophagosomal degradation of α-synuclein in oligodendroglial cells, Journal of Neurochemistry, vol. 135, no. 1. Wiley-Blackwell, pp. 194-205, 12-Aug.-2015.
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Malishkevich, A., Leyk, J., Goldbaum, O., Richter-Landsberg, C., and Gozes, I., ADNP/ADNP2 expression in oligodendrocytes: implication for myelin-related neurodevelopment, J Mol Neurosci, vol. 57, no. 2. Springer Science + Business Media, pp. 304-313, 28-Aug.-2015.
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Wichmann, H., Vocke, F., Brinkhoff, T., Simon, M., and Richter-Landsberg, C., Cytotoxic Effects of Tropodithietic Acid on Mammalian Clonal Cell Lines of Neuronal and Glial Origin, Marine Drugs, vol. 13, no. 12. MDPI AG, pp. 7113-7123, 27-Nov.-2015.
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Pukaß, K. and Richter-Landsberg, C., Inhibition of UCH-L1 in oligodendroglial cells results in microtubule stabilization and prevents α-synuclein aggregate formation by activating the autophagic pathway: implications for multiple system atrophy, Frontiers in cellular neuroscience, vol. 9. p. 163, 2015.
Abstract DOI
α-Synuclein (α-syn) positive glial cytoplasmic inclusions (GCI) originating in oligodendrocytes (ODC) are a characteristic hallmark in multiple system atrophy (MSA). Their occurrence may be linked to a failure of the ubiquitin proteasome system (UPS) or the autophagic pathway. For proteasomal degradation, proteins need to be covalently modified by ubiquitin, and deubiquitinated by deubiquitinating enzymes (DUBs) before proteolytic degradation is performed. The DUB ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) is a component of the UPS, it is abundantly expressed in neuronal brain cells and has been connected to Parkinson's disease (PD). It interacts with α-syn and tubulin. The present study was undertaken to investigate whether UCH-L1 is a constituent of ODC, the myelin forming cells of the CNS, and is associated with GCIs in MSA. Furthermore, LDN-57444 (LDN), a specific UCH-L1 inhibitor, was used to analyze its effects on cell morphology, microtubule (MT) organization and the proteolytic degradation system. Towards this an oligodendroglial cell line (OLN cells), stably transfected with α-syn or with α-syn and GFP-LC3, to monitor the autophagic flux, was used. The data show that UCH-L1 is expressed in ODC derived from the brains of newborn rats and colocalizes with α-syn in GCIs of MSA brain sections. LDN treatment had a direct impact on the MT network by affecting tubulin posttranslational modifications, i.e., acetylation and tyrosination. An increase in α-tubulin detyrosination was observed and detyrosinated MT were abundantly recruited to the cellular extensions. Furthermore, small α-syn aggregates, which are constitutively expressed in OLN cells overexpressing α-syn, were abolished, and LDN caused the upregulation of the autophagic pathway. Our data add to the knowledge that the UPS and the autophagy-lysosomal pathway are tightly balanced, and that UCH-L1 and its regulation may play a role in neurodegenerative diseases with oligodendroglia pathology
Seiberlich, V., Bauer, N. G., Schwarz, L., Ffrench-Constant, C., Goldbaum, O., and Richter-Landsberg, C., Downregulation of the microtubule associated protein tau impairs process outgrowth and myelin basic protein mRNA transport in oligodendrocytes, Glia, vol. 63, no. 9. pp. 1621-1635, Sep.-2015.
Abstract DOI
Oligodendrocytes, the myelin forming cells of the CNS, are characterized by their numerous membranous extensions, which enwrap neuronal axons and form myelin sheaths. During differentiation oligodendrocytes pass different morphological stages, downregulate the expression of the proteoglycan NG2, and acquire major myelin specific proteins, such as myelin basic proteins (MBP) and proteolipid protein. MBP mRNA is transported in RNA granules along the microtubules (MTs) to the periphery and translated locally. MTs participate in the elaboration and stabilization of the myelin forming extensions and are essential for cellular sorting processes. Their dynamic properties are regulated by microtubule associated proteins (MAPs). The MAP tau is present in oligodendrocytes and involved in the regulation and stabilization of the MT network. To further elucidate the functional significance of tau in oligodendrocytes, we have downregulated tau by siRNA technology and studied the effects on cell differentiation and neuron-glia contact formation. The data show that tau knockdown impairs process outgrowth and leads to a decrease in MBP expression. Furthermore, MBP mRNA transport to distant cellular extensions is impaired and cells remain in the NG2 stage. In myelinating cocultures with dorsal root ganglion neurons, oligodendrocyte precursor cells after tau miR RNA lentiviral knockdown develop into NG2 positive cells with very long and thin processes, contacting axons loosely, but fail to form internodes. This demonstrates that tau is important for MBP mRNA transport and involved in process formation. The disturbance of the balance of tau leads to abnormalities in oligodendrocyte differentiation, neuron-glia contact formation and the early myelination process
Gozes, I., Baas, P. W., and Richter-Landsberg, C., International Meeting Molecular Neurodegeneration: News and Views in Molecular Neuroscience in Health and Disease. Delmenhorst, Germany, July 20–22, 2015, J Mol Neurosci, vol. 57, no. 2. Springer Science + Business Media, pp. 153-159, 29-Aug.-2015.
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Beutelmann, R., Laumen, G., Tollin, D., and Klump, G. M., Amplitude and phase equalization of stimuli for click evoked auditory brainstem responses, J. Acoust. Soc. Am., vol. 137, no. 1. Acoustical Society of America (ASA), pp. EL71-EL77, Jan.-2015.
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Li, J., Parisi, J., and Kolny-Olesiak, J., Synthesis of CuInS2-ZnS Alloyed Nanorods and Hybrid Nanostructures, MRS Proceedings, vol. 1780. Cambridge University Press (CUP), 2015.
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Borchert, H., Scheunemann, D., Frevert, K., Witt, F., Klein, A., and Parisi, J., Schottky Solar Cells with CuInS2 Nanocrystals as Absorber Material, Zeitschrift für Physikalische Chemie, vol. 229, no. 1-2. Walter de Gruyter GmbH, 28-Jan.-2015.
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Oehl, N., Knipper, M., Parisi, J., Plaggenborg, T., and Kolny-Olesiak, J., Size-Dependent Lattice Distortion in ε-Ag 3 Sn Alloy Nanoparticles , The Journal of Physical Chemistry C. American Chemical Society (ACS), p. 150611093527001, 11-Jun.-2015.
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Augustin, M., Fenske, D., Bardenhagen, I., Westphal, A., Knipper, M., Plaggenborg, T., Kolny-Olesiak, J., and Parisi, J., Manganese oxide phases and morphologies: A study on calcination temperature and atmospheric dependence, Beilstein journal of nanotechnology, vol. 6. pp. 47-59, 2015.
Abstract DOI
Manganese oxides are one of the most important groups of materials in energy storage science. In order to fully leverage their application potential, precise control of their properties such as particle size, surface area and Mn (x) (+) oxidation state is required. Here, Mn3O4 and Mn5O8 nanoparticles as well as mesoporous α-Mn2O3 particles were synthesized by calcination of Mn(II) glycolate nanoparticles obtained through an economical route based on a polyol synthesis. The preparation of the different manganese oxides via one route facilitates assigning actual structure-property relationships. The oxidation process related to the different MnO x species was observed by in situ X-ray diffraction (XRD) measurements showing time- and temperature-dependent phase transformations occurring during oxidation of the Mn(II) glycolate precursor to α-Mn2O3 via Mn3O4 and Mn5O8 in O2 atmosphere. Detailed structural and morphological investigations using transmission electron microscopy (TEM) and powder XRD revealed the dependence of the lattice constants and particle sizes of the MnO x species on the calcination temperature and the presence of an oxidizing or neutral atmosphere. Furthermore, to demonstrate the application potential of the synthesized MnO x species, we studied their catalytic activity for the oxygen reduction reaction in aprotic media. Linear sweep voltammetry revealed the best performance for the mesoporous α-Mn2O3 species
Altmann, L., Wang, X., Borchert, H., Kolny-Olesiak, J., Zielasek, V., Parisi, J., Kunz, S., and Bäumer, M., Influence of Sn content on the hydrogenation of crotonaldehyde catalysed by colloidally prepared PtSn nanoparticles, Physical chemistry chemical physics : PCCP, vol. 17, no. 42. pp. 28186-28192, Nov.-2015.
Abstract DOI
Bimetallic PtSn nanoparticles (NPs) of well-defined size and metal composition were prepared by means of colloidal methods. The mean particle diameter was about 2 nm for all samples irrespective of the Pt/Sn-ratio, which enables a systematic study of the influence of the composition on the catalytic properties while excluding particle size effects. The hydrogenation of crotonaldehyde was investigated as a reaction for which chemoselectivity is known to be a challenging task. Already very low atomic Sn contents (≈10%) were found to lead to a significantly improved activity which may be attributed to an electronic effect of Sn on Pt. For further increasing tin contents the activity decreased gradually. This trend was accompanied by a steady increase in selectivity towards the desired product (crotylalcohol). The results show that the highest crotylalcohol time yields can be obtained by using catalysts with an atomic Sn content of approximately 23%. In contrast, maximum crotylalcohol selectivities are achieved by using catalysts with a high tin content (>50%)
SPIE, Christoph Lienau plenary presentation: Ultrafast Coherent Charge Transfer in Solar Cells and Artificial Light Harvesting Systems: Toward Movies of Electronic Motion, SPIE Newsroom. SPIE-Intl Soc Optical Eng, 5-Mar.-2015.
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Christoffers, J., Freimuth, L., Rozzi, C., and Lienau, C., A Diaminoterephthalate–C60 Dyad: A New Material for Optoelectronic Applications, Synthesis, vol. 47, no. 09. Thieme Publishing Group, pp. 1325-1328, 18-Mar.-2015.
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Vogelsang, J., Robin, J., Nagy, B. J., Dombi, P., Rosenkranz, D., Schiek, M., Groß, P., and Lienau, C., Ultrafast Electron Emission from a Sharp Metal Nanotaper Driven by Adiabatic Nanofocusing of Surface Plasmons, Nano letters, vol. 15, no. 7. pp. 4685-4691, Jul.-2015.
Abstract DOI
We report photoelectron emission from the apex of a sharp gold nanotaper illuminated via grating coupling at a distance of 50 μm from the emission site with few-cycle near-infrared laser pulses. We find a fifty-fold increase in electron yield over that for direct apex illumination. Spatial localization of the electron emission to a nanometer-sized region is demonstrated by point-projection microscopic imaging of a silver nanowire. Our results reveal negligible plasmon-induced electron emission from the taper shaft and thus efficient nanofocusing of few-cycle plasmon wavepackets. This novel, remotely driven emission scheme offers a particularly compact source of ultrashort electron pulses of immediate interest for miniaturized electron microscopy and diffraction schemes with ultrahigh time resolution
Talebi, N., Sigle, W., Vogelgesang, R., Esmann, M., Becker, S. F., Lienau, C., and Aken, P. A., Excitation of Mesoscopic Plasmonic Tapers by Relativistic Electrons: Phase Matching versus Eigenmode Resonances, ACS nano, vol. 9, no. 7. pp. 7641-7648, Jul.-2015.
Abstract DOI
We investigate the optical modes in three-dimensional single-crystalline gold tapers by means of electron energy-loss spectroscopy. At the very proximity to the apex, a broad-band excitation at all photon energies from 0.75 to 2 eV, which is the onset for interband transitions, is detected. At large distances from the apex, though, we observe distinct resonances with energy dispersions roughly proportional to the inverse local radius. The nature of these phenomena is unraveled by finite difference time-domain simulations of the taper and an analytical treatment of the energy loss in fibers. Our calculations and the perfect agreement with our experimental results demonstrate the importance of phase-matching between electron field and radiative taper modes in mesoscopic structures. The local taper radius at the electron impact location determines the selective excitation of radiative modes with discrete angular momenta
Diederich, A., Books received for review (October 2014), Journal of Mathematical Psychology, vol. 64-65. Elsevier BV, p. 87, Feb.-2015.
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Diederich, A. and Colonius, H., The time window of multisensory integration: relating reaction times and judgments of temporal order, Psychological review, vol. 122, no. 2. pp. 232-241, Apr.-2015.
Abstract DOI
Even though visual and auditory information of 1 and the same event often do not arrive at the sensory receptors at the same time, due to different physical transmission times of the modalities, the brain maintains a unitary perception of the event, at least within a certain range of sensory arrival time differences. The properties of this "temporal window of integration" (TWIN), its recalibration due to task requirements, attention, and other variables, have recently been investigated intensively. Up to now, however, there has been no consistent definition of "temporal window" across different paradigms for measuring its width. Here we propose such a definition based on our TWIN model (Colonius & Diederich, 2004). It applies to judgments of temporal order (or simultaneity) as well as to reaction time (RT) paradigms. Reanalyzing data from Mégevand, Molholm, Nayak, & Foxe (2013) by fitting the TWIN model to data from both paradigms, we confirmed the authors' hypothesis that the temporal window in an RT task tends to be wider than in a temporal-order judgment (TOJ) task. This first step toward a unified concept of TWIN should be a valuable tool in guiding investigations of the neural and cognitive bases of this so-far-somewhat elusive concept
Alavash, M., Hilgetag, C. C., Thiel, C. M., and Gießing, C., Persistency and flexibility of complex brain networks underlie dual-task interference, Hum. Brain Mapp., vol. 36, no. 9. Wiley-Blackwell, pp. 3542-3562, 12-Jun.-2015.
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Breckel, T. P. K., Gießing, C., Gieseler, A., Querbach, S., Reuter, M., and Thiel, C. M., Nicotinergic Modulation of Attention-Related Neural Activity Differentiates Polymorphisms of DRD2 and CHRNA4 Receptor Genes, PLoS ONE, vol. 10, no. 6. Public Library of Science (PLoS), p. e0126460, 16-Jun.-2015.
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Dombrowe, I., Juravle, G., Alavash, M., Gießing, C., and Hilgetag, C. C., The Effect of 10 Hz Repetitive Transcranial Magnetic Stimulation of Posterior Parietal Cortex on Visual Attention, PLoS ONE, vol. 10, no. 5. Public Library of Science (PLoS), p. e0126802, 13-May-2015.
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Alavash, M., Doebler, P., Holling, H., Thiel, C. M., and Gießing, C., Is functional integration of resting state brain networks an unspecific biomarker for working memory performance?, NeuroImage, vol. 108. Elsevier BV, pp. 182-193, Mar.-2015.
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Li, P. H., Gauthier, J. L., Schiff, M., Sher, A., Ahn, D., Field, G. D., Greschner, M., Callaway, E. M., Litke, A. M., and Chichilnisky, E. J., Anatomical identification of extracellularly recorded cells in large-scale multielectrode recordings, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 35, no. 11. pp. 4663-4675, Mar.-2015.
Abstract DOI
This study combines for the first time two major approaches to understanding the function and structure of neural circuits: large-scale multielectrode recordings, and confocal imaging of labeled neurons. To achieve this end, we develop a novel approach to the central problem of anatomically identifying recorded cells, based on the electrical image: the spatiotemporal pattern of voltage deflections induced by spikes on a large-scale, high-density multielectrode array. Recordings were performed from identified ganglion cell types in the macaque retina. Anatomical images of cells in the same preparation were obtained using virally transfected fluorescent labeling or by immunolabeling after fixation. The electrical image was then used to locate recorded cell somas, axon initial segments, and axon trajectories, and these signatures were used to identify recorded cells. Comparison of anatomical and physiological measurements permitted visualization and physiological characterization of numerically dominant ganglion cell types with high efficiency in a single preparation
Freeman, J., Field, G. D., Li, P. H., Greschner, M., Gunning, D. E., Mathieson, K., Sher, A., Litke, A. M., Paninski, L., Simoncelli, E. P., and Chichilnisky, E. J., Mapping nonlinear receptive field structure in primate retina at single cone resolution, eLife, vol. 4. 2015.
Abstract DOI
The function of a neural circuit is shaped by the computations performed by its interneurons, which in many cases are not easily accessible to experimental investigation. Here, we elucidate the transformation of visual signals flowing from the input to the output of the primate retina, using a combination of large-scale multi-electrode recordings from an identified ganglion cell type, visual stimulation targeted at individual cone photoreceptors, and a hierarchical computational model. The results reveal nonlinear subunits in the circuity of OFF midget ganglion cells, which subserve high-resolution vision. The model explains light responses to a variety of stimuli more accurately than a linear model, including stimuli targeted to cones within and across subunits. The recovered model components are consistent with known anatomical organization of midget bipolar interneurons. These results reveal the spatial structure of linear and nonlinear encoding, at the resolution of single cells and at the scale of complete circuits
Strüber, D., Rach, S., Neuling, T., and Herrmann, C. S., On the possible role of stimulation duration for after-effects of transcranial alternating current stimulation, Front. Cell. Neurosci., vol. 9. Frontiers Media SA, 10-Aug.-2015.
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Hens, C., Dana, S. K., and Feudel, U., Extreme multistability: Attractor manipulation and robustness, Chaos (Woodbury, N.Y.), vol. 25, no. 5. p. 053112, May-2015.
Abstract DOI
The coexistence of infinitely many attractors is called extreme multistability in dynamical systems. In coupled systems, this phenomenon is closely related to partial synchrony and characterized by the emergence of a conserved quantity. We propose a general design of coupling that leads to partial synchronization, which may be a partial complete synchronization or partial antisynchronization and even a mixed state of complete synchronization and antisynchronization in two coupled systems and, thereby reveal the emergence of extreme multistability. The proposed design of coupling has wider options and allows amplification or attenuation of the amplitude of the attractors whenever it is necessary. We demonstrate that this phenomenon is robust to parameter mismatch of the coupled oscillators
Savin, D. V., Kuznetsov, A. P., Savin, A. V., and Feudel, U., Different types of critical behavior in conservatively coupled Henon maps, Physical review. E, Statistical, nonlinear, and soft matter physics, vol. 91, no. 6. p. 062905, Jun.-2015.
Abstract DOI
We study the dynamics of two conservatively coupled Hénon maps at different levels of dissipation. It is shown that the decrease of dissipation leads to changes in the structure of the parameter plane and the scenarios of transition to chaos compared to the case of infinitely strong dissipation. Particularly, the Feigenbaum line becomes divided into several fragments. Some of these fragments have critical points of different types, namely, of C and H type, as their terminal points. Also the mechanisms of formation of these Feigenbaum line ruptures are described
Joglekar, M., Feudel, U., and Yorke, J. A., Geometry of the edge of chaos in a low-dimensional turbulent shear flow model, Physical review. E, Statistical, nonlinear, and soft matter physics, vol. 91, no. 5. p. 052903, May-2015.
Abstract
We investigate the geometry of the edge of chaos for a nine-dimensional sinusoidal shear flow model and show how the shape of the edge of chaos changes with increasing Reynolds number. Furthermore, we numerically compute the scaling of the minimum perturbation required to drive the laminar attracting state into the turbulent region. We find this minimum perturbation to scale with the Reynolds number as Re(-2)
Bauer, J. M. and Diekmann, R., Protein and Older Persons, Clinics in geriatric medicine, vol. 31, no. 3. pp. 327-338, Aug.-2015.
Abstract DOI
An optimal protein intake is important for the preservation of muscle mass, functionality, and quality of life in older persons. In recent years, new recommendations regarding the optimal intake of protein in this population have been published. Based on the available scientific literature, 1.0 to 1.2 g protein/kg body weight (BW)/d are recommended in healthy older adults. In certain disease states, a daily protein intake of more than 1.2 g/kg BW may be required. The distribution of protein intake over the day, the amount per meal, and the amino acid profile of proteins are also discussed
Verlaan, S., Aspray, T. J., Bauer, J. M., Cederholm, T., Hemsworth, J., Hill, T. R., Mcphee, J. S., Piasecki, M., Seal, C., Sieber, C. C., Ter Borg, S., Wijers, S. L., and Brandt, K., Nutritional status, body composition, and quality of life in community-dwelling sarcopenic and non-sarcopenic older adults: A case-control study, Clinical nutrition (Edinburgh, Scotland). Nov.-2015.
Abstract
Sarcopenia, the age-related decrease in muscle mass, strength, and function, is a main cause of reduced mobility, increased falls, fractures and nursing home admissions. Cross-sectional and prospective studies indicate that sarcopenia may be influenced in part by reversible factors like nutritional intake. The aim of this study was to compare functional and nutritional status, body composition, and quality of life of older adults between age and sex-matched older adults with and without sarcopenia.In a multi-centre setting, non-sarcopenic older adults (n = 66, mean ± SD: 71 ± 4 y), i.e. Short Physical Performance Battery (SPPB): 11-12 and normal skeletal muscle mass index, were recruited to match 1:1 by age and sex to previously recruited adults with sarcopenia: SPPB 4-9 and low skeletal muscle mass index. Health-related quality of life, self-reported physical activity levels and dietary intakes were measured using the EQ-5D scale and index, Physical Activity Scale for the Elderly (PASE), and 3-day prospective diet records, respectively. Concentrations of 25-OH-vitamin D, α-tocopherol (adjusted for cholesterol), folate, and vitamin B-12 were assessed in serum samples.In addition to the defined components of sarcopenia, i.e. muscle mass, strength and function, reported physical activity levels and health-related quality of life were lower in the sarcopenic adults (p < 0.001). For similar energy intakes (mean ± SD: sarcopenic, 1710 ± 418; non-sarcopenic, 1745 ± 513, p = 0.50), the sarcopenic group consumed less protein/kg (-6%), vitamin D (-38%), vitamin B-12 (-22%), magnesium (-6%), phosphorus (-5%), and selenium (-2%) (all p < 0.05) compared to the non-sarcopenic controls. The serum concentration of vitamin B-12 was 15% lower in the sarcopenic group (p = 0.015), and all other nutrient concentrations were similar between groups.In non-malnourished older adults with and without sarcopenia, we observed that sarcopenia substantially impacted self-reported quality of life and physical activity levels. Differences in nutrient concentrations and dietary intakes were identified, which might be related to the differences in muscle mass, strength and function between the two groups. This study provides information to help strengthen the characterization of this geriatric syndrome sarcopenia and indicates potential target areas for nutritional interventions
Bauer, J. M. and Diekmann, R., Protein supplementation with aging, Current opinion in clinical nutrition and metabolic care, vol. 18, no. 1. pp. 24-31, Jan.-2015.
Abstract DOI
PURPOSE OF REVIEW: To highlight the recent evicence for optimal protein intake and protein supplementation in older adults. A special focus has been placed on the effects on muscle protein synthesis, strength and overall performance in this population. RECENT FINDINGS: Although for older adults, some additional evidence on the benefits of a higher protein intake than 0.8 g/kg body weight per day has been provided, the results of studies focusing on the timing of protein intake over the day have been contradictory. Supplementation with so-called 'fast' proteins, which are also rich in leucine, for example whey protein, proved superior with regard to muscle protein synthesis. First studies in frail older persons showed increased strength after supplementation with milk protein, whereas the combination with physical exercise increased muscle mass without additional benefit for strength or functionality. SUMMARY: Recent evidence suggests positive effects of protein supplementation on muscle protein synthesis, muscle mass and muscle strength. However, as most studies included only small numbers of participants for short treatment periods, larger studies with longer duration are necessary to support the clinical relevance of these observations
Sanford, A. M., Orrell, M., Tolson, D., Abbatecola, A. M., Arai, H., Bauer, J. M., Cruz-Jentoft, A. J., Dong, B., Ga, H., Goel, A., Hajjar, R., Holmerova, I., Katz, P. R., Koopmans, R. T. C. M., Rolland, Y., Visvanathan, R., Woo, J., Morley, J. E., and Vellas, B., An international definition for "nursing home", Journal of the American Medical Directors Association, vol. 16, no. 3. pp. 181-184, Mar.-2015.
Abstract DOI
There is much ambiguity regarding the term "nursing home" in the international literature. The definition of a nursing home and the type of assistance provided in a nursing home is quite varied by country. The International Association of Gerontology and Geriatrics and AMDA foundation developed a survey to assist with an international consensus on the definition of "nursing home."
Latus, H., Hachmann, P., Gummel, K., Khalil, M., Yerebakan, C., Bauer, J. M., Schranz, D., and Apitz, C., Impact of residual right ventricular outflow tract obstruction on biventricular strain and synchrony in patients after repair of tetralogy of Fallot: a cardiac magnetic resonance feature tracking study, European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, vol. 48, no. 1. pp. 83-90, Jul.-2015.
Abstract DOI
Residual right ventricular outflow tract (RVOT) obstruction (RVOTO) is considered beneficial in patients after repair of tetralogy of Fallot (TOF) although underlying mechanisms are unknown. We sought to elucidate differences in myocardial strain and dyssynchrony parameters in patients after TOF repair with and without residual RVOTO using cardiovascular magnetic resonance (CMR) feature-tracking (CMR-FT) analysis.Fifty-four patients (mean age 16.4 ± 8.4 years) were assessed by CMR 14.2 ± 7.3 years after repair of TOF. Residual RVOTO on echocardiography was defined as a peak systolic RVOT gradient >25 mmHg and was present in 27 patients (no RVOTO in n = 27 patients). Right ventricular (RV) and left ventricular (LV) strain measurements were performed using CMR-FT software.The two groups were well matched for age at CMR scan, time and type of surgical repair. There was no difference in the degree of pulmonary regurgitation (PR) and RV end-diastolic volume. Patients with RVOTO showed significant higher RV circumferential strain (CS) (P = 0.02) and RV radial strain (RS) (P = 0.02) values, whereas RV longitudinal strain (LS) did not differ between the two groups (P = 0.39). The degree of RVOTO showed a significant correlation with RV-CS (r = 0.37; P = 0.006) and RV-RS (r = 0.30; P = 0.03) while RV-LS was unrelated to RVOTO (r = 0.06; P = 0.68). Significant relationships between RV and LV strain parameters were only found in the RVOTO group. Interventricular dyssynchrony was significantly higher in the group without RVOTO (P = 0.03) while LV-LS (P = 0.03) and LV intraventricular synchrony (P = 0.05) were impaired in the RVOTO group.In patients after TOF repair, residual RVOTO seems to preserve RV strain and results in stronger RV-LV interactions and less interventricular dyssynchrony and may therefore possess an early protective effect on RV remodelling. However, the potential negative impact of residual pulmonary stenosis on LV strain and intraventricular synchrony needs further investigation
Alert, B., Michalik, A., Thiele, N., Bottesch, M., and Mouritsen, H., Re-calibration of the magnetic compass in hand-raised European robins (Erithacus rubecula), Scientific reports, vol. 5. p. 14323, 2015.
Abstract DOI
Migratory birds can use a variety of environmental cues for orientation. A primary calibration between the celestial and magnetic compasses seems to be fundamental prior to a bird's first autumn migration. Releasing hand-raised or rescued young birds back into the wild might therefore be a problem because they might not have established a functional orientation system during their first calendar year. Here, we test whether hand-raised European robins that did not develop any functional compass before or during their first autumn migration could relearn to orient if they were exposed to natural celestial cues during the subsequent winter and spring. When tested in the geomagnetic field without access to celestial cues, these birds could orient in their species-specific spring migratory direction. In contrast, control birds that were deprived of any natural celestial cues throughout remained unable to orient. Our experiments suggest that European robins are still capable of establishing a functional orientation system after their first autumn. Although the external reference remains speculative, most likely, natural celestial cues enabled our birds to calibrate their magnetic compass. Our data suggest that avian compass systems are more flexible than previously believed and have implications for the release of hand-reared migratory birds
Alert, B., Michalik, A., Helduser, S., Mouritsen, H., and Güntürkün, O., Perceptual strategies of pigeons to detect a rotational centre--a hint for star compass learning?, PloS one, vol. 10, no. 3. p. e0119919, 2015.
Abstract DOI
Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy
Lefeldt, N., Dreyer, D., Schneider, N. -L., Steenken, F., and Mouritsen, H., Migratory blackcaps tested in Emlen funnels can orient at 85 degrees but not at 88 degrees magnetic inclination, The Journal of experimental biology, vol. 218, no. Pt 2. pp. 206-211, Jan.-2015.
Abstract DOI
Migratory birds are known to use the Earth's magnetic field as an orientation cue on their tremendous journeys between their breeding and overwintering grounds. The magnetic compass of migratory birds relies on the magnetic field's inclination, i.e. the angle between the magnetic field lines and the Earth's surface. As a consequence, vertical or horizontal field lines corresponding to 0 or 90 deg inclination should offer no utilizable information on where to find North or South. So far, very little is known about how small the deviations from horizontal or vertical inclination are that migratory birds can detect and use as a reference for their magnetic compass. Here, we asked: what is the steepest inclination angle at which a migratory bird, the Eurasian blackcap (Sylvia atricapilla), can still perform magnetic compass orientation in Emlen funnels? Our results show that blackcaps are able to orient in an Earth's strength magnetic field with inclination angles of 67 and 85 deg, but fail to orient in a field with 88 deg inclination. This suggests that the steepest inclination angle enabling magnetic compass orientation in migratory blackcaps tested in Emlen funnels lies between 85 and 88 deg
Liebmann, M., Poppe, B., and Boetticher, H., Computed tomography dosimetry with high-resolution detectors commonly used in radiotherapy - an energy dependence study, Journal of applied clinical medical physics / American College of Medical Physics, vol. 16, no. 5. p. 5302, 2015.
Abstract
New methods of dosimetry in computed tomography (CT) X-ray fields require the use of high-resolution detectors instead of pencil-type ionization chambers typically used for CT dose index (CTDI) measurements. This paper presents a study on the suitability of a wide range of ionization chambers, diodes, and a two-dimensional detector array, used primarily in radiation therapy, for CT and cone-beam CT dosimetry. Specifically, the energy dependence of these detectors from 50 kVp up to 125 kVp is reported. All measurements were performed in reference to a calibrated diode for use in this energy region. The radiation quality correction factors provided by the manufacturer were used, depending on the measured half-value layer (HVL) for the particular X-ray beam. Our study demonstrated the general usability of thimble ionization chambers. These thimble ionization chambers showed a maximum variation in energy response of 5%. Ionization chambers with even smaller sensitive volume, and which exhibit similar variation in energy dependence, can be used if higher spatial resolution is required. Furthermore, the investigated detectors are better suited for dosimetry at CT and CBCT units than conventional large volume or flat detectors, due to their rotational symmetry. Nevertheless, a flat detector can be used for certain measurement tasks, such as the acquisition of percent depth-dose curves or beam profiles for nonrotating beams, which are important for beam characterization
Bendixen, A., Schwartze, M., and Kotz, S. A., Temporal dynamics of contingency extraction from tonal and verbal auditory sequences, Brain Lang., vol. 148. 2015.
Abstract DOIFull Text
Consecutive sound events are often to some degree predictive of each other. Here we investigated the brain’s capacity to detect contingencies between consecutive sounds by means of electroencephalography (EEG) during passive listening. Contingencies were embedded either within tonal or verbal stimuli. Contingency extraction was measured indirectly via the elicitation of the mismatch negativity (MMN) component of the event-related potential (ERP) by contingency violations. MMN results indicate that structurally identical forms of predictability can be extracted from both tonal and verbal stimuli. We also found similar generators to underlie the processing of contingency violations across stimulus types, as well as similar performance in an active-listening follow-up test. However, the process of passive contingency extraction was considerably slower (twice as many rule exemplars were needed) for verbal than for tonal stimuli These results suggest caution in transferring findings on complex predictive regularity processing obtained with tonal stimuli directly to the speech domain.
Özyurt, J., Mueller, H. L., and Thiel, C. M., A systematic review of cognitive performance in patients with childhood craniopharyngioma , JOURNAL OF NEURO-ONCOLOGY, vol. 125, no. 1. 2015.
Abstract
Craniopharyngiomas are rare brain tumors of the sellar/suprasellar region, often adversely affecting patients\\\\\\\\\\\\\\\' physical and psychosocial functioning. Until a few years ago, knowledge on cognitive deficits in craniopharyngioma patients was based on little valid evidence, with considerable inconsistencies across studies. Findings from recent research, with partly larger sample sizes, add to existing evidence to provide a more clear and reliable picture. The current review aims to summarize and systemize current findings on cognitive deficits in childhood craniopharyngioma, taking account of patient- and treatment-related variables where possible. Those studies were included that reported results of childhood craniopharyngioma patients tested with formalized neuropsychological tests (irrespective of their age at study, group size a parts per thousand yen10). A systematic assignment of test results to subcomponents of broader cognitive domains (e.g. to specific memory systems and processes) allows for a first comprehensive overview of patterns of spared and impaired cognitive functions. We show that episodic memory recall in particular is impaired, largely sparing other memory components. In accordance with recent knowledge on mammillary function, patients with hypothalamic involvement appear to be at particular risk. Deficits in higher cognitive processes, relying on the integrity of the prefrontal cortex and its subcortical pathways, may also occur, but results are still inconsistent. To gain deeper insight into the pattern of deficits and their association with patient- and treatment-related variables, further multi-site research with larger cohorts is needed.
Ahrens, S., Markett, S., Breckel, T. P. K., Behler, O., Reuter, M., and Thiel, C. M., Modulation of nicotine effects on selective attention by DRD2 and CHRNA4 gene polymorphisms, Psychopharmacology, vol. 232, no. 13. 2015.
Abstract
Alavash, M., Hilgetag, C. C., Thiel, C. M., and Gießing, C., Persistency and flexibility of complex brain networks underlie dual-task interference, Hum. Brain Mapp., vol. 36, no. 9. 2015.
Abstract
Previous studies on multitasking suggest that performance decline during concurrent task processing arises from interfering brain modules. Here, we used graph-theoretical network analysis to define functional brain modules and relate the modular organization of complex brain networks to behavioral dual-task costs. Based on resting-state and task fMRI we explored two organizational aspects potentially associated with behavioral interference when human subjects performed a visuospatial and speech task simultaneously: the topological overlap between persistent single-task modules, and the flexibility of single-task modules in adaptation to the dual-task condition. Participants showed a significant decline in visuospatial accuracy in the dual-task compared with single visuospatial task. Global analysis of topological similarity between modules revealed that the overlap between single-task modules significantly correlated with the decline in visuospatial accuracy. Subjects with larger overlap between single-task modules showed higher behavioral interference. Furthermore, lower flexible reconfiguration of single-task modules in adaptation to the dual-task condition significantly correlated with larger decline in visuospatial accuracy. Subjects with lower modular flexibility showed higher behavioral interference. At the regional level, higher overlap between single-task modules and less modular flexibility in the somatomotor cortex positively correlated with the decline in visuospatial accuracy. Additionally, higher modular flexibility in cingulate and frontal control areas and lower flexibility in right-lateralized nodes comprising the middle occipital and superior temporal gyri supported dual-tasking. Our results suggest that persistency and flexibility of brain modules are important determinants of dual-task costs. We conclude that efficient dual-tasking benefits from a specific balance between flexibility and rigidity of functional brain modules.
Colonius, H. and Diederich, A., A new measure of multisensory integration in a single neuron based on dependent probability summation, arXiv, vol. arXiv:1507.08505 [q-bio.NC]. 2015.
Abstract DOIFull Text
A neuron from the deep layers of the superior colliculus, is categorized as \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"multisensory\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\" if it responds to both unisensory and multisensory stimulation. However, being responsive to multiple sensory modalities does not guarantee that a neuron has actually engaged in integrating its multiple sensory inputs rather than simply responding to the most salient stimulus. A common response measure for both uni- and crossmodal stimulation is the mean, or the absolute number, of impulses (spikes) registered within a fixed time interval after stimulus presentation. The traditional criterion for identifying \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"multisensory enhancement\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\" is a statistically significant increase of the response measure elicited by a crossmodal stimulus compared to the value of the response measure to the most effective of the individual components. Here we propose a probabilistic foundation for a slightly modified criterion and argue that it is more powerful than the traditional criterion.
Medina, J. M., Wong, W., Díaz, J. A., and Colonius, H., Advances in modern mental chronometry, Front. Hum. Neurosci., vol. 9. 2015.
Abstract DOIFull Text
Colonius, H., Behavioral measures of multisensory integration: bounds on bimodal detection probability, Brain Topogr., vol. 28, no. 1. 2015.
Abstract DOIFull Text
One way to test and quantify multisensory integration in a behavioral paradigm is to compare bimodal detection probability with bounds defined by some combination of the unimodal detection probabilities. Here we (1) improve on an upper bound recently suggested by Stevenson et al. (Brain Topogr 27(6):707–730, 2014), (2) present a lower bound, (3) interpret the bounds in terms of stochastic dependency between the detection probabilities, (4) discuss some additional assumptions required for the validity of any such bound, (5) suggest some potential applications to neurophysiologic measures, and point out some parallels to the ‘race model inequality’ for reaction times.
Mendonça, C., Escher, A., van de Par, S., and Colonius, H., Predicting auditory space calibration from recent multisensory experience, Exp. Brain Res., vol. 233, no. 7. 2015.
Abstract DOIFull Text
Multisensory experience can lead to auditory space recalibration. After exposure to discrepant audiovisual stimulation, sound percepts are displaced in space, in the direction of the previous visual stimulation. This study focuses on identifying the factors in recent sensory experience leading to such auditory space shifts. Sequences of five audiovisual pairs were presented, each randomly congruent or discrepant in space. Each sequence was followed by a single auditory trial and two visual trials. In each trial, participants had to identify the perceived stimuli positions. We found that auditory localization is shifted during audiovisual discrepant trials and during subsequent auditory trials, suggesting a recalibration effect. Time did not lead to greater recalibration effects. The last audiovisual trial affects the subsequent auditory shift the most. The number of discrepant trials in a sequence, and the number of consecutive trials in sequence, also correlated with the subsequent auditory shift. To estimate the individual contribution of previously presented trials to the recalibration effect, a best-fitting model was developed to predict the shift in a linear weighted combination of stimulus features: (1) whether matching or discrepant trials occurred in the sequence, (2) total number of discrepant trials, and (3) maximum number of consecutive discrepant trials, (4) whether the last trial was discrepant or not. The selected model consists of a function including as properties the type of stimulus of the last audiovisual sequence trial and the overall probability of mismatching trials in sequence.
Chen, L. -C., Sandmann, P., Thorne, J. D., Herrmann, C. S., and Debener, S., Association of Concurrent fNIRS and EEG Signatures in Response to Auditory and Visual Stimuli, Brain Topogr., vol. 28, no. 5. 2015.
Abstract DOIFull Text
Functional near-infrared spectroscopy (fNIRS) has been proven reliable for investigation of low-level visual processing in both infants and adults. Similar investigation of fundamental auditory processes with fNIRS, however, remains only partially complete. Here we employed a systematic three-level validation approach to investigate whether fNIRS could capture fundamental aspects of bottom-up acoustic processing. We performed a simultaneous fNIRS-EEG experiment with visual and auditory stimulation in 24 participants, which allowed the relationship between changes in neural activity and hemoglobin concentrations to be studied. In the first level, the fNIRS results showed a clear distinction between visual and auditory sensory modalities. Specifically, the results demonstrated area specificity, that is, maximal fNIRS responses in visual and auditory areas for the visual and auditory stimuli respectively, and stimulus selectivity, whereby the visual and auditory areas responded mainly toward their respective stimuli. In the second level, a stimulus-dependent modulation of the fNIRS signal was observed in the visual area, as well as a loudness modulation in the auditory area. Finally in the last level, we observed significant correlations between simultaneously-recorded visual evoked potentials and deoxygenated hemoglobin (DeoxyHb) concentration, and between late auditory evoked potentials and oxygenated hemoglobin (OxyHb) concentration. In sum, these results suggest good sensitivity of fNIRS to low-level sensory processing in both the visual and the auditory domain, and provide further evidence of the neurovascular coupling between hemoglobin concentration changes and non-invasive brain electrical activity.
Bleichner, M. G., Lundbeck, M., Selisky, M., Minow, F., Jäger, M., Emkes, R., Debener, S., and De Vos, M., Exploring miniaturized EEG electrodes for brain-computer interfaces. An EEG you do not see?, Physiol. Rep., vol. 3, no. 4. 2015.
Abstract DOIFull Text
Electroencephalography (EEG) allows the study of the brain–behavior relationship in humans. Most of what we have learned with EEG was through observing the brain–behavior relationship under well‐controlled laboratory conditions. However, by reducing “normal” behavior to a minimum the ecological validity of the results can be limited. Recent developments toward mobile EEG solutions allow to study the brain–behavior relationship outside the laboratory in more natural situations. Besides mobility and robustness with respect to motion, mobile EEG systems should also interfere as little as possible with the participant\\\\\\\\\\\\\\\'s behavior. For example, natural interaction with other people could be hindered when it is obvious that a participant wears an EEG cap. This study evaluates the signal quality obtained with an unobtrusive solution for EEG monitoring through the integration of miniaturized EEG ton‐electrodes into both a discreet baseball cap and an individualized ear piece. We show that such mini electrodes located at scalp and ear locations can reliably record event related potentials in a P300 brain–computer–interface application.
Mirkovic, B., Debener, S., Jaeger, M., and De Vos, M., Decoding the attended speech stream with multi-channel EEG: implications for online, daily-life applications, J. Neural Eng., vol. 12, no. 4. 2015.
Abstract DOIFull Text
Objective. Recent studies have provided evidence that temporal envelope driven speech decoding from high-density electroencephalography (EEG) and magnetoencephalography recordings can identify the attended speech stream in a multi-speaker scenario. The present work replicated the previous high density EEG study and investigated the necessary technical requirements for practical attended speech decoding with EEG. Approach. Twelve normal hearing participants attended to one out of two simultaneously presented audiobook stories, while high density EEG was recorded. An offline iterative procedure eliminating those channels contributing the least to decoding provided insight into the necessary channel number and optimal cross-subject channel configuration. Aiming towards the future goal of near real-time classification with an individually trained decoder, the minimum duration of training data necessary for successful classification was determined by using a chronological cross-validation approach. Main results. Close replication of the previously reported results confirmed the method robustness. Decoder performance remained stable from 96 channels down to 25. Furthermore, for less than 15 min of training data, the subject-independent (pre-trained) decoder performed better than an individually trained decoder did. Significance. Our study complements previous research and provides information suggesting that efficient low-density EEG online decoding is within reach.
Bauer, A. -K. R., Kreutz, G., and Herrmann, C. S., Individual musical tempo preference correlates with EEG beta rhythm, Psychophysiology, vol. 52, no. 4. 2015.
Abstract DOIFull Text
Every individual has a preferred musical tempo, which peaks slightly above 120 beats per minute and is subject to interindividual variation. The preferred tempo is believed to be associated with rhythmic body movements as well as motor cortex activity. However, a long-standing question is whether preferred tempo is determined biologically. To uncover the neural correlates of preferred tempo, we first determined an individual\\\'s preferred tempo using a multistep procedure. Subsequently, we correlated the preferred tempo with a general EEG timing parameter as well as perceptual and motor EEG correlates-namely, individual alpha frequency, auditory evoked gamma band response, and motor beta activity. Results showed a significant relation between preferred tempo and the frequency of motor beta activity. These findings suggest that individual tempo preferences result from neural activity in the motor cortex, explaining the interindividual variation.
Escoffier, N., Herrmann, C. S., and Schirmer, A., Auditory rhythms entrain visual processes in the human brain: Evidence from evoked oscillations and event-related potentials, NeuroImage, vol. 111. 2015.
Abstract DOIFull Text
Temporal regularities in the environment are thought to guide the allocation of attention in time. Here, we explored whether entrainment of neuronal oscillations underpins this phenomenon. Participants viewed a regular stream of images in silence, or in-synchrony or out-of-synchrony with an unmarked beat position of a slow (1.3 Hz) auditory rhythm. Focusing on occipital recordings, we analyzed evoked oscillations shortly before and event-related potentials (ERPs) shortly after image onset. The phase of beta-band oscillations in the in-synchrony condition differed from that in the out-of-synchrony and silence conditions. Additionally, ERPs revealed rhythm effects for a stimulus onset potential (SOP) and the N1. Both were more negative for the in-synchrony as compared to the out-of-synchrony and silence conditions and their amplitudes positively correlated with the beta phase effects. Taken together, these findings indicate that rhythmic expectations are supported by a reorganization of neural oscillations that seems to benefit stimulus processing at expected time points. Importantly, this reorganization emerges from global rhythmic cues, across modalities, and for frequencies significantly higher than the external rhythm. As such, our findings support the idea that entrainment of neuronal oscillations represents a general mechanism through which the brain uses predictive elements in the environment to optimize attention and stimulus perception.
Neuling, T., Ruhnau, P., Fuscà, M., Demarchi, G., Herrmann, C. S., and Weisz, N., Friends, not foes: magnetoencephalography as a tool to uncover brain dynamics during transcranial alternating current stimulation, NeuroImage, vol. 118. 2015.
Abstract DOIFull Text
Brain oscillations are supposedly crucial for normal cognitive functioning and alterations are associated with cognitive dysfunctions. To demonstrate their causal role on behavior, entrainment approaches in particular aim at driving endogenous oscillations via rhythmic stimulation. Within this context, transcranial electrical stimulation, especially transcranial alternating current stimulation (tACS), has received renewed attention. This is likely due to the possibility of defining oscillatory stimulation properties precisely. Also, measurements comparing pre-tACS with post-tACS electroencephalography (EEG) have shown impressive modulations. However, the period during tACS has remained a blackbox until now, due to the enormous stimulation artifact. By means of application of beamforming to magnetoencephalography (MEG) data, we successfully recovered modulations of the amplitude of brain oscillations during weak and strong tACS. Additionally, we demonstrate that also evoked responses to visual and auditory stimuli can be recovered during tACS. The main contribution of the present study is to provide critical evidence that during ongoing tACS, subtle modulations of oscillatory brain activity can be reconstructed even at the stimulation frequency. Future tACS experiments will be able to deliver direct physiological insights in order to further the understanding of the contribution of brain oscillations to cognition and behavior.
Riecke, L., Formisano, E., Herrmann, C. S., and Sack, A. T., 4-Hz transcranial alternating current stimulation phase modulates hearing, Brain Stimul., vol. 8, no. 4. 2015.
Abstract
Vosskuhl, J., Huster, R. J., and Herrmann, C. S., Increase in short-term memory capacity induced by down-regulating individual theta frequency via transcranial alternating current stimulation, Front. Hum. Neurosci., vol. 8:257, no. 9. 2015.
Abstract
Dreyer, A. M. and Herrmann, C. S., Frequency-modulated steady-state visual evoked potentials: a new stimulation method for brain-computer interfaces, J. Neurosci. Methods, vol. 241. 2015.
Abstract
Background Steady-state visual evoked potentials (SSVEPs) are widely used for brain–computer interfaces. However, users experience fatigue due to exposure to flickering stimuli. High-frequency stimulation has been proposed to reduce this problem. We adapt frequency-modulated (FM) stimulation from the auditory domain, where it is commonly used to evoke steady-state responses, and compare the EEG as well as behavioral flicker perceptibility ratings. New method We evoke SSVEPs with a green light-emitting diode (LED) driven by FM signals. Results FM-SSVEPs with different carrier and modulation frequencies can reliably be evoked with spectral peaks at the lower FM sideband. Subjective perceptibility ratings decrease with increasing FM carrier frequencies, while the peak amplitude and signal-to-noise ratio (SNR) remain the same. Comparison with existing method There are neither amplitude nor SNR differences between SSVEPs evoked rectangularly, sinusoidally or via FM. Perceptibility ratings were lower for FM-SSVEPs with carrier frequencies of 20 Hz and above than for sinusoidally evoked SSVEPs. Conclusions FM-SSVEPs seem to be beneficial for BCI usage. Reduced flicker perceptibility in FM-SSVEPs suggests reduced fatigue, which leads to an enhanced user experience and performance.
Behrens, D. and Klump, G. M., Comparison of the sensitivity of prepulse inhibition of the startle reflex and operant conditioning in an auditory intensity difference limen paradigm, Hear. Res., vol. 321. 2015.
Abstract DOI
Reward-based operant conditioning (OC) procedures and reflex-based prepulse inhibition (PPI) procedures are used in mouse psychoacoustics. Therefore it is important to know whether both procedures provide comparable results for perceptual measurements. Here we evaluate the sensitivity of the C57BL/6N mouse in both procedures by testing the same individuals in the same Intensity Difference Limen (IDL) task. Level increments of a 10 kHz tone were presented in a train of 10 kHz reference tones. Objective analysis based on signal-detection theory was applied to compare the results of OC and PPI procedures. In both procedures the sensitivity increased with level increment. In agreement with the near miss to Weber\\\'s law, sensitivity increased with sound level of the reference stimuli. The sensitivity observed in the OC procedure was considerably larger than the sensitivity in the PPI procedure. Applying a sensitivity of 1.0 as the threshold criterion, mean IDLs in the OC procedure were 5.0, 4.0 and 3.5 dB at reference levels of 30, 50 and 75 dB SPL respectively. In the PPI procedure, mean IDLs of 18.9 and 17.0 dB at reference levels of 50 and 75 dB SPL respectively were observed. Due to the low sensitivity, IDLs could not be determined in the PPI procedure at a reference level of 30 dB SPL. Possible causes for the low sensitivity in the PPI procedure are discussed. These results challenge the idea that both procedures can be used as simple substitutes of one another and the experimenter must be aware of the limitations of the respective procedure.
Tolnai, S., Dolležal, L. -V., and Klump, G. M., Binaural cues provide for a release from informational masking, Behav. Neurosci., vol. 129, no. 5. 2015.
Abstract DOI
Informational masking (IM) describes the insensitivity of detecting a change in sound features in a complex acoustical environment when such a change could easily be detected in the absence of distracting sounds. IM occurs because of the similarity between deviant sound and distracting sounds (so-called similarity-based IM) and/or stimulus uncertainty stemming from trial-to-trial variability (so-called uncertainty-based IM). IM can be abolished if similarity-based or uncertainty-based IM are minimized. Here, we modulated similarity-based IM using binaural cues. Standard/deviant tones and distracting tones were presented sequentially, and level-increment thresholds were measured. Deviant tones differed from standard tones by a higher sound level. Distracting tones covered a wide range of levels. Standard/deviant tones and distracting tones were characterized by their interaural time difference (ITD), interaural level difference (ILD), or both ITD and ILD. The larger the ITD or ILD was, the better similarity-based IM was overcome. If both interaural differences were applied to standard/deviant tones, the release from IM was larger than when either interaural difference was used. The results show that binaural cues are potent cues to abolish similarity-based IM and that the auditory system makes use of multiple available cues.
Xiong, F., Meyer, B. T., Moritz, N., Rehr, R., Anemüller, J., Gerkmann, T., Doclo, S., and Goetze, S., Front-end technologies for robust ASR in reverberant environments—spectral enhancement-based dereverberation and auditory modulation filterbank features, EURASIP J. Adv. Signal Process., vol. 2015:70. 2015.
Abstract DOIFull Text
This paper presents extended techniques aiming at the improvement of automatic speech recognition (ASR) in single-channel scenarios in the context of the REVERB (REverberant Voice Enhancement and Recognition Benchmark) challenge. The focus is laid on the development and analysis of ASR front-end technologies covering speech enhancement and feature extraction. Speech enhancement is performed using a joint noise reduction and dereverberation system in the spectral domain based on estimates of the noise and late reverberation power spectral densities (PSDs). To obtain reliable estimates of the PSDs—even in acoustic conditions with positive direct-to-reverberation energy ratios (DRRs)—we adopt the statistical model of the room impulse response explicitly incorporating DRRs, as well in combination with a novel proposed joint estimator for the reverberation time T 60 and the DRR. The feature extraction approach is inspired by processing strategies of the auditory system, where an amplitude modulation filterbank is applied to extract the temporal modulation information. These techniques were shown to improve the REVERB baseline in our previous work. Here, we investigate if similar improvements are obtained when using a state-of-the-art ASR framework, and to what extent the results depend on the specific architecture of the back-end. Apart from conventional Gaussian mixture model (GMM)-hidden Markov model (HMM) back-ends, we consider subspace GMM (SGMM)-HMMs as well as deep neural networks in a hybrid system. The speech enhancement algorithm is found to be helpful in almost all conditions, with the exception of deep learning systems in matched training-test conditions. The auditory feature type improves the baseline for all system architectures. The relative word error rate reduction achieved by combining our front-end techniques with current back-ends is 52.7% on average with the REVERB evaluation test set compared to our original REVERB result.
Doclo, S., Kellermann, W., Makino, S., and Nordholm, S. E., Multichannel Signal Enhancement Algorithms for Assisted Listening Devices: Exploiting spatial diversity using multiple microphones, IEEE Sig. Proc. Mag., vol. 32, no. 2. 2015.
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In everyday environments, we are frequently immersed by unwanted acoustic noise and interference while we want to listen to acoustic signals, most often speech. Technology for assisted listening is then desired to increase the efficiency of speech communication, reduce listener fatigue, or just allow for enjoying undisturbed sounds (e.g., music). For people with normal hearing, assisted listening devices (ALDs) mainly aim to achieve hearing protection or increase listening comfort; however, for hearing-impaired individuals, as the most prominent user group so far, further progress of assisted listening technology is crucial for better inclusion into our world of pervasive acoustic communication.
Lawin-Ore, T. C. and Doclo, S., Analysis of the average performance of the multi-channel Wiener filter for distributed microphone arrays using statistical room acoustics, Sig. Proc., vol. 107, no. SI. 2015.
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Wang, L., Gerkmann, T., and Doclo, S., Noise Power Spectral Density Estimation Using MaxNSR Blocking Matrix, IEEE Trans. Aud. Sp. Lang. Proc., vol. 23, no. 9. 2015.
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In this paper, a multi-microphone noise reduction system based on the generalized sidelobe canceller (GSC) structure is investigated. The system consists of a fixed beamformer providing an enhanced speech reference, a blocking matrix providing a noise reference by suppressing the target speech, and a single-channel spectral post-filter. The spectral post-filter requires the power spectral density (PSD) of the residual noise in the speech reference, which can in principle be estimated from the PSD of the noise reference. However, due to speech leakage in the noise reference, the noise PSD is overestimated, leading to target speech distortion. To minimize the influence of the speech leakage, a maximum noise-to-speech ratio (MaxNSR) blocking matrix is proposed, which maximizes the ratio between the noise and the speech leakage in the noise reference. The proposed blocking matrix can be computed from the generalized eigenvalue decomposition of the correlation matrix of the microphone signals and the noise coherence matrix, which is assumed to be time-invariant. Experimental results in both stationary and nonstationary diffuse noise fields show that the proposed algorithm outperforms existing blocking matrices in terms of target speech blocking ability, noise estimation and noise reduction performance.
Jukić, A., Waterschoot, T., Gerkmann, T., and Doclo, S., Multi-Channel Linear Prediction-Based Speech Dereverberation With Sparse Priors, IEEE Trans. Aud. Sp. Lang. Proc., vol. 23, no. 9. 2015.
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The quality of speech signals recorded in an enclosure can be severely degraded by room reverberation. In this paper, we focus on a class of blind batch methods for speech dereverberation in a noiseless scenario with a single source, which are based on multi-channel linear prediction in the short-time Fourier transform domain. Dereverberation is performed by maximum-likelihood estimation of the model parameters that are subsequently used to recover the desired speech signal. Contrary to the conventional method, we propose to model the desired speech signal using a general sparse prior that can be represented in a convex form as a maximization over scaled complex Gaussian distributions. The proposed model can be interpreted as a generalization of the commonly used time-varying Gaussian model. Furthermore, we reformulate both the conventional and the proposed method as an optimization problem with an ${ell _p}$ -norm cost function, emphasizing the role of sparsity in the considered speech dereverberation methods. Experimental evaluation in different acoustic scenarios show that the proposed approach results in an improved performance compared to the conventional approach in terms of instrumental measures for speech quality.
Cauchi, B., Kodrasi, I., Rehr, R., Gerlach, S., Jukić, A., Gerkmann, T., Doclo, S., and Goetze, S., Combination of MVDR beamforming and single-channel spectral processing for enhancing noisy and reverberant speech, EURASIP J. Adv. Signal Process., vol. 2015:61. 2015.
Abstract
This paper presents a system aiming at joint dereverberation and noise reduction by applying a combination of a beamformer with a single-channel spectral enhancement scheme. First, a minimum variance distortionless response beamformer with an online estimated noise coherence matrix is used to suppress noise and reverberation. The output of this beamformer is then processed by a single-channel spectral enhancement scheme, based on statistical room acoustics, minimum statistics, and temporal cepstrum smoothing, to suppress residual noise and reverberation. The evaluation is conducted using the REVERB challenge corpus, designed to evaluate speech enhancement algorithms in the presence of both reverberation and noise. The proposed system is evaluated using instrumental speech quality measures, the performance of an automatic speech recognition system, and a subjective evaluation of the speech quality based on a MUSHRA test. The performance achieved by beamforming, single-channel spectral enhancement, and their combination are compared, and experimental results show that the proposed system is effective in suppressing both reverberation and noise while improving the speech quality. The achieved improvements are particularly significant in conditions with high reverberation times.
Sankowsky-Rothe, T., Blau, M., Schepker, H., and Doclo, S., Reciprocal measurement of acoustic feedback paths in hearing aids, J. Acoust. Soc. Am., vol. 138, no. 4. 2015.
Abstract
A reciprocal measurement procedure to measure the acoustic feedback path in hearing aids is investigated. The advantage of the reciprocal measurement compared to the direct measurement is a significantly reduced sound pressure in the ear. The direct and reciprocal measurements are compared using measurements on a dummy head with adjustable ear canals, different earmolds, and variations in the outer sound field. The results show that the reciprocal measurement procedure can be used to obtain plausible feedback paths, while reducing the sound pressure in the ear canal by 30 to 40 dB.
Schepker, H., Rennies, J., and Doclo, S., Speech-in-noise enhancement using amplification and dynamic range compression controlled by the speech intelligibility index, J. Acoust. Soc. Am., vol. 138, no. 5. 2015.
Abstract
In many speech communication applications, such as public address systems, speech is degraded by additive noise, leading to reduced speech intelligibility. In this paper a pre-processing algorithm is proposed that is capable of increasing speech intelligibility under an equal-power constraint. The proposed AdaptDRC algorithm comprises two time- and frequency-dependent stages, i.e., an amplification stage and a dynamic range compression stage that are both dependent on the Speech Intelligibility Index (SII). Experiments using two objective measures, namely, the extended SII and the short-time objective intelligibility measure (STOI), and a formal listening test were conducted to compare the AdaptDRC algorithm with a modified version of a recently proposed algorithm in three different noise conditions (stationary car noise and speech-shaped noise and non-stationary cafeteria noise). While the objective measures indicate a similar performance for both algorithms, results from the formal listening test indicate that for the two stationary noises both algorithms lead to statistically significant improvements in speech intelligibility and for the non-stationary cafeteria noise only the proposed AdaptDRC algorithm leads to statistically significant improvements. A comparison of both objective measures and results from the listening test shows high correlations, although, in general, the performance of both algorithms is overestimated.
Schasse, A., Gerkmann, T., Martin, R., Sorgel, W., Pilgrim, T., and Puder, H., Two-Stage Filter-Bank System for Improved Single-Channel Noise Reduction in Hearing Aids, IEEE Trans. Aud. Sp. Lang. Proc., vol. 23, no. 2. 2015.
Abstract
The filter-bank system implemented in hearing aids has to fulfill various constraints such as low latency and high stop-band attenuation, usually at the cost of low frequency resolution. In the context of frequency-domain noise-reduction algorithms, insufficient frequency resolution may lead to annoying residual noise artifacts since the spectral harmonics of the speech cannot properly be resolved. Especially in case of female speech signals, the noise between the spectral harmonics causes a distinct roughness of the processed signals. Therefore, this work proposes a two-stage filter-bank system, such that the frequency resolution can be improved for the purpose of noise reduction, while the original first-stage hearing-aid filter-bank system can still be used for compression and amplification. We also propose methods to implement the second filter-bank stage with little additional algorithmic delay. Furthermore, the computational complexity is an important design criterion. This finally leads to an application of the second filter-bank stage to lower frequency bands only, resulting in the ability to resolve the harmonics of speech. The paper presents a systematic description of the second filter-bank stage, discusses its influence on the processed signals in detail and further presents the results of a listening test which indicates the improved performance compared to the original single-stage filter-bank system.
Gerkmann, T., Krawczyk-Becker, M., and Le Roux, J., Phase Processing for Single-Channel Speech Enhancement: History and recent advances, IEEE Sig. Proc. Mag., vol. 32, no. 2. 2015.
Abstract
With the advancement of technology, both assisted listening devices and speech communication devices are becoming more portable and also more frequently used. As a consequence, users of devices such as hearing aids, cochlear implants, and mobile telephones, expect their devices to work robustly anywhere and at any time. This holds in particular for challenging noisy environments like a cafeteria, a restaurant, a subway, a factory, or in traffic. One way to making assisted listening devices robust to noise is to apply speech enhancement algorithms. To improve the corrupted speech, spatial diversity can be exploited by a constructive combination of microphone signals (so-called beamforming), and by exploiting the different spectro?temporal properties of speech and noise. Here, we focus on single-channel speech enhancement algorithms which rely on spectrotemporal properties. On the one hand, these algorithms can be employed when the miniaturization of devices only allows for using a single microphone. On the other hand, when multiple microphones are available, single-channel algorithms can be employed as a postprocessor at the output of a beamformer. To exploit the short-term stationary properties of natural sounds, many of these approaches process the signal in a time-frequency representation, most frequently the short-time discrete Fourier transform (STFT) domain. In this domain, the coefficients of the signal are complex-valued, and can therefore be represented by their absolute value (referred to in the literature both as STFT magnitude and STFT amplitude) and their phase. While the modeling and processing of the STFT magnitude has been the center of interest in the past three decades, phase has been largely ignored.
Grimm, G., Ewert, S., and Hohmann, V., Evaluation of Spatial Audio Reproduction Schemes for Application in Hearing Aid Research, Acta Acust. united with Acust., vol. 101, no. 4. 2015.
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Dietz, M., Klein-Hennig, M., and Hohmann, V., The influence of pause, attack, and decay duration of the ongoing envelope on sound lateralization, J. Acoust. Soc. Am., vol. 137, no. 2. 2015.
Abstract
Klein-Hennig et al. [J. Acoust. Soc. Am. 129, 3856–3872 (2011)] introduced a class of high-frequency stimuli for which the envelope shape can be altered by independently varying the attack, hold, decay, and pause durations. These stimuli, originally employed for testing the shape dependence of human listeners\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\' sensitivity to interaural temporal differences (ITDs) in the ongoing envelope, were used to measure the lateralization produced by fixed interaural disparities. Consistent with the threshold ITD data, a steep attack and a non-zero pause facilitate strong ITD-based lateralization. In contrast, those conditions resulted in the smallest interaural level-based lateralization.
Chen, Z. and Hohmann, V., Online Monaural Speech Enhancement Based on Periodicity Analysis and A Priori SNR Estimation, IEEE Trans. Aud. Sp. Lang. Proc., vol. 23, no. 11. 2015.
Abstract
This paper describes an online algorithm for enhancing monaural noisy speech. First, a novel phase-corrected low-delay gammatone filterbank is derived for signal subband decomposition and resynthesis; the subband signals are then analyzed frame by frame. Second, a novel feature named periodicity degree (PD) is proposed to be used for detecting and estimating the fundamental period (P-0) in each frame and for estimating the signal-to-noise ratio (SNR) in each frame-subband signal unit. The PD is calculated in each unit as the multiplication of the normalized autocorrelation and the comb filter ratio, and shown to be robust in various low-SNR conditions. Third, the noise energy level in each signal unit is estimated recursively based on the estimated SNR for units with high PD and based on the noisy signal energy level for units with low PD. Then the a priori SNR is estimated using a decision-directed approach with the estimated noise level. Finally, a revised Wiener gain is calculated, smoothed, and applied to each unit; the processed units are summed across subbands and frames to form the enhanced signal. The detection accuracy of the algorithm was evaluated on two corpora and showed comparable performance on one corpus and better performance on the other corpus when compared to a recently published pitch detection algorithm. The speech enhancement effect of the algorithm was evaluated on one corpus with two objective criteria and showed better performance in one highly non-stationary noise and comparable performance in two other noises when compared to a state-of-the-art statistical-model based algorithm.
Adiloğlu, K., Kayser, H., Baumgärtel, R. M., Rennebeck, S., Dietz, M., and Hohmann, V., A Binaural Steering Beamformer System for Enhancing a Moving Speech Source, Trends Hear., vol. 19:2331216515618903. 2015.
Abstract
Williges, B., Dietz, M., Hohmann, V., and Jürgens, T., Spatial Release From Masking in Simulated Cochlear Implant Users With and Without Access to Low-Frequency Acoustic Hearing, Trends Hear., vol. 19:2331216515616940. 2015.
Abstract
Hochmuth, S., Jürgens, T., Brand, T., and Kollmeier, B., Talker- and language-specific effects on speech intelligibility in noise assessed with bilingual talkers: Which language is more robust against noise and reverberation?, Int. J. Audiol., vol. 54 (Supp 2). 2015.
Abstract
Objective: Investigate talker- and language-specific aspects of speech intelligibility in noise and reverberation using highly comparable matrix sentence tests across languages. Design: Matrix sentences spoken by German/Russian and German/Spanish bilingual talkers were recorded. These sentences were used to measure speech reception thresholds (SRTs) with native listeners in the respective languages in different listening conditions (stationary and fluctuating noise, multi-talker babble, reverberated speech-in-noise condition). Study sample: Four German/Russian and four German/Spanish bilingual talkers; 20 native German-speaking, 10 native Russian-speaking, and 10 native Spanish-speaking listeners. Results: Across-talker SRT differences of up to 6 dB were found for both groups of bilinguals. SRTs of German/Russian bilingual talkers were the same in both languages. SRTs of German/Spanish bilingual talkers were higher when they talked in Spanish than when they talked in German. The benefit from listening in the gaps was similar across all languages. The detrimental effect of reverberation was larger for Spanish than for German and Russian. Conclusions: Within the limitations set by the number and slight accentedness of talkers and other possible confounding factors, talker- and test-condition-dependent differences were isolated from the language effect: Russian and German exhibited similar intelligibility in noise and reverberation, whereas Spanish was more impaired in these situations.
Hochmuth, S., Kollmeier, B., Brand, T., and Jürgens, T., Influence of noise type on speech reception thresholds across four languages measured with matrix sentence tests , Int. J. Audiol., vol. 54 (Supp 2). 2015.
Abstract
Objective: To compare speech reception thresholds (SRTs) in noise using matrix sentence tests in four languages: German, Spanish, Russian, Polish. Design: The four tests were composed of equivalent five-word sentences and were all designed and optimized using the same principles. Six stationary speech-shaped noises and three non-stationary noises were used as maskers. Study sample: Forty native listeners with normal hearing: 10 for each language. Results: SRTs were about 3 dB higher for the German and Spanish tests than for the Russian and Polish tests when stationary noise was used that matched the long-term frequency spectrum of the respective speech test materials. This general SRT difference was also observed for the other stationary noises. The within-test variability across noise conditions differed between languages. About 56% of the observed variance was predicted by the speech intelligibility index. The observed SRT benefit in fluctuating noise was similar for all tests, with a slightly smaller benefit for the Spanish test. Conclusions: Of the stationary noises employed, noise with the same spectrum as the speech yielded the best masking. SRT differences across languages and noises could be attributed in part to spectral differences. These findings provide the feasibility and limits of comparing audiological results across languages.
Reed, D. K. and van de Par, S., Lateralization of noise bursts in interaurally correlated or uncorrelated background noise using interaural level differences, J. Acoust. Soc. Am., vol. 138. 2015.
Abstract
The interaural level difference (ILD) of a lateralized target source may be effectively reduced when the target is presented together with background noise containing zero ILD. It is not certain whether listeners perceive a position congruent with the reduced ILD or the actual target ILD in a lateralization task. Two sets of behavioral experiments revealed that many listeners perceived a position at or even larger than that corresponding to the presented target ILD when a temporal onset/offset asynchrony between the broadband target and the broadband background noise was present. When no temporal asynchrony was present, however, the perceived lateral position indicated a dependency on the coherence of the background noise for several listeners. With interaurally correlated background noise, listeners reported a reduced ILD resulting from the combined target and background noise stimulus. In contrast, several of the listeners made a reasonable estimate of the position corresponding to the target ILD for interaurally uncorrelated, broadband, background noise. No obvious difference in performance was seen between low- or high-frequency stimuli. Extension of a weighting template to the output of a standard equalization-cancellation model was shown to remove a lateral bias on the predicted target ILD resulting from the presence of background noise. Provided that an appropriate weighting template is applied based on knowledge of the background noise coherence, good prediction of the behavioral data is possible.
Grosse, J. and van de Par, S., Perceptually accurate reproduction of recorded sound fields in a reverberant room using spatially distributed loudspeakers, IEEE J. Sel. Top. Signal Process., vol. 9, no. 5. 2015.
Abstract DOIFull Text
In sound reproduction, it can be desirable to reproduce a recording made, e.g., in a concert hall, in a playback room, such that the listener has a reasonable accurate impression of the original sound source, including the room acoustics of the recording room. A perceptually motivated approach is developed which aims to accurately reproduce the perceptual spatial and monaural cues of the direct and reverberant sound fields of the recording room for playback in a reverberant room. For this approach, the direct sound, recorded close to the sound source, is optimized and processed with an auditory motivated gammatone filterbank such that spectral cues (the coloration) are faithfully reproduced in the playback room. In addition, the reverberant sound is recorded at two distant positions from the sound source in the recording room. These signals are rendered over two dipole loudspeakers. Due to the arrangement of the dipoles, the listener receives no direct sound field from the dipoles and, thus, only the diffuse field in the playback room is excited. In this way the reverberant field can be adjusted independent of the direct sound. Therefore, the spectral cues and the interaural cross correlation of the reverberant sound field can be optimized separately to make sure they match the cues which were present in the recording room.
Reed, D. K. and van de Par, S., Characterizing perceptual properties of a binaurally modulated stimulus , J. Acoust. Soc. Am., vol. 138, no. 6. 2015.
Abstract
The majority of everyday listening situations involve a complex mixture of multiple sound sources. Assuming a spectro-temporally sparse target signal, e.g., speech, the binaural cues in these complex listening environments do not simply result from a single sound source, but are often rapidly switching between the most dominant sources at any given moment. To investigate the perception of rapidly switching interaural time difference (ITD) cues, a noise stimulus that periodically alternates between two different values of ITD was created. This stimulus appears to evoke a purely binaural percept of modulation, which is the focus of the studies presented here. Results indicate that listeners can reliably discriminate this ITD-switching stimulus from a stimulus composed of stationary ITD cues. Frequency discrimination of this ITD-switching stimulus was tested in a separate experiment, which showed that listeners are generally able to discriminate a 50% change in modulation frequency for reference rates below 16 Hz. The final study investigated if modulation masking exists between the monaural and binaural auditory pathways. Although a statistically significant increase in modulation detection thresholds was observed when both types of modulations were presented together, the increase was relatively small, indicating only a weak interaction. (C) 2015 Acoustical Society of America.
Hildebrandt, K. J., Benda, J., and Hennig, R. M., Computational themes of peripheral processing in the auditory pathway of insects., J. Comp. Physiol. A, vol. 201, no. 1. 2015.
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Hearing in insects serves to gain information in the context of mate finding, predator avoidance or host localization. For these goals, the auditory pathways of insects represent the computational substrate for object recognition and localization. Before these higher level computations can be executed in more central parts of the nervous system, the signals need to be preprocessed in the auditory periphery. Here, we review peripheral preprocessing along four computational themes rather than discussing specific physiological mechanisms: (1) control of sensitivity by adaptation, (2) recoding of amplitude modulations of an acoustic signal into a labeled-line code (3) frequency processing and (4) conditioning for binaural processing. Along these lines, we review evidence for canonical computations carried out in the peripheral auditory pathway and show that despite the vast diversity of insect hearing, signal processing is governed by common computational motifs and principles.
Hildebrandt, K. J., Ronacher, B., Hennig, R. M., and Benda, J., A Neural Mechanism for Time-Window Separation Resolves Ambiguity of Adaptive Coding, PLOS Biol., vol. 13, no. 3. 2015.
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Clemens, J., Rau, F., Hennig, M. R., and Hildebrandt, K. J., Context-dependent coding and gain control in the auditory system of crickets, Eur. J. Neurosci., vol. 42, no. 7. 2015.
Abstract
Sensory systems process stimuli that greatly vary in intensity and complexity. To maintain efficient information transmission, neural systems need to adjust their properties to these different sensory contexts, yielding adaptive or stimulus-dependent codes. Here, we demonstrate adaptive spectrotemporal tuning in a small neural network - the peripheral auditory system of the cricket. We find that tuning of cricket auditory neurons is sharper for complex multi-band than for simple single-band stimuli. Information theoretical considerations reveal that this sharpening improves information transmission by separating the neural representations of individual stimulus components. A network model inspired by the structure of the cricket auditory system suggests two putative mechanisms underlying this adaptive tuning: a saturating peripheral nonlinearity can change the spectral tuning while broad feed-forward inhibition is able to reproduce the observed adaptive sharpening of temporal tuning. Our study reveals a surprisingly dynamic code usually found in more complex nervous systems and suggests that stimulus-dependent codes can be implemented using common neural computations.
Schell-Majoor, L., Rennies, J., Ewert, S. D., and Kollmeier, B., Application of psychophysical models for audibility prediction of technical signals in real-world background noise, Appl. Acoust., vol. 88. 2015.
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A valid, objective computation of whether a real-world sound is detectable in a real-world acoustical environment is highly desirable in many noise control applications. However, most current prediction approaches have not been validated for this purpose and have not been tailored towards predicting the influence of certain signal features, such as the temporal structure or the spectral content of the masker or target. In order to evaluate the applicability of prediction approaches with respect to these signal features, detection thresholds of various real-world signals were measured for normal-hearing listeners. The detection thresholds depended on the temporal structure and spectrum of the target and the spectrum of the masker. The data were compared to predictions of five approaches ranging from time-averaged technical measures to psychoacoustic models, which incorporate these signal features to different extents. In general, the correspondence between predictions and the experimental data was better for the psychoacoustic models than for the results of the technical measures. Even though all models could account for most of the key effects in the experimental data, only the psychoacoustic models were able to predict the influence of the temporal structure of the signals. One of the models showed clear advantages in prediction performance, reaching an overall determination coefficient of R2 = 0.94. This underlines the applicability of psychoacoustic models for correctly predicting audibility in real-world applications.
Akeroyd, M. A., Arlinger, S., Bentler, R. A., Boothroyd, A., Dillier, N., Dreschler, W. A., Gagné, J. -P., Lutman, M., Wouters, J., Wong, L., and Kollmeier, B., International Collegium of Rehabilitative Audiology (ICRA) recommendations for the construction of multilingual speech tests. ICRA Working Group on Multilingual Speech Tests, Int. J. Audiol., vol. 54 (Supp 2). 2015.
Abstract DOIFull Text
Objective: To provide guidelines for the development of two types of closed-set speech-perception tests that can be applied and interpreted in the same way across languages. The guidelines cover the digit triplet and the matrix sentence tests that are most commonly used to test speech recognition in noise. They were developed by a working group on Multilingual Speech Tests of the International Collegium of Rehabilitative Audiology (ICRA). Design: The recommendations are based on reviews of existing evaluations of the digit triplet and matrix tests as well as on the research experience of members of the ICRA Working Group. They represent the results of a consensus process. Results: The resulting recommendations deal with: Test design and word selection; Talker characteristics; Audio recording and stimulus preparation; Masking noise; Test administration; and Test validation. Conclusions: By following these guidelines for the development of any new test of this kind, clinicians and researchers working in any language will be able to perform tests whose results can be compared and combined in cross-language studies.
Kollmeier, B., Warzybok, A., Hochmuth, S., Zokoll, M. A., Uslar, V., Brand, T., and Wagener, K. C., The multilingual matrix test: Principles, applications, and comparison across languages: A review, Int. J. Audiol., vol. 54 (Supp 2). 2015.
Abstract
Objective: A review of the development, evaluation, and application of the so-called ‘matrix sentence test’ for speech intelligibility testing in a multilingual society is provided. The format allows for repeated use with the same patient in her or his native language even if the experimenter does not understand the language. Design: Using a closed-set format, the syntactically fixed, semantically unpredictable sentences (e.g. ʽPeter bought eight white shipsʼ) provide a vocabulary of 50 words (10 alternatives for each position in the sentence). The principles (i.e. construction, optimization, evaluation, and validation) for 14 different languages are reviewed. Studies of the influence of talker, language, noise, the training effect, open vs. closed conduct of the test, and the subjects’ language proficiency are reported and application examples are discussed. Results: The optimization principles result in a steep intelligibility function and a high homogeneity of the speech materials presented and test lists employed, yielding a high efficiency and excellent comparability across languages. The characteristics of speakers generally dominate the differences across languages. Conclusion: The matrix test format with the principles outlined here is recommended for producing efficient, reliable, and comparable speech reception thresholds across different languages.
Warzybok, A., Zokoll, M., Wardenga, N., Ozimek, E., Boboshko, M., and Kollmeier, B., Development of the Russian matrix sentence test, Int. J. Audiol., vol. 54 (Supp 2). 2015.
Abstract
Objective: To develop the Russian matrix sentence test for speech intelligibility measurements in noise. Design: Test development included recordings, optimization of speech material, and evaluation to investigate the equivalency of the test lists and training. For each of the 500 test items, the speech intelligibility function, speech reception threshold (SRT: signal-to-noise ratio, SNR, that provides 50% speech intelligibility), and slope was obtained. The speech material was homogenized by applying level corrections. In evaluation measurements, speech intelligibility was measured at two fixed SNRs to compare list-specific intelligibility functions. To investigate the training effect and establish reference data, speech intelligibility was measured adaptively. Study sample: Overall, 77 normal-hearing native Russian listeners. Results: The optimization procedure decreased the spread in SRTs across words from 2.8 to 0.6 dB. Evaluation measurements confirmed that the 16 test lists were equivalent, with a mean SRT of − 9.5 ± 0.2 dB and a slope of 13.8 ± 1.6%/dB. The reference SRT, − 8.8 ± 0.8 dB for the open-set and − 9.4 ± 0.8 dB for the closed-set format, increased slightly for noise levels above 75 dB SPL. Conclusions: The Russian matrix sentence test is suitable for accurate and reliable speech intelligibility measurements in noise.
Schädler, M. R. and Kollmeier, B., Separable spectro-temporal Gabor filter bank features: Reducing the complexity of robust features for automatic speech recognition, J. Acoust. Soc. Am., vol. 137, no. 4. 2015.
Abstract
To test if simultaneous spectral and temporal processing is required to extract robust features for automatic speech recognition (ASR), the robust spectro-temporal two-dimensional-Gabor filter bank (GBFB) front-end from Schädler, Meyer, and Kollmeier [J. Acoust. Soc. Am. 131, 4134-4151 (2012)] was de-composed into a spectral one-dimensional-Gabor filter bank and a temporal one-dimensional-Gabor filter bank. A feature set that is extracted with these separate spectral and temporal modulation filter banks was introduced, the separate Gabor filter bank (SGBFB) features, and evaluated on the CHiME (Computational Hearing in Multisource Environments) keywords-in-noise recognition task. From the perspective of robust ASR, the results showed that spectral and temporal processing can be performed independently and are not required to interact with each other. Using SGBFB features permitted the signal-to-noise ratio (SNR) to be lowered by 1.2 dB while still performing as well as the GBFB-based reference system, which corresponds to a relative improvement of the word error rate by 12.8%. Additionally, the real time factor of the spectro-temporal processing could be reduced by more than an order of magnitude. Compared to human listeners, the SNR needed to be 13 dB higher when using Mel-frequency cepstral coefficient features, 11 dB higher when using GBFB features, and 9 dB higher when using SGBFB features to achieve the same recognition performance.
Schädler, M. R., Warzybok, A., Hochmuth, S., and Kollmeier, B., Matrix sentence intelligibility prediction using an automatic speech recognition system, Int. J. Audiol., vol. 54 (Supp 2). 2015.
Abstract
Objective: The feasibility of predicting the outcome of the German matrix sentence test for different types of stationary background noise using an automatic speech recognition (ASR) system was studied. Design: Speech reception thresholds (SRT) of 50% intelligibility were predicted in seven noise conditions. The ASR system used Mel-frequency cepstral coefficients as a front-end and employed whole-word Hidden Markov models on the back-end side. The ASR system was trained and tested with noisy matrix sentences on a broad range of signal-to-noise ratios. Study sample: The ASR-based predictions were compared to data from the literature (Hochmuth et al, 2015) obtained with 10 native German listeners with normal hearing and predictions of the speech intelligibility index (SII). Results: The ASR-based predictions showed a high and significant correlation (R² = 0.95, p < 0.001) with the empirical data across different noise conditions, outperforming the SII-based predictions which showed no correlation with the empirical data (R² = 0.00, p = 0.987). Conclusions: The SRTs for the German matrix test for listeners with normal hearing in different stationary noise conditions could well be predicted based on the acoustical properties of the speech and noise signals. Minimum assumptions were made about human speech processing already incorporated in a reference-free ordinary ASR system.
Hu, H., Kollmeier, B., and Dietz, M., Reduction of stimulation coherent artifacts in electrically evoked auditory brainstem responses, Biomed. Sig. Proc. Control, vol. 21. 2015.
Abstract
The electrically evoked auditory brainstem response (eABR) is one of the clinically employed objective evaluation tools for cochlear implant (CI) subjects. It is commonly obtained by averaging responses, but because of the electric CI stimulation, some artifacts are phase locked to the stimulus and do not average out by increasing repetitions. A series of artifact reduction methods, such as general post-processing procedures for all subjects and individual post-processing procedures for some subjects, were developed in this study, aiming at reducing CI stimulation coherent artifacts. Seven bilateral CI subjects were recruited, and both monaural and binaural multi-channel eABRs were recorded in this study. The results show that the CI stimulation pulse artifacts can be efficiently removed by the general post-processing procedure, using alternating polarity stimuli combined with linear interpolation. Recordings obtained with non-alternating polarity show a strong exponential decay. Exponential fitting and subtraction worked reasonably well in this case. For eABR recordings contaminated with facial nerve stimulation (FNS) artifacts, principle component analysis was introduced to minimize the FNS artifacts for potential clinic application in the future.
Buschermöhle, M., Wagener, K. C., Berg, D., Meis, M., and Kollmeier, B., The German Digit Triplets Test (Part II): Validation and Pass/Fail Criteria, Z. Audiol., vol. 54, no. 1. 2015.
Abstract
Baumgärtel, R. M., Krawczyk-Becker, M., Marquardt, D., Völker, C., Hu, H., Herzke, T., Coleman, G., Adiloglu, K., Ernst, S. M. A., Gerkmann, T., Doclo, S., Kollmeier, B., Hohmann, V., and Dietz, M., Comparing binaural signal pre-processing strategies I: Instrumental evaluation, Trends Hear., vol. 19:2331216515617916. 2015.
Abstract
Baumgärtel, R. M., Hu, H., Krawczyk-Becker, M., Marquardt, D., Herzke, T., Coleman, G., Adiloglu, K., Bomke, K., Plotz, K., Gerkmann, T., Doclo, S., Kollmeier, B., Hohmann, V., and Dietz, M., Comparing binaural signal pre-processing strategies II: Speech intelligibility of bilateral cochlear implant user, Trends Hear., vol. 19:2331216515617917. 2015.
Abstract
Zokoll, M. A., Fidan, D., Turkyilmaz, D., Hochmuth, S., Ergenç, İ., Sennaroğlu, G., and Kollmeier, B., Development and evaluation of the Turkish Matrix Sentence Test, Int. J. Audiol., vol. 54 (Supp 2). 2015.
Abstract
Objectives: The Turkish matrix sentence test, TURMatrix, was developed for precise, internationally comparable speech intelligibility testing. Design: The TURMatrix comprises a base matrix of ten well-known Turkish names, numbers, adjectives, objects, verbs, from which syntactically fixed sentences were randomly composed. Test conduction may be in an open-set (standard), or closed-set response format. Homogeneity in intelligibility of the test material was optimized by applying level adaptations (maximal ± 3 dB) based on word-specific speech reception thresholds (SRTs). Test list equivalence was verified and reference values were determined. Study sample: Thirty-eight native listeners of Turkish with normal hearing. Results: After training, mean SRT and slope of the final test lists were − 8.3 ± 0.2 dB SNR and 14.1 ± 1.0%/dB, respectively (fixed SNR measurements; inter-list variability). For adaptive measurements, average across listeners was − 7.2 ± 0.7 dB SNR in the open-set and − 7.9 ± 0.7 dB SNR in the closed-set response format. Mean SRT for adaptive measurements in the open-set response format in quiet was 20.3 ± 4.1 dB. Individual SRTs in quiet correlated more closely with audiograms than with SRTs in noise. Conclusions: The TURMatrix was developed according to European standards and provides reliable speech intelligibility measurements in noise and quiet.
Dietz, A., Buschermöhle, M., Sivonen, V., Aarnisalo, A., Willberg, T., Lenarz, T., and Kollmeier, B., Characteristics and international comparability of the Finnish matrix sentence test in cochlear implant recipients, Int. J. Audiol., vol. 54 Suppl 2. 2015.
Abstract
Objectives: The first Finnish sentence-based speech test in noise—the Finnish matrix sentence test—was recently developed. The aim of this study was to determine the characteristics of the new test with respect to test-retest reliability, speech recognition curve, and international comparability in Finnish cochlear implant (CI) recipients. Design: The speech reception thresholds (SRT) were measured by means of an adaptive test procedure and compared with the results of the traditional Finnish word test. Additional measurements for concurrent slope and SRT estimation were conducted to determine the speech recognition curve and to check the test-retest reliability. Study sample: The measurements were performed on 78 Finnish CI recipients. In a subset of 25 patients, additional measurements for test-retest reliability and slope determination were performed. Results: The mean SRT was − 3.5 ± 1.7 dB SNR, with only a weak correlation with the Finnish word test. Test-retest reliability was within ± 1 dB and the mean slope of the speech recognition curve was 14.6 ± 3.6 %/dB. The rehabilitation results were similar to the results published for the German matrix test. Conclusions: The Finnish matrix test was found to be suitable and efficient in CI recipients with similar characteristics as the German matrix test.
Kollmeier, B., Overcoming Language Barriers: Matrix sentence tests with closed speech corpora, Int. J. Audiol., vol. 54 (Supp 2). 2015.
Abstract DOIFull Text
Kayser, H., Hohmann, V., Ewert, S. D., Kollmeier, B., and Anemüller, J., Robust auditory localization using probabilistic inference and coherence-based weighting of interaural cues, J. Acoust. Soc. Am., vol. 138, no. 5. 2015.
Abstract
Robust sound source localization is performed by the human auditory system even in challenging acoustic conditions and in previously unencountered, complex scenarios. Here a computational binaural localization model is proposed that possesses mechanisms for handling of corrupted or unreliable localization cues and generalization across different acoustic situations. Central to the model is the use of interaural coherence, measured as interaural vector strength (IVS), to dynamically weight the importance of observed interaural phase (IPD) and level (ILD) differences in frequency bands up to 1.4 kHz. This is accomplished through formulation of a probabilistic model in which the ILD and IPD distributions pertaining to a specific source location are dependent on observed interaural coherence. Bayesian computation of the direction-of-arrival probability map naturally leads to coherence-weighted integration of location cues across frequency and time. Results confirm the model's validity through statistical analyses of interaural parameter values. Simulated localization experiments show that even data points with low reliability (i.e., low IVS) can be exploited to enhance localization performance. A temporal integration length of at least 200 ms is required to gain a benefit; this is in accordance with previous psychoacoustic findings on temporal integration of spatial cues in the human auditory system.
Schlueter, A., Brand, T., Lemke, U., Nitschner, S., Kollmeier, B., and Holube, I., Speech perception at positive signal-to-noise ratios using adaptive adjustment of time compression, J. Acoust. Soc. Am., vol. 138, no. 5. 2015.
Abstract
Fontaine, B., Köppl, C., and Peña, J. L., Reverse Correlation Analysis of Auditory-Nerve Fiber Responses to Broadband Noise in a Bird, the Barn Owl., J. Assoc. Res. Otolaryngol., vol. 16, no. 1. 2015.
Abstract DOIFull Text
While the barn owl has been extensively used as a model for sound localization and temporal coding, less is known about the mechanisms at its sensory organ, the basilar papilla (homologous to the mammalian cochlea). In this paper, we characterize, for the first time in the avian system, the auditory nerve fiber responses to broadband noise using reverse correlation. We use the derived impulse responses to study the processing of sounds in the cochlea of the barn owl. We characterize the frequency tuning, phase, instantaneous frequency, and relationship to input level of impulse responses. We show that, even features as complex as the phase dependence on input level, can still be consistent with simple linear filtering. Where possible, we compare our results with mammalian data. We identify salient differences between the barn owl and mammals, e.g., a much smaller frequency glide slope and a bimodal impulse response for the barn owl, and discuss what they might indicate about cochlear mechanics. While important for research on the avian auditory system, the results from this paper also allow us to examine hypotheses put forward for the mammalian cochlea.
Bergevin, C., Manley, G. A., and Köppl, C., Salient features of otoacoustic emissions are common across tetrapod groups and suggest shared properties of generation mechanisms, Proc. Natl. Acad. Sci., vol. 112, no. 11. 2015.
Abstract DOIFull Text
Otoacoustic emissions (OAEs) are faint sounds generated by healthy inner ears that provide a window into the study of auditory mechanics. All vertebrate classes exhibit OAEs to varying degrees, yet the biophysical origins are still not well understood. Here, we analyzed both spontaneous (SOAE) and stimulus-frequency (SFOAE) otoacoustic emissions from a bird (barn owl, Tyto alba) and a lizard (green anole, Anolis carolinensis). These species possess highly disparate macromorphologies of the inner ear relative to each other and to mammals, thereby allowing for novel insights into the biomechanical mechanisms underlying OAE generation. All ears exhibited robust OAE activity, and our chief observation was that SFOAE phase accumulation between adjacent SOAE peak frequencies clustered about an integral number of cycles. Being highly similar to published results from human ears, we argue that these data indicate a common underlying generator mechanism of OAEs across all vertebrates, despite the absence of morphological features thought essential to mammalian cochlear mechanics. We suggest that otoacoustic emissions originate from phase coherence in a system of coupled oscillators, which is consistent with the notion of “coherent reflection” but does not explicitly require a mammalian-type traveling wave. Furthermore, comparison between SFOAE delays and auditory nerve fiber responses for the barn owl strengthens the notion that most OAE delay can be attributed to tuning.
Palanca-Castan, N. and Köppl, C., In vivo Recordings from Low-Frequency Nucleus Laminaris in the Barn Owl, Brain. Behav. Evol., vol. 85, no. 4. 2015.
Abstract DOIFull Text
Localization of sound sources relies on 2 main binaural cues: interaural time differences (ITD) and interaural level differences. ITD computing is first carried out in tonotopically organized areas of the brainstem nucleus laminaris (NL) in birds and the medial superior olive (MSO) in mammals. The specific way in which ITD are derived was long assumed to conform to a delay line model in which arrays of systematically arranged cells create a representation of auditory space, with different cells responding maximally to specific ITD. This model conforms in many details to the particular case of the high-frequency regions (above 3 kHz) in the barn owl NL. However, data from recent studies in mammals are not consistent with a delay line model. A new model has been suggested in which neurons are not topographically arranged with respect to ITD and coding occurs through assessment of the overall response of 2 large neuron populations - 1 in each brainstem hemisphere. Currently available data comprise mainly low-frequency (<1,500 Hz) recordings in the case of mammals and higher-frequency recordings in the case of birds. This makes it impossible to distinguish between group-related adaptations and frequency-related adaptations. Here we report the first comprehensive data set from low-frequency NL in the barn owl and compare it to data from other avian and mammalian studies. Our data are consistent with a delay line model, so differences between ITD processing systems are more likely to have originated through divergent evolution of different vertebrate groups.
Palanca-Castán, N. and Köppl, C., Change in the coding of interaural time difference along the tonotopic axis of the chicken nucleus laminaris, Front Neural Circ, vol. 9:43. 2015.
Abstract DOIFull Text
Interaural time differences (ITDs) are an important cue for the localization of sounds in azimuthal space. Both birds and mammals have specialized, tonotopically organized nuclei in the brain stem for the processing of ITD: medial superior olive in mammals and nucleus laminaris (NL) in birds. The specific way in which ITDs are derived was long assumed to conform to a delay-line model in which arrays of systematically arranged cells create a representation of auditory space with different cells responding maximally to specific ITDs. This model was supported by data from barn owl NL taken from regions above 3 kHz and from chicken above 1 kHz. However, data from mammals often do not show defining features of the Jeffress model such as a systematic topographic representation of best ITDs or the presence of axonal delay lines, and an alternative has been proposed in which neurons are not topographically arranged with respect to ITD and coding occurs through the assessment of the overall response of two large neuron populations, one in each hemisphere. Modeling studies have suggested that the presence of different coding systems could be related to the animal’s head size and frequency range rather than their phylogenetic group. Testing this hypothesis requires data from across the tonotopic range of both birds and mammals. The aim of this study was to obtain in vivo recordings from neurons in the low-frequency range (<1000 Hz) of chicken NL. Our data argues for the presence of a modified Jeffress system that uses the slopes of ITD-selective response functions instead of their peaks to topographically represent ITD at mid- to high frequencies. At low frequencies, below several 100 Hz, the data did not support any current model of ITD coding. This is different to what was previously shown in the barn owl and suggests that constraints in optimal ITD processing may be associated with the particular demands on sound localization determined by the animal’s ecological niche in the same way as other perceptual systems such as field of best vision.
Ashida, G., Funabiki, K., and Kretzberg, J., Minimal Conductance-Based Model of Auditory Coincidence Detector Neurons, PLOS ONE, vol. 10, no. 4. 2015.
Abstract DOIFull Text
Sound localization is a fundamental sensory function of a wide variety of animals. The interaural time difference (ITD), an important cue for sound localization, is computed in the auditory brainstem. In our previous modeling study, we introduced a two-compartment Hodgkin-Huxley type model to investigate how cellular and synaptic specializations may contribute to precise ITD computation of the barn owl\\\\\\\\\\\\\\\'s auditory coincidence detector neuron. Although our model successfully reproduced fundamental physiological properties observed in vivo, it was unsuitable for mathematical analyses and large scale simulations because of a number of nonlinear variables. In the present study, we reduce our former model into three types of conductance-based integrate-and-fire (IF) models. We test their electrophysiological properties using data from published in vivo and in vitro studies. Their robustness to parameter changes and computational efficiencies are also examined. Our numerical results suggest that the single-compartment active IF model is superior to other reduced models in terms of physiological reproducibility and computational performance. This model will allow future theoretical studies that use more rigorous mathematical analysis and network simulations.
Bharadwaj, H. M., Masud, S., Mehraei, G., Verhulst, S., and Shinn-Cunningham, B. G., Individual differences reveal correlates of hidden hearing deficits, J. Neurosci., vol. 35, no. 5. 2015.
Abstract
Clinical audiometry has long focused on determining the detection thresholds for pure tones, which depend on intact cochlear mechanics and hair cell function. Yet many listeners with normal hearing thresholds complain of communication difficulties, and the causes for such problems are not well understood. Here, we explore whether normal-hearing listeners exhibit such suprathreshold deficits, affecting the fidelity with which subcortical areas encode the temporal structure of clearly audible sound. Using an array of measures, we evaluated a cohort of young adults with thresholds in the normal range to assess both cochlear mechanical function and temporal coding of suprathreshold sounds. Listeners differed widely in both electrophysiological and behavioral measures of temporal coding fidelity. These measures correlated significantly with each other. Conversely, these differences were unrelated to the modest variation in otoacoustic emissions, cochlear tuning, or the residual differences in hearing threshold present in our cohort. Electroencephalography revealed that listeners with poor subcortical encoding had poor cortical sensitivity to changes in interaural time differences, which are critical for localizing sound sources and analyzing complex scenes. These listeners also performed poorly when asked to direct selective attention to one of two competing speech streams, a task that mimics the challenges of many everyday listening environments. Together with previous animal and computational models, our results suggest that hidden hearing deficits, likely originating at the level of the cochlear nerve, are part of \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"normal hearing.\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"
Shelton, J. A., Sheikh, A. -S., Bornschein, J., Sterne, P., and Lücke, J., Nonlinear Spike-And-Slab Sparse Coding for Interpretable Image Encoding, PLOS ONE, vol. 10, no. 5. 2015.
Abstract
Hutter, F., Lücke, J., and Schmidt-Thieme, L., Beyond Manual Tuning of Hyperparameters, KI - Künstliche Intelligenz, vol. 29, no. 4. 2015.
Abstract DOIFull Text
The success of hand-crafted machine learning systems in many applications raises the question of making machine learning algorithms more autonomous, i.e., to reduce the requirement of expert input to a minimum. We discuss two strategies towards this goal: (1) automated optimization of hyperparameters (including mechanisms for feature selection, preprocessing, model selection, etc) and (2) the development of algorithms with reduced sets of hyperparameters. Since many research directions (e.g., deep learning), show a tendency towards increasingly complex algorithms with more and more hyperparamters, the demand for both of these strategies continuously increases. We review recent hyperparameter optimization methods and discuss data-driven approaches to avoid the introduction of hyperparameters using unsupervised learning. We end in discussing how these complementary strategies can work hand-in-hand, representing a very promising approach towards autonomous machine learning.
Nothwang, H. G., Ebbers, L., Schlüter, T., and Willaredt, M. A., The emerging framework of mammalian auditory hindbrain development, Cell Tissue Res., vol. 361, no. 1. 2015.
Abstract
Willaredt, M. A., Schlüter, T., and Nothwang, H. G., The gene regulatory networks underlying formation of the auditory hindbrain, Cell. Mol. Life Sci., vol. 72, no. 3. 2015.
Abstract DOIFull Text
Llano, O., Smirnov, S., Soni, S., Golubtsov, A., Guillemin, I., Hotulainen, P., Medina, I., Nothwang, H. G., Rivera, C., and Ludwig, A., KCC2 regulates actin dynamics in dendritic spines via interaction with β-PIX, J. Cell Biol., vol. 209, no. 5. 2015.
Abstract DOIFull Text
Chloride extrusion in mature neurons is largely mediated by the neuron-specific potassium-chloride cotransporter KCC2. In addition, independently of its chloride transport function, KCC2 regulates the development and morphology of dendritic spines through structural interactions with the actin cytoskeleton. The mechanism of this effect remains largely unknown. In this paper, we show a novel pathway for KCC2-mediated regulation of the actin cytoskeleton in neurons. We found that KCC2, through interaction with the b isoform of Rac/Cdc42 guanine nucleotide exchange factor β-PIX, regulates the activity of Rac1 GTPase and the phosphorylation of one of the major actin-regulating proteins, cofilin-1. KCC2-deficient neurons had abnormally high levels of phosphorylated cofilin-1. Consistently, dendritic spines of these neurons exhibited a large pool of stable actin, resulting in reduced spine motility and diminished density of functional synapses. In conclusion, we describe a novel signaling pathway that couples KCC2 to the cytoskeleton and regulates the formation of glutamatergic synapses.
Mahadevan, V., Dargaei, Z., Ivakine, E., Hartmann, A. -M., Ng, D., Chevrier, J., Ormond, J., Nothwang, H. G., McInnes, R., and Woodin, M. A., Neto2-null mice have impaired GABAergic inhibition and are susceptible to seizures, Front. Cell. Neurosci., vol. 9:368. 2015.
Abstract
Neto2 is a transmembrane protein that interacts with the neuron-specific K+-Cl− cotransporter (KCC2) in the central nervous system (CNS). Efficient KCC2 transport is essential for setting the neuronal Cl− gradient, which is required for fast GABAergic inhibition. Neto2 is required to maintain the normal abundance of KCC2 in neurons, and increases KCC2 function by binding to the active oligomeric form of this cotransporter. In the present study, we characterized GABAergic inhibition and KCC2-mediated neuronal chloride homeostasis in pyramidal neurons from adult hippocampal slices. Using gramicidin perforated patch clamp recordings we found that the reversal potential for GABA (EGABA) was significantly depolarized. We also observed that surface levels of KCC2 and phosphorylation of KCC2 serine 940 (Ser940) were reduced in Neto2−/− neurons compared to wild-type controls. To examine GABAergic inhibition we recorded spontaneous inhibitory postsynaptic currents (sIPSCs) and found that Neto2−/− neurons had significant reductions in both their amplitude and frequency. Based on the critical role of Neto2 in regulating GABAergic inhibition we rationalized that Neto2-null mice would be prone to seizure activity. We found that Neto2-null mice demonstrated a decrease in the latency to pentylenetetrazole (PTZ)-induced seizures and an increase in seizure severity.
Hartmann, A. -maria and Nothwang, H. G., Molecular and evolutionary insights into the structural organization of cation chloride cotransporters, Front. Cell Neurosci, vol. 8:470. 2015.
DOIFull Text
Nothwang, H. G., Ebbers, L., Schlüter, T., and Willaredt, M. A., Erratum to: The emerging framework of mammalian auditory hindbrain development, Cell Tissue Res., vol. 361, no. 2. 2015.
Abstract
Ebbers, L., Satheesh, S. V., Janz, K., Ruettiger, L., Blosa, M., Hofmann, F., Morawski, M., Griesemer, D., Knipper, M., Friauf, E., and Nothwang, H. G., L-type Calcium Channel Ca(v)1.2 Is Required for Maintenance of Auditory Brainstem Nuclei, JOURNAL OF BIOLOGICAL CHEMISTRY, vol. 290, no. 39. 2015.
Abstract
Ca(v)1.2andCa(v)1.3are the major L-type voltage-gated Ca2+ channels in the CNS. Yet, their individual in vivo functions are largely unknown. Both channel subunits are expressed in the auditory brainstem, where Ca(v)1.3 is essential for proper maturation. Here, we investigated the role of Ca(v)1.2 by targeted deletion in the mouse embryonic auditory brainstem. Similar to Ca(v)1.3, loss of Ca(v)1.2 resulted in a significant decrease in the volume and cell number of auditory nuclei. Contrary to the deletion of Ca(v)1.3, the action potentials of lateral superior olive (LSO) neurons were narrower compared with controls, whereas the firing behavior and neurotransmission appeared unchanged. Furthermore, auditory brainstem responses were nearly normal in mice lacking Ca(v)1.2. Perineuronal nets were also unaffected. The medial nucleus of the trapezoid body underwent a rapid cell loss between postnatal days P0 and P4, shortly after circuit formation. Phosphorylated cAMP response element-binding protein (CREB), nuclear NFATc4, and the expression levels of p75NTR, Fas, and FasL did not correlate with cell death. These data demonstrate for the first time that both Ca(v)1.2 and Ca(v)1.3 are necessary for neuronal survival but are differentially required for the biophysical properties of neurons. Thus, they perform common as well as distinct functions in the same tissue.
Eckhard, A., Dos Santos, A., Liu, W., Bassiouni, M., Arnold, H., Gleiser, C., Hirt, B., Harteneck, C., Müller, M., Rask-Andersen, H., and Löwenheim, H., Regulation of the perilymphatic–endolymphatic water shunt in the cochlea by membrane translocation of aquaporin-5, Eur. J. Physiol., vol. 467, no. 12. 2015.
Abstract DOI
Volume homeostasis of the cochlear endolymph depends on radial and longitudinal endolymph movements (LEMs). LEMs measured in vivo have been exclusively recognized under physiologically challenging conditions, such as experimentally induced alterations of perilymph osmolarity or endolymph volume. The regulatory mechanisms that adjust LEMs to the physiological requirements of endolymph volume homeostasis remain unknown. Here, we describe the formation of an aquaporin (AQP)-based “water shunt” during the postnatal development of the mouse cochlea and its regulation by different triggers. The final complementary expression pattern of AQP5 (apical membrane) and AQP4 (basolateral membrane) in outer sulcus cells (OSCs) of the cochlear apex is acquired at the onset of hearing function (postnatal day (p)8–p12). In vitro, hyperosmolar perfusion of the perilymphatic fluid spaces or the administration of the muscarinic agonist pilocarpine in cochlear explants (p14) induced the translocation of AQP5 channel proteins into the apical membranes of OSCs. AQP5 membrane translocation was blocked by the muscarinic antagonist atropine. The muscarinic M3 acetylcholine (ACh) receptor (M3R) was identified in murine OSCs via mRNA expression, immunolabeling, and in vitro binding studies using an M3R-specific fluorescent ligand. Finally, the water shunt elements AQP4, AQP5, and M3R were also demonstrated in OSCs of the human cochlea. The regulation of the AQP4/AQP5 water shunt in OSCs of the cochlear apex provides a molecular basis for regulated endolymphatic volume homeostasis. Moreover, its dysregulation or disruption may have pathophysiologic implications for clinical conditions related to endolymphatic hydrops, such as Ménière’s disease.
Bako, P., Bassiouni, M., Eckhard, A., Gerlinger, I., Frick, C., Löwenheim, H., and Müller, M., Methyl methacrylate embedding to study the morphology and immunohistochemistry of adult guinea pig and mouse cochleae, J. Neurosci. Methods, vol. 254. 2015.
Abstract DOI
Background: Histological analysis of the cochlea is required to understand the physiological and pathological processes in the inner ear. In the past, many embedding techniques have been tested in the cochlea to find an optimal protocol that gives both good morphological and immunohistochemical results. Resins provide high quality cochlear morphology with reduced immunogenicity due to the higher polymerization temperature. New method: We used Technovit 9100 New (R), a low temperature embedding system based on methyl methacrylate, on adult guinea pig and mouse cochleae to evaluate preservation of the morphology and maintenance of the antigenicity. Results: Conventional toluidine blue staining, as well as immunohistochemical staining with a set of commonly used antibodies, showed highly preserved morphology and immunogenicity of decalcified adult guinea pig and mouse cochleae. Comparison with existing method(s): We demonstrate both, well-preserved morphology and preservation of antigenicity, superior to other embedding techniques. Conclusions: Our results showed that the Technovit 9100 New (R) embedding system provided highly preserved morphology and immunogenicity with our protocol in adult guinea pig and mouse cochleae.
Baltus, A. and Herrmann, C. S., Auditory temporal resolution is linked to resonance frequency of the auditory cortex, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 98, no. 1. pp. 1-7, Oct.-2015.
Abstract DOI
A brief silent gap embedded in an otherwise continuous sound is missed by a human listener when it falls below a certain threshold: the gap detection threshold. This can be interpreted as an indicator that auditory perception is a non-continuous process, during which acoustic input is fragmented into a discrete chain of events. Current research provides evidence for a covariation between rhythmic properties of speech and ongoing rhythmic activity in the brain. Therefore, the discretization of acoustic input is thought to facilitate speech processing. Ongoing oscillations in the auditory cortex are suggested to represent a neuronal mechanism which implements the discretization process and leads to a limited auditory temporal resolution. Since gap detection thresholds seem to vary considerably between individuals, the present study addresses the question of whether individual differences in the frequency of underlying ongoing oscillatory mechanisms can be associated with auditory temporal resolution. To address this question we determined an individual gap detection threshold and a preferred oscillatory frequency for each participant. The preferred frequency of the auditory cortex was identified using an auditory steady state response (ASSR) paradigm: amplitude-modulated sounds with modulation frequencies in the gamma range were presented binaurally; the frequency which elicited the largest spectral amplitude was considered the preferred oscillatory frequency. Our results show that individuals with higher preferred auditory frequencies perform significantly better in the gap detection task. Moreover, this correlation between oscillation frequency and gap detection was supported by high test-retest reliabilities for gap detection thresholds as well as preferred frequencies
Schicktanz, S., Amelung, T., and Rieger, J. W., Qualitative assessment of patients’ attitudes and expectations toward BCIs and implications for future technology development, Frontiers in Systems Neuroscience, vol. 9. Frontiers Media SA, p. 64, 27-Apr.-2015.
Abstract DOIFull Text
Brain-Computer-Interfaces (BCIs) are important for the next generation of neuro-prosthesis innovations. Only few pilot projects have tested patients’ abilities to control BCIs as well as their satisfaction with the offered technologies. On the one hand, little is known about patients’ moral attitudes towards the benefit-risk-ratio of BCIs as well as their needs, priorities, and expectations. On the other hand, ethics experts intensively discuss the general risks of BCIs as well as the limits of neuro-enhancement. To our knowledge, we present here the first qualitative interview study with ten chronic patients matching the potential user categories for motor and communication BCIs to assess their practical and moral attitudes towards this technology. The interviews reveal practical and moral attitudes towards motor BCIs that can impact future technology development. We discuss our empirical findings on patients’ perspectives and compare them to neuroscientists’ and ethicists’ perspectives. This analysis indicates only partial overlap between the potential users’ and the experts’ assessments of BCI-technology. It points out the importance of considering the needs and desires of the targeted patient group. Based on our findings, we suggest a multi-fold approach to the development of clinical BCIs, rooted in the participatory technology-development. We conclude that clinical BCI development needs to be explored in a disease-related and culturally sensitive way.
Pannese, A., Herrmann, C. S., and Sussman, E., Analyzing the auditory scene: neurophysiologic evidence of a dissociation between detection of regularity and detection of change, Brain topography, vol. 28, no. 3. pp. 411-422, May-2015.
Abstract DOI
Detecting regularity and change in the environment is crucial for survival, as it enables making predictions about the world and informing goal-directed behavior. In the auditory modality, the detection of regularity involves segregating incoming sounds into distinct perceptual objects (stream segregation). The detection of change from this within-stream regularity is associated with the mismatch negativity, a component of auditory event-related brain potentials (ERPs). A central unanswered question is how the detection of regularity and the detection of change are interrelated, and whether attention affects the former, the latter, or both. Here we show that the detection of regularity and the detection of change can be empirically dissociated, and that attention modulates the detection of change without precluding the detection of regularity, and the perceptual organization of the auditory background into distinct streams. By applying frequency spectra analysis on the EEG of subjects engaged in a selective listening task, we found distinct peaks of ERP synchronization, corresponding to the rhythm of the frequency streams, independently of whether the stream was attended or ignored. Our results provide direct neurophysiological evidence of regularity detection in the auditory background, and show that it can occur independently of change detection and in the absence of attention
Vosskuhl, J., Strüber, D., and Herrmann, C. S., Transkranielle Wechselstromstimulation, Der Nervenarzt, vol. 86, no. 12. Springer, 2015.
Hartmann, A. -M., A SECOND EDITION OF APPROACHES. L. Edmunds (ed.) Approaches to Greek Myth. Second edition. Pp. x + 470, ills, maps. Baltimore: Johns Hopkins University Press, 2014 (first edition 1990). Paper, US$29.95 (Cased, US$69.95). ISBN: 978-1-4214-1419-5 (978-1-4214-1418-8 hbk)., The Class. Rev., vol. 66, no. 01. Cambridge University Press (CUP), pp. 22-24, 16-Nov.-2015.
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Kishkinev, D., Chernetsov, N., Pakhomov, A., Heyers, D., and Mouritsen, H., Eurasian reed warblers compensate for virtual magnetic displacement, CURRENT BIOLOGY, vol. 25, no. 19. CELL PRESS, Oct.-2015.
Abstract
Klar, M., Fenske, P., Vega, F. R., Dame, C., and Braeuer, A. U., Transcription factor Yin-Yang 2 alters neuronal outgrowth in vitro, CELL AND TISSUE RESEARCH, vol. 362, no. 2. SPRINGER, Nov.-2015.
Abstract
The Yin-Yang 2 (YY2) protein is the most recently described member of the family of YY transcription factors. Despite its high structural and functional homology with the well-characterized YY1, less is known about its role in biological processes. In previous studies, we have found differential yy2 mRNA expression levels in various cell types of the murine brain. To investigate the functional implication of yy2 in neurons, we have examined the influence of altered cellular yy2 concentrations during neuronal differentiation. Our results indicate that both the up- and down-regulation of yy2 significantly impairs the outgrowth of the major neurite of primary hippocampal neurons and the numbers of neuronal processes in proximate extensions. Moreover, enhanced expression of wild-type yy2 results in increased cell death, whereas elevated expression levels of a yy2 DNA-binding mutant have no effect on cell viability. Therefore, stringent regulation of the cellular yy2 content might be needed to ensure proper neurite outgrowth and cell vitality.
Pohland, M., Glumm, R., Stoenica, L., Hoeltje, M., Kiwit, J., Ahnert-Hilger, G., Strauss, U., Braeuer, A. U., Paul, F., and Glumm, J., Studying Axonal Outgrowth and Regeneration of the Corticospinal Tract in Organotypic Slice Cultures, JOURNAL OF NEUROTRAUMA, vol. 32, no. 19. MARY ANN LIEBERT, INC, Oct.-2015.
Abstract
Studies of axonal outgrowth and regeneration after spinal cord injury are hampered by the complexity of the events involved. Here, we present a simple and improved in vitro approach to investigate outgrowth, regeneration of the corticospinal tract, and intrinsic parenchymal responses. We prepared organotypic co-cultures using explants from the motor cortex of postnatal donor mice ubiquitously expressing green fluorescent protein and cervical spinal cord from wild type pups of the same age. Our data show that: a) motor-cortical outgrowth is already detectable after 1 d in culture and is source specific; b) treatment with neurotrophin-3 and C3 transferase from Clostridium botulinum significantly enhances axonal outgrowth during the course of cultivation; c) outgrowing axons form synaptic connections, as demonstrated by immunohistochemistry and calcium imaging; and d) migrating cells of motor-cortical origin can be reliably identified without previous tracing and are mostly neural precursors that survive and mature in the spinal cord parenchyma. Thus, our model is suitable for screening for candidate substances that enhance outgrowth and regeneration of the corticospinal tract and for studying the role of endogenous neural precursors after lesion induction.
Neubert, J., Wagner, S., Kiwit, J., Braeuer, A. U., and Glumm, J., New findings about iron oxide nanoparticles and their different effects on murine primary brain cells, INTERNATIONAL JOURNAL OF NANOMEDICINE, vol. 10. DOVE MEDICAL PRESS LTD, 2015.
Abstract
The physicochemical properties of superparamagnetic iron oxide nanoparticles (SPIOs) enable their application in the diagnostics and therapy of central nervous system diseases. However, since crucial information regarding side effects of particle-cell interactions within the central nervous system is still lacking, we investigated the influence of novel very small iron oxide particles or the clinically approved ferucarbotran or ferumoxytol on the vitality and morphology of brain cells. We exposed primary cell cultures of microglia and hippocampal neurons, as well as neuron-glia cocultures to varying concentrations of SPIOs for 6 and/or 24 hours, respectively. Here, we show that SPIO accumulation by microglia and subsequent morphological alterations strongly depend on the respective nanoparticle type. Microglial viability was severely compromised by high SPIO concentrations, except in the case of ferumoxytol. While ferumoxytol did not cause immediate microglial death, it induced severe morphological alterations and increased degeneration of primary neurons. Additionally, primary neurons clearly degenerated after very small iron oxide particle and ferucarbotran exposure. In neuron-glia cocultures, SPIOs rather stimulated the outgrowth of neuronal processes in a concentration- and particle-dependent manner. We conclude that the influence of SPIOs on brain cells not only depends on the particle type but also on the physiological system they are applied to.
Schroeder, J., Goetze, S., and Anemueller, J., Spectro-Temporal Gabor Filterbank Features for Acoustic Event Detection, IEEE-ACM TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING, vol. 23, no. 12. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Dec.-2015.
Abstract
Algorithms for the automatic detection and recognition of acoustic events are increasingly gaining relevance for the reliable and robust functioning of consumer, assistive and monitoring systems. The extraction of appropriate task relevant acoustic features from the raw sound signal clearly influences performance of subsequent statistical classification, in particular in adverse acoustic situations. The present contribution investigates the use of biologically-inspired features, derived from a filterbank of two-dimensional Gabor functions, that decompose the spectro-temporal power density into components which capture spectral, temporal and joint spectro-temporal modulation patterns. It is hypothesized that the comparably large joint spectral and temporal extent of these Gabor functions results in features that allow for robust classification. Evaluation of the proposed feature extraction scheme together with an hidden Markov model (HMM) classifier is conducted on two corpora comprising acoustic events in realistic adverse conditions from the D-CASE and CLEAR'07 evaluation campaigns. Relevance of each Gabor filter for classification is analyzed and an optimized parameter set for the Gabor filterbank (GFB) is identified. Performance of the optimized GFB is evaluated in comparison to other state-of-the-art algorithms on isolated event classification and on the full acoustic event detection (AED) including joint classification and temporal segmentation of events. Results show that Gabor features result in a signal representation that exhibits separated average class-specific patterns. An improvement in classification accuracy of up to 26\% relative to the Mel-frequency cepstral coefficient (MFCC) baseline is obtained with the optimized GFB. Further experiments demonstrate that this improvement cannot be explained by purely temporal or purely spectral Gabor basis functions. Rather, a GFB with features extending in joint spectro-temporal directions is required to obtain optimum performance. Performance on AED with the D-CASE challenge dataset is shown to improve on previous algorithms from the recent literature.
Kayser, H., Hohmann, V., Ewert, S. D., Kollmeier, B., and Anemueller, J., Robust auditory localization using probabilistic inference and coherence-based weighting of interaural cues, JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, vol. 138, no. 5. ACOUSTICAL SOC AMER AMER INST PHYSICS, Nov.-2015.
Abstract
Robust sound source localization is performed by the human auditory system even in challenging acoustic conditions and in previously unencountered, complex scenarios. Here a computational binaural localization model is proposed that possesses mechanisms for handling of corrupted or unreliable localization cues and generalization across different acoustic situations. Central to the model is the use of interaural coherence, measured as interaural vector strength (IVS), to dynamically weight the importance of observed interaural phase (IPD) and level (ILD) differences in frequency bands up to 1.4 kHz. This is accomplished through formulation of a probabilistic model in which the ILD and IPD distributions pertaining to a specific source location are dependent on observed interaural coherence. Bayesian computation of the direction-of-arrival probability map naturally leads to coherence-weighted integration of location cues across frequency and time. Results confirm the model's validity through statistical analyses of interaural parameter values. Simulated localization experiments show that even data points with low reliability (i.e., low IVS) can be exploited to enhance localization performance. A temporal integration length of at least 200 ms is required to gain a benefit; this is in accordance with previous psychoacoustic findings on temporal integration of spatial cues in the human auditory system. (C) 2015 Acoustical Society of America.
Moritz, N., Anemueller, J., and Kollmeier, B., An Auditory Inspired Amplitude Modulation Filter Bank for Robust Feature Extraction in Automatic Speech Recognition, IEEE-ACM TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING, vol. 23, no. 11. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Nov.-2015.
Abstract
The human ability to classify acoustic sounds is still unmatched compared to recent methods in machine learning. Psychoacoustic and physiological studies indicate that the auditory system of mammals decomposes audio signals into their acoustic and modulation frequency components prior to further analysis. Since it is known that most linguistic information is coded in amplitude fluctuations, mimicking temporal processing strategies of the auditory system in automatic speech recognition (ASR) promises to increase recognition accuracies. We present an amplitude modulation filter bank (AMFB) that is used as a feature extraction scheme in ASR systems. The time-frequency resolution of the employed FIR filters, i.e., bandwidth and modulation frequency settings, are adopted from a psychophysically inspired model of Dau et al. (1997) that was originally proposed to describe data from human psychoacoustics. Investigations on modulation phase indicate the need for preserving such information in amplitude modulation features. We show that the filter symmetry has an important impact on ASR performance. The proposed feature extraction scheme exhibits significant word error rate (WER) reductions using the Aurora-2, Aurora-4, and REVERB ASR tasks compared to other recent feature extraction methods, such as MFCC, FDLP, and PNCC features. Thereby, AMFB features reveal high robustness against additive noise, different transmission channel characteristics, and room reverberation. Using the Aurora-4 benchmark, for instance, an average WER of 12.33\% with raw and 11.31\% with bottleneck transformed features is attained, which constitutes a relative improvement of 19.6\% and 29.2\% over raw MFCC features, respectively.
Xiong, F., Meyer, B. T., Moritz, N., Rehr, R., Anemueller, J., Gerkmann, T., Doclo, S., and Goetze, S., Front-end technologies for robust ASR in reverberant environments-spectral enhancement-based dereverberation and auditory modulation filterbank features, EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING. SPRINGER INTERNATIONAL PUBLISHING AG, Aug.-2015.
Abstract
This paper presents extended techniques aiming at the improvement of automatic speech recognition (ASR) in single-channel scenarios in the context of the REVERB (REverberant Voice Enhancement and Recognition Benchmark) challenge. The focus is laid on the development and analysis of ASR front-end technologies covering speech enhancement and feature extraction. Speech enhancement is performed using a joint noise reduction and dereverberation system in the spectral domain based on estimates of the noise and late reverberation power spectral densities (PSDs). To obtain reliable estimates of the PSDs-even in acoustic conditions with positive direct-to-reverberation energy ratios (DRRs)-we adopt the statistical model of the room impulse response explicitly incorporating DRRs, as well in combination with a novel proposed joint estimator for the reverberation time T-60 and the DRR. The feature extraction approach is inspired by processing strategies of the auditory system, where an amplitude modulation filterbank is applied to extract the temporal modulation information. These techniques were shown to improve the REVERB baseline in our previous work. Here, we investigate if similar improvements are obtained when using a state-of-the-art ASR framework, and to what extent the results depend on the specific architecture of the back-end. Apart from conventional Gaussian mixture model (GMM)-hidden Markov model (HMM) back-ends, we consider subspace GMM (SGMM)-HMMs as well as deep neural networks in a hybrid system. The speech enhancement algorithm is found to be helpful in almost all conditions, with the exception of deep learning systems in matched training-test conditions. The auditory feature type improves the baseline for all system architectures. The relative word error rate reduction achieved by combining our front-end techniques with current back-ends is 52.7\% on average with the REVERB evaluation test set compared to our original REVERB result.
Tzvi, E., Stoldt, A., Witt, K., and Kraemer, U. M., Striatal-cerebellar networks mediate consolidation in a motor sequence learning task: An fMRI study using dynamic causal modelling, NEUROIMAGE, vol. 122. ACADEMIC PRESS INC ELSEVIER SCIENCE, Nov.-2015.
Abstract
The fast and slow learning stages of motor sequence learning are suggested to be realized through plasticity in a distributed cortico-striato-cerebellar network. To better understand the causal interactions within this network in the different phases of motor sequence learning, we investigated the effective connectivity within this network during encoding (Day 1) and after consolidation (Day 2) of a serial reaction time task. Using Dynamic Causal Modelling of fMRI data, we found general changes in network connections reflected in altered input nodes and endogenous connections when comparing the early and fast learning session to the late and slow learning session. Whereas encoding of a motor memory early on modulated several connections in a distributed network, slow learning resulted in a pruned network. More specifically, we found a negative modulation of connections from left M1 to right cerebellum, right premotor cortex to left cerebellum, as well as backward connections from putamen to cerebellum bilaterally in the encoding session. While connections during pre-sleep were significantly modulated by learning per se (i.e., specifically modulated by performance on sequence conditions), the connections observed after sleep were rather modulated by general performance (i.e., modulated by performance on both sequence and random conditions). A forward connection from left cerebellum to right putamen was found to be consistent across participants for the sequence condition only during slow learning. Together these findings suggest that whereas encoding in the fast learning phase requires plasticity in several connections implementing both motor and perceptual learning components, slow learning is mediated through connectivity from left cerebellum to right putamen. (C) 2015 Elsevier Inc. All rights reserved.
Reuter, S., Deuschl, G., Falk, D., Mehdorn, M., and Witt, K., Uncoupling of Dopaminergic and Subthalamic Stimulation: Life-Threatening DBS Withdrawal Syndrome, MOVEMENT DISORDERS, vol. 30, no. 10. WILEY-BLACKWELL, Sep.-2015.
Abstract
Background: Deep brain stimulation (DBS) in therapy for advanced Parkinson's disease (PD) is an accepted treatment. Infections of the system and other complications occasionally result in hardware removal and subsequent medical treatment alone for months. Methods: We have analyzed the clinical course of 15 patients requiring removal of at least parts of the DBS system, resulting in a cessation of stimulation. Results: Most had an uncomplicated return to medical treatment. Three had an unfavorable course during withdrawal, including two deaths. These patients had suffered from PD for more than 18 y and had had DBS for more than 8 y. Conclusions: We conclude that DBS withdrawal can be life- threatening, because the whole range of dopaminergic and nondopaminergic medical treatments may be ineffective at this stage. The lack of response to medical treatment might be attributable to advanced disease and longterm changes of the basal ganglia loop in PD. (c) 2015 International Parkinson and Movement Disorder Society
Alexoudi, A., Shalash, A., Knudsen, K., Witt, K., Mehdorn, M., Volkmann, J., and Deuschl, G., The medical treatment of patients with Parkinson's disease receiving subthalamic neurostimulation, PARKINSONISM \& RELATED DISORDERS, vol. 21, no. 6. ELSEVIER SCI LTD, Jun.-2015.
Abstract
Introduction: Deep brain stimulation of subthalamic nucleus (STN-DBS) for Parkinson's disease allows for a reduction in medication dosage. Changes in total levodopa equivalent daily dose (LEDD) have been frequently reported, there is little information about changes within the drug classes. Methods: We retrospectively assessed the changes in antiparkinsonian drugs dosages in 150 patients from one center who had preoperative and postoperative evaluations at 6 months and 3 years. Two long term subgroups with postoperative follow-up till the 5th-6th year (n = 58) and 10th year (n = 15) were included. Results: The major modifications in medication dosage occurred during the initial postoperative period. LEDD was reduced by 53.4\% compared to baseline at 6 months and 47.9\% at 3 years. Fifty six percent and 41.3\% of the patients were on monotherapy, 9.3\% on no medication at 6 months and 6.7\% at 3 years post surgery. Patients on levodopa, or dopamine agonists showed similar reductions. At the 3rd year the oldest group of patients showed a significant decrease in dopamine agonists. The number of patients treated with amantadine was significantly reduced; however the number of patients treated with antidepressants was significantly increased over the first 3 years. Annual medication costs per patient were decreased after the DBS-STN implantation by 61.3\% at 6 months and 55.4\% at 3 years. Conclusion: STN-DBS allows for a reduction in the dosage of medication and the costs are similarly reduced. In this cohort different medication groups were reduced to a similar extent. Patients' demographic factors did not play a major role in the selection of treatment. (C) 2015 Elsevier Ltd. All rights reserved.
Zeuner, K. E., Knutzen, A., Granert, O., Goetz, J., Wolff, S., Jansen, O., Dressler, D., Hefter, H., Hallett, M., Deuschl, G., van Eimeren, T., and Witt, K., Increased volume and impaired function: the role of the basal ganglia in writer's cramp, BRAIN AND BEHAVIOR, vol. 5, no. 2. JOHN WILEY \& SONS INC, Feb.-2015.
Abstract
IntroductionThe pathophysiology of writer's cramp, a task-specific dystonia, remains unclear. The objective of this study was to investigate the basal ganglia circuit and the cerebellum during a complex motor sequence learning task carried out with the nonaffected hand in writer's cramp patients. MethodsWe applied structural and functional imaging in 22 writer's cramp patients and 28 matched controls using 3T MRI. With the asymptomatic left hand all participants learned a complex, sequential, five-element sequence-tapping task as accurately and quickly as possible. Functional imaging was measured during a repeated (15 times), fixed block design with tapping (30sec) and rest (30sec). Additionally, gray matter volume of the basal ganglia was analyzed using voxel-based morphometry (VBM). ResultsWhile behavior was comparable between groups, after small volume correction the anterior part of the right putamen and the left globus pallidus exhibited reduced blood oxygen level-dependent (BOLD) activity in patients during the sequential finger-tapping task. VBM analysis showed larger gray matter volume bilateral in the posterior part of the putamen and globus pallidus. There were no group differences in the cerebellum. ConclusionThe results indicate an impairment of anterior basal ganglia loops involved in producing complex sequential movements of the unaffected hand. These findings are in line with previous reports of reduced neuronal activity in the globus pallidus internus. Higher gray matter volume of the putamen and globus pallidus may stem from elevated activity of the direct pathway, which could reflect a compensatory phenomenon or a primary predisposition, that is, endophenotypic trait.
Balzer, F. and Schiek, M., Automated Polarized Microscopy Analysis of Fluorescent and Birefrigent Nano- and Microfibers, Springer Series in Materials Science. Springer Science + Business Media, pp. 151-176, 2015.
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Isken, M., Frenken, T., Frenken, M., and Hein, A., Towards Pervasive Mobility Assessments in Clinical and Domestic Environments, Lecture Notes in Computer Science. Springer Science + Business Media, pp. 71-98, 2015.
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Kretschmer, T. and Heinen, C., Iatrogenic Injuries of the Nerves, Nerves and Nerve Injuries. Elsevier BV, pp. 557-585, 2015.
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Rösler, M. and Philipsen, A., ADHS im Erwachsenenalter (ICD-10 F90), Therapie Psychischer Erkrankungen. Elsevier BV, pp. 395-409, 2015.
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Ebert, D., Philipsen, A., and Heßlinger, B., Die Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) des Erwachsenenalters, Psychische Erkrankungen. Elsevier BV, pp. 803-812, 2015.
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Weyland, A. and Jelschen, F., Hämodynamisches Monitoring in der Sepsis, Sepsis und MODS. Springer Science + Business Media, pp. 101-116, 11-Nov.-2015.
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Richter-Landsberg, C., The α-Tubulin Deacetylase HDAC6 in Aggresome Formation and Autophagy, Autophagy: Cancer, Other Pathologies, Inflammation, Immunity, Infection, and Aging. Elsevier BV, pp. 273-282, 2015.
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Lienau, C., Raschke, M., and Ropers, C., Ultrafast Nano-Focusing for Imaging and Spectroscopy with Electrons and Light, From Basic Science to Applications. Wiley-Blackwell, pp. 281-324, 30-Jan.-2015.
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Diederich, A., Decision and Choice: Sequential Decision Making, International Encyclopedia of the Social & Behavioral Sciences. Elsevier BV, pp. 906-910, 2015.
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Colonius, H. and Marley, A. A. J., Decision and choice: random utility models of choice and response time, International Encyclopedia of the Social & Behavioral Sciences, vol. 5. pp. 901–905, 2015.
Abstract
Horse race random utility models for choice and response time are studied, and conditions on the observable choice probabilities and decision times necessary and sufficient for a random utility representation are investigated. We state conditions for stochastic independence of option chosen from time of choice. Context-free accumulator models, like the linear ballistic accumulator model, are presented as horse race models with additional structure. Models with multiplicative and with additive drift rate variability are discussed.
Colonius, H., From coupling to copula, Contextuality from Quantum Physics to Psychology. pp. 51–62, 2015.
Abstract
Reichert, C., Kennel, M., Kruse, R., Heinze, H. -J., Schmucker, U., Hinrichs, H., and Rieger, J. W., Brain-Controlled Selection of Objects Combined with Autonomous Robotic Grasping, Neurotechnology, Electronics, and Informatics. Springer Science + Business Media, pp. 65-77, 2015.
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Puschmann, S., Sandmann, P., Bendixen, A., and Thiel, C. M., Age-related hearing loss increases cross-modal distractibility, Int. Conf. Cog. Hear. Sc. Comm. (CHSCOM). 2015.
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Debener, S., Hearing Impairment and The Brain: Cross-modal Reorganization after Cochlear Implantation, J. Int. Adv. Otol. (EFAS), vol. 11 (suppl 1). 2015.
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Müller, J., Kollmeier, B., Debener, S., and Brand, T., Assessing the influence of auditory attention on sentence recognition using neural entrainment, Int. Conf. Cog. Hear. Sc. Comm. (CHSCOM). 2015.
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Stropahl, M., Plotz, K., Schönfeld, R., Lenarz, T., Sandmann, P., De Vos, M., and Debener, S., Hearing Faces: Lip Reading and Face Processing in Cochlear Implant Users, Int. Conf. Cog. Hear. Sc. Comm. (CHSCOM). 2015.
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Jäger, M., Debener, S., Mirkovic, B., and Bleichner, M., Selective spatial attention in a two-stream auditory steady-state paradigm, Int. Conf. Cog. Hear. Sc. Comm. (CHSCOM). 2015.
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Mirkovic, B., Debener, S., Jäger, M., and De Vos, M., Attended speech reconstruction from EEG: towards the online, every day application, Int. Conf. Cog. Hear. Sc. Comm. (CHSCOM). 2015.
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Winkler, I., Debener, S., Müller, K. -R., and Tangermann, M., On the influence of high-pass filtering on ICA-based artifact reduction in EEG-ERP, International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) , vol. (online). 2015.
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Standard artifact removal methods for electroen- cephalographic (EEG) signals are either based on Independent Component Analysis (ICA) or they regress out ocular activity measured at electrooculogram (EOG) channels. Successful ICA- based artifact reduction relies on suitable pre-processing. Here we systematically evaluate the effects of high-pass filtering at different frequencies. Offline analyses were based on event- related potential data from 21 participants performing a standard auditory oddball task and an automatic artifactual component classifier method (MARA). As a pre-processing step for ICA, high-pass filtering between 1-2Hz consistently produced good results in terms of signal-to-noise ratio (SNR), single-trial classification accuracy and the percentage of ’near- dipolar’ ICA components. Relative to no artifact reduction, ICA-based artifact removal significantly improved SNR and classification accuracy. This was not the case for a regression- based approach to remove EOG artifacts.
Schepers, I. M., Beck, A. -k., Bräuer, S., Schwabe, K., Lütjens, G., Krauss, J. K., and Rieger, J. W., Electrophysiological Recordings In Humans Implicate The Involvement Of The Centromedian-Parafascicular Complex In Speech And Non-Speech Cue Signaling, Brain States: Characterization and Neuromodulation by DBS. 2015.
Finke, M., Büchner, A., Ruigendijk, E., Meyer, M., and Sandmann, P., Does verbal intelligence relates to speech intelligibility in cochlear-implant users?, J. Int. Adv. Otol. (EFAS), vol. 11 (suppl 1). 2015.
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Following cochlear-implant (CI) implantation, the (re-)acquisition of speech intelligibility is considered as a desirable result of CI rehabilitation. The successful adaptation of auditory cognition to the CI input depends to a substantial degree on individual factors. However, it is currently not well understood whether in CI users the observed differences in speech intelligibility and listening effort are related to working memory capacity (WMC) and/or linguistic competence. The aim of the present study was to investigate whether cognitive/ linguistic competence relates to speech understanding with a CI. We recorded event-related potentials (ERPs) to study the neuronal processing of auditory stimuli at early and later processing stages in the auditory hierarchy. CI users
Finke, M., Büchner, A., Ruigendijk, E., Meyer, M., and Sandmann, P., On the relationship between speech understanding and cognition in cochlear-implant users, Int. Conf. Cog. Hear. Sc. Comm. (CHSCOM). 2015.
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Laumen, G., Tollin, D., and Klump, G. M., A Comparison of the Binaural Difference Potential of the Auditory Brainstem Response in the Young and Old Mongolian Gerbil (Meriones unguiculatus), Assoc. Res. Otolaryng. MidWinter Meeting (ARO), vol. 38, no. PS-659. 2015.
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Background The auditory brainstem response (ABR) is a clinical non-inva- sive tool for the investigation of hearing abilities (e.g. auditory thresholds) and the determination of hearing loss. The binau- ral difference potential (BDP) of the ABR, yields information about binaural interaction within the brainstem. To study the influence of age on physiological mechanisms underlying bin- aural hearing, BDPs of young and old gerbils were measured for different interaural times (ITD) and level differences (ILD). Methods ABRs and associated BDPs of ketamine-anesthetized young (<1 year;n=10) and old (>3 years;n=9) gerbils were measured at ~30dB above threshold using flat frequency spectrum (1- 14 kHz) click stimuli presented monaurally and binaurally with ITDs ranging from ±2000 µs and ILDs ranging from ±30 dB. Needle electrodes were placed at vertex and neck. The am- plitudes and latencies of DN1, and the corresponding binau- rally-evoked ABR wave IV were determined. Results The so-called DN1 peak of the BDP correlates in its latency with wave IV of the ABR indicates an inhibitory-reduction in the binaural ABR amplitude. For both young and old gerbils, an increase in latency with increasing ITDs was observed for both the DN1 and binaural wave IV, while different ILDs had no effect on the latency of these responses. With increas- ing ITDs the amplitude of the DN1 and binaural wave IV de- creased in both age groups. However, older animals showed overall lower DN1 amplitudes than younger animals. More- over, the amplitude of the DN1 decreased with increasing ILDs in both age groups with lower amplitudes in old gerbils. In contrast the amplitude of the binaural wave IV increased with increasing ILDs in the young group whereas ILD had only little effect on the binaural wave IV for old individuals. Conclusion The binaurally-evoked ABR was smaller in amplitude than the sum of monaurally-evoked ABRs. Therefore, the results suggest that the BDP arises from IE-type neurons in the later- al superior olive (LSO) or dorsal nucleus of the lateral lemniscus (DNLL). The decreased amplitude and longer latency of the DN1 component might be due to shifts in the timing of ex- citatory/inhibitory inputs from both sites and delays of these inputs, respectively. The reduction in the DN1 amplitude for old individuals might be explained by a reduced inhibitory in- put into the LSO. This could originate from a decrease in in- hibitory neurotransmitter and/or response synchrony in older individuals.
Thiemann, J., Doclo, S., and van de Par, S., Features for speaker localization in multichannel bilateral hearing aids, Eur. Signal Process. Conf. (EUSIPCO). 2015.
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Jukić, A., Waterschoot, T., Gerkmann, T., and Doclo, S., Group sparsity for mimo speech dereverberation, IEEE Work. Appl. Signal Process. to Audio Acoust. (WASPAA). IEEE, 2015.
Abstract
Schepker, H., Hülsmeier, D., Rennies, J., and Doclo, S., Model-based integration of reverberation for noise-adaptive near-end listening enhancement, Conf. Int. Speech Comm. Assoc. (Interspeech). 2015.
Abstract
Cauchi, B., Naylor, P. A., Gerkmann, T., Doclo, S., and Goetze, S., LATE REVERBERANT SPECTRAL VARIANCE ESTIMATION USING ACOUSTIC CHANNEL EQUALIZATION, Eur. Signal Process. Conf. (EUSIPCO). 2015.
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In many single- and multi-channel speech dereverberation methods an estimate of the late reverberant spectral vari- ance (LRSV) is required. Contrary to LRSV estimators based on room acoustical properties, such as reverberation time, or based on isotropic models of the reverberant sound field, in this paper we propose to use acoustic channel equalization with estimated room impulse responses (RIRs) for LRSV estimation. Unlike the typical application of acoustic channel equalization, where the objective is to estimate the anechoic or the early reverberant speech component, here the late reverberant part of the estimated RIR is set as the target re- sponse. The combination of the proposed LRSV estimator with a beamformer and a spectral gain aims at a tradeoff between the performance of acoustic channel equalization and the robustness of methods based on models of the rever- berant sound field. The performance, evaluated for different levels of RIR estimation error, is compared to the results ob- tained using a maximum likelihood estimator (MLE) of the LRSV, based on an isotropic model of the reverberant sound field, and to a state-of-the-art acoustic channel equalization method. Experimental results for different acoustic scenarios show that for medium levels of RIR estimation errors the proposed method outperforms acoustic channel equalization as well as the maximum-likelihood LRSV estimator in terms of instrumental speech quality measures.
Hu, M., Peso Parada, P., Sharma, D., Doclo, S., van Waterschoot, T., Brookes, M., and Naylor, P. A., Single-channel speaker diarization based on spatial features, IEEE Work. Appl. Signal Process. to Audio Acoust. (WASPAA). 2015.
Abstract
Aroudi, A., Mirkovic, B., De Vos, M., and Doclo, S., Influence of Noisy Reference Signals on Selective Attention Decoding, Proc. International Conference of the IEEE Engineering in Medicine and Biology Society. 2015.
Abstract
Hu, M., Doclo, S., Sharma, D., Brookes, M., and Naylor, P. A., Noise-robust blind system identification algorithms based on a Rayleight quotient cost function, Eur. Signal Process. Conf. (EUSIPCO). 2015.
Abstract
Rennies, J., Volgenandt, A., Schepker, H., and Doclo, S., Model-based adaptive pre-processing of speech for enhanced intelligibility in noise and reverberation, Conf. Int. Speech Comm. Assoc. (Interspeech). 2015.
Abstract
Krawczyk-Becker, M., Fischer, D., and Gerkmann, T., Utilizing Spectro-Temporal Correlations for an Improved Speech Presence Probability Based Noise Power Estimation, IEEE Int. Conf. Acoust. Speech Sig. Process. (ICASSP). 2015.
Abstract
Rehr, R. and Gerkmann, T., On the bias of adaptive first-order recursive smoothing, IEEE Work. Appl. Signal Process. to Audio Acoust. (WASPAA). IEEE, 2015.
Abstract
In signal processing, first-order recursive smoothing is often used to determine the mean of a nonstationary random variable. In order to find a better compromise between the tracking speed and the variance of the estimate, adaptive smoothing factors have been proposed, e.g., for single-channel background noise power spectral density estimators. In this paper, the bias of recursive smoothing using adaptive smoothing functions is investigated. For adaptive functions that do not depend on the estimated mean an analytical derivation of the bias is given. For adaptive functions having a dependence on the recursively estimated mean, an iterative procedure is proposed which allows to approximately determine the bias with a sufficiently high precision.
Krawczyk-Becker, M. and Gerkmann, T., MMSE-optimal combination of wiener filtering and harmonic model based speech enhancement in a general framework, IEEE Work. Appl. Signal Process. to Audio Acoust. (WASPAA). 2015.
Abstract
Josupeit, A. and Hohmann, V., Modeling localization and word recognition in a multitalker setting, Proc. German Annual Conf. Acoust. (DAGA). 2015.
Abstract
In ”cocktail party” situations with multiple talkers, listeners are able to identify, track and understand a target talker. This study investigates an auditory model framework to simulate aspects of this ”Auditory Scene Analysis”. In particular, a call-sign-based listening task with spatially separated talkers [Brungart and Simpson, Perception & Psychophysics, 2007, 69 (1)] is modeled. The subject’s first task is to identify the target talker’s identity and location via a fixed call-sign (”Baron”). This is obtained by a template matching procedure using harmonicity features to identify target-dominant time-frequency bins, which serve as a basis for the readout of target-related binaural information [cf. Josupeit and Hohmann, DAGA 2014]. The subject’s second task is to recognize the color and number words uttered by the target talker. This is obtained by extracting the target- related harmonicity features based on the previously estimated location. The most likely color and number are then estimated using a ”reverse” template matching procedure. Pilot tests show that both the identification of the target talker and its location, as well as the recognition of color and number work well for two talker conditions and that performance degrades for more talkers. [supported by DFG SFB/TRR 31]
Heeren, J., Grimm, G., and Hohmann, V., The Influence of Dynamic Binaural Cues on Speech Intelligibility in Headphone and Free-field Listening, Proc. German Annual Conf. Acoust. (DAGA). 2015.
Abstract
Grimm, G., Herzke, T., Ewert, S. D., and Hohmann, V., Implementation and Evaluation of an Experimental Hearing Aid Dynamic Range Compressor, Proc. German Annual Conf. Acoust. (DAGA). 2015.
Abstract
Mfon, E. V., Grimm, G., and Hohmann, V., Analysis of the Influence of Repositioning Hearing Aids on Interaural Time Difference (ITD) Errors of Bilateral Directional Microphones in Hearing Aids, Proc. German Annual Conf. Acoust. (DAGA). 2015.
Abstract
Williges, B., Dietz, M., Hohmann, V., and Jürgens, T., Modellierung des elektro-akustischen Gewinns: Welche Rolle spielt der bessere akustische Input und welche Rolle die retrocochleäre Verarbeitung?, Jahrestagung der Dt. Ges. für Audiologie (DGA). 2015.
Abstract
Jürgens, T., Büchner, A., Hohmann, V., and Nogueira, W., Individual prediction of speech intelligibility in cochlear implant users, Jahrestagung der Dt. Ges. für Audiologie (DGA). 2015.
Abstract
Williges, B., Hohmann, V., Dietz, M., and Jürgens, T., Modelling of Spatial Release from Masking in Simulated Cochlear Implanted and Electroacoustic Listeners, Assoc. Res. Otolaryng. MidWinter Meeting (ARO), vol. 38, no. PS-190. 2015.
AbstractFull Text
Cochlear implant users, who can use an additional hearing aid in their implanted or non-implanted ear often show better speech intelligibility performance with than without the hear- ing aid. Many studies have assessed this “electroacoustic benefit” using spatially co-located speech and noise. Howev- er, for normal-hearing listeners, it is well known that separat- ing speech and noise also leads to improved speech intelligi- bility due to better-ear listening and binaural processing. The amount of this “spatial release of masking” depends on the acoustic condition and the individual hearing loss. Goals of the study: The goals of this study are to assess (i) the electroacoustic benefit and (ii) possible binaural cues for speech perception in different combinations of simulated electric and acoustic hearing and different spatial positions of speech and noise. Furthermore (iii), a model of binaural speech intelligibility is used to predict the results obtained from the speech recogni- tion experiments. Methods: A headphone experiment with virtual acoustics was designed to assess speech-in-noise-performance (speech reception thresholds, SRTs) using a sentence test in German. A vocod- er (mimicking closely the signal processing and physiology in electric hearing) and a low-frequency band pass were used to simulate 10 different forms of “hearing configurations” (bi- lateral CI, bimodal, hybrid monaural and others). SRTs were assessed for 3 noise azimuths with 10 normal-hearing listen- ers. A standard model of binaural speech intelligibility (BSIM) in combination with the same signal processing as used for the experiments was used for the predictions. Results: Electroacoustic benefit was found in monaural and symmet- ric binaural electroacoustic hearing for all three noise direc- tions, and in bimodal hearing with additional acoustic hearing on the implanted ear. No electroacoustic benefit was found for bimodal hearing. Head shadow (around 10 dB) and bin- aural summation were found for bilateral cochlear implanted condition and bilateral electroacoustic condition; in addition, binaural squelch was found for the latter configuration. The model of binaural speech intelligibility showed considerable matches to almost all measured SRTs, when fitted to only two conditions. Electroacoustic benefits and quantitative amounts of binaural cues agreed with measurements. Conclusion: Acoustic hearing in combination with simulated cochlear im- plantation offers electroacoustic benefit in spatially co-located and spatially separated speech and noise conditions. These effects can be successfully modelled using a standard model of (normal) binaural speech intelligibility, which indicates that the interaction between the electroacoustic input and binaural processing is captured by the model.
Seifert, C., Payá-Vayá, G., Blume, H., Herzke, T., and Hohmann, V., A mobile SoC-based platform for evaluating hearing aid algorithms and architectures, 2015 IEEE 5th International Conference on Consumer Electronics - Berlin (ICCE-Berlin). IEEE, 2015.
Abstract
Oetjen, A., Volk, P., and van de Par, S., Tonality perception of stationary and transient signals, EuroNoise. 2015.
AbstractFull Text
Haeussler, A. and van de Par, S., Spectral and perceptual properties of a transfer chain of two rooms, EuroNoise. 2015.
AbstractFull Text
Grosse, J. and van de Par, S., Evaluation of a perceptually optimized room-in-room reproduction method for playback room compensation, EuroNoise. 2015.
AbstractFull Text
Thiemann, J., Escher, A., and van de Par, S., Multiple Model High-Spatial Resolution HRTF Measurements, Proc. German Annual Conf. Acoust. (DAGA). 2015.
Abstract
Verhulst, S., Ernst, F., and van de Par, S., In Search for the Cochlear Neuropathy Component of Audiometric Hearing Loss, Assoc. Res. Otolaryng. MidWinter Meeting (ARO), vol. 38, no. PS-708. 2015.
AbstractFull Text
The finding that cochlear neuropathy can greatly reduce the number of auditory nerve-fibers available to encode sound while leaving auditory thresholds intact, has significantly changed our views on hearing loss. Human perceptual con- sequences of cochlear neuropathy are likely related to cod- ing fidelity of supra-threshold sound, and more pronounced in noisy scenarios where redundancy in auditory information coding is important. Recent studies have focused on isolat- ing this component of hearing loss in normal-hearing listeners and reported correlations between EEG metrics and psycho- acoustic tasks targeting temporal coding precision, that were uncorrelated to audibility. However, it is not known how co- chlear neuropathy interacts with the well-studied outer-hair- cell-loss component of hearing loss, or whether cochlear neu- ropathy is equally important. This study tries to find answers through the design of psycho- acoustic tasks with various types of masking noise to target performance either to be limited by the auditory filter width (broadband noise), or by temporal coding fidelity (narrow- band noise). We tested both clinically normal-hearing listen- ers and listeners with mild-to-moderate losses, and correlated our results with a metric of pre-neural performance (DPOAE growth), and one of brainstem coding fidelity (ABR and EFR). In the broadband noise condition, signal-to-noise ratios for pure-tones at fixed stimulus levels were dominated by the audiometric losses. The higher the loss, the smaller the de- crease of performance as stimulus level increased, consis- tent with the idea that the increase of the amount of noise entering auditory filters as stimulus level increases is less pronounced for subjects that already have wider filters at lower stimulus levels. In the narrowband conditions, people with elevated thresholds often outperformed normal-hearing listeners. Cochlear neuropathy, as a loss of redundancy of coding within a single auditory filter, may be counteracted by cochlear compression loss leading to effective modulation depth enhancement at the output of the individual filter for listeners with elevated thresholds, compared to normal-hear- ing listeners that don’t have this compression loss benefit. We are currently further analyzing these results in relation to the recorded otoacoustic emission and brainstem EEG metrics to see whether individual differences in performance are caused by differences in cochlear mechanics, or whether reduced coding fidelity at the auditory brainstem can explain these results.
Gonçalves, P., Hildebrandt, K. J., Linden, J. F., and Sahani, M., Optogenetic modulation of transient and sustained response to tones in auditory cortex of awake mice, Int. Conf. Computational Systems Neuroscience (COSYNE). 2015.
Abstract
Osterhagen, L. and Hildebrandt, K. J., The role of parvalbumin-positive interneurons in auditory gap detection, Neurosci. (SfN). 2015.
Abstract
Hildebrandt, K. J., Gonçalves, P. J., Linden, J. F., and , Activation of parvalbumin-positive interneurons enhances transient responses and changes tuning of offset responses in awake auditory cortex, Neural Coding, Computation and Dynamics 2015 (NCCD2015). 2015.
AbstractFull Text
Alterations of cortical inhibition have been proposed to play a crucial role in modulation of cortical activity. While optogenetic manipulation of different functional groups of interneurons has become an important tool to study the roles of different cells in sensory processing, the timing of light relative to sensory stimulation becomes a confounding factor, and the pattern of supra-threshold activation of inhibitory neurons may not be physiologically accurate. Here, we circumvent these limitations by using stable step-function opsin (SSFO), which can be rendered continuously active or inactive with short pulses of light. We expressed SSFO in parvalbumin-positive (PV+) interneurons in the primary auditory cortex of mice, and recorded both local field potentials (LFP) and spiking responses to tone pips of varying frequency in awake animals. Prolonged low-level activation of PV+ cells profoundly changed the dynamics of spike responses in several and diverse ways. While spontaneous activity and sustained responses to the tones were mostly suppressed during PV+ activation, onset and offset responses were either enhanced or reduced less than spontaneous responses, thus increasing signal-to-noise ratio. More consistently, we observed that best frequencies of offset responses shifted towards lower frequency by as much as an octave when SSFO was turned on. This shift was much less pronounced in sustained and onset responses. Additionally, PV+ activation resulted in finer tuning of offset responses in the majority of recorded cells. Intriguingly, tuning broadened for a small fraction of units whose spontaneous activity increased during activation. Possibly, theses units were PV+ cells directly activated by SSFO. Analysis of LFP data confirmed the contrary effect of PV+ activation on transient and sustained responses. Activation of SSFO caused a decrease of the power in the high-γ range (50-150Hz) during spontaneous and sustained tone-response phases. Both onset and offset responses were boosted compared to control, and offset responses increased more than onset response. Generally, SSFO activation increased power in the low-frequency range of the LFP (<50Hz) and decreased power in the high-frequency range (50-150Hz, high-γ).
Carroll, R., Warzybok, A., Ruigendijk, E., and Kollmeier, B., Influence of Vocabulary Knowledge & Lexical Access Times on Speech Intelligibility in Different Acoustic Conditions, Jahrestagung der Dt. Ges. für Audiologie (DGA). 2015.
Abstract
Schädler, M. R., Warzybok, A., Hochmuth, S., and Kollmeier, B., Matrix sentence intelligibility predictions in noise using an automatic speech recognitizer, Proc. German Annual Conf. Acoust. (DAGA). 2015.
Abstract
Buschermöhle, M., Dietz, A., and Kollmeier, B., Application of Speech Audiometric Matrix Tests with Hearing Impaired Patients: Experiences with CIPatients , J. Int. Adv. Otol. (EFAS), vol. 11 (suppl 1). 2015.
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Warzybok, A., Rennies, J., Brand, T., and Kollmeier, B., Binaural Speech Intelligibility in Noise and Reverberation in Young and Older normal-hearing and hearing-impaired Listeners, J. Int. Adv. Otol. (EFAS), vol. 11 (suppl 1). 2015.
AbstractFull Text
Kollmeier, B., Schädler, M. R., Warzybok, A., Brand, T., and Meyer, B. T., Modelling Matrix Test Intelligibility in Normal and Impaired Listeners across Languages Using Automatic Speech Recognition (ASR), J. Int. Adv. Otol. (EFAS), vol. 11 (suppl 1). 2015.
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Kollmeier, B., Denk, F., Hiipakka, M., Grimm, G., Neher, T., De Taillez, T., and Ernst, S., Towards a Scalable, Binaural Hearing Device: Acoustic Transparency Interacts with Interaural Processing, J. Int. Adv. Otol. (EFAS), vol. 11 (suppl 1). 2015.
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Brand, T., Warzybok, A., and Kollmeier, B., Speech Intelligibility Models in Audiological Diagnostics, J. Int. Adv. Otol. (EFAS), vol. 11 (suppl 1). 2015.
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Carroll, R., Warzybok, A., Ruigendijk, E., and Kollmeier, B., Not speed but precision define lexical access efficiency of word recognition in noise, Int. Conf. Cog. Hear. Sc. Comm. (CHSCOM). 2015.
Abstract
Wächtler, M., Rennies, J., and Kollmeier, B., Automatische Erkennung von Abschnitten mit kritischer Sprachverständlichkeit für Normal- und Schwerhörende in Film und Fernsehen, Proc. German Annual Conf. Acoust. (DAGA). 2015.
Abstract
Schmidt, F., Kollmeier, B., and Uppenkamp, S., Lautheitsbeurteilung von Musik: Methoden und Modellvergleiche, Proc. German Annual Conf. Acoust. (DAGA). 2015.
Abstract
Schell-Majoor, L., Rennies, J., Ewert, S. D., and Kollmeier, B., Deriving Sound Quality Measures from a Perceptual Model, Proc. German Annual Conf. Acoust. (DAGA). 2015.
Abstract
Kubiak, A., Rennies, J., Volgenandt, A., and Kollmeier, B., Individualized and noise-adaptive enhancement of speech intelligibility, Proc. German Annual Conf. Acoust. (DAGA). 2015.
Abstract
Müller, J., Kollmeier, B., Debener, S., and Brand, T., Assessment of the influence of auditory attention on sentence recognition in modulated noise, Jahrestagung der Dt. Ges. für Audiologie (DGA). 2015.
Abstract
Baumgärtel, R. M., Rennebeck, S., Adiloglu, K., Hohmann, V., Kollmeier, B., and Dietz, M., Evaluation of a steering beamformer algorithm in spatial listening conditions for bilaterally implanted CI -users, Jahrestagung der Dt. Ges. für Audiologie (DGA). 2015.
Abstract
Köppl, C., Otoacoustic Emissions (Part II): A Moderated Discussion, AIP Conf. Proc., vol. 1703, no. 090014. 2015.
Abstract
Saremi, A., Verhulst, S., Dietz, M., Beutelmann, R., and Kretzberg, J., A Comparative Study of Human Auditory Periphery Models, Assoc. Res. Otolaryng. MidWinter Meeting (ARO), vol. 38, no. PD-137. 2015.
AbstractFull Text
For over seven decades, auditory models have been devel- oped and used to sharpen our understanding of the hearing system. Here six recently-published models, that can cover the mainstream approaches in modern auditory modelling, are selected to be studied: four filter bank models (Irino and Patterson, 2006; Lyon, 2001; Lopez-poveda and Meddis, 2001), one transmission-line model (Verhulst et al., 2012) and one biophysical model (Saremi and Stenfelt, 2013). These chosen models are extensively used today in various appli- cations ranging from biological studies to cochlear mechan- ics, otoacoustic emission generation and applications within digital industry. Nevertheless, it is often unknown how these models respond to stimuli they were not designed for, or how well they compare to other auditory models. This study com- pares the performances in response to a fixed set of stimuli in order to quantitatively explore their respective advantages and limitations. Methods The responses of the models to pure tones and to nar- row-band noise stimuli with center frequencies of 0.5, 1, 2 and 4 kHz and at intensities ranging from 30 dB SPL to 85 dB SPL are simulated. The spectral responses and the shapes of the resultant filters are compared in terms of amplitude, compression and slopes. This procedure is repeated for clicks between 0 and 90 dB SPL, as well. Moreover, each model’s capability in predicting the outcome of the psycho- acoustic experiments is evaluated by simulating the pulsation thresholds, that had been reported by Plack and Oxenham (2001). Results Although the filter models are to some extent based on sim- ilar modelling principles, they process the incoming stimuli differently due to their underlying differences in generating the cochlear nonlinearity, compression and tuning. For ex- ample, the preliminary results demonstrate that the double resonator nonlinear filter model (Lopez-poveda and Meddis, 2001) produces a transmission delay as well as high levels of distortion: two fundamental issues that can impose serious limitations to real-life applications of this particular model. Summary The auditory models are widely used in hearing machines, speech processors and hearing aid designs. We plan on systematically comparing all six models in this study to discuss the advantages as well as limitations of each approach. The outcome of this study is important for those modelers seeking the best model for their specific application.
Dong, W. and Verhulst, S., Otoacoustic Emissions (part I) and Central Auditory Effects: A Moderated Discussion, AIP Conf. Proc., vol. 1703, no. 090010. 2015.
Abstract DOIFull Text
Verhulst, S. and Shera, C. A., Relating the Variability of Tone-burst Otoacoustic Emission and Auditory Brainstem Response Latencies to the Underlying Cochlear Mechanics, Mechanics of Hearing: Protein to Perception. AIP Conf. Proc., vol. 1703, no. 090003. AIP Publishing, 2015.
Abstract DOIFull Text
Forward and reverse cochlear latency and its relation to the frequency tuning of the auditory filters can be assessed using tone bursts (TBs). Otoacoustic emissions (TBOAEs) estimate the cochlear roundtrip time, while auditory brainstem responses (ABRs) to the same stimuli aim at measuring the auditory filter buildup time. Latency ratios are generally close to two and controversy exists about the relationship of this ratio to cochlear mechanics. We explored why the two methods provide different estimates of filter buildup time, and ratios with large inter-subject variability, using a time-domain model for OAEs and ABRs. We compared latencies for twenty models, in which all parameters but the cochlear irregularities responsible for reflection-source OAEs were identical, and found that TBOAE latencies were much more variable than ABR latencies. Multiple reflection-sources generated within the evoking stimulus bandwidth were found to shape the TBOAE envelope and complicate the interpretation of TBOAE latency and TBOAE/ABR ratios in terms of auditory filter tuning.
Raufer, S., Tolnai, S., and Verhulst, S., Otoacoustic Estimates of Suprathreshold Auditory Filter Tuning, Assoc. Res. Otolaryng. MidWinter Meeting (ARO), vol. 38, no. PS-284. 2015.
AbstractFull Text
Frequency selectivity of the human auditory system has been studied in great variety over the past years. However, little is known about human auditory filter tuning above the auditory threshold because of methodological limitations that require high suppressor tone levels (psychoacoustics) or an assump- tion of linearity (SFOAE group delays). Nonetheless, reliable estimates of suprathreshold filter tuning are necessary for studies explaining individual differences of supra-threshold coding of sound. The proposed method is based on temporal suppression (or, forward masking) of click-evoked otoacoustic emissions (CEOAE), with the underlying thought that basilar-membrane impulse-response durations can be estimated from spectral peaks in an individual’s CEOAE spectrum. Using temporal suppression, we determined the range of inter-click intervals (ICI) that kept a spectral peak in the CEOAE spectrum sup- pressed, as beyond a certain ICI, the forward masking effect disappears. We investigated the relationship between this ICI (i.e., the release of suppression) and that of the duration of the assumed underlying impulse response at that frequency. Using linear filter theory and the release-of-suppression val- ues, we were able to find correlates of human auditory filter tuning. Results from 11 subjects, recorded at 65 and 71 dB peSPL for ICIs between 0 and 8 ms, demonstrated a clear frequen- cy-dependence of the release of suppression. High-frequen- cy CEOAE peaks demonstrated suppression only for small ICIs, whereas longer ICIs were still capable of suppressing lower frequency CEOAE components. This frequency-de- pendence links to the basilar-membrane impulse-response duration that is shorter at higher frequencies than lower fre- quencies. When we derived tuning estimates from the OAE metric, both the 65 and 71dB peSPL conditions showed a strong frequency dependence of tuning, in agreement with near-threshold otoacoustic emission tuning estimates. Ob- tained by using a novel method, our data supports previous findings that Q values increase with increasing frequency in humans. Our OAE method may underestimate the tuning systematically, because release of suppression indicates the point in time where basilar-membrane impulse responses stop behaving nonlinearly, rather than estimating its full time course. Aside from this drawback, this method can be easily used to check whether a listener falls within “normal” ranges, and is much faster than deriving psychophysical measures tuning because tuning of all frequencies in the CEOAE spec- trum can be investigated at once.
Nothwang, H. G., Schlüter, T., Rosengauer, E., and Steel, K., The Role of miR-96 in the Central Auditory System, Assoc. Res. Otolaryng. MidWinter Meeting (ARO), vol. 38, no. SYM-90. 2015.
AbstractFull Text
MicroRNA-96 (miR-96) is part of the microRNA-183 cluster (miR-183, miR-92 and miR-182) and shows abundant expres- sion in sensory cells such as photoreceptors and hair cells. It was the first microRNA associated with a human mendelian disorder (Mencia et al. 2009). Point mutations in this gene result in deafness due to arrest of hair cell development and subsequent degeneration of these cells. We recently reported an increase in miR-96 expression in the developing mouse brainstem (Rosengauer et al., 2012). Using RNA in-situ hybridization, we also observed prominent expression of miR- 183/miR-96 in the chicken auditory brainstem. To explore whether miR-96 is involved in development of central audi- tory structures, we characterized homozygote dmdo mice. These mice harbor a point mutation in miR-96, which caus- es peripheral deafness. Quantitative anatomical analyses of Nissl-stained brainstem sections containing the cochlear nu- cleus complex and the superior olivary complex revealed a significant volume reduction of auditory nuclei in young-adult (P25-P30) dmdo mice, ranging from 25% to 35%. In contrast, no volume difference was observed in neonatal dmdo mice, whereas 4 days old mice showed an intermediate reduction. To investigate whether the volume reduction was restricted to the auditory brainstem, we also determined the volume of the nucleus of the 7 th nerve, a non-auditory brainstem struc- ture. This nucleus showed only a slight volume decrease of 7.5% in young-adult dmdo mice. To estimate the contribution of peripheral deafness to the volume reduction in the auditory brainstem of dmdo mice, we included deaf claudin14 -/- mice in our analysis. These animals show a cochlear phenotype similar to dmdo mice, yet no volume reduction of auditory nu- clei was observed. This indicates that the disturbed anatomy in dmdo animals is caused by an on-site role of mutated miR- 96 in the auditory brainstem. Cell counts and determination of cross sectional area identified reduced cell size as the ma- jor contributor to the observed volume decrease. In summa- ry, our data reveal that mutation in miR-96 affects postnatal development of the auditory brainstem. The gene therefore adds to the growing list of peripheral deafness genes with functions in the central auditory system as well. Furthermore, the expression pattern in the avian brainstem points to an evolutionary conserved role of miR-96 in central auditory structures across different vertebrate groups.
Oetting, D., Hohmann, V., Ewert, S., and Appell, J., Vorrichtung und Verfahren zum Ansteuern des Dynamikkompressors und Verfahren zum Ermitteln von Verstärkungswerten für einen Dynamikkompressor, U.S. Patent 102015203855.62015.
Abstract
Hiipakka, M., Kollmeier, B., Ernst, S., and Denk, F., Verfahren zum Betreiben eines elektroakustischen Systems und ein elektroakustisches System, U.S. Patent AKZ 10 2015 003 855.92015.
Abstract
Noack, M., Leyk, J., and Richter-Landsberg, C., HDAC6 inhibition results in tau acetylation and modulates tau phosphorylation and degradation in oligodendrocytes, Glia, vol. 62.2014, no. 4. 2014.
Abstract DOIFull Text
Pukaß, K. and Richter-Landsberg, C., Oxidative stress promotes uptake, accumulation, and oligomerization of extracellular æ-synuclein in oligodendrocytes, Journal of molecular neuroscience : JMN online, vol. 52.2014, no. 3. 2014.
Abstract DOIFull Text
Poppinga, D., Schönfeld, A. A., Dörner, K. -J., Blanck, O., Harder, D., and Poppe, B., A new correction method serving to eliminate the parabola effect of flatbed scanners used in radiochromic film dosimetry, In: Medical physics / American Association of Physicists in Medicine; American Institute of Physics. - New York, NY, 41.2014, 2. - 8. - ISSN 0094-2405, vol. 8. 2014.
Abstract DOIFull Text
Helmers, H., Bett, A. W., Parisi, J., and Agert, C., Modeling of concentrating photovoltaic and thermal systems, In: Progress in photovoltaics : research and applications. - Chichester, 22.2014, 4. - S. 427-439. - ISSN 1099-159X. 2014.
Abstract DOIFull Text
Brück, S., Krause, C., Turrisi, R., Beverina, L., Wilken, S., Saak, W., Lützen, A., Borchert, H., Schiek, M., and Parisi, J., Structure-property relationship of anilino-squaraines in organic solar cells, Physical chemistry, chemical physics : PCCP ; a journal of European chemical societies / RSC, Royal Society of Chemistry, vol. 16.2014, no. 3. 2014.
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Balzer, F., Schiek, M., Osadnik, A., Wallmann, I., Parisi, J., Rubahn, H. -G., and Lützen, A., Substrate steered crystallization of naphthyl end-capped oligothiophenes into nanofibers: the influence of methoxy-functionalization, Physical chemistry, chemical physics : PCCP ; a journal of European chemical societies / RSC, Royal Society of Chemistry, vol. 16.2014. 2014.
Abstract DOIFull Text
Riedel, I., Keller, J., Parisi, J., Dalibor, T., and Avellán, A., One-dimensional simulation of sequentially processed Cu(In1 xGax)(Se1 ySy)2Cu(In1 xGax)(Se1 ySy)2 heterojunction solar cells with vertically graded absorber composition, Physica. *B* Condensed matter [Elektronische Ressource], vol. 439.2014, no. 15. (April). 2014.
Abstract DOIFull Text
Balzer, F., Henrichsen, H. H., Klarskov, M. B., Booth, T. J., Sun, R., Parisi, J., Schiek, M., and Bøggild, P., Directed self-assembled crystalline oligomer domains on graphene and graphite, In: Nanotechnology. - Bristol, Bd. 25.2014, 3, S. 035602, insges. 8 S. - S. 035602. - 8. - ISSN 1361-6528. 2014.
Abstract DOIFull Text
Hartmann, A. -M., Tesch, D., Nothwang, H. G., and Bininda-Emonds, O. R. P., Evolution of the cation chloride cotransporter family : ancient origins, gene losses, and subfunctionalization through duplication, Molecular biology and evolution : MBE, vol. 31.2014, no. 2. 2014.
Abstract DOIFull Text
Willaredt, M. A., Ebbers, L., and Nothwang, H. G., Central auditory function of deafness genes, Hearing research, vol. 312.2014. 2014.
Abstract DOIFull Text
Noack, M., Leyk, J., and Richter-Landsberg, C., HDAC6 inhibition results in tau acetylation and modulates tau phosphorylation and degradation in oligodendrocytes, Glia, vol. 62.2014, no. 4. 2014.
Abstract DOIFull Text
Pukaß, K. and Richter-Landsberg, C., Oxidative stress promotes uptake, accumulation, and oligomerization of extracellular æ-synuclein in oligodendrocytes, Journal of molecular neuroscience : JMN online, vol. 52.2014, no. 3. 2014.
Abstract DOIFull Text
Poppinga, D., Schönfeld, A. A., Dörner, K. -J., Blanck, O., Harder, D., and Poppe, B., A new correction method serving to eliminate the parabola effect of flatbed scanners used in radiochromic film dosimetry, In: Medical physics / American Association of Physicists in Medicine; American Institute of Physics. - New York, NY, 41.2014, 2. - 8. - ISSN 0094-2405, vol. 8. 2014.
Abstract DOIFull Text
Helmers, H., Bett, A. W., Parisi, J., and Agert, C., Modeling of concentrating photovoltaic and thermal systems, In: Progress in photovoltaics : research and applications. - Chichester, 22.2014, 4. - S. 427-439. - ISSN 1099-159X. 2014.
Abstract DOIFull Text
Brück, S., Krause, C., Turrisi, R., Beverina, L., Wilken, S., Saak, W., Lützen, A., Borchert, H., Schiek, M., and Parisi, J., Structure-property relationship of anilino-squaraines in organic solar cells, Physical chemistry, chemical physics : PCCP ; a journal of European chemical societies / RSC, Royal Society of Chemistry, vol. 16.2014, no. 3. 2014.
Abstract DOIFull Text
Balzer, F., Schiek, M., Osadnik, A., Wallmann, I., Parisi, J., Rubahn, H. -G., and Lützen, A., Substrate steered crystallization of naphthyl end-capped oligothiophenes into nanofibers: the influence of methoxy-functionalization, Physical chemistry, chemical physics : PCCP ; a journal of European chemical societies / RSC, Royal Society of Chemistry, vol. 16.2014. 2014.
Abstract DOIFull Text
Riedel, I., Keller, J., Parisi, J., Dalibor, T., and Avellán, A., One-dimensional simulation of sequentially processed Cu(In1 xGax)(Se1 ySy)2Cu(In1 xGax)(Se1 ySy)2 heterojunction solar cells with vertically graded absorber composition, Physica. *B* Condensed matter [Elektronische Ressource], vol. 439.2014, no. 15. (April). 2014.
Abstract DOIFull Text
Balzer, F., Henrichsen, H. H., Klarskov, M. B., Booth, T. J., Sun, R., Parisi, J., Schiek, M., and Bøggild, P., Directed self-assembled crystalline oligomer domains on graphene and graphite, In: Nanotechnology. - Bristol, Bd. 25.2014, 3, S. 035602, insges. 8 S. - S. 035602. - 8. - ISSN 1361-6528. 2014.
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Hartmann, A. -M., Tesch, D., Nothwang, H. G., and Bininda-Emonds, O. R. P., Evolution of the cation chloride cotransporter family : ancient origins, gene losses, and subfunctionalization through duplication, Molecular biology and evolution : MBE, vol. 31.2014, no. 2. 2014.
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Willaredt, M. A., Ebbers, L., and Nothwang, H. G., Central auditory function of deafness genes, Hearing research, vol. 312.2014. 2014.
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Dai, Z. and Lücke, J., Autonomous document cleaning : a generative approach to reconstruct strongly corrupted scanned texts, IEEE transactions on pattern analysis and machine intelligence : TPAMI / Institute of Electrical and Electronics Engineers, vol. 36.2014, no. 10. 2014.
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Svensson, C. -M., Krusekopf, S., Lücke, J., and Figge, M. T., Automated detection of circulating tumor cells with naive Bayesian classifiers, Cytometry. Part A [Elektronische Ressource], vol. 85.2014, no. 6. 2014.
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Sheikh, A. -S., Shelton, J. A., and Lücke, J., A truncated EM approach for spike-and-slab sparse coding, Journal of machine learning research : JMLR, vol. 15.2014. 2014.
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Henniges, M., Turner, R. E., Sahani, M., Eggert, J., and Lücke, J., Efficient occlusice components analysis, Journal of machine learning research : JMLR, vol. 15.2014. 2014.
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Hillmann, J., Kneib, T., Köpcke, L., Juárez Paz, L. M., and Kretzberg, J., Bivariate cumulative probit model for the comparison of neuronal encoding hypotheses, Biometrical journal, vol. 56.2014, no. 1. 2014.
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Vinas-Rios, J. M., Sanchez-Aguilar, M., Sanchez-Rodriguez, J. J., Gonzalez-Aguirre, D., Heinen, C., Meyer, F., and Kretschmer, T., Hypocalcaemia as a prognostic factor of early mortality in moderate and severe traumatic brain injury, Neurological research, vol. 36.2014, no. 2. 2014.
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Bäumer, P., Kele, H., Kretschmer, T., König, R. W., Pedro, M. T., Bendszus, M., and Pham, M., Thoracic outlet syndrome in 3T MR neurography-fibrous bands causing discernible lesions of the lower brachial plexus, European radiology : official organ of the European Association of Radiology, vol. 24.2014, no. 3. 2014.
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Janson, J., Thorne, J. D., and Kranczioch, C., The influence of pretarget distracter stream properties on the skeletal attentional blink, In: Neuroreport. - London, 25.2014, 5. - S. 330-334. - ISSN 1473-558X. 2014.
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MacColgan, T., Shah, S., Köppl, C., Carr, C., and Wagner, H., A functional circuit model of interaural time difference processing, Journal of neurophysiology / publ. by The American Physiological Society, vol. 112.2014, no. 11. 2014.
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Fontaine, B., MacLeod, K. M., Lubejko, S. T., Steinberg, L. J., Köppl, C., and Peña, J. L., Emergence of band-pass filtering through adaptive spiking in the owls cochlear nucleus, Journal of neurophysiology / publ. by The American Physiological Society, vol. 112.2014, no. 2. 2014.
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Sienknecht, U. J., Köppl, C., and Fritzsch, B., Evolution and development of hair cell polarity and efferent function in the inner ear, Brain, behavior and evolution : official journal of the J. B. Johnston Club, vol. 83.2014, no. 2. 2014.
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Geven, L. I., Köppl, C., Kleine, E. de, and Dijk, P. van, Plasticity in tinnitus patients : a role for the efferent auditory system?, Otology & neurotology : an international forum ; official publication of American Otological Society (AOS), American Neurotology Society (ANS), European Academy of Otology and Neurotology (EAONO), vol. 35.2014, no. 5. 2014.
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Puglisi, G. E., Warzybok, A., Hochmuth, S., Astolfi, A., Prodi, N., Visentin, C., and Kollmeier, B., Construction and first evaluation of the Italian Matrix Sentence Test for the assessment of speech intelligibility in noise, In: Forum Acusticum 2014 : Krakow, 7 - 12 September 2014 / European Acoustics Association (EAA). - [s.l.], 2014. - 5, vol. 5. 2014.
Abstract
Brand, T., Warzybok, A., Rennies, J., and Kollmeier, B., Model of binaural speech intelligibility in rooms : [abstract], The journal of the Acoustical Society of America : JASA-O, vol. 135.2014. 2014.
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Kollmeier, B., Hochmuth, S., Jürgens, T., Warzybok, A., and Brand, T., Comparison across languages using the multilingual Matrix Test : which language is best to survive in a cocktail party? ; [abstract], The journal of the Acoustical Society of America : JASA-O, vol. 135.2014. 2014.
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Warzybok, A., Hochmuth, S., Rennies, J., Brand, T., and Kollmeier, B., Measurement and prediction of speech intelligibility in noise and reverberation for different sentence materials, speakers, and languages : [abstract], The journal of the Acoustical Society of America : JASA-O, vol. 136.2014. 2014.
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Diekmann, R. and Bauer, J. M., Proteinbedarf älterer Menschen = Protein requirements of elderly people, Deutsche medizinische Wochenschrift : DMW ; Organ der Deutschen Gesellschaft für Innere Medizin (DGIM) ; Organ der Gesellschaft Deutscher Naturforscher und Ärzte (GDNÄ), vol. 139.2014, no. 6. 2014.
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Kuhn-Thiel, A. M., Weiß, C., and Wehling, M., Consensus validation of the FORTA (Fit fOR The Aged) list : a clinical tool for increasing the appropriateness of pharmacotherapy in the elderly, Drugs & aging : evaluations of age-related changes in drug disposition and drug therapy in the elderly, vol. 31.2014, no. 2. 2014.
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Haux, R., Hein, A., Kolb, G., Künemund, H., Eichelberg, M., Appell, J. -E., Appelrath, H. -J., Bartsch, C., Bauer, J. M., Becker, M., Bente, P., Bitzer, J., Boll, S., Büsching, F., Dasenbrock, L., Deparade, R., Depner, D., Elbers, K., Fachinger, U., Felber, J., Feldwieser, F., Forberg, A., Gietzelt, M., Goetze, S., and Gövercin, M., Information and communication technologies for promoting and sustaining quality of life, health and self-sufficiency in ageing societies : outcomes of the Lower Saxony Research Network Design of Environments for Ageing (GAL), Informatics for health and social care, vol. 39.2014, no. 3/4. 2014.
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Strüber, D., Rach, S., Trautmann-Lengsfeld, S. A., Engel, A. K., and Herrmann, C. S., Antiphasic 40 Hz oscillatory current stimulation affects bistable motion perception, Brain topography : journal of functional neurophysiolgy, vol. 27.2014, no. 1. 2014.
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Helfrich, R. F., Schneider, T. R., Rach, S., Trautmann- Lengsfeld, S. A., Engel, A. K., and Herrmann, C. S., Entrainment of brain oscillations by transcranial alternating current stimulation, Current biology : CB, vol. 24.2014, no. 3. 2014.
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Wagner, S., Rampersad, S. M., Aydin, Ü., Vorwerk, J., Oostendorp, T. F., Neuling, T., Herrmann, C. S., Stegeman, D. F., and Wolters, C. H., Investigation of tDCS volume conduction effects in a highly realistic head model, In: Journal of neural engineering. - Bristol, Bd. 11.2014, 1, S. 016002, insges. 14 S. - S. 016002. - <14>. - ISSN 1741-2552. 2014.
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Huster, R. J., Mokom, Z. N., Enriquez Geppert, S., and Herrmann, C. S., Braincomputer interfaces for EEG neurofeedback : peculiarities and solutions, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 91, no. 1. pp. 36-45, 2014.
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Neurofeedback training procedures designed to alter a person's brain activity have been in use for nearly four decades now and represent one of the earliest applications of brain-computer interfaces (BCI). The majority of studies using neurofeedback technology relies on recordings of the electroencephalogram (EEG) and applies neurofeedback in clinical contexts, exploring its potential as treatment for psychopathological syndromes. This clinical focus significantly affects the technology behind neurofeedback BCIs. For example, in contrast to other BCI applications, neurofeedback BCIs usually rely on EEG-derived features with only a minimum of additional processing steps being employed. Here, we highlight the peculiarities of EEG-based neurofeedback BCIs and consider their relevance for software implementations. Having reviewed already existing packages for the implementation of BCIs, we introduce our own solution which specifically considers the relevance of multi-subject handling for experimental and clinical trials, for example by implementing ready-to-use solutions for pseudo-/sham-neurofeedback
Trautmann-Lengsfeld, S. A. and Herrmann, C. S., Virtually simulated social pressure influences early visual processing more in low compared to high autonomous participants, Psychophysiology / publ. for the Society for Psychophysiological Research, vol. 51.2014, no. 2. 2014.
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Zägel, P. and Koch, K. -W., Dysfunction of outer segment guanylate cyclase caused by retinal disease related mutations, Frontiers in molecular neuroscience, vol. 7. 2014.
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Köster, M., Dell'Orco, D., and Koch, K. -W., The interaction network of rhodopsin involving the heterotrimeric G-protein transducin and the monomeric GTPase Rac1 is determined by distinct binding processes, The FEBS journal, vol. 281, no. 23. Dec.-2014.
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Sulmann, S., Dell'Orco, D., Marino, V., Behnen, P., and Koch, K. -W., Conformational changes in calcium-sensor proteins under molecular crowding conditions, Chemistry (Weinheim an der Bergstrasse, Germany), vol. 20, no. 22. May-2014.
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Dell'Orco, D., Sulmann, S., Zägel, P., Marino, V., and Koch, K. -W., Impact of cone dystrophy-related mutations in GCAP1 on a kinetic model of phototransduction, Cellular and molecular life sciences : CMLS, vol. 71, no. 19. Oct.-2014.
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Invergo, B. M., Dell'Orco, D., Montanucci, L., Koch, K. -W., and Bertranpetit, J., A comprehensive model of the phototransduction cascade in mouse rod cells, Molecular bioSystems, vol. 10, no. 6. Jun.-2014.
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Karbasi, S., Frazier, R. J., Koch, K. -W., Hawkins, T., Ballato, J., and Mafi, A., Image transport through a disordered optical fibre mediated by transverse Anderson localization, Nature communications, vol. 5. 2014.
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Tulli, D., Hart, S. D., Mazumder, P., Carrilero, A., Tian, L., Koch, K. -W., Yongsunthon, R., Piech, G. A., and Pruneri, V., Monolithically integrated micro- and nanostructured glass surface with antiglare, antireflection, and superhydrophobic properties, ACS applied materials & interfaces, vol. 6, no. 14. Jul.-2014.
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Brüggen, B., Meyer, A., Boven, F., Weiler, R., and Dedek, K., Type 2 wide-field amacrine cells in TH::GFP mice show a homogenous synapse distribution and contact small ganglion cells, Eur J Neurosci, vol. 41, no. 6. Wiley-Blackwell, pp. 734-747, 29-Dec.-2014.
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Arango-Gonzalez, B., Trifunović, D., Sahaboglu, A., Kranz, K., Michalakis, S., Farinelli, P., Koch, S., Koch, F., Cottet, S., Janssen-Bienhold, U., Dedek, K., Biel, M., Zrenner, E., Euler, T., Ekström, P., Ueffing, M., and Paquet-Durand, F., Identification of a Common Non-Apoptotic Cell Death Mechanism in Hereditary Retinal Degeneration, PLoS ONE, vol. 9, no. 11. Public Library of Science (PLoS), p. e112142, 13-Nov.-2014.
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Haghighi, A., Tiwari, A., Piri, N., Nürnberg, G., Saleh-Gohari, N., Haghighi, A., Neidhardt, J., Nürnberg, P., and Berger, W., Homozygosity Mapping and Whole Exome Sequencing Reveal a Novel Homozygous COL18A1 Mutation Causing Knobloch Syndrome, PLoS ONE, vol. 9, no. 11. Public Library of Science (PLoS), p. e112747, 13-Nov.-2014.
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Bordo, K., Schiek, M., and Rubahn, H. -G., Nanowires and nanotubes from π-conjugated organic materials fabricated by template wetting, Applied Physics A, vol. 114, no. 4. Springer Science + Business Media, pp. 1067-1074, 31-Jan.-2014.
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Chernov, I., Greb, H., Janssen-Bienhold, U., Parisi, J., Weiler, R., and von Hauff, E., Binding and potential-triggered release of l-glutamate with molecularly imprinted polypyrrole in neutral pH solutions, Sensors and Actuators B: Chemical, vol. 203. Elsevier BV, pp. 327-332, Nov.-2014.
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Meyer, A., Hilgen, G., Dorgau, B., Sammler, E. M., Weiler, R., Monyer, H., Dedek, K., and Hormuzdi, S. G., AII amacrine cells discriminate between heterocellular and homocellular locations when assembling connexin36-containing gap junctions, Journal of cell science, vol. 127, no. Pt 6. pp. 1190-1202, Mar.-2014.
Abstract DOI
Electrical synapses (gap junctions) rapidly transmit signals between neurons and are composed of connexins. In neurons, connexin36 (Cx36) is the most abundant isoform; however, the mechanisms underlying formation of Cx36-containing electrical synapses are unknown. We focus on homocellular and heterocellular gap junctions formed by an AII amacrine cell, a key interneuron found in all mammalian retinas. In mice lacking native Cx36 but expressing a variant tagged with enhanced green fluorescent protein at the C-terminus (KO-Cx36-EGFP), heterocellular gap junctions formed between AII cells and ON cone bipolar cells are fully functional, whereas homocellular gap junctions between two AII cells are not formed. A tracer injected into an AII amacrine cell spreads into ON cone bipolar cells but is excluded from other AII cells. Reconstruction of Cx36-EGFP clusters on an AII cell in the KO-Cx36-EGFP genotype confirmed that the number, but not average size, of the clusters is reduced - as expected for AII cells lacking a subset of electrical synapses. Our studies indicate that some neurons exhibit at least two discriminatory mechanisms for assembling Cx36. We suggest that employing different gap-junction-forming mechanisms could provide the means for a cell to regulate its gap junctions in a target-cell-specific manner, even if these junctions contain the same connexin
Bendixen, A., Predictability effects in auditory scene analysis: a review, Frontiers in neuroscience, vol. 8. p. 60, 2014.
Abstract DOI
Many sound sources emit signals in a predictable manner. The idea that predictability can be exploited to support the segregation of one source's signal emissions from the overlapping signals of other sources has been expressed for a long time. Yet experimental evidence for a strong role of predictability within auditory scene analysis (ASA) has been scarce. Recently, there has been an upsurge in experimental and theoretical work on this topic resulting from fundamental changes in our perspective on how the brain extracts predictability from series of sensory events. Based on effortless predictive processing in the auditory system, it becomes more plausible that predictability would be available as a cue for sound source decomposition. In the present contribution, empirical evidence for such a role of predictability in ASA will be reviewed. It will be shown that predictability affects ASA both when it is present in the sound source of interest (perceptual foreground) and when it is present in other sound sources that the listener wishes to ignore (perceptual background). First evidence pointing toward age-related impairments in the latter capacity will be addressed. Moreover, it will be illustrated how effects of predictability can be shown by means of objective listening tests as well as by subjective report procedures, with the latter approach typically exploiting the multi-stable nature of auditory perception. Critical aspects of study design will be delineated to ensure that predictability effects can be unambiguously interpreted. Possible mechanisms for a functional role of predictability within ASA will be discussed, and an analogy with the old-plus-new heuristic for grouping simultaneous acoustic signals will be suggested
Bendixen, A., Scharinger, M., Strauß, A., and Obleser, J., Prediction in the service of comprehension: modulated early brain responses to omitted speech segments, Cortex; a journal devoted to the study of the nervous system and behavior, vol. 53. pp. 9-26, Apr.-2014.
Abstract DOI
Speech signals are often compromised by disruptions originating from external (e.g., masking noise) or internal (e.g., inaccurate articulation) sources. Speech comprehension thus entails detecting and replacing missing information based on predictive and restorative neural mechanisms. The present study targets predictive mechanisms by investigating the influence of a speech segment's predictability on early, modality-specific electrophysiological responses to this segment's omission. Predictability was manipulated in simple physical terms in a single-word framework (Experiment 1) or in more complex semantic terms in a sentence framework (Experiment 2). In both experiments, final consonants of the German words Lachs ([laks], salmon) or Latz ([lats], bib) were occasionally omitted, resulting in the syllable La ([la], no semantic meaning), while brain responses were measured with multi-channel electroencephalography (EEG). In both experiments, the occasional presentation of the fragment La elicited a larger omission response when the final speech segment had been predictable. The omission response occurred ∼125-165 msec after the expected onset of the final segment and showed characteristics of the omission mismatch negativity (MMN), with generators in auditory cortical areas. Suggestive of a general auditory predictive mechanism at work, this main observation was robust against varying source of predictive information or attentional allocation, differing between the two experiments. Source localization further suggested the omission response enhancement by predictability to emerge from left superior temporal gyrus and left angular gyrus in both experiments, with additional experiment-specific contributions. These results are consistent with the existence of predictive coding mechanisms in the central auditory system, and suggestive of the general predictive properties of the auditory system to support spoken word recognition
Puschmann, S., Sandmann, P., Bendixen, A., and Thiel, C. M., Age-related hearing loss increases cross-modal distractibility, Hearing research, vol. 316. pp. 28-36, Oct.-2014.
Abstract DOI
Recent electrophysiological studies have provided evidence that changes in multisensory processing in auditory cortex cannot only be observed following extensive hearing loss, but also in moderately hearing-impaired subjects. How the reduced auditory input affects audio-visual interactions is however largely unknown. Here we used a cross-modal distraction paradigm to investigate multisensory processing in elderly participants with an age-related high-frequency hearing loss as compared to young and elderly subjects with normal hearing. During the experiment, participants were simultaneously presented with independent streams of auditory and visual input and were asked to categorize either the auditory or visual information while ignoring the other modality. Unisensory sequences without any cross-modal input served as control conditions to assure that all participants were able to perform the task. While all groups performed similarly in these unisensory conditions, hearing-impaired participants showed significantly increased error rates when confronted with distracting cross-modal stimulation. This effect could be observed in both the auditory and the visual task. Supporting these findings, an additional regression analysis indicted that the degree of high-frequency hearing loss significantly modulates cross-modal visual distractibility in the auditory task. These findings provide new evidence that already a moderate sub-clinical hearing loss, a common phenomenon in the elderly population, affects the processing of audio-visual information
Spielmann, M. I., Schröger, E., Kotz, S. A., and Bendixen, A., Attention effects on auditory scene analysis: insights from event-related brain potentials, Psychological research, vol. 78, no. 3. pp. 361-378, 2014.
Abstract DOI
Sounds emitted by different sources arrive at our ears as a mixture that must be disentangled before meaningful information can be retrieved. It is still a matter of debate whether this decomposition happens automatically or requires the listener's attention. These opposite positions partly stem from different methodological approaches to the problem. We propose an integrative approach that combines the logic of previous measurements targeting either auditory stream segregation (interpreting a mixture as coming from two separate sources) or integration (interpreting a mixture as originating from only one source). By means of combined behavioral and event-related potential (ERP) measures, our paradigm has the potential to measure stream segregation and integration at the same time, providing the opportunity to obtain positive evidence of either one. This reduces the reliance on zero findings (i.e., the occurrence of stream integration in a given condition can be demonstrated directly, rather than indirectly based on the absence of empirical evidence for stream segregation, and vice versa). With this two-way approach, we systematically manipulate attention devoted to the auditory stimuli (by varying their task relevance) and to their underlying structure (by delivering perceptual tasks that require segregated or integrated percepts). ERP results based on the mismatch negativity (MMN) show no evidence for a modulation of stream integration by attention, while stream segregation results were less clear due to overlapping attention-related components in the MMN latency range. We suggest future studies combining the proposed two-way approach with some improvements in the ERP measurement of sequential stream segregation
Kocsis, Z., Winkler, I., Szalárdy, O., and Bendixen, A., Effects of multiple congruent cues on concurrent sound segregation during passive and active listening: an event-related potential (ERP) study, Biological psychology, vol. 100. pp. 20-33, Jul.-2014.
Abstract DOI
In two experiments, we assessed the effects of combining different cues of concurrent sound segregation on the object-related negativity (ORN) and the P400 event-related potential components. Participants were presented with sequences of complex tones, half of which contained some manipulation: one or two harmonic partials were mistuned, delayed, or presented from a different location than the rest. In separate conditions, one, two, or three of these manipulations were combined. Participants watched a silent movie (passive listening) or reported after each tone whether they perceived one or two concurrent sounds (active listening). ORN was found in almost all conditions except for location difference alone during passive listening. Combining several cues or manipulating more than one partial consistently led to sub-additive effects on the ORN amplitude. These results support the view that ORN reflects a combined, feature-unspecific assessment of the auditory system regarding the contribution of two sources to the incoming sound
Schröger, E., Bendixen, A., Denham, S. L., Mill, R. W., Bőhm, T. M., and Winkler, I., Predictive regularity representations in violation detection and auditory stream segregation: from conceptual to computational models, Brain topography, vol. 27, no. 4. pp. 565-577, Jul.-2014.
Abstract DOI
Predictive accounts of perception have received increasing attention in the past 20 years. Detecting violations of auditory regularities, as reflected by the Mismatch Negativity (MMN) auditory event-related potential, is amongst the phenomena seamlessly fitting this approach. Largely based on the MMN literature, we propose a psychological conceptual framework called the Auditory Event Representation System (AERS), which is based on the assumption that auditory regularity violation detection and the formation of auditory perceptual objects are based on the same predictive regularity representations. Based on this notion, a computational model of auditory stream segregation, called CHAINS, has been developed. In CHAINS, the auditory sensory event representation of each incoming sound is considered for being the continuation of likely combinations of the preceding sounds in the sequence, thus providing alternative interpretations of the auditory input. Detecting repeating patterns allows predicting upcoming sound events, thus providing a test and potential support for the corresponding interpretation. Alternative interpretations continuously compete for perceptual dominance. In this paper, we briefly describe AERS and deduce some general constraints from this conceptual model. We then go on to illustrate how these constraints are computationally specified in CHAINS
Malmierca, M. S., Sanchez-Vives, M. V., Escera, C., and Bendixen, A., Neuronal adaptation, novelty detection and regularity encoding in audition, Frontiers in systems neuroscience, vol. 8. p. 111, 2014.
Abstract DOI
The ability to detect unexpected stimuli in the acoustic environment and determine their behavioral relevance to plan an appropriate reaction is critical for survival. This perspective article brings together several viewpoints and discusses current advances in understanding the mechanisms the auditory system implements to extract relevant information from incoming inputs and to identify unexpected events. This extraordinary sensitivity relies on the capacity to codify acoustic regularities, and is based on encoding properties that are present as early as the auditory midbrain. We review state-of-the-art studies on the processing of stimulus changes using non-invasive methods to record the summed electrical potentials in humans, and those that examine single-neuron responses in animal models. Human data will be based on mismatch negativity (MMN) and enhanced middle latency responses (MLR). Animal data will be based on the activity of single neurons at the cortical and subcortical levels, relating selective responses to novel stimuli to the MMN and to stimulus-specific neural adaptation (SSA). Theoretical models of the neural mechanisms that could create SSA and novelty responses will also be discussed
Szalárdy, O., Bendixen, A., Böhm, T. M., Davies, L. A., Denham, S. L., and Winkler, I., The effects of rhythm and melody on auditory stream segregation, The Journal of the Acoustical Society of America, vol. 135, no. 3. pp. 1392-1405, Mar.-2014.
Abstract DOI
While many studies have assessed the efficacy of similarity-based cues for auditory stream segregation, much less is known about whether and how the larger-scale structure of sound sequences support stream formation and the choice of sound organization. Two experiments investigated the effects of musical melody and rhythm on the segregation of two interleaved tone sequences. The two sets of tones fully overlapped in pitch range but differed from each other in interaural time and intensity. Unbeknownst to the listener, separately, each of the interleaved sequences was created from the notes of a different song. In different experimental conditions, the notes and/or their timing could either follow those of the songs or they could be scrambled or, in case of timing, set to be isochronous. Listeners were asked to continuously report whether they heard a single coherent sequence (integrated) or two concurrent streams (segregated). Although temporal overlap between tones from the two streams proved to be the strongest cue for stream segregation, significant effects of tonality and familiarity with the songs were also observed. These results suggest that the regular temporal patterns are utilized as cues in auditory stream segregation and that long-term memory is involved in this process
Shestopalova, L., Bőhm, T. M., Bendixen, A., Andreou, A. G., Georgiou, J., Garreau, G., Hajdu, B., Denham, S. L., and Winkler, I., Do audio-visual motion cues promote segregation of auditory streams?, Frontiers in neuroscience, vol. 8. p. 64, 2014.
Abstract DOI
An audio-visual experiment using moving sound sources was designed to investigate whether the analysis of auditory scenes is modulated by synchronous presentation of visual information. Listeners were presented with an alternating sequence of two pure tones delivered by two separate sound sources. In different conditions, the two sound sources were either stationary or moving on random trajectories around the listener. Both the sounds and the movement trajectories were derived from recordings in which two humans were moving with loudspeakers attached to their heads. Visualized movement trajectories modeled by a computer animation were presented together with the sounds. In the main experiment, behavioral reports on sound organization were collected from young healthy volunteers. The proportion and stability of the different sound organizations were compared between the conditions in which the visualized trajectories matched the movement of the sound sources and when the two were independent of each other. The results corroborate earlier findings that separation of sound sources in space promotes segregation. However, no additional effect of auditory movement per se on the perceptual organization of sounds was obtained. Surprisingly, the presentation of movement-congruent visual cues did not strengthen the effects of spatial separation on segregating auditory streams. Our findings are consistent with the view that bistability in the auditory modality can occur independently from other modalities
Hauthal, N., Debener, S., Rach, S., Sandmann, P., and Thorne, J. D., Visuo-tactile interactions in the congenitally deaf: a behavioral and event-related potential study, Frontiers in integrative neuroscience, vol. 8. p. 98, 2014.
Abstract DOI
Auditory deprivation is known to be accompanied by alterations in visual processing. Yet not much is known about tactile processing and the interplay of the intact sensory modalities in the deaf. We presented visual, tactile, and visuo-tactile stimuli to congenitally deaf and hearing individuals in a speeded detection task. Analyses of multisensory responses showed a redundant signals effect that was attributable to a coactivation mechanism in both groups, although the redundancy gain was less in the deaf. In line with these behavioral results, on a neural level, there were multisensory interactions in both groups that were again weaker in the deaf. In hearing but not deaf participants, somatosensory event-related potential N200 latencies were modulated by simultaneous visual stimulation. A comparison of unisensory responses between groups revealed larger N200 amplitudes for visual and shorter N200 latencies for tactile stimuli in the deaf. Furthermore, P300 amplitudes were also larger in the deaf. This group difference was significant for tactile and approached significance for visual targets. The differences in visual and tactile processing between deaf and hearing participants, however, were not reflected in behavior. Both the behavioral and electroencephalography (EEG) results suggest more pronounced multisensory interaction in hearing than in deaf individuals. Visuo-tactile enhancements could not be explained by perceptual deficiency, but could be partly attributable to inverse effectiveness
Braun, N., Thorne, J. D., Hildebrandt, H., and Debener, S., Interplay of agency and ownership: the intentional binding and rubber hand illusion paradigm combined, PloS one, vol. 9, no. 11. p. e111967, 2014.
Abstract DOI
The sense of agency (SoA) refers to the phenomenal experience of initiating and controlling an action, whereas the sense of ownership (SoO) describes the feeling of myness an agent experiences towards his or her own body parts. SoA has been investigated with intentional binding paradigms, and the sense of ownership (SoO) with the rubber-hand illusion (RHI). We investigated the relationship between SoA and SoO by incorporating intentional binding into the RHI. Explicit and implicit measures of agency (SoA-questionnaire, intentional binding) and ownership (SoO-questionnaire, proprioceptive drift) were used. Artificial hand position (congruent/incongruent) and mode of agent (self-agent/other-agent) were systematically varied. Reported SoO varied mainly with position (higher in congruent conditions), but also with agent (higher in self-agent conditions). Reported SoA was modulated by agent (higher in self-agent conditions), and moderately by position (higher in congruent conditions). Implicit and explicit agency measures were not significantly correlated. Finally, intentional binding tended to be stronger in self-generated than observed voluntary actions. Results provide further evidence for a partial double dissociation between SoA and SoO, empirically distinct agency levels, and moderate intentional binding differences between self-generated and observed voluntary actions
Timm, L., Vuust, P., Brattico, E., Agrawal, D., Debener, S., Büchner, A., Dengler, R., and Wittfoth, M., Residual neural processing of musical sound features in adult cochlear implant users, Frontiers in human neuroscience, vol. 8. p. 181, 2014.
Abstract DOI
Auditory processing in general and music perception in particular are hampered in adult cochlear implant (CI) users. To examine the residual music perception skills and their underlying neural correlates in CI users implanted in adolescence or adulthood, we conducted an electrophysiological and behavioral study comparing adult CI users with normal-hearing age-matched controls (NH controls). We used a newly developed musical multi-feature paradigm, which makes it possible to test automatic auditory discrimination of six different types of sound feature changes inserted within a musical enriched setting lasting only 20 min. The presentation of stimuli did not require the participants' attention, allowing the study of the early automatic stage of feature processing in the auditory cortex. For the CI users, we obtained mismatch negativity (MMN) brain responses to five feature changes but not to changes of rhythm, whereas we obtained MMNs for all the feature changes in the NH controls. Furthermore, the MMNs to deviants of pitch of CI users were reduced in amplitude and later than those of NH controls for changes of pitch and guitar timber. No other group differences in MMN parameters were found to changes in intensity and saxophone timber. Furthermore, the MMNs in CI users reflected the behavioral scores from a respective discrimination task and were correlated with patients' age and speech intelligibility. Our results suggest that even though CI users are not performing at the same level as NH controls in neural discrimination of pitch-based features, they do possess potential neural abilities for music processing. However, CI users showed a disrupted ability to automatically discriminate rhythmic changes compared with controls. The current behavioral and MMN findings highlight the residual neural skills for music processing even in CI users who have been implanted in adolescence or adulthood.-Automatic brain responses to musical feature changes reflect the limitations of central auditory processing in adult Cochlear Implant users.-The brains of adult CI users automatically process sound features changes even when inserted in a musical context.-CI users show disrupted automatic discriminatory abilities for rhythm in the brain.-Our fast paradigm demonstrate residual musical abilities in the brains of adult CI users giving hope for their future rehabilitation
Kranczioch, C., Zich, C., Schierholz, I., and Sterr, A., Mobile EEG and its potential to promote the theory and application of imagery-based motor rehabilitation, International Journal of Psychophysiology, vol. 91, no. 1. Elsevier BV, pp. 10-15, Jan.-2014.
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Janson, J., De Vos, M., Thorne, J. D., and Kranczioch, C., Endogenous and Rapid Serial Visual Presentation-induced Alpha Band Oscillations in the Attentional Blink, Journal of Cognitive Neuroscience, vol. 26, no. 7. MIT Press - Journals, pp. 1454-1468, Jul.-2014.
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Dhinakaran, J., De Vos, M., Thorne, J. D., and Kranczioch, C., Neuroticism focuses attention: evidence from SSVEPs, Experimental Brain Research, vol. 232, no. 6. Springer Science + Business Media, pp. 1895-1903, 1-Mar.-2014.
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Süsskind, D., Altpeter, E. K., Moser, L., Foerster, M. H., and Aisenbrey, S., Proton beam radiotherapy of progressive pediatric choroidal osteoma: First experience, Canadian Journal of Ophthalmology / Journal Canadien d'Ophtalmologie, vol. 49, no. 5. Elsevier BV, pp. e123-e127, Oct.-2014.
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Bantel, C., Childs, S., Casely, E., Kuehler, B., Ward, S., Halmshaw, C., Thomas, S., and Goodall, I., The clinical psychologist and the management of inpatient pain: a small case series, Neuropsychiatric Disease and Treatment. Dove Medical Press Ltd., p. 2291, Dec.-2014.
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Matthies, S., Philipsen, A., Lackner, H. K., Sadohara, C., and Svaldi, J., Regulation of sadness via acceptance or suppression in adult Attention Deficit Hyperactivity Disorder (ADHD), Psychiatry Research, vol. 220, no. 1-2. Elsevier BV, pp. 461-467, Dec.-2014.
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Burmeister, K., Höschel, K., von Auer, A., Reiske, S., Schweiger, U., Sipos, V., Philipsen, A., Priebe, K., and Bohus, M., Dialektisch Behaviorale Therapie – Weiterentwicklungen und empirische Evidenz, Psychiat Prax, vol. 41, no. 05. Thieme Publishing Group, pp. 242-249, 10-Apr.-2014.
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Philipsen, A., Die Hypersensitivität gegenüber sozialen Bedrohungsreizen wird reduziert, InFo Neurologie & Psychiatrie, vol. 16, no. 4. Springer Science + Business Media, pp. 12-12, Apr.-2014.
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Berger, N. A. A., Müller, A., Brähler, E., Philipsen, A., and de Zwaan, M., Association of symptoms of attention-deficit/hyperactivity disorder with symptoms of excessive exercising in an adult general population sample, BMC Psychiatry, vol. 14, no. 1. Springer Nature, 12-Sep.-2014.
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Huss, M., Ginsberg, Y., Arngrim, T., Philipsen, A., Carter, K., Chen, C. -W., Gandhi, P., and Kumar, V., Open-label dose optimization of methylphenidate modified release long acting (MPH-LA): a post hoc analysis of real-life titration from a 40-week randomized trial, Clinical drug investigation, vol. 34, no. 9. pp. 639-649, Sep.-2014.
Abstract DOI
BACKGROUND AND OBJECTIVES: In the management of attention-deficit hyperactivity disorder (ADHD) in adults it is important to recognize that individual patients respond to a wide range of methylphenidate doses. Studies with methylphenidate modified release long acting (MPH-LA) in children have reported the need for treatment optimization for improved outcomes. We report the results from a post hoc analysis of a 5-week dose optimization phase from a large randomized, placebo-controlled, multicenter 40-week study (9-week double-blind dose confirmation phase, 5-week open-label dose optimization phase, and 26-week double-blind maintenance of effect phase). METHODS: Patients entering the open-label dose optimization phase initiated treatment with MPH-LA 20 mg/day; up/down titrated to their optimal dose (at which there was balance between control of symptoms and side effects) of 40, 60, or 80 mg/day in increments of 20 mg/week by week 12 or 13. Safety was assessed by monitoring the adverse events (AEs) and serious AEs. Efficacy was assessed by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, Attention-Deficit Hyperactivity Disorder Rating Scale (DSM-IV ADHD RS) and Sheehan Disability Scale (SDS) total scores. RESULTS: At the end of the dose confirmation phase, similar numbers of patients were treated optimally with each of the 40, 60, and 80 mg/day doses (152, 177, and 160, respectively) for MPH-LA. Mean improvement from baseline in the dose confirmation phase in total scores of DSM-IV ADHD RS and SDS were 23.5 ± 9.90 and 9.7 ± 7.36, respectively. CONCLUSIONS: Dose optimization with MPH-LA (40, 60, or 80 mg/day) improved treatment outcomes and was well-tolerated in adult ADHD patients
Huss, M., Ginsberg, Y., Tvedten, T., Arngrim, T., Philipsen, A., Carter, K., Chen, C. -W., and Kumar, V., Methylphenidate hydrochloride modified-release in adults with attention deficit hyperactivity disorder: a randomized double-blind placebo-controlled trial, Advances in therapy, vol. 31, no. 1. pp. 44-65, Jan.-2014.
Abstract DOI
INTRODUCTION: Treatment options for adults with attention deficit hyperactivity disorder (ADHD) are limited. The study was conducted to confirm the clinically effective and safe dose of methylphenidate hydrochloride modified-release (MPH-LA) in adults with ADHD and evaluate the maintenance of effect of MPH-LA. METHODS: The study consisted of three treatment phases. The double-blind dose-confirmation phase: 9-week double-blind period (3-week titration period, 6-week fixed dose) with randomization to MPH-LA 40, 60, or 80 mg/day or placebo. The real-life dose-optimization phase: a 5-week re-titration period to optimal dose; and the double-blind maintenance of effect phase, a 6-month double-blind randomized placebo-controlled maintenance of effect phase. The three co-primary endpoints were change in Diagnostic and Statistical Manual of Mental Disorders-IV ADHD Rating Scale (DSM-IV ADHD RS) and Sheehan Disability Scale (SDS) total scores from baseline to end of 9-week confirmation phase and the percentage of treatment failures during the 6-month maintenance of effect phase. RESULTS: 725 of 863 screened patients were randomized to 40 (N = 181), 60 (N = 182), or 80 mg (N = 181) MPH-LA or placebo (N = 181), and 584 (80.6%) completed. 489 (83.7%) of completers were re-randomized to the double-blinded maintenance of effect phase and 235 (48.1%) of them completed. Improvement from baseline in DSM-IV ADHD RS (P < 0.0001 for all comparisons) and SDS (40 mg, P = 0.0003; 60 mg, P = 0.0176; 80 mg, P < 0.0001) total scores was significantly greater vs. placebo for all MPH-LA doses. Treatment failure rate was significantly lower with MPH-LA (21.3%) versus placebo (49.6%) during the 6-month maintenance of effect phase. Safety profile was consistent with the profile for MPH-LA in children; percentage of serious adverse events was comparable between all MPH-LA arms (1.3%) and placebo (1.5%), while percentage of adverse events was higher in MPH-LA arms. CONCLUSION: MPH-LA provided and maintained significant symptomatic and functional improvement in adult ADHD patients
Ginsberg, Y., Arngrim, T., Philipsen, A., Gandhi, P., Chen, C. -W., Kumar, V., and Huss, M., Long-term (1 year) safety and efficacy of methylphenidate modified-release long-acting formulation (MPH-LA) in adults with attention-deficit hyperactivity disorder: a 26-week, flexible-dose, open-label extension to a 40-week, double-blind, randomised, placebo-controlled core study, CNS drugs, vol. 28, no. 10. pp. 951-962, Oct.-2014.
Abstract DOI
Previously, in a 40-week, randomised, double-blind, placebo-controlled core study comprising three phases (9-week dose confirmation, 5-week open-label dose optimisation and 6-month maintenance of effect) in adults with attention-deficit/hyperactivity disorder (ADHD), methylphenidate modified-release long-acting formulation (MPH-LA) at 40-80 mg/day controlled ADHD symptoms as well as decreased functional impairment with a good tolerability profile (NCT01259492). Here, we report the long-term efficacy and safety from a 26-week, open-label extension phase of the same study (NCT01338818).Patients in the extension study (n = 298) initiated treatment with MPH-LA (20 mg/day), up-titrated in increments of 20 mg/week to reach individual patient's daily optimal dose of 40-80 mg. Adverse events (AEs) and serious adverse events (SAEs) were reported at the end of extension study for events monitored from (1) maintenance of effect phase baseline (core study; 12 months) and (2) extension study baseline (6 months). Mean changes in DSM-IV ADHD Rating Scale (DSM-IV ADHD RS) and Sheehan Disability Scale (SDS) total scores are reported for both the timelines. Efficacy was also evaluated using clinician-rated instruments, namely Clinical Global Impression-Improvement Scale (CGI-I) and Clinical Global Impression-Severity Scale (CGI-S).No unexpected AEs were reported in the extension study. Incidence of SAEs reported during 6 months and 12 months were similar (0.7 %), and no deaths were reported. No SAEs were considered attributable to the drug at the end of 12 months. There were no reports of patients with QT, QTcB or QTcF >500 ms. The mean improvement in DSM-IV ADHD RS and SDS total scores at the end of 12 months were 0.9 and 1.4 points, respectively; and at the end of 6 months were 7.2 and 4.8, respectively. The proportion of patients with improvement in CGI-S scale was 31.4 % and 52.1 % at the end of 12 and 6 months, respectively. Overall, 69.4 % of patients showed clinical improvement in CGI-I scale at the end of 6 months.In adult patients with ADHD, use of MPH-LA up to 1 year continued to be well tolerated while maintaining the clinical efficacy
Scheel, C. N., Bender, C., Tuschen-Caffier, B., Brodführer, A., Matthies, S., Hermann, C., Geisse, E. K., Svaldi, J., Brakemeier, E. -L., Philipsen, A., and Jacob, G. A., Do patients with different mental disorders show specific aspects of shame?, Psychiatry Research, vol. 220, no. 1-2. Elsevier BV, pp. 490-495, Dec.-2014.
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Jelschen, F., Zundel, J., and Weyland, A., Kasuistik – Hämodynamik während nicht invasiver Wiedererwärmung bei schwerer akzidenteller Hypothermie, Anästhesiol Intensivmed Notfallmed Schmerzther, vol. 49, no. 09. Thieme Publishing Group, pp. 514-519, 19-Sep.-2014.
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Grüne, F., Kazmaier, S., Sonntag, H., Stolker, R. J., and Weyland, A., Moderate Hyperventilation during Intravenous Anesthesia Increases Net Cerebral Lactate Efflux, Anesthesiology, vol. 120, no. 2. Ovid Technologies (Wolters Kluwer Health), pp. 335-342, Feb.-2014.
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Bloos, F., Thomas-Rüddel, D., Rüddel, H., Engel, C., Schwarzkopf, D., Marshall, J. C., Harbarth, S., Simon, P., Riessen, R., Keh, D., Dey, K., Weiß, M., Toussaint, S., Schädler, D., Weyland, A., Ragaller, M., Schwarzkopf, K., Eiche, J., Kuhnle, G., Hoyer, H., Hartog, C., Kaisers, U., Reinhart, K., and , Impact of compliance with infection management guidelines on outcome in patients with severe sepsis: a prospective observational multi-center study, Critical care (London, England), vol. 18, no. 2. p. R42, 2014.
Abstract DOI
INTRODUCTION: Current sepsis guidelines recommend antimicrobial treatment (AT) within one hour after onset of sepsis-related organ dysfunction (OD) and surgical source control within 12 hours. The objective of this study was to explore the association between initial infection management according to sepsis treatment recommendations and patient outcome. METHODS: In a prospective observational multi-center cohort study in 44 German ICUs, we studied 1,011 patients with severe sepsis or septic shock regarding times to AT, source control, and adequacy of AT. Primary outcome was 28-day mortality. RESULTS: Median time to AT was 2.1 (IQR 0.8 - 6.0) hours and 3 hours (-0.1 - 13.7) to surgical source control. Only 370 (36.6%) patients received AT within one hour after OD in compliance with recommendation. Among 422 patients receiving surgical or interventional source control, those who received source control later than 6 hours after onset of OD had a significantly higher 28-day mortality than patients with earlier source control (42.9% versus 26.7%, P <0.001). Time to AT was significantly longer in ICU and hospital non-survivors; no linear relationship was found between time to AT and 28-day mortality. Regardless of timing, 28-day mortality rate was lower in patients with adequate than non-adequate AT (30.3% versus 40.9%, P < 0.001). CONCLUSIONS: A delay in source control beyond 6 hours may have a major impact on patient mortality. Adequate AT is associated with improved patient outcome but compliance with guideline recommendation requires improvement. There was only indirect evidence about the impact of timing of AT on sepsis mortality
Dolležal, L. -V., Brechmann, A., Klump, G. M., and Deike, S., Evaluating auditory stream segregation of SAM tone sequences by subjective and objective psychoacoustical tasks, and brain activity, Frontiers in neuroscience, vol. 8. p. 119, 2014.
Abstract DOI
Auditory stream segregation refers to a segregated percept of signal streams with different acoustic features. Different approaches have been pursued in studies of stream segregation. In psychoacoustics, stream segregation has mostly been investigated with a subjective task asking the subjects to report their percept. Few studies have applied an objective task in which stream segregation is evaluated indirectly by determining thresholds for a percept that depends on whether auditory streams are segregated or not. Furthermore, both perceptual measures and physiological measures of brain activity have been employed but only little is known about their relation. How the results from different tasks and measures are related is evaluated in the present study using examples relying on the ABA- stimulation paradigm that apply the same stimuli. We presented A and B signals that were sinusoidally amplitude modulated (SAM) tones providing purely temporal, spectral or both types of cues to evaluate perceptual stream segregation and its physiological correlate. Which types of cues are most prominent was determined by the choice of carrier and modulation frequencies (f mod) of the signals. In the subjective task subjects reported their percept and in the objective task we measured their sensitivity for detecting time-shifts of B signals in an ABA- sequence. As a further measure of processes underlying stream segregation we employed functional magnetic resonance imaging (fMRI). SAM tone parameters were chosen to evoke an integrated (1-stream), a segregated (2-stream), or an ambiguous percept by adjusting the f mod difference between A and B tones (Δf mod). The results of both psychoacoustical tasks are significantly correlated. BOLD responses in fMRI depend on Δf mod between A and B SAM tones. The effect of Δf mod, however, differs between auditory cortex and frontal regions suggesting differences in representation related to the degree of perceptual ambiguity of the sequences
Frenken, T., Lohmann, O., Frenken, M., Steen, E. -E., and Hein, A., Performing gait analysis within the timed up & go assessment test: comparison of aTUG to a marker-based tracking system, Informatics for Health and Social Care, vol. 39, no. 3-4. Informa UK Limited, pp. 232-248, 22-Aug.-2014.
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Schmuelling, G., Oehl, N., Knipper, M., Kolny-Olesiak, J., Plaggenborg, T., Meyer, H. -W., Placke, T., Parisi, J., and Winter, M., Synthesis and electrochemical performance of surface-modified nano-sized core/shell tin particles for lithium ion batteries, Nanotechnology, vol. 25, no. 35. p. 355401, Sep.-2014.
Abstract DOI
Tin is able to lithiate and delithiate reversibly with a high theoretical specific capacity, which makes it a promising candidate to supersede graphite as the state-of-the-art negative electrode material in lithium ion battery technology. Nevertheless, it still suffers from poor cycling stability and high irreversible capacities. In this contribution, we show the synthesis of three different nano-sized core/shell-type particles with crystalline tin cores and different amorphous surface shells consisting of SnOx and organic polymers. The spherical size and the surface shell can be tailored by adjusting the synthesis temperature and the polymer reagents in the synthesis, respectively. We determine the influence of the surface modifications with respect to the electrochemical performance and characterize the morphology, structure, and thermal properties of the nano-sized tin particles by means of high-resolution transmission electron microscopy, x-ray diffraction, and thermogravimetric analysis. The electrochemical performance is investigated by constant current charge/discharge cycling as well as cyclic voltammetry
Li, J., Bloemen, M., Parisi, J., and Kolny-Olesiak, J., Role of copper sulfide seeds in the growth process of CuInS2 nanorods and networks, ACS applied materials & interfaces, vol. 6, no. 22. pp. 20535-20543, Nov.-2014.
Abstract DOI
CuInS2 nanorods and networks are interesting candidates for applications requiring efficient charge transport, such as solar energy conversion, because of the increased electrical conductivity in elongated or interconnected nanocrystals, compared to isolated, quasi-spherical ones. However, little is known about the growth mechanisms involved in the formation of this kind of nanostructures, yet. Here, CuInS2 nanorods and networks were synthesized through a facile low-cost and phosphine-free method. Copper and indium sources were added together in the presence of oleylamine and oleic acid. Changing the amount of oleic acid present in the reaction solution influenced the reactivity of the monomers, and consequently, the size of copper sulfide seeds formed in situ after the injection of tert-dodecanethiol, serving as the source of sulfur. Two different growth mechanisms of CuInS2 nanorods were observed, depending on the size of the copper sulfide seeds. Larger seeds (8 nm), which were generated with relatively small amounts of oleic acid, resulted in the formation of hybrid copper sulfide-copper indium disulfide nanocrystals as intermediates in the growth process of the nanorods, while smaller seeds (4 nm) obtained with relatively large amounts of oleic acid were gradually converted to copper indium sulfide nanorods. At longer reaction times, these nanorods formed network structures. The reaction between oleylamine and oleic acid at high temperature turned out to be the crucial factor to induce the attachment of nanorods to multipods and networks
Lienau, C., Noginov, M. A., and Lončar, M., Light–matter interactions at the nanoscale, J. Opt., vol. 16, no. 11. IOP Publishing, p. 110201, 1-Nov.-2014.
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Pittalis, S., Delgado, A., Robin, J., Freimuth, L., Christoffers, J., Lienau, C., and Rozzi, C. A., Charge Separation Dynamics and Opto-Electronic Properties of a Diaminoterephthalate-C 60 Dyad , Advanced Functional Materials, vol. 25, no. 13. Wiley-Blackwell, pp. 2047-2053, 10-Nov.-2014.
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Kollmann, H., Piao, X., Esmann, M., Becker, S. F., Hou, D., Huynh, C., Kautschor, L. -O., Bösker, G., Vieker, H., Beyer, A., Gölzhäuser, A., Park, N., Vogelgesang, R., Silies, M., and Lienau, C., Toward plasmonics with nanometer precision: nonlinear optics of helium-ion milled gold nanoantennas, Nano letters, vol. 14, no. 8. pp. 4778-4784, Aug.-2014.
Abstract DOI
Plasmonic nanoantennas are versatile tools for coherently controlling and directing light on the nanoscale. For these antennas, current fabrication techniques such as electron beam lithography (EBL) or focused ion beam (FIB) milling with Ga(+)-ions routinely achieve feature sizes in the 10 nm range. However, they suffer increasingly from inherent limitations when a precision of single nanometers down to atomic length scales is required, where exciting quantum mechanical effects are expected to affect the nanoantenna optics. Here, we demonstrate that a combined approach of Ga(+)-FIB and milling-based He(+)-ion lithography (HIL) for the fabrication of nanoantennas offers to readily overcome some of these limitations. Gold bowtie antennas with 6 nm gap size were fabricated with single-nanometer accuracy and high reproducibility. Using third harmonic (TH) spectroscopy, we find a substantial enhancement of the nonlinear emission intensity of single HIL-antennas compared to those produced by state-of-the-art gallium-based milling. Moreover, HIL-antennas show a vastly improved polarization contrast. This superior nonlinear performance of HIL-derived plasmonic structures is an excellent testimonial to the application of He(+)-ion beam milling for ultrahigh precision nanofabrication, which in turn can be viewed as a stepping stone to mastering quantum optical investigations in the near-field
Wang, W., Vasa, P., Pomraenke, R., Vogelgesang, R., De Sio, A., Sommer, E., Maiuri, M., Manzoni, C., Cerullo, G., and Lienau, C., Interplay between strong coupling and radiative damping of excitons and surface plasmon polaritons in hybrid nanostructures, ACS nano, vol. 8, no. 1. pp. 1056-1064, Jan.-2014.
Abstract DOI
We report on the interplay between strong coupling and radiative damping of strongly coupled excitons (Xs) and surface plasmon polaritons (SPPs) in a hybrid system made of J-aggregates and metal nanostructures. The optical response of the system is probed at the field level by angle-resolved spectral interferometry. We show that two different energy transfer channels coexist: coherent resonant dipole-dipole interaction and an incoherent exchange due to the spontaneous emissions of a photon by one emitter and its subsequent reabsorption by another. The interplay between both pathways results in a pronounced modification of the radiative damping due to the formation of super- and subradiant polariton states. This is confirmed by probing the ultrafast nonlinear response of the polariton system and explained within a coupled oscillator model. Such a strong modification of the radiative damping opens up interesting directions in coherent active plasmonics
Vogelsang, J., Robin, J., Piglosiewicz, B., Manzoni, C., Farinello, P., Melzer, S., Feru, P., Cerullo, G., Lienau, C., and Groß, P., High passive CEP stability from a few-cycle, tunable NOPA-DFG system for observation of CEP-effects in photoemission, Optics express, vol. 22, no. 21. pp. 25295-25306, Oct.-2014.
Abstract DOI
The investigation of fundamental mechanisms taking place on a femtosecond time scale is enabled by ultrafast pulsed laser sources. Here, the control of pulse duration, center wavelength, and especially the carrier-envelope phase has been shown to be of essential importance for coherent control of high harmonic generation and attosecond physics and, more recently, also for electron photoemission from metallic nanostructures. In this paper we demonstrate the realization of a source of 2-cycle laser pulses tunable between 1.2 and 2.1 μm, and with intrinsic CEP stability. The latter is guaranteed by difference frequency generation between the output pulse trains of two noncollinear optical parametric amplifier stages that share the same CEP variations. The CEP stability is better than 50 mrad over 20 minutes, when averaging over 100 pulses. We demonstrate the good CEP stability by measuring kinetic energy spectra of photoemitted electrons from a single metal nanostructure and by observing a clear variation of the electron yield with the CEP
Falke, S. M., Rozzi, C. A., Brida, D., Maiuri, M., Amato, M., Sommer, E., De Sio, A., Rubio, A., Cerullo, G., Molinari, E., and Lienau, C., Coherent ultrafast charge transfer in an organic photovoltaic blend, Science (New York, N.Y.), vol. 344, no. 6187. pp. 1001-1005, May-2014.
Abstract DOI
Blends of conjugated polymers and fullerene derivatives are prototype systems for organic photovoltaic devices. The primary charge-generation mechanism involves a light-induced ultrafast electron transfer from the light-absorbing and electron-donating polymer to the fullerene electron acceptor. Here, we elucidate the initial quantum dynamics of this process. Experimentally, we observed coherent vibrational motion of the fullerene moiety after impulsive optical excitation of the polymer donor. Comparison with first-principle theoretical simulations evidences coherent electron transfer between donor and acceptor and oscillations of the transferred charge with a 25-femtosecond period matching that of the observed vibrational modes. Our results show that coherent vibronic coupling between electronic and nuclear degrees of freedom is of key importance in triggering charge delocalization and transfer in a noncovalently bound reference system
Diederich, A., Projective probability theory, Journal of Mathematical Psychology, vol. 58. Elsevier BV, pp. 55-57, Jan.-2014.
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Colonius, H. and Diederich, A., Recalibration of the Multisensory Temporal Window of Integration, Procedia - Social and Behavioral Sciences, vol. 126. Elsevier BV, pp. 67-68, Mar.-2014.
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Diederich, A. and Oswald, P., Sequential sampling model for multiattribute choice alternatives with random attention time and processing order, Front. Hum. Neurosci., vol. 8. Frontiers Media SA, 9-Sep.-2014.
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Diederich, A., Books received for review 2014–05, Journal of Mathematical Psychology, vol. 60. Elsevier BV, p. 87, Jun.-2014.
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Diederich, A., Schomburg, A., and Vugt, M., Fronto-central theta oscillations are related to oscillations in saccadic response times (SRT): an EEG and behavioral data analysis, PloS one, vol. 9, no. 11. p. e112974, 2014.
Abstract DOI
The phase reset hypothesis states that the phase of an ongoing neural oscillation, reflecting periodic fluctuations in neural activity between states of high and low excitability, can be shifted by the occurrence of a sensory stimulus so that the phase value become highly constant across trials (Schroeder et al., 2008). From EEG/MEG studies it has been hypothesized that coupled oscillatory activity in primary sensory cortices regulates multi sensory processing (Senkowski et al. 2008). We follow up on a study in which evidence of phase reset was found using a purely behavioral paradigm by including also EEG measures. In this paradigm, presentation of an auditory accessory stimulus was followed by a visual target with a stimulus-onset asynchrony (SOA) across a range from 0 to 404 ms in steps of 4 ms. This fine-grained stimulus presentation allowed us to do a spectral analysis on the mean SRT as a function of the SOA, which revealed distinct peak spectral components within a frequency range of 6 to 11 Hz with a modus of 7 Hz. The EEG analysis showed that the auditory stimulus caused a phase reset in 7-Hz brain oscillations in a widespread set of channels. Moreover, there was a significant difference in the average phase at which the visual target stimulus appeared between slow and fast SRT trials. This effect was evident in three different analyses, and occurred primarily in frontal and central electrodes
Steenken, R., Weber, L., Colonius, H., and Diederich, A., Designing driver assistance systems with crossmodal signals: multisensory integration rules for saccadic reaction times apply, PloS one, vol. 9, no. 5. p. e92666, 2014.
Abstract DOI
Modern driver assistance systems make increasing use of auditory and tactile signals in order to reduce the driver's visual information load. This entails potential crossmodal interaction effects that need to be taken into account in designing an optimal system. Here we show that saccadic reaction times to visual targets (cockpit or outside mirror), presented in a driving simulator environment and accompanied by auditory or tactile accessories, follow some well-known spatiotemporal rules of multisensory integration, usually found under confined laboratory conditions. Auditory nontargets speed up reaction time by about 80 ms. The effect tends to be maximal when the nontarget is presented 50 ms before the target and when target and nontarget are spatially coincident. The effect of a tactile nontarget (vibrating steering wheel) was less pronounced and not spatially specific. It is shown that the average reaction times are well-described by the stochastic "time window of integration" model for multisensory integration developed by the authors. This two-stage model postulates that crossmodal interaction occurs only if the peripheral processes from the different sensory modalities terminate within a fixed temporal interval, and that the amount of crossmodal interaction manifests itself in an increase or decrease of second stage processing time. A qualitative test is consistent with the model prediction that the probability of interaction, but not the amount of crossmodal interaction, depends on target-nontarget onset asynchrony. A quantitative model fit yields estimates of individual participants' parameters, including the size of the time window. Some consequences for the design of driver assistance systems are discussed
Doebler, P., Alavash, M., and Gießing, C., Adaptive experiments with a multivariate Elo-type algorithm, Behavior Research Methods, vol. 47, no. 2. Springer Science + Business Media, pp. 384-394, 31-May-2014.
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Greschner, M., Field, G. D., Li, P. H., Schiff, M. L., Gauthier, J. L., Ahn, D., Sher, A., Litke, A. M., and Chichilnisky, E. J., A polyaxonal amacrine cell population in the primate retina, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 34, no. 10. pp. 3597-3606, Mar.-2014.
Abstract DOI
Amacrine cells are the most diverse and least understood cell class in the retina. Polyaxonal amacrine cells (PACs) are a unique subset identified by multiple long axonal processes. To explore their functional properties, populations of PACs were identified by their distinctive radially propagating spikes in large-scale high-density multielectrode recordings of isolated macaque retina. One group of PACs exhibited stereotyped functional properties and receptive field mosaic organization similar to that of parasol ganglion cells. These PACs had receptive fields coincident with their dendritic fields, but much larger axonal fields, and slow radial spike propagation. They also exhibited ON-OFF light responses, transient response kinetics, sparse and coordinated firing during image transitions, receptive fields with antagonistic surrounds and fine spatial structure, nonlinear spatial summation, and strong homotypic neighbor electrical coupling. These findings reveal the functional organization and collective visual signaling by a distinctive, high-density amacrine cell population
Li, P. H., Field, G. D., Greschner, M., Ahn, D., Gunning, D. E., Mathieson, K., Sher, A., Litke, A. M., and Chichilnisky, E. J., Retinal representation of the elementary visual signal, Neuron, vol. 81, no. 1. pp. 130-139, Jan.-2014.
Abstract DOI
The propagation of visual signals from individual cone photoreceptors through parallel neural circuits was examined in the primate retina. Targeted stimulation of individual cones was combined with simultaneous recording from multiple retinal ganglion cells of identified types. The visual signal initiated by an individual cone produced strong responses with different kinetics in three of the four numerically dominant ganglion cell types. The magnitude and kinetics of light responses in each ganglion cell varied nonlinearly with stimulus strength but in a manner that was independent of the cone of origin after accounting for the overall input strength of each cone. Based on this property of independence, the receptive field profile of an individual ganglion cell could be well estimated from responses to stimulation of each cone individually. Together, these findings provide a quantitative account of how elementary visual inputs form the ganglion cell receptive field
Strüber, N., Strüber, D., and Roth, G., Impact of early adversity on glucocorticoid regulation and later mental disorders, Neuroscience & Biobehavioral Reviews, vol. 38. Elsevier BV, pp. 17-37, Jan.-2014.
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Helfrich, R. F., Knepper, H., Nolte, G., Strüber, D., Rach, S., Herrmann, C. S., Schneider, T. R., and Engel, A. K., Selective Modulation of Interhemispheric Functional Connectivity by HD-tACS Shapes Perception, PLoS Biol, vol. 12, no. 12. Public Library of Science (PLoS), p. e1002031, 30-Dec.-2014.
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Pisarchik, A. N. and Feudel, U., Control of multistability, Physics Reports, vol. 540, no. 4. Elsevier BV, pp. 167-218, Jul.-2014.
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Karnatak, R., Ansmann, G., Feudel, U., and Lehnertz, K., Route to extreme events in excitable systems, Phys. Rev. E, vol. 90, no. 2. American Physical Society (APS), 27-Aug.-2014.
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Finke, C., Rosa, E., Braun, H. A., and Feudel, U., On the Role of Intrinsic Neuronal Dynamics for Relay Synchronization, IEICE Proceeding Series, vol. 1. The Institute of Electronics, Information and Communication Engineers, pp. 364-364, 2014.
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Chakraborty, S. and Feudel, U., Harmful algal blooms: combining excitability and competition, Theor Ecol, vol. 7, no. 3. Springer Science + Business Media, pp. 221-237, 26-Jan.-2014.
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Bengfort, M., Feudel, U., Hilker, F. M., and Malchow, H., Plankton blooms and patchiness generated by heterogeneous physical environments, Ecological Complexity, vol. 20. Elsevier BV, pp. 185-194, Dec.-2014.
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Patel, M. S., Patel, U., Sen, A., Sethia, G. C., Hens, C., Dana, S. K., Feudel, U., Showalter, K., Ngonghala, C. N., and Amritkar, R. E., Experimental observation of extreme multistability in an electronic system of two coupled Rossler oscillators, Physical review. E, Statistical, nonlinear, and soft matter physics, vol. 89, no. 2. p. 022918, Feb.-2014.
Abstract
We report the first experimental observation of extreme multistability in a controlled laboratory investigation. Extreme multistability arises when infinitely many attractors coexist for the same set of system parameters. The behavior was predicted earlier on theoretical grounds, supported by numerical studies of models of two coupled identical or nearly identical systems. We construct and couple two analog circuits based on a modified coupled Rössler system and demonstrate the occurrence of extreme multistability through a controlled switching to different attractor states purely through a change in initial conditions for a fixed set of system parameters. Numerical studies of the coupled model equations are in agreement with our experimental findings
Hinz, C., Namekawa, I., Behrmann-Godel, J., Oppelt, C., Jaeschke, A., Müller, A., Friedrich, R. W., and Gerlach, G., ERRATUM: Olfactory imprinting is triggered by MHC peptide ligands, Scientific Reports, vol. 4. Nature Publishing Group, 13-Jan.-2014.
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Lefeldt, N., Heyers, D., Schneider, N. -L., Engels, S., Elbers, D., and Mouritsen, H., Magnetic field-driven induction of ZENK in the trigeminal system of pigeons (Columba livia), Journal of the Royal Society, Interface / the Royal Society, vol. 11, no. 100. p. 20140777, Nov.-2014.
Abstract DOI
Magnetoreception remains one of the few unsolved mysteries in sensory biology. The upper beak, which is innervated by the ophthalmic branch of the trigeminal nerve (V1), has been suggested to contain magnetic sensors based on ferromagnetic structures. Recently, its existence in pigeons has been seriously challenged by studies suggesting that the previously described iron-accumulations are macrophages, not magnetosensitive nerve endings. This raised the fundamental question of whether V1 is involved in magnetoreception in pigeons at all. We exposed pigeons to either a constantly changing magnetic field (CMF), to a zero magnetic field providing no magnetic information, or to CMF conditions after V1 was cut bilaterally. Using immediate early genes as a marker of neuronal responsiveness, we report that the trigeminal brainstem nuclei of pigeons, which receive V1 input, are activated under CMF conditions and that this neuronal activation disappears if the magnetic stimuli are removed or if V1 is cut. Our data suggest that the trigeminal system in pigeons is involved in processing magnetic field information and that V1 transmits this information from currently unknown, V1-associated magnetosensors to the brain
Engels, S., Schneider, N. -L., Lefeldt, N., Hein, C. M., Zapka, M., Michalik, A., Elbers, D., Kittel, A., Hore, P. J., and Mouritsen, H., Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird, Nature, vol. 509, no. 7500. pp. 353-356, May-2014.
Abstract DOI
Electromagnetic noise is emitted everywhere humans use electronic devices. For decades, it has been hotly debated whether man-made electric and magnetic fields affect biological processes, including human health. So far, no putative effect of anthropogenic electromagnetic noise at intensities below the guidelines adopted by the World Health Organization has withstood the test of independent replication under truly blinded experimental conditions. No effect has therefore been widely accepted as scientifically proven. Here we show that migratory birds are unable to use their magnetic compass in the presence of urban electromagnetic noise. When European robins, Erithacus rubecula, were exposed to the background electromagnetic noise present in unscreened wooden huts at the University of Oldenburg campus, they could not orient using their magnetic compass. Their magnetic orientation capabilities reappeared in electrically grounded, aluminium-screened huts, which attenuated electromagnetic noise in the frequency range from 50 kHz to 5 MHz by approximately two orders of magnitude. When the grounding was removed or when broadband electromagnetic noise was deliberately generated inside the screened and grounded huts, the birds again lost their magnetic orientation capabilities. The disruptive effect of radiofrequency electromagnetic fields is not confined to a narrow frequency band and birds tested far from sources of electromagnetic noise required no screening to orient with their magnetic compass. These fully double-blinded tests document a reproducible effect of anthropogenic electromagnetic noise on the behaviour of an intact vertebrate
Schoenfeld, A. A., Poppinga, D., Harder, D., Doerner, K. -J., and Poppe, B., The artefacts of radiochromic film dosimetry with flatbed scanners and their causation by light scattering from radiation-induced polymers, Physics in medicine and biology, vol. 59, no. 13. pp. 3575-3597, Jul.-2014.
Abstract DOI
Optical experiments and theoretical considerations have been undertaken in order to understand the causes of the 'orientation effect' and the 'parabola effect', the artefacts impairing the desired light absorption measurement on radiochromic EBT3 films with flatbed scanners. EBT3 films exposed to doses up to 20.9 Gy were scanned with an Epson Expression 10000XL flatbed scanner in landscape and portrait orientation. The horizontally and vertically polarized light components of the scanner were determined, and another Epson Expression 10000XL flatbed scanner was disassembled to examine its optical components. The optical properties of exposed and unexposed EBT3 films were studied with incident polarized and unpolarized white light, and the transmitted red light was investigated for its polarization and scattering properties including the distribution of the scattering angles. Neutral density filters were studied for comparison. Guidance was sought from the theory of light scattering from rod-like macromolecular structures. The drastic dose-dependent variation of the transmitted total light current as function of the orientation of front and rear polarizers, interpreted by light scattering theory, shows that the radiation-induced polymerization of the monomers of EBT3 films produces light scattering oscillators preferably polarized at right angles with the coating direction of the film. The directional distribution of the scattered light is partly anisotropic, with a preferred scattering plane at right angles with the coating direction, indicating light scattering from stacks of coherently vibrating oscillators piled up along the monomer crystals. The polyester carrier film also participates in these effects. The 'orientation' and 'parabola' artefacts due to flatbed scanning of radiochromic films can be explained by the interaction of the polarization-dependent and anisotropic light scattering from exposed and unexposed EBT3 films with the quantitative difference between the scanner's horizontally and vertically polarized light supply and with the limited directional acceptance of the scanner's light recording system
Denham, S., Böhm, T. M., Bendixen, A., Szalárdy, O., Kocsis, Z., Mill, R., and Winkler, I., Stable individual characteristics in the perception of multiple embedded patterns in multistable auditory stimuli, Front. Neurosci., vol. 8. 2014.
Abstract
The ability of the auditory system to parse complex scenes into component objects in order to extract information from the environment is very robust, yet the processing principles underlying this ability are still not well understood. This study was designed to investigate the proposal that the auditory system constructs multiple interpretations of the acoustic scene in parallel, based on the finding that when listening to a long repetitive sequence listeners report switching between different perceptual organizations. Using the “ABA-” auditory streaming paradigm we trained listeners until they could reliably recognize all possible embedded patterns of length four which could in principle be extracted from the sequence, and in a series of test sessions investigated their spontaneous reports of those patterns. With the training allowing them to identify and mark a wider variety of possible patterns, participants spontaneously reported many more patterns than the ones traditionally assumed (Integrated vs. Segregated). Despite receiving consistent training and despite the apparent randomness of perceptual switching, we found individual switching patterns were idiosyncratic; i.e., the perceptual switching patterns of each participant were more similar to their own switching patterns in different sessions than to those of other participants. These individual differences were found to be preserved even between test sessions held a year after the initial experiment. Our results support the idea that the auditory system attempts to extract an exhaustive set of embedded patterns which can be used to generate expectations of future events and which by competing for dominance give rise to (changing) perceptual awareness, with the characteristics of pattern discovery and perceptual competition having a strong idiosyncratic component. Perceptual multistability thus provides a means for characterizing both general mechanisms and individual differences in human perception.
Tavano, A., Widmann, A., Bendixen, A., Trujillo-Barreto, N., and Schröger, E., Temporal regularity facilitates higher-order sensory predictions in fast auditory sequences, Eur. J. Neurosci., vol. 39, no. 2. 2014.
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Does temporal regularity facilitate prediction in audition? To test this, we recorded human event-related potentials to frequent standard tones and infrequent pitch deviant tones, pre-attentively delivered within isochronous and anisochronous (20% onset jitter) rapid sequences. Deviant tones were repeated, either with high or low probability. Standard tone repetition sets a first-order prediction, which is violated by deviant tone onset, leading to a first-order prediction error response (Mismatch Negativity). The response to highly probable deviant repetitions is, however, attenuated relative to less probable repetitions, reflecting the formation of higher-order sensory predictions. Results show that temporal regularity is required for higher-order predictions, but does not modulate first-order prediction error responses. Inverse solution analyses (Variable Resolution Electrical Tomography; VARETA) localized the error response attenuation to posterior regions of the left superior temporal gyrus. In a control experiment with a slower stimulus rate, we found no evidence for higher-order predictions, and again no effect of temporal information on first-order prediction error. We conclude that: (i) temporal regularity facilitates the establishing of higher-order sensory predictions, i.e. \\\'knowing what next\\\', in fast auditory sequences; (ii) first-order prediction error relies predominantly on stimulus feature mismatch, reflecting the adaptive fit of fast deviance detection processes.
Bendixen, A., Denham, S. L., and Winkler, I., Feature Predictability Flexibly Supports Auditory Stream Segregation or Integration, Acta Acust. united with Acust., vol. 100, no. 5. 2014.
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Many sound sources emit series of discrete sounds. Auditory perception must bind these sounds together (stream integration) while separating them from sounds emitted by other sources (stream segregation). One cue for identifying successive sounds that belong together is the predictability between their feature values. Previous studies have demonstrated that independent predictable patterns appearing separately in two interleaved sound sequences support perceptual segregation. The converse case, whether a joint predictable pattern in a mixture of interleaved sequences supports perceptual integration, has not yet been put to a rigorous empirical test. This was mainly due to difficulties in manipulating the predictability of the full sequence independently of the predictability of the interleaved subsequences. The present study implemented such an independent manipulation. Listeners continuously indicated whether they perceived a tone sequence as integrated or segregated, while predictable patterns set up to support one or the other percept were manipulated without the participants\\\' knowledge. Perceptual reports demonstrate that predictability supports stream segregation or integration depending on the type of predictable pattern that is present in the sequence. The effects of predictability were so pronounced as to qualitatively flip perception from predominantly (62%) integrated to predominantly (73%) segregated. These results suggest that auditory perception flexibly responds to encountered regular patterns, favoring predictable perceptual organizations over unpredictable ones. Besides underlining the role of predictability as a cue within auditory scene analysis, the present design also provides a general framework that accommodates previous investigations focusing on sub-comparisons within the present set of experimental manipulations. Results of intermediate conditions shed light on why some previous studies have obtained little to no effects of predictability on auditory scene analysis.
Li, S., Weerda, R., Milde, C., Wolf, O. T., and Thiel, C. M., ADRA2B genotype differentially modulates stress-induced neural activity in the amygdala and hippocampus during emotional memory retrieval, Psychopharmacology, vol. 232, no. 4. 2014.
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Rationale Noradrenaline interacts with stress hormones in the amygdala and hippocampus to enhance emotional memory consolidation, but the noradrenergic-glucocorticoid interaction at retrieval, where stress impairs memory, is less understood. Objectives We used a genetic neuroimaging approach to investigate whether a genetic variation of the noradrenergic system impacts stress-induced neural activity in amygdala and hippocampus during recognition of emotional memory. Methods This study is based on genotype-dependent reanalysis of data from our previous publication (Li et al. Brain Imaging Behav 2014). Twenty-two healthy male volunteers were genotyped for the ADRA2B gene encoding the α2B-adrenergic receptor. Ten deletion carriers and 12 noncarriers performed an emotional face recognition task, while their brain activity was measured with fMRI. During encoding, 50 fearful and 50 neutral faces were presented. One hour later, they underwent either an acute stress (Trier Social Stress Test) or a control procedure which was followed immediately by the retrieval session, where participants had to discriminate between 100 old and 50 new faces. Results A genotype-dependent modulation of neural activity at retrieval was found in the bilateral amygdala and right hippocampus. Deletion carriers showed decreased neural activity in the amygdala when recognizing emotional faces in control condition and increased amygdala activity under stress. Noncarriers showed no differences in emotional modulated amygdala activation under stress or control. Instead, stress-induced increases during recognition of emotional faces were present in the right hippocampus. Conclusion The genotype-dependent effects of acute stress on neural activity in amygdala and hippocampus provide evidence for noradrenergic-glucocorticoid interaction in emotional memory retrieval.
Behler, O., Breckel, T. P. K., and Thiel, C. M., Nicotine reduces distraction under low perceptual load., Psychopharmacology, vol. 232, no. 7. 2014.
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RATIONALE: Several studies provide evidence that nicotine alleviates the detrimental effects of distracting sensory stimuli. It is been suggested that nicotine may either act as a stimulus filter that prevents irrelevant stimuli entering awareness or by enhancing the attentional focus to relevant stimuli via a boost in processing capacity. OBJECTIVES: To differentiate between these two accounts, we administered nicotine to healthy non-smokers and investigated distractor interference in a visual search task with low and high perceptual load to tax processing capacity. METHODS: Thirty healthy non-smokers received either 7 mg transdermal nicotine or a matched placebo in a double blind within subject design 1 h prior to performing the visual search task with different fixation distractors. RESULTS: Nicotine reduced interference of incongruent distractors, but only under low-load conditions, where distractor effects were large. No effects of nicotine were observed under high-load conditions. Highly distractible subjects showed the largest effects of nicotine. CONCLUSIONS: The findings suggest that nicotine acts primarily as a stimulus filter that prevents irrelevant stimuli from entering awareness in situations of high distractor interference.
Kandil, F. I., Diederich, A., and Colonius, H., Parameter recovery for the time-window-of-integration (TWIN) model of multisensory integration in focused attention., J. Vis., vol. 14, no. 11. 2014.
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In multisensory settings such as the focused attention paradigm (FAP), subjects are instructed to respond to stimuli of the target modality only, yet reaction times tend to be shorter if an unattended stimulus is presented within a certain spatiotemporal vicinity of the target. The time window of integration (TWIN) model predicts successfully these observed cross-modal reaction time effects. It proposes that all the initially unimodal information must arrive at a point of integration within a certain time window in order to be integrated and thus to initiate response enhancements like the observed reaction time reductions. Here we conducted a parameter recovery study of the TWIN model for focused attention tasks, with five parameters (the durations of the visual and auditory unimodal and the integrated second stage, the width of the time window, and the effect size). Results show that parameter estimates were highly accurate (unbiased, constant error less than 5 ms) and precise (variable error less than 8 ms) throughout, speaking to a high reliability and criterion validity of the process. Further analyses ensured that the estimation procedure is consistent and sufficiently robust against contamination (faulty integration). It can thus be used to estimate reliably the point of integration and the width of the time window.
Gulberti, A., Arndt, P. A., and Colonius, H., Stopping eyes and hands: evidence for non-independence of stop and go processes and for a separation of central and peripheral inhibition, Front. Hum. Neurosci., vol. 8. 2014.
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In the stop-signal paradigm, participants perform a primary reaction task, for example a visual or auditory discrimination task, and have to react to a go stimulus as quickly as possible with a specified motor response. In a certain percentage of trials, after presentation of the stimulus (go signal), another stimulus (stop signal) is presented with a variable stop-signal delay. Whenever a stop signal occurs, the participant is asked to inhibit the execution of the response. Here, an extended test of the popular horse race model for this task (Logan and Cowan, 1984) is presented. Responses for eye and hand movements in both single-task and dual-task conditions were collected. Saccadic reaction times revealed some significant violations of the model\\\'s basic assumption of independent go and inhibition processes for all six participants. Saccades that escaped an early stop signal were systematically slower and had smaller amplitudes compared to saccades without a stop signal. Moreover, the analysis of concomitant electromyographic responses recorded from the upper arm suggests the existence of two separate inhibitory mechanisms: a slow, selective, central inhibitory mechanism and a faster, highly efficient, peripheral one, which is probably ineffective for saccades.
Enriquez-Geppert, S., Huster, R. J., Figge, C., and Herrmann, C. S., Self-regulation of frontal-midline theta facilitates memory updating and mental set shifting, Front. Behav. Neurosci., vol. 8. 2014.
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Frontal-midline (fm) theta oscillations as measured via the electroencephalogram (EEG) have been suggested as neural “working language” of executive functioning. Their power has been shown to increase when cognitive processing or task performance is enhanced. Thus, the question arises whether learning to increase fm-theta amplitudes would functionally impact the behavioral performance in tasks probing executive functions (EFs). Here, the effects of neurofeedback (NF), a learning method to self-up-regulate fm-theta over fm electrodes, on the four most representative EFs, memory updating, set shifting, conflict monitoring, and motor inhibition are presented. Before beginning and after completing an individualized, eight-session gap-spaced NF intervention, the three-back, letter/number task-switching, Stroop, and stop-signal tasks were tested while measuring the EEG. Self-determined up-regulation of fm-theta and its putative role for executive functioning were compared to an active control group, the so-called pseudo-neurofeedback group. Task-related fm-theta activity after training differed significantly between groups. More importantly, though, after NF significantly enhanced behavioral performance was observed. The training group showed higher accuracy scores in the three-back task and reduced mixing and shifting costs in letter/number task-switching. However, this specific protocol type did not affect performance in tasks probing conflict monitoring and motor inhibition. Thus, our results suggest a modulation of proactive but not reactive mechanisms of cognitive control. Furthermore, task-related EEG changes show a distinct pattern for fm-theta after training between the NF and the pseudo-neurofeedback group, which indicates that NF training indeed tackles EFs-networks. In sum, the modulation of fm-theta via NF may serve as potent treatment approach for executive dysfunctions.
Itatani, N. and Klump, G. M., Neural correlates of auditory streaming in an objective behavioral task, Proc. Natl. Acad. Sci., vol. 111, no. 29. 2014.
Abstract DOI
Segregating streams of sounds from sources in complex acoustic scenes is crucial for perception in real world situations. We analyzed an objective psychophysical measure of stream segregation obtained while simultaneously recording forebrain neurons in the European starlings to investigate neural correlates of segregating a stream of A tones from a stream of B tones presented at one-half the rate. The objective measure, sensitivity for time shift detection of the B tone, was higher when the A and B tones were of the same frequency (one stream) compared with when there was a 6- or 12-semitone difference between them (two streams). The sensitivity for representing time shifts in spiking patterns was correlated with the behavioral sensitivity. The spiking patterns reflected the stimulus characteristics but not the behavioral response, indicating that the birds’ primary cortical field represents the segregated streams, but not the decision process.
Rasumow, E., Blau, M., Hansen, M., van de Par, S., Doclo, S., Mellert, V., and Püschel, D., Smoothing individual head-related transfer functions in the frequency and spatial domains, J. Acoust. Soc. Am., vol. 135, no. 4. 2014.
Abstract
Gerlach, S., Bitzer, J., Goetze, S., and Doclo, S., Joint Estimation of Pitch and Direction of Arrival: Improving Robustness and Accuracy for multi speaker scenario , EURASIP J. Aud. Speech Music Process., vol. 2014, no. 31. 2014.
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Gerkmann, T., Bayesian Estimation of Clean Speech Spectral Coefficients Given a Priori Knowledge of the Phase, IEEE Trans. Sig. Proc., vol. 62, no. 16. 2014.
Abstract
While most short-time discrete Fourier transform-based single-channel speech enhancement algorithms only modify the noisy spectral amplitude, in recent years the interest in phase processing has increased in the field. The goal of this paper is twofold. First, we derive Bayesian probability density functions and estimators for the clean speech phase when different amounts of prior knowledge about the speech and noise amplitudes is given. Second, we derive a joint Bayesian estimator of the clean speech amplitudes and phases, when uncertain a priori knowledge on the phase is available. Instrumental measures predict that by incorporating uncertain prior information of the phase, the quality and intelligibility of processed speech can be improved both over traditional phase insensitive approaches, and approaches that treat prior information on the phase as deterministic.
Krawczyk, M. and Gerkmann, T., STFT Phase Reconstruction in Voiced Speech for an Improved Single-Channel Speech Enhancement, IEEE Trans. Aud. Sp. Lang. Proc., vol. 22, no. 12. 2014.
Abstract
The enhancement of speech which is corrupted by noise is commonly performed in the short-time discrete Fourier transform domain. In case only a single microphone signal is available, typically only the spectral amplitude is modified. However, it has recently been shown that an improved spectral phase can as well be utilized for speech enhancement, e.g., for phase-sensitive amplitude estimation. In this paper, we therefore present a method to reconstruct the spectral phase of voiced speech from only the fundamental frequency and the noisy observation. The importance of the spectral phase is highlighted and we elaborate on the reason why noise reduction can be achieved by modifications of the spectral phase. We show that, when the noisy phase is enhanced using the proposed phase reconstruction, instrumental measures predict an increase of speech quality over a range of signal to noise ratios, even without explicit amplitude enhancement.
Neher, T., Grimm, G., and Hohmann, V., Perceptual Consequences of Different Signal Changes Due to Binaural Noise Reduction: Do Hearing Loss and Working Memory Capacity Play a Role?, Ear Hear., vol. Epub ahead of print, no. 2013. 2014.
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OBJECTIVES:: In a previous study, Neher et al. (2013) investigated whether pure-tone average (PTA) hearing loss and working memory capacity (WMC) modulate benefit from different binaural noise reduction (NR) settings. Results showed that listeners with smaller WMC preferred strong over moderate NR even at the expense of poorer speech recognition due to greater speech distortion (SD), whereas listeners with larger WMC did not. To enable a better understanding of these findings, the main aims of the present study were (1) to explore the perceptual consequences of changes to the signal mixture, target speech, and background noise caused by binaural NR, and (2) to determine whether response to these changes varies with WMC and PTA.DESIGN:: As in the previous study, four age-matched groups of elderly listeners (with N = 10 per group) characterized by either mild or moderate PTAs and either better or worse performance on a visual measure of WMC participated. Five processing conditions were tested, which were based on the previously used (binaural coherence-based) NR scheme designed to attenuate diffuse signal components at mid to high frequencies. The five conditions differed in terms of the type of processing that was applied (no NR, strong NR, or strong NR with restoration of the long-term stimulus spectrum) and in terms of whether the target speech and background noise were processed in the same manner or whether one signal was left unprocessed while the other signal was processed with the gains computed for the signal mixture. Comparison across these conditions allowed assessing the effects of changes in high-frequency audibility (HFA), SD, and noise attenuation and distortion (NAD). Outcome measures included a dual-task paradigm combining speech recognition with a visual reaction time (VRT) task as well as ratings of perceived effort and overall preference. All measurements were carried out using headphone simulations of a frontal target speaker in a busy cafeteria.RESULTS:: Relative to no NR, strong NR was found to impair speech recognition and VRT performance slightly and to improve perceived effort and overall preference markedly. Relative to strong NR, strong NR with restoration of the long-term stimulus spectrum and thus HFA did not affect speech recognition, restored VRT performance to that achievable with no NR, and increased perceived effort and reduced overall preference markedly. SD had negative effects on speech recognition and perceived effort, particularly when both speech and noise were processed with the gains computed for the signal mixture. NAD had positive effects on speech recognition, perceived effort, and overall preference, particularly when the target speech was left unprocessed. VRT performance was unaffected by SD and NAD. None of the datasets exhibited any clear signs that response to the different signal changes varies with PTA or WMC.CONCLUSIONS:: For the outcome measures and stimuli applied here, the present study provides little evidence that PTA or WMC affect response to changes in HFA, SD, and NAD caused by binaural NR. However, statistical power restrictions suggest further research is needed. This research should also investigate whether partial HFA restoration combined with some pre-processing that reduces co-modulation distortion results in a more favorable balance of the effects of binaural NR across outcome dimensions and whether NR strength has any influence on these results.
Panda, M. R., Lecluyse, W., Tan, C. M., Jürgens, T., and Meddis, R., Hearing dummies: Individualized computer models of hearing impairment., Int. J. Audiol., vol. 53, no. 10. 2014.
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Objective: Our aim was to explore the usage of individualized computer models to simulate hearing loss based on detailed psychophysical assessment and to offer hypothetical diagnoses of the underlying pathology. Design: Individualized computer models of normal and impaired hearing were constructed and evaluated using the psychophysical data obtained from human listeners. Computer models of impaired hearing were generated to reflect the hypothesized underlying pathology (e.g. dead regions, outer hair cell dysfunction, or reductions in endocochlear potential). These models were evaluated in terms of their ability to replicate the original patient data. Study sample: Auditory profiles were measured for two normal and five hearing-impaired listeners using a battery of three psychophysical tests (absolute thresholds, frequency selectivity, and compression). Results: The individualized computer models were found to match the data. Useful fits to the impaired profiles could be obtained by changing only a single parameter in the model of normal hearing. Sometimes, however, it was necessary to include an additional dead region. Conclusion: The creation of individualized computer models of hearing loss can be used to simulate auditory profiles of impaired listeners and suggest hypotheses concerning the underlying peripheral pathology.
Hildebrandt, K. J., Neural maps in insect versus vertebrate auditory systems, Curr. Opin. Neurobiol., vol. 24, no. 1. 2014.
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The convergent evolution of hearing in insects and vertebrates raises the question about similarity of the central representation of sound in these distant animal groups. Topographic representations of spectral, spatial and temporal cues have been widely described in mammals, but evidence for such maps is scarce in insects. Recent data on insect sound encoding provides evidence for an early integration of sound parameters to form highly-specific representation that predict behavioral output. In mammals, new studies investigating neural representation of perceptual features in behaving animals allow asking similar questions. A comparative approach may help in understanding principles underlying the formation of perceptual categories and behavioral plasticity. ?? 2013 Elsevier Ltd.
Neher, T., Grimm, G., Hohmann, V., and Kollmeier, B., Do hearing loss and cognitive function modulate benefit from different binaural noise-reduction settings?, Ear Hear., vol. 35, no. 3. 2014.
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OBJECTIVES: Although previous research indicates that cognitive skills influence benefit from different types of hearing aid algorithms, comparatively little is known about the role of, and potential interaction with, hearing loss. This holds true especially for noise reduction (NR) processing. The purpose of the present study was thus to explore whether degree of hearing loss and cognitive function modulate benefit from different binaural NR settings based on measures of speech intelligibility, listening effort, and overall preference. DESIGN: Forty elderly listeners with symmetrical sensorineural hearing losses in the mild to severe range participated. They were stratified into four age-matched groups (with n = 10 per group) based on their pure-tone average hearing losses and their performance on a visual measure of working memory (WM) capacity. The algorithm under consideration was a binaural coherence-based NR scheme that suppressed reverberant signal components as well as diffuse background noise at mid to high frequencies. The strength of the applied processing was varied from inactive to strong, and testing was carried out across a range of fixed signal-to-noise ratios (SNRs). Potential benefit was assessed using a dual-task paradigm combining speech recognition with a visual reaction time (VRT) task indexing listening effort. Pairwise preference judgments were also collected. All measurements were made using headphone simulations of a frontal speech target in a busy cafeteria. Test-retest data were gathered for all outcome measures. RESULTS: Analysis of the test-retest data showed all data sets to be reliable. Analysis of the speech scores showed that, for all groups, speech recognition was unaffected by moderate NR processing, whereas strong NR processing reduced intelligibility by about 5%. Analysis of the VRT scores revealed a similar data pattern. That is, while moderate NR did not affect VRT performance, strong NR impaired the performance of all groups slightly. Analysis of the preference scores collapsed across SNR showed that all groups preferred some over no NR processing. Furthermore, the two groups with smaller WM capacity preferred strong over moderate NR processing; for the two groups with larger WM capacity, preference did not differ significantly between the moderate and strong settings. CONCLUSIONS: The present study demonstrates that, for the algorithm and the measures of speech recognition and listening effort used here, the effects of different NR settings interact with neither degree of hearing loss nor WM capacity. However, preferred NR strength was found to be associated with smaller WM capacity, suggesting that hearing aid users with poorer cognitive function may prefer greater noise attenuation even at the expense of poorer speech intelligibility. Further research is required to enable a more detailed (SNR-dependent) analysis of this effect and to test its wider applicability.
Buschermöhle, M., Wagener, K. C., Berg, D., Meis, M., and Kollmeier, B., The German digit triplets test (Part I): Implementations for telephone, internet and mobile devices, Z. Audiol., vol. 53, no. 4. 2014.
AbstractFull Text
Jürgens, T., Ewert, S. D., Kollmeier, B., and Brand, T., Prediction of consonant recognition in quiet for listeners with normal and impaired hearing using an auditory model., J. Acoust. Soc. Am., vol. 135, no. 3. 2014.
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Wendt, D., Brand, T., and Kollmeier, B., An eye-tracking paradigm for analyzing the processing time of sentences with different linguistic complexities., PLOS ONE, vol. 9, no. 6. 2014.
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An eye-tracking paradigm was developed for use in audiology in order to enable online analysis of the speech comprehension process. This paradigm should be useful in assessing impediments in speech processing. In this paradigm, two scenes, a target picture and a competitor picture, were presented simultaneously with an aurally presented sentence that corresponded to the target picture. At the same time, eye fixations were recorded using an eye-tracking device. The effect of linguistic complexity on language processing time was assessed from eye fixation information by systematically varying linguistic complexity. This was achieved with a sentence corpus containing seven German sentence structures. A novel data analysis method computed the average tendency to fixate the target picture as a function of time during sentence processing. This allowed identification of the point in time at which the participant understood the sentence, referred to as the decision moment. Systematic differences in processing time were observed as a function of linguistic complexity. These differences in processing time may be used to assess the efficiency of cognitive processes involved in resolving linguistic complexity. Thus, the proposed method enables a temporal analysis of the speech comprehension process and has potential applications in speech audiology and psychoacoustics.
Schlueter, A., Lemke, U., Kollmeier, B., and Holube, I., Intelligibility of time-compressed speech: the effect of uniform versus non-uniform time-compression algorithms., J. Acoust. Soc. Am., vol. 135, no. 3. 2014.
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For assessing hearing aid algorithms, a method is sought to shift the threshold of a speech-in-noise test to (mostly positive) signal-to-noise ratios (SNRs) that allow discrimination across algorithmic settings and are most relevant for hearing-impaired listeners in daily life. Hence, time-compressed speech with higher speech rates was evaluated to parametrically increase the difficulty of the test while preserving most of the relevant acoustical speech cues. A uniform and a non-uniform algorithm were used to compress the sentences of the German Oldenburg Sentence Test at different speech rates. In comparison, the non-uniform algorithm exhibited greater deviations from the targeted time compression, as well as greater changes of the phoneme duration, spectra, and modulation spectra. Speech intelligibility for fast Oldenburg sentences in background noise at different SNRs was determined with 48 normal-hearing listeners. The results confirmed decreasing intelligibility with increasing speech rate. Speech had to be compressed to more than 30\\% of its original length to reach 50\\% intelligibility at positive SNRs. Characteristics influencing the discrimination ability of the test for assessing effective SNR changes were investigated. Subjective and objective measures indicated a clear advantage of the uniform algorithm in comparison to the non-uniform algorithm for the application in speech-in-noise tests.
Rennies, J., Schepker, H., Holube, I., and Kollmeier, B., Listening effort and speech intelligibility in listening situations affected by noise and reverberation, J. Acoust. Soc. Am., vol. 136, no. 5. 2014.
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Dietz, A., Buschermöhle, M., Aarnisalo, A. A., Vanhanen, A., Hyyrynen, T., Aaltonen, O., Löppönen, H., Zokoll, M. A., and Kollmeier, B., The development and evaluation of the Finnish Matrix Sentence Test for speech intelligibility assessment., Acta oto-laryngologica, vol. 134, no. 7. 2014.
Abstract DOIFull Text
Conclusion: The Finnish Matrix Test is the first sentence test in noise for the Finnish language. It was developed according to the HearCom standards and provides reliable speech intelligibility measurements with highly comparable results with the other international matrix tests. Objectives: The aim of the study was to develop an accurate speech intelligibility test in noise for the Finnish language that is comparable across different languages. Methods: We chose a matrix sentence test, which comprises a base matrix of 10 names, verbs, numerals, adjectives and nouns. Test lists were formed from this matrix quasi randomly, providing test sentences of the same syntactical structure. The speech material corresponds to everyday spoken language and the phoneme distribution is representative of the Finnish language. The test was optimized by determining the speech recognition thresholds of the individual words and subsequently by applying level corrections of up to ±3 dB. Evaluation measurements were performed to check the equivalence of the different test lists with respect to speech intelligibility and to provide reference values for further clinical applications. Results: After training, the mean speech recognition threshold (SRT) and the slope of the final test lists were –10.1 ± 0.1 dB signal-to-noise-ratio (SNR)and 16.7 ± 1.2%/dB, respectively (measurements at constant level; inter-list variability). The mean SRT and the slope of the test subjects were –10.1 ± 0.7 dB SNR and 17.5 ± 2.2%/dB (measurements at constant level; inter-subject variability). The expected SRT range for normal-hearing young adults for adaptive measurements is –9.7 ± 0.7 dB SNR.
Rennies, J., Warzybok, A., Brand, T., and Kollmeier, B., Modeling the effects of a single reflection on binaural speech intelligibility, J. Acoust. Soc. Am., vol. 135, no. 3. 2014.
Abstract DOIFull Text
Recently the influence of delay and azimuth of a single speech reflection on speech reception thresholds (SRTs) was systematically investigated using frontal, diffuse, and lateral noise [Warzybok et al. (2013). J. Acoust. Soc. Am. 133, 269–282]. The experiments showed that the benefit of an early reflection was independent of its azimuth and mostly independent of noise type, but that the detrimental effect of a late reflection depended on its direction relative to the noise. This study tests if different extensions of a binaural speech intelligibility model can predict these data. The extensions differ in the order in which binaural processing and temporal integration of early reflections take place. Models employing a correction for the detrimental effects of reverberation on speech intelligibility after performing the binaural processing predict SRTs in symmetric masking conditions (frontal, diffuse), but cannot predict the measured interaction of temporal and spatial integration. In contrast, a model extension accounting for the distinction between useful and detrimental reflections before the binaural processing stage predicts the data with an overall R 2 of 0.95. This indicates that any model framework predicting speech intelligibility in rooms should incorporate an interaction between binaural and temporal integration of reflections at a comparatively early stage.
Kollmeier, B., Lenarz, T., Kießling, J., Müller-Deile, J., Steffens, T., von Wedel, H., Döring, W. H., Buschermöhle, M., Wagener, K., and Brand, T., Zur Diskussion um den Freiburger Einsilbertest [Contribution to the discussion surrounding the Freiburg speech test]., HNO, vol. 62, no. 1. 2014.
Abstract DOIFull Text
Buschermöhle, M., Berg, D., Wittkop, T., Zokoll, M. A., and Kollmeier, B., Sprachaudiometrie mit Matrixtests [Speech audiometry with matrix tests], Z. Audiol., vol. 53, no. 3. 2014.
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Altoè, A., Pulkki, V., and Verhulst, S., Transmission line cochlear models: Improved accuracy and efficiency, J. Acoust. Soc. Am., vol. 136, no. 4. 2014.
Abstract DOIFull Text
This paper presents an efficient method to compute the numerical solutions of transmission-line (TL) cochlear models, and its application on the model of Verhulst et al. The stability region of the model is extended by adopting a variable step numerical method to solve the system of ordinary differential equations that describes it, and by adopting an adaptive scheme to take in account variations in the system status within each numerical step. The presented method leads to improve simulations numerical accuracy and large computational savings, leading to employ TL models for more extensive simulations than currently possible.
Bharadwaj, H. M., Verhulst, S., Shaheen, L., Liberman, M. C., and Shinn-Cunningham, B. G., Cochlear neuropathy and the coding of supra-threshold sound., Front. Syst. Neurosci., vol. 8:26. 2014.
Abstract DOIFull Text
Many listeners with hearing thresholds within the clinically normal range nonetheless complain of difficulty hearing in everyday settings and understanding speech in noise. Converging evidence from human and animal studies points to one potential source of such difficulties: differences in the fidelity with which supra-threshold sound is encoded in the early portions of the auditory pathway. Measures of auditory subcortical steady-state responses (SSSRs) in humans and animals support the idea that the temporal precision of the early auditory representation can be poor even when hearing thresholds are normal. In humans with normal hearing thresholds (NHTs), paradigms that require listeners to make use of the detailed spectro-temporal structure of supra-threshold sound, such as selective attention and discrimination of frequency modulation (FM), reveal individual differences that correlate with subcortical temporal coding precision. Animal studies show that noise exposure and aging can cause a loss of a large percentage of auditory nerve fibers (ANFs) without any significant change in measured audiograms. Here, we argue that cochlear neuropathy may reduce encoding precision of supra-threshold sound, and that this manifests both behaviorally and in SSSRs in humans. Furthermore, recent studies suggest that noise-induced neuropathy may be selective for higher-threshold, lower-spontaneous-rate nerve fibers. Based on our hypothesis, we suggest some approaches that may yield particularly sensitive, objective measures of supra-threshold coding deficits that arise due to neuropathy. Finally, we comment on the potential clinical significance of these ideas and identify areas for future investigation.
Hansen, R., Santurette, S., and Verhulst, S., Effects of spontaneous otoacoustic emissions on pure-tone frequency difference limensa), J. Acoust. Soc. Am., vol. 136, no. 6. 2014.
Abstract DOIFull Text
Pure-tone frequency difference limens (FDLs) have been shown to vary in the vicinity of spontaneous otoacoustic emissions (SOAEs). As lower FDLs have been observed near SOAEs when measured ipsi- and contralaterally to the emission ear, it has been proposed that prolonged ongoing stimulation of nerve cells tuned to the SOAE frequency could lead to a central oversensitivity to that frequency, hence a better frequency-discrimination ability. However, it is also known that tones close in frequency to an SOAE can “entrain” the emission to oscillate at their own frequency. This may instead explain the variations in FDL near SOAE frequencies as arising from peripheral interactions between SOAEs and external tones in the cochlea. To test these two hypotheses, SOAE entrainment patterns and FDLs were recorded in seven subjects with an ipsilateral SOAE and no neighboring contralateral SOAE. Ipsilateral FDLs were lowest in the SOAE entrainment region and worsened significantly when beating between the external tone and SOAE occurred. FDLs remained unaffected in the non-emission ear and did not alter with continuous ipsilateral or contralateral presentation of a pure tone aimed at emulating an SOAE. These findings suggest a mechanical rather than neural origin for the variations in FDL near SOAE frequencies.
Henniges, M., Turner, R. E., Sahani, M., Eggert, J., and Lücke, J., Efficient Occlusive Components Analysis, J. Mach. Learn. Res., vol. 15. 2014.
AbstractFull Text
We study unsupervised learning in a probabilistic generative model for occlusion. The model uses two types of latent variables: one indicates which objects are present in the image, and the other how they are ordered in depth. This depth order then determines how the positions and appearances of the objects present, specified in the model parameters, combine to form the image. We show that the object parameters can be learned from an unlabeled set of images in which objects occlude one another. Exact maximum-likelihood learning is intractable. Tractable approximations can be derived, however, by applying a truncated variational approach to Expectation Maximization (EM). In numerical experiments it is shown that these approximations recover the underlying set of object parameters including data noise and sparsity. Experiments on a novel version of the bars test using colored bars, and experiments on more realistic data, show that the algorithm performs well in extracting the generating components. The studied approach demonstrates that the multiple-causes generative approach can be generalized to extract occluding components, which links research on occlusion to the field of sparse coding approaches.
Weber, M., Hartmann, A. -M., Beyer, T., Ripperger, A., and Nothwang, H. G., A Novel Regulatory Locus of Phosphorylation in the C Terminus of the Potassium Chloride Cotransporter KCC2 That Interferes with N-Ethylmaleimide or Staurosporine-mediated Activation., J. Biol. Chem., vol. 289, no. 27. 2014.
Abstract DOIFull Text
The neuron-specific cation chloride cotransporter KCC2 plays a crucial role in hyperpolarizing synaptic inhibition. Transporter dysfunction is associated with various neurological disorders, raising interest in regulatory mechanisms. Phosphorylation has been identified as a key regulatory process. Here, we retrieved experimentally observed phosphorylation sites of KCC2 from public databases and report on the systematic analysis of six phosphorylated serines, Ser(25), Ser(26), Ser(937), Ser(1022), Ser(1025), and Ser(1026). Alanine or aspartate substitutions of these residues were analyzed in HEK-293 cells. All mutants were expressed in a pattern similar to wild-type KCC2 (KCC2(WT)). Tl(+) flux measurements demonstrated unchanged transport activity for Ser(25), Ser(26), Ser(1022), Ser(1025), and Ser(1026) mutants. In contrast, KCC2(S937D), mimicking phosphorylation, resulted in a significant up-regulation of transport activity. Aspartate substitution of Thr(934), a neighboring putative phosphorylation site, resulted in a comparable increase in KCC2 transport activity. Both KCC2(T934D) and KCC2(S937D) mutants were inhibited by the kinase inhibitor staurosporine and by N-ethylmaleimide, whereas KCC2(WT), KCC2(T934A), and KCC2(S937A) were activated. The inverse staurosporine effect on aspartate versus alanine substitutions reveals a cross-talk between different phosphorylation sites of KCC2. Immunoblot and cell surface labeling experiments detected no alterations in total abundance or surface expression of KCC2(T934D) and KCC2(S937D) compared with KCC2(WT). These data reveal kinetic regulation of transport activity by these residues. In summary, our data identify a novel key regulatory phosphorylation site of KCC2 and a functional interaction between different conformation-changing post-translational modifications. The action of pharmacological agents aimed to modulate KCC2 activity for therapeutic benefit might therefore be highly context-specific.
Van Den Heuvel, I. M., Cherry, M. I., and Klump, G. M., Crimson-breasted Shrike females with extra pair offspring contributed more to duets, Behav Ecol Sociobiol, vol. 68, no. 8. Springer Science + Business Media, pp. 1245-1252, 26-Apr.-2014.
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Klump, G. M., Dollezal, L. -vanessa, and Itatani, N., Behavioral and neuronal sensitivity concerning objective measures of auditory stream segregation, J. Acoust. Soc. Am., vol. 135, no. 4. Acoustical Society of America (ASA), pp. 2171-2171, Apr.-2014.
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Reichert, C., Fendrich, R., Bernarding, J., Tempelmann, C., Hinrichs, H., and Rieger, J. W., Online tracking of the contents of conscious perception using real-time fMRI, Frontiers in Neuroscience, vol. 8. Frontiers Media SA, 23-May-2014.
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Martin, S., Brunner, P., Holdgraf, C., Heinze, H. -J., Crone, N. E., Rieger, J. W., Schalk, G., Knight, R. T., and Pasley, B. N., Decoding spectrotemporal features of overt and covert speech from the human cortex, Frontiers in Neuroengineering, vol. 7. Frontiers Media SA, 27-May-2014.
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Lavallee, C. F., Meemken, M. T., Herrmann, C. S., and Huster, R. J., When holding your horses meets the deer in the headlights: time-frequency characteristics of global and selective stopping under conditions of proactive and reactive control, Frontiers in human neuroscience, vol. 8. p. 994, 2014.
Abstract DOI
The ability to inhibit unwanted thoughts or actions is crucial for successful functioning in daily life; however, this ability is often impaired in a number of psychiatric disorders. Despite the relevance of inhibition in everyday situations, current models of inhibition are rather simplistic and provide little generalizability especially in the face of clinical disorders. Thus, given the importance of inhibition for proper cognitive functioning, the need for a paradigm, which incorporates factors that will subsequently improve the current model for understanding inhibition, is of high demand. A popular paradigm used to assess motor inhibition, the stop-signal paradigm, can be modified to further advance the current conceptual model of inhibitory control and thus provide a basis for better understanding different facets of inhibition. Namely, in this study, we have developed a novel version of the stop-signal task to assess how preparation (that is, whether reactive or proactive) and selectivity of the stopping behavior effect well-known time-frequency characteristics associated with successful inhibition and concomitant behavioral measures. With this innovative paradigm, we demonstrate that the selective nature of the stopping task modulates theta and motoric beta activity and we further provide the first account of delta activity as an electrophysiological feature sensitive to both manipulations of selectivity and preparatory control
Lavallee, C. F., Herrmann, C. S., Weerda, R., and Huster, R. J., Stimulus-response mappings shape inhibition processes: a combined EEG-fMRI study of contextual stopping, PloS one, vol. 9, no. 4. p. e96159, 2014.
Abstract DOI
Humans are rarely faced with one simple task, but are typically confronted with complex stimulus constellations and varying stimulus-relevance in a given situation. Through modifying the prototypical stop-signal task and by combined recording and analysis of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), we studied the effects of stimulus relevance for the generation of a response or its inhibition. Stimulus response mappings were modified by contextual cues, indicating which of two different stimuli following a go stimulus was relevant for stopping. Overall, response inhibition, that is comparing successful stopping to a stop-signal against go-signal related processes, was associated with increased activity in right inferior and left midfrontal regions, as well as increased EEG delta and theta power; however, stimulus-response conditions in which the most infrequent stop-signal was relevant for inhibition, were associated with decreased activity in regions typically involved in response inhibition, as well as decreased activity in the delta and theta bands as compared to conditions wherein the relevant stop-signal frequency was higher. Behaviorally, this (aforementioned) condition, which demanded inhibition only from the most infrequent stimulus, was also associated with reduced reaction times and lower error rates. This pattern of results does not align with typical stimulus frequency-driven findings and suggests interplay between task relevance and stimulus frequency of the stop-signal. Moreover, with a multimodal EEG-fMRI analysis, we demonstrated significant parameterization for response inhibition with delta, theta and beta time-frequency values, which may be interpreted as reflecting conflict monitoring, evaluative and/or motor processes as suggested by previous work (Huster et al., 2013; Aron, 2011). Further multimodal results suggest a possible neurophysiological and behavioral benefit under conditions whereby the most infrequent stimulus demanded inhibition, indicating that the frequency of the stop-signal interacts with the current stimulus-response contingency. These results demonstrate that response inhibition is prone to influence from other cognitive functions, making it difficult to dissociate real inhibitory capabilities from the influence of moderating mechanisms
Huster, R. J., Plis, S. M., Lavallee, C. F., Calhoun, V. D., and Herrmann, C. S., Functional and effective connectivity of stopping, NeuroImage, vol. 94. pp. 120-128, Jul.-2014.
Abstract DOI
Behavioral inhibition often is studied by comparing the electroencephalographic responses to stop and to go signals. Most studies simply assess amplitude differences of the N200 and P300 event-related potentials, which seem to best correspond to increased activity in the theta and delta frequency bands, respectively. However, neither have reliable indicators for successful behavioral inhibition been identified nor have the causal dependencies of stop-related neurocognitive processes been addressed yet. By studying functional and effective connectivity underlying stopping behavior, this study opens new directions for the investigation of behavioral inhibition. Group independent component analysis was used to infer functionally coherent networks from electroencephalographic data, which were recorded from healthy human participants during processing of a stop signal task. Then, the temporal dynamics of causal dependencies between independent components were identified by means of Bayesian network estimations. The mean clustering coefficient and the characteristic path length measure indicated time windows between 130 and 180 ms and between 420 and 500 ms to express significantly different connectivity profiles between conditions. Three components showed significant correlations between 120 and 260 ms with stop signal reaction times and the number of failed stops. Two of these components acted as sources of causal flow, one capturing P300/delta characteristics while the other was characterized by alpha power depletion putatively representing the evaluation or processing of stimulus features. Although results suggest that the P300 and associated delta activity seem to be statistically dependent on earlier processes associated with behavioral inhibition, the time window critical for inhibition coincides with early changes in causal patterns and largely precedes peak amplitude differences between go and stop trials. Altogether, utilizing the analysis of stopping-related connectivity, previously undetected patterns emerged that warrant further investigation
Prada, L., Barceló, F., Herrmann, C. S., and Escera, C., EEG delta oscillations index inhibitory control of contextual novelty to both irrelevant distracters and relevant task-switch cues, Psychophysiology, vol. 51, no. 7. pp. 658-672, Jul.-2014.
Abstract DOI
Delta oscillations contribute to the human P300 event-related potential evoked by oddball targets, although it is unclear whether they index contextual novelty (event oddballness, novelty P3, nP3), or target-related processes (event targetness, target P3b). To examine this question, the electroencephalogram (EEG) was recorded during a cued task-switching version of the Wisconsin card-sorting test. Each target card was announced by a tone cueing either to switch or repeat the task. Novel sound distracters were interspersed among trials. Time-frequency EEG analyses revealed bursts of delta (2-4 Hz) power associated with enhanced nP3 amplitudes to both task-switch cues and novel distracters-but no association with target P3b. These findings indicate that the P300-delta response indexes contextual novelty regardless of whether novelty emanates from endogenous (new task rules) or exogenous (novel distracters) sources of information
Fehr, T., Achtziger, A., Roth, G., and Strüber, D., Neural correlates of the empathic perceptual processing of realistic social interaction scenarios displayed from a first-order perspective, Brain research, vol. 1583. Elsevier, 2014.
Hartmann, A. -M., The strange antiquity of Francis Bacon'sNew Atlantis, Renaissance Studies, vol. 29, no. 3. Wiley-Blackwell, pp. 375-393, 19-Jun.-2014.
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Schepers, I. M., Yoshor, D., and Beauchamp, M. S., Electrocorticography Reveals Enhanced Visual Cortex Responses to Visual Speech, Cerebral Cortex, vol. 25, no. 11. Oxford University Press (OUP), pp. 4103-4110, 5-Jun.-2014.
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Lefeldt, N., Heyers, D., Schneider, N. -L., Engels, S., Elbers, D., and Mouritsen, H., Magnetic field-driven induction of ZENK in the trigeminal system of pigeons (Columba livia), JOURNAL OF THE ROYAL SOCIETY INTERFACE, vol. 11, no. 100. ROYAL SOC, Nov.-2014.
Abstract
Magnetoreception remains one of the few unsolved mysteries in sensory biology. The upper beak, which is innervated by the ophthalmic branch of the trigeminal nerve (V1), has been suggested to contain magnetic sensors based on ferromagnetic structures. Recently, its existence in pigeons has been seriously challenged by studies suggesting that the previously described iron-accumulations are macrophages, not magnetosensitive nerve endings. This raised the fundamental question of whether V1 is involved in magneto-reception in pigeons at all. We exposed pigeons to either a constantly changing magnetic field (CMF), to a zero magnetic field providing no magnetic information, or to CMF conditions after V1 was cut bilaterally. Using immediate early genes as a marker of neuronal responsiveness, we report that the trigeminal brainstem nuclei of pigeons, which receive V1 input, are activated under CMF conditions and that this neuronal activation disappears if the magnetic stimuli are removed or if V1 is cut. Our data suggest that the trigeminal system in pigeons is involved in processing magnetic field information and that V1 transmits this information from currently unknown, V1-associated magnetosensors to the brain.
Coiro, P., Stoenica, L., Strauss, U., and Braeuer, A. U., Plasticity-related Gene 5 Promotes Spine Formation in Murine Hippocampal Neurons, JOURNAL OF BIOLOGICAL CHEMISTRY, vol. 289, no. 36. AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC, Sep.-2014.
Abstract
The transmembrane protein plasticity-related genes 3 and 5 (PRG3 and PRG5) increase filopodial formation in various cell lines, independently of Cdc42. However, information on the effects of PRG5 during neuronal development is sparse. Here, we present several lines of evidence for the involvement of PRG5 in the genesis and stabilization of dendritic spines. First, PRG5 was strongly expressed during mouse brain development from embryonic day 14 (E14), peaked around the time of birth, and remained stable at least until early adult stages (i.e. P30). Second, on a subcellular level, PRG5 expression shifted from an equal distribution along all neurites toward accumulation only along dendrites during hippocampal development in vitro. Third, overexpression of PRG5 in immature hippocampal neurons induced formation of spine-like structures ahead of time. Proper amino acid sequences in the extracellular domains (D1 to D3) of PRG5 were a prerequisite for trafficking and induction of spine-like structures, as shown by mutation analysis. Fourth, at stages when spines are present, knockdown of PRG5 reduced the number but not the length of protrusions. This was accompanied by a decrease in the number of excitatory synapses and, consequently, by a reduction of miniature excitatory postsynaptic current frequencies, although miniature excitatory postsynaptic current amplitudes remained similar. In turn, overexpressing PRG5 in mature neurons not only increased Homer-positive spine numbers but also augmented spine head diameters. Mechanistically, PRG5 interacts with phosphorylated phosphatidylinositols, phospholipids involved in dendritic spine formation by different lipid-protein assays. Taken together, our data propose that PRG5 promotes spine formation.
Huebner, A., Derkow, K., and Braeuer, A. U., Efficient isolation of CD8 alpha positive T cells from postnatal mice using a combined MACS approach, JOURNAL OF IMMUNOLOGICAL METHODS, vol. 406. ELSEVIER SCIENCE BV, Apr.-2014.
Abstract
Magnetic activated cell sorting (MACS) is a commonly used cell separation technique. Miltenyi Biotec has developed an efficient MACS protocol for isolation of CD8 alpha(+). T cells from adult mice spleen. However, due to a low percentage of CD8 alpha(+). T cells in spleen of postnatal mice, MACS isolation of CD8 alpha(+). T cells results in a low purity. Our study illustrates how this problem can be solved by performing a CD45R(+) B cell depletion prior to a positive selection of CD8 alpha(+) T cells. This protocol can be used when low frequencies of CD8 alpha(+) T cells are present in a tissue also populated with CD45R(+) B cells, and a high purity is required for downstream applications. (C) 2014 Elsevier B.V. All rights reserved.
Rupprecht, A., Sittner, D., Smorodchenko, A., Hilse, K. E., Goyn, J., Moldzio, R., Seiler, A. E. M., Braeuer, A. U., and Pohl, E. E., Uncoupling Protein 2 and 4 Expression Pattern during Stem Cell Differentiation Provides New Insight into Their Putative Function, PLOS ONE, vol. 9, no. 2. PUBLIC LIBRARY SCIENCE, Feb.-2014.
Abstract
Apart from the first family member, uncoupling protein 1 (UCP1), the functions of other UCPs (UCP2-UCP5) are still unknown. In analyzing our own results and those previously published by others, we have assumed that UCP's cellular expression pattern coincides with a specific cell metabolism and changes if the latter is altered. To verify this hypothesis, we analyzed the expression of UCP1-5 in mouse embryonic stem cells before and after their differentiation to neurons. We have shown that only UCP2 is present in undifferentiated stem cells and it disappears simultaneously with the initiation of neuronal differentiation. In contrast, UCP4 is simultaneously up-regulated together with typical neuronal marker proteins TUJ-1 and NeuN during mESC differentiation in vitro as well as during murine brain development in vivo. Notably, several tested cell lines express UCP2, but not UCP4. In line with this finding, neuroblastoma cells that display metabolic features of tumor cells express UCP2, but not UCP4. UCP2's occurrence in cancer, immunological and stem cells indicates that UCP2 is present in cells with highly proliferative potential, which have a glycolytic type of metabolism as a common feature, whereas UCP4 is strongly associated with non-proliferative highly differentiated neuronal cells.
Stadler, K., Bierwirth, C., Stoenica, L., Battefeld, A., Reetz, O., Mix, E., Schuchmann, S., Velmans, T., Rosenberger, K., Braeuer, A. U., Lehnardt, S., Nitsch, R., Budt, M., Wolff, T., Kole, M. H. P., and Strauss, U., Elevation in Type I Interferons Inhibits HCN1 and Slows Cortical Neuronal Oscillations, CEREBRAL CORTEX, vol. 24, no. 1. OXFORD UNIV PRESS INC, Jan.-2014.
Abstract
Central nervous system (CNS) inflammation involves the generation of inducible cytokines such as interferons (IFNs) and alterations in brain activity, yet the interplay of both is not well understood. Here, we show that in vivo elevation of IFNs by viral brain infection reduced hyperpolarization-activated currents (Ih) in cortical pyramidal neurons. In rodent brain slices directly exposed to type I IFNs, the hyperpolarization-activated cyclic nucleotide (HCN)-gated channel subunit HCN1 was specifically affected. The effect required an intact type I receptor (IFNAR) signaling cascade. Consistent with Ih inhibition, IFNs hyperpolarized the resting membrane potential, shifted the resonance frequency, and increased the membrane impedance. In vivo application of IFN-gamma to the rat and to the mouse cerebral cortex reduced the power of higher frequencies in the cortical electroencephalographic activity only in the presence of HCN1. In summary, these findings identify HCN1 channels as a novel neural target for type I IFNs providing the possibility to tune neural responses during the complex event of a CNS inflammation.
Meyer, A. F., Diepenbrock, J. -P., Ohl, F. W., and Anemueller, J., Temporal variability of spectro-temporal receptive fields in the anesthetized auditory cortex, FRONTIERS IN COMPUTATIONAL NEUROSCIENCE, vol. 8. FRONTIERS MEDIA SA, Dec.-2014.
Abstract
Temporal variability of neuronal response characteristics during sensory stimulation is a ubiquitous phenomenon that may reflect processes such as stimulus-driven adaptation, top-down modulation or spontaneous fluctuations. It poses a challenge to functional characterization methods such as the receptive field, since these often assume stationarity. We propose a novel method for estimation of sensory neurons' receptive fields that extends the classic static linear receptive field model to the time-varying case. Here, the long-term estimate of the static receptive field serves as the mean of a probabilistic prior distribution from which the short-term temporally localized receptive field may deviate stochastically with time-varying standard deviation. The derived corresponding generalized linear model permits robust characterization of temporal variability in receptive field structure also for highly non-Gaussian stimulus ensembles. We computed and analyzed short-term auditory spectro-temporal receptive field (SIRE) estimates with characteristic temporal resolution 5-30 s based on model simulations and responses from in total 60 single-unit recordings in anesthetized Mongolian gerbil auditory midbrain and cortex. Stimulation was performed with short (100 ms) overlapping frequency-modulated tones. Results demonstrate identification of time-varying STRFs, with obtained predictive model likelihoods exceeding those from baseline static SIRE estimation. Quantitative characterization of SIRE variability reveals a higher degree thereof in auditory cortex compared to midbrain. Cluster analysis indicates that significant deviations from the long-term static SIRE are brief, but reliably estimated. We hypothesize that the observed variability more likely reflects spontaneous or state-dependent internal fluctuations that interact with stimulus-induced processing, rather than experimental or stimulus design.
Meyer, A. F., Diepenbrock, J. -P., Happel, M. F. K., Ohl, F. W., and Anemueller, J., Discriminative Learning of Receptive Fields from Responses to Non-Gaussian Stimulus Ensembles, PLOS ONE, vol. 9, no. 4. PUBLIC LIBRARY SCIENCE, Apr.-2014.
Abstract
Analysis of sensory neurons' processing characteristics requires simultaneous measurement of presented stimuli and concurrent spike responses. The functional transformation from high-dimensional stimulus space to the binary space of spike and non-spike responses is commonly described with linear-nonlinear models, whose linear filter component describes the neuron's receptive field. From a machine learning perspective, this corresponds to the binary classification problem of discriminating spike-eliciting from non-spike-eliciting stimulus examples. The classification-based receptive field (CbRF) estimation method proposed here adapts a linear large-margin classifier to optimally predict experimental stimulus-response data and subsequently interprets learned classifier weights as the neuron's receptive field filter. Computational learning theory provides a theoretical framework for learning from data and guarantees optimality in the sense that the risk of erroneously assigning a spike-eliciting stimulus example to the non-spike class (and vice versa) is minimized. Efficacy of the CbRF method is validated with simulations and for auditory spectro-temporal receptive field (STRF) estimation from experimental recordings in the auditory midbrain of Mongolian gerbils. Acoustic stimulation is performed with frequency-modulated tone complexes that mimic properties of natural stimuli, specifically non-Gaussian amplitude distribution and higher-order correlations. Results demonstrate that the proposed approach successfully identifies correct underlying STRFs, even in cases where second-order methods based on the spike-triggered average (STA) do not. Applied to small data samples, the method is shown to converge on smaller amounts of experimental recordings and with lower estimation variance than the generalized linear model and recent information theoretic methods. Thus, CbRF estimation may prove useful for investigation of neuronal processes in response to natural stimuli and in settings where rapid adaptation is induced by experimental design.
Probst, C. C., Winter, L. M., Moeller, B., Weber, H., Weintraub, D., Witt, K., Deuschl, G., Katzenschlager, R., and van Eimeren, T., Validation of the questionnaire for impulsive-compulsive disorders in Parkinson's disease (QUIP) and the QUIP-rating scale in a German speaking sample, JOURNAL OF NEUROLOGY, vol. 261, no. 5. SPRINGER HEIDELBERG, May-2014.
Abstract
Impulsive-compulsive disorders are frequent in patients with Parkinson's disease (PD). Recently, a screening questionnaire and rating scale were developed for these disorders: the questionnaire for impulsive-compulsive disorders (QUIP) and QUIP-rating scale (QUIP-RS). We assessed the validity of these instruments in the German language in order to reevaluate the benefit and to obtain German screening tools in clinical practice. A convenience sample of 156 patients was assessed in Kiel and Vienna. The patients filled out the QUIP-current, the QUIP-anytime and the QUIP-RS. We validated the questionnaires against a gold standard diagnosis via receiver operating characteristic curves and determined optimal cut-off scores for the instruments. Excluding walkabout, which was not shown to be valid, sensitivities ranged from 60-92 \% for the QUIP-current, 68-91 \% for the QUIP-anytime, and 73-100 \% for the QUIP-RS. Specificities were > 71 \% for QUIP-current, > 69 \% for QUIP-anytime and > 62 \% for QUIP-RS. With its very good sensitivities, the QUIP-RS is a valid instrument to assess impulsive-compulsive disorders and makes an early detection of behavioral disorders in PD possible. The QUIP-anytime was also shown to be a valid screening instrument. Both are expected to prove useful in scientific and clinical practice.
Schmalbach, B., Guenther, V., Raethjen, J., Wailke, S., Falk, D., Deuschl, G., and Witt, K., The Subthalamic Nucleus Influences Visuospatial Attention in Humans, JOURNAL OF COGNITIVE NEUROSCIENCE, vol. 26, no. 3. MIT PRESS, Mar.-2014.
Abstract
Spatial attention is a lateralized feature of the human brain. Whereas the role of cortical areas of the nondominant hemisphere on spatial attention has been investigated in detail, the impact of the BG, and more precisely the subthalamic nucleus, on signs and symptoms of spatial attention is not well understood. Here we used unilateral deep brain stimulation of the subthalamic nucleus to reversibly, specifically, and intraindividually modify the neuronal BG outflow and its consequences on signs and symptoms of visuospatial attention in patients suffering from Parkinson disease. We tested 13 patients with Parkinson disease and chronic deep brain stimulation in three stimulation settings: unilateral right and left deep brain stimulation of the subthalamic nucleus as well as bilateral deep brain stimulation of the subthalamic nucleus. In all three stimulation settings, the patients viewed a set of pictures while an eye-tracker system recorded eye movements. During the exploration of the visual stimuli, we analyzed the time spent in each visual hemispace, as well as the number, duration, amplitude, peak velocity, acceleration peak, and speed of saccades. In the unilateral left-sided stimulation setting, patients show a shorter ipsilateral exploration time of the extrapersonal space, whereas number, duration, and speed of saccades did not differ between the different stimulation settings. These results demonstrated reduced visuospatial attention toward the side contralateral to the right subthalamic nucleus that was not being stimulated in a unilateral left-sided stimulation. Turning on the right stimulator, the reduced visuospatial attention vanished. These results support the involvement of the subthalamic nucleus in modulating spatial attention. Therefore, the subthalamic nucleus is part of the subcortical network that subserves spatial attention.
Witt, K. and Moeller, B., Deep Brain Stimulation for Parkinson's Disease, ZEITSCHRIFT FUR NEUROPSYCHOLOGIE, vol. 25, no. 1. VERLAG HANS HUBER, Mar.-2014.
Abstract
Deep brain stimulation is one of the most effective therapies to treat Parkinson's disease. The subthalamic nucleus (STN), the internal part of globus pallidum (GPi) and the nucleus ventrointermedius (VIM) of the thalamus are common stimulation sites. A comprehensive neuropsychological test-battery should be applied prior to surgery to exclude dementia and to specifically examine executive functioning, because executive functions can worsen after surgery. Whereas neuropsychological changes are not common after stimulation of the VIM and the GPi, STN stimulation may lead to mild worsening in executive functioning. These changes have been examined extensively for STN-DBS. A decline in verbal fluency (Cohens' d-0.5) and Stroop task performance (Cohens' d-0.4) has been shown. However, these changes have no impact on the improvement of quality of life after surgery. Patients with an older age, suffering from axial motor symptoms and taking a higher levo-dopa equivalence dosage are at risk to decline in executive functions after surgery. If the electrode trajectories hit the caudate nucleus, patients showed a worsening in global cognition and working memory abilities. A worsening of verbal fluency and Stroop test performance are the consequence of the electrode placement itself, either due to a micro-lesional effect or an effect of electrode stimulation. As it can be switched off, DBS can may serve as a reversible, intra-individual lesion model of the STN. The modulation of the stimulation settings is a useful method to assess the impact of the STN on different cognitive domains such as spatial orientation, recognition of emotional stimuli and decision making to explore the role of the STN in the cognitive and the affective domain. Changes in these domains are only detectable using experimental designs and these changes have only minor consequences for patients' daily routine.
Goerlich-Dobre, K. S., Probst, C., Winter, L., Witt, K., Deuschl, G., Moeller, B., and van Eimeren, T., Alexithymia-an independent risk factor for impulsive-compulsive disorders in Parkinson's disease, MOVEMENT DISORDERS, vol. 29, no. 2. WILEY-BLACKWELL, Feb.-2014.
Abstract
Impulsive-compulsive disorders (ICDs) are frequent side effects of dopaminergic medication in Parkinson's disease (PD). Alexithymia, a personality trait characterized by difficulties identifying and describing feelings and an externally oriented thinking style, has been linked to various impulse-control problems in the general population. In PD, the prevalence of alexithymia is approximately twice as high as in the general population. However, whether alexithymia is associated with ICDs in PD is currently unknown. We examined the relationship between self-reported ICDs and alexithymia in a sample of 91 PD patients (89 on dopaminergic medication). Additional self-report measures assessed impulsivity, depression, anxiety, behavioral inhibition/approach, and emotion-regulation strategies. We observed that alexithymia, and particularly difficulty identifying feelings and difficulty describing feelings, was significantly correlated with ICDs, even when controlling for impulsivity, anxiety, and depression. In addition, a group analysis revealed that PD patients with clinical and moderate levels of alexithymia had significantly more ICDs than non-alexithymic patients, suggesting that even moderately high alexithymia levels increase the risk for ICDs in PD. Our results identify alexithymia as an independent risk factor for ICDs in PD. Thus, the inclusion of alexithymia in the neuropsychiatric assessment of patients with PD may help identify patients at risk for ICDs. (c) 2013 International Parkinson and Movement Disorder Society
Assmus, T. K. ; G. A. ; H., Nervenchirurgie : Trauma, Tumor, Kompression. Berlin, Heidelberg : Springer Berlin Heidelberg, 2014.
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Fisahn, C. A., Antimikrobielle Aktivität von Moxifloxacin gegen MRSA- und Pseudomonas-aeruginosa-Wundinfektion im Großtier- und Verbrennungsmodell. 2014.
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Kretschmer, T. and Antoniadis, G., Traumatische Nervenläsionen, Nervenchirurgie. Springer Science + Business Media, pp. 95-182, 2014.
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Heinen, C., Kretschmer, T., and Weis, J., Nerventumoren, Nervenchirurgie. Springer Science + Business Media, pp. 227-259, 2014.
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Kretschmer, T. and Krishnan, K. G., Chirurgische Techniken, Nervenchirurgie. Springer Science + Business Media, pp. 67-93, 2014.
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Brook, G. A., Hodde, D., and Kretschmer, T., Grundlegendes zu Degeneration und Regeneration von Nerven, Nervenchirurgie. Springer Science + Business Media, pp. 1-10, 2014.
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Lassner, F., Becker, M., Antoniadis, G., and Kretschmer, T., Verletzungen des Plexus brachialis, Nervenchirurgie. Springer Science + Business Media, pp. 183-226, 2014.
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Kretschmer, T., Antoniadis, G., and Assmus, H., Erratum to: Kretschmer/Antoniadis/Assmus: Nervenchirurgie ISBN 978-3-642-36894-3 / eISBN 978-3-662-45894-5 Springer‐Verlag Berlin Heidelberg, Nervenchirurgie. Springer Science + Business Media, pp. E1-E1, 2014.
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Kretschmer, T., Antoniadis, G., and Assmus, H., Erratum to: Kretschmer/Antoniadis/Assmus: Nervenchirurgie ISBN 978-3-642-36894-3 / eISBN 978-3-642-36895-0 Springer‐Verlag Berlin Heidelberg, Nervenchirurgie. Springer Science + Business Media, pp. E1-E1, 2014.
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König, R. W., Kretschmer, T., Pedro, M. T., Bischoff, C., Schulte-Mattler, W., Kele, H., Bäumer, P., Bendszus, M., and Pham, M., Diagnoseverfahren, Nervenchirurgie. Springer Science + Business Media, pp. 11-65, 2014.
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Vogelgesang, R., Wang, W., Vasa, P., Pomraenke, R., Sommer, E., De Sio, A., and Lienau, C., Interplay Between Strong Coupling and Radiative Damping in Hybrid Excitonic-Plasmonic Nanostructures, Nano-Optics and Nanophotonics. Springer Science + Business Media, pp. 119-136, 28-Dec.-2014.
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Busemeyer, J. R. and Diederich, A., Estimation and Testing of Computational Psychological Models, Neuroeconomics. Elsevier BV, pp. 49-61, 2014.
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Köppl, C., Avian Hearing, Sturkie´s Avian Physiology, vol. 6. p. 71--111, 2014.
Abstract
The sense of hearing has special meaning to many birds, be it for communication, hunting, or orienting in the dark. This chapter summarizes the sensory aspects of hearing in birds. How do their middle and inner ears work? How is sound encoded in the auditory nerve and how is it processed in the brain? Important insights into auditory physiology that have come from studies on birds are discussed, such as the mechanisms of regeneration of sensory hair cells after damage, the neural computations underlying sound localization, or the neural processing and learning of vocalizations. Some fascinating auditory specializations in birds are also highlighted: infrasound hearing in pigeons, asymmetric ears in owls, and echolocation in oilbirds and swiftlets.
Strüber, D., Neuropsychologie der Gewalt, Behinderung, Bildung, Partizipation. Enzyklopädisches Handbuch der Behindertenpädagogik, Bd. 10: Emotion und Persönlichkeit. Kohlhammer, pp. 262-266, 2014.
Abstract
Mendonça, C., Hiipakka, M., van de Par, S., and Colonius, H., Adaptation To Non-individualized Spatial Sound Through Audiovisual Experience, Conf. Spat. Audio. AES, 2014.
Abstract
Recent Brief audiovisual experience affects subsequent auditory localization. In this study we were interested in the localization of non-individualized auralised sounds before and after exposure to audiovisual stimulation. First there was a pre-test in auditory localization. Then we presented listeners with alternating auditory and audiovisual stimuli which either: were constantly mismatched (Experiment 1); had a varying mismatch with average around a mode value (Experiment 2); or had a varying mismatch with average not around a mode value (Experiment 3). In the end of each experiment, there was a post-test in auditory localization. Results showed that the perceived auditory source position was shifted in the post-test in the direction of where the visual source was in the audiovisual trials. This shift was greater when the audiovisual mismatch was constant than when it varied. There was an improvement in localization accuracy when the mismatch was constant, but not when it varied. These results reveal that audiovisual stimulation leads to an improvement of localization accuracy with non-individualized auralisations, even when light and sound are not matching in space. However, this mismatch should be predictable, otherwise worsening of localization accuracy might occur.
Laumen, G., Tollin, D., and Klump, G. M., Auditory Brainstem Response: Binaural Difference Potential in the Mongolian Gerbil (Meriones Unguiculatus), Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2014.
Eipert, L., Klinge-Strahl, A., and Klump, G. M., Harmonicity Outplays Direction Cues in Grouping Tasks, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2014.
Dolležal, L. -V., Tolnai, S., and Klump, G. M., Release from Sequential Informational Masking by Spatial Cues, Assoc. Res. Otolaryng. MidWinter Meeting (ARO). 2014.
Warzybok, A., Kodrasi, I., Jungmann, J. O., Habets, E., Gerkmann, T., Mertins, A., Doclo, S., Kollmeier, B., and Goetze, S., Subjective speech quality and speech intelligibility evaluation of single-channel dereverberation algorithms, Int. Work. Acoust. Signal Enhanc. (IWAENC), no. 316969. IEEE, 2014.
Abstract
Jukić, A., Waterschoot, T. V., Gerkmann, T., and Doclo, S., Speech Dereverberation With Multi-Channel Linear Prediction, Proc. Jt. Workshop Hands-Free Speech Comm. Mic. Arrays (HSCMA), no. 1. IEEE, 2014.
Abstract
Jukić, A., Waterschoot, T. V., Gerkmann, T., and Doclo, S., Speech Dereverberation With Convolutive Transfer Function Approximation Using Map And Variational Deconvolution Approaches, Int. Work. Acoust. Signal Enhanc. (IWAENC), no. 1. IEEE, 2014.
Abstract
Rennies, J., Schepker, H., Kubiak, A., and Doclo, S., Adaptive Verbesserung der Sprachverständlichkeit und Medienwiedergabe in Fahr- und Verkehrsgeräuschen, Jahrestagung der Dt. Ges. für Audiologie (DGA). DGA, 2014.
Abstract
Goetze, S., Warzybok, A., Kodrasi, I., Jungmann, J. O., Cauchi, B., Rennies, J., Habets, A. P., Mertins, A., Gerkmann, T., Doclo, S., and Kollmeier, B., A Study on Speech Quality and Speech Intelligibility Measures for Quality Assessment of Single-channel Dereverberation Algorithms, Int. Work. Acoust. Signal Enhanc. (IWAENC), no. 4. IEEE, 2014.
Abstract
Xiong, F., Moritz, N., Rehr, R., Anemüller, J., Meyer, B. T., Gerkmann, T., Doclo, S., and Goetze, S., Robust ASR in Reverberant Environments using Temporal Cepstrum Smoothing for Speech Enhancement and an Amplitude Modulation Filterbank for Feature Extraction, Proc. REVERB Challenge Workshop. IEEE, 2014.
Abstract
Müller, M., Thiemann, J., Marquardt, D., Doclo, S., and van de Par, S., Erhaltung der räumlichen Wahrnehmung bei Störgeräuschreduktion in Hörgeräten, Proc. German Annual Conf. Acoust. (DAGA). 2014.
Abstract
Schepker, H. and Doclo, S., Modeling the common part of feedback paths in hearing aids using a pole-zero model, IEEE Int. Conf. Acoust. Speech Sig. Process. (ICASSP). IEEE, 2014.
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Jukić, A. and Doclo, S., Speech dereverberation using weighted prediction error with Laplacian model of the desired signal, IEEE Int. Conf. Acoust. Speech Sig. Process. (ICASSP). IEEE, 2014.
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Fodor, B. and Gerkmann, T., A Posteriori Speech Presence Probability Estimation Based on Averaged Observations and a Super-gaussian Speech Model , Int. Work. Acoust. Signal Enhanc. (IWAENC). IEEE, 2014.
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Gerkmann, T., MMSE-optimal enhancement of complex speech coefficients with uncertain prior knowledge of the clean speech phase, IEEE Int. Conf. Acoust. Speech Sig. Process. (ICASSP), no. 2. IEEE, 2014.
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Rehr, R., Krawczyk, M., and Gerkmann, T., A Posteriori Voiced/Unvoiced Probability Estimation Based on a Sinusoidal Model, IEEE Int. Conf. Acoust. Speech Sig. Process. (ICASSP), no. 2. 2014.
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Kortlang, S., Ewert, S. D., and Gerkmann, T., Single Channel Noise Reduction Based On An Auditory Filterbank, Int. Work. Acoust. Signal Enhanc. (IWAENC). IEEE, 2014.
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May, T. and Gerkmann, T., Generalization of supervised learning for binary mask estimation, Int. Work. Acoust. Signal Enhanc. (IWAENC). IEEE, 2014.
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Williges, B., Hohmann, V., and Jürgens, T., Räumliche Demaskierung von Sprache bei Hörkonfigurationen mit simulierter elektro-akustischer Stimulation, Jahrestagung der Dt. Ges. für Audiologie (DGA), no. 2009. 2014.
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Zamaninezhad, L., Hohmann, V., and Jürgens, T., Towards Developing an Electro-acoustic Model of Speech Intelligibility, Jahrestagung der Dt. Ges. für Audiologie (DGA), no. 1. 2014.
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Chen, Z. and Hohmann, V., SNR Estimation and Enhancement of Voiced Speech Based on Periodicity Analysis, ITG Conf. Speech Comm. VDE, 2014.
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Wendt, T., van de Par, S., and Ewert, S. D., Perceptual and room acoustical evaluation of a computational efficient binaural room impulse response simulation method, Proc. EAA Jt. Symp. Auralization Ambisonics, no. April. EAA, 2014.
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Wendt, T., van de Par, S., and Ewert, S. D., Efficient synthesis of perceptually plausible binaural room impulse responses Simulation method, Proc. German Annual Conf. Acoust. (DAGA). DEGA, 2014.
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Thiemann, J., Vincent, E., and van de Par, S., Spatial Properties of the DEMAND Noise Recordings, Proc. German Annual Conf. Acoust. (DAGA). 2014.
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Schoenmaker, E., Brand, T., and van de Par, S., The relative contributions of better ear listening and binaural masking level differences in a cocktail party: Experiment and model predictions, Proc. German Annual Conf. Acoust. (DAGA). 2014.
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Hildebrandt, K. J., Auswirkungen veränderter Inhibition im auditorischen Cortex, Jahrestagung der Dt. Ges. für Audiologie (DGA). 2014.
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Hildebrandt, K. J., Gonçalves, P. J., Sahani, M., and Linden, J. F., Prolonged low-level manipulation of parvalbumin-positive interneuron activity alters neural dynamics in awake auditory cortex , International Conference on Auditory Cortex. 2014.
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Hildebrandt, K. J., Precise dissection of the functional role of neurotransmitter systems by optogenetic manipulation, Jahrestagung der Gesellschaft für Neuropsychologie. 2014.
Abstract
Manipulations of neural circuitry in animal models provide important evidence to establish causal relationships between brain activity and behaviour in health and disease. In order to gain detailed understanding of function and pathologies of neurotransmitter systems, we need to be able to precisely control transmitter release by a specific population of cells, release triggered by a specific projection or from neurons residing in a certain structure of the brain. Current approaches include knock-down animals or systemic, pharmacological interventions. However, these methods often lack the necessary spatial or temporal specificity and reversibility. Recently developed optogenetic tools enable the precise manipulation of genetically defined cell types, particular brain structures or specific projections by shining light on the brain. As these manipulations can be carried out while animals are performing behavioural tasks, direct and causal links between the neural system under study and animal behaviour can be established. The talk will give a short introduce to the rapidly growing optogenetic toolbox and review some recent studies on the function and dysfunction of neurotransmitter system, e. g. cholinergic and GABAergic signalling. DOI: http://dx.doi.org/10.1024/1016-264X/a000138
Seidel, M., Kortlang, S., Mauermann, M., Kollmeier, B., and Ewert, S. D., Untersuchungen zu überschwelligen auditiven Verarbeitungsstörungen, Jahrestagung der Dt. Ges. für Audiologie (DGA). DGA, 2014.
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Hu, H., Ewert, S., Campbell, T., Kollmeier, B., and Dietz, M., An interaural electrode pairing clinical research system for bilateral cochlear implants, IEEE China Summit & Int. Conf. Signal Inform. Process. (ChinaSIP). IEEE, 2014.
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Fleßner, J. -H., Ewert, S. D., Kollmeier, B., and Huber, R., Quality assessment of multi-channel audio processing schemes based on a binaural auditory model, IEEE Int. Conf. Acoust. Speech Sig. Process. (ICASSP). IEEE, 2014.
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Warzybok, A., Hochmuth, S., Rennies, J., Brand, T., and Kollmeier, B., Measurement and prediction of speech intelligibility in noise and reverberation for different sentence materials, speakers, and languages, J. Acoust. Soc. Am., vol. 136, no. 4. 2014.
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Hiipakka, M. and Kollmeier, B., Individualized binaural earpiece for hearing-aid applications, Proc. German Annual Conf. Acoust. (DAGA). 2014.
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Kubiak, A., Saft, M., Rennies, J., and Kollmeier, B., Listener’s Preferences with Respect to Frequency Shaping and Loudness Adjustments for Music and Speech Reproduction, Proc. German Annual Conf. Acoust. (DAGA). 2014.
Abstract
Schädler, M. R. and Kollmeier, B., Separate spektrale und temporale Verarbeitung spektro-temporaler Merkmale, Proc. German Annual Conf. Acoust. (DAGA). 2014.
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Warzybok, A., Rennies, J., Brand, T., and Kollmeier, B., Prediction of binaural speech intelligibility in normal-hearing and hearing-impaired listeners:a psychoacoustically motivated extension, Proc. German Annual Conf. Acoust. (DAGA). 2014.
Abstract
Buhl, M., Kollmeier, B., and Ernst, S. M. A., Technische Evaluierung verschiedener Verfahren zur binauralen Synchronisation der Dynamikkompression in Hörgeräten, Proc. German Annual Conf. Acoust. (DAGA). 2014.
Abstract
Lücke, J., Sparse Encoding and Dictionary Learning for Sensory Data, Proc. German Annual Conf. Acoust. (DAGA). 2014.
Abstract
Wong, M. B., Goodwin, J., Norazit, A., Meedeniya, A. C. B., Richter-Landsberg, C., Gai, W. P., and Pountney, D. L., SUMO-1 is associated with a subset of lysosomes in glial protein aggregate diseases, Neurotoxicity research : neurodegeneration, neuroregeneration, neurotrophic action, neuroprotection ; official journal of the Neurotoxicity Society, vol. 23.2013, no. 1. 2013.
Abstract
Richter-Landsberg, C. and Leyk, J., Inclusion body formation, macroautophagy, and the role of HDAC6 in neurodegeneration, Acta neuropathologica, vol. 126.2013, no. 6. 2013.
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Seiberlich, V., Borchert, J., Zhukareva, V., and Richter-Landsberg, C., Inhibition of protein deubiquitination by PR-619 activates the autophagic pathway in OLN-t40 oligodendroglial cells, Cell biochemistry and biophysics, vol. 67.2013, no. 1 (Sep.). 2013.
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Kragh, C. L., Fillon, G., Gysbers, A., Hansen, H. D., Neumann, M., Richter-Landsberg, C., Haass, C., Zalc, B., Lubetzki, C., and Gai, W. P., FAS-dependent cell death in æ-synuclein transgenic oligodendrocyte models of multiple system atrophy, In: PLoS one / Public Library of Science. - Lawrence, Kan, Bd. 8.2013, 1, S. e55243, insges. 9 S. - 9. - ISSN 1932-6203, vol. 9. 2013.
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Poppe, B., Stelljes, T. S., Looe, H. K., Chofor, N., Harder, D., and Willborn, K. C., Performance parameters of a liquid filled ionization chamber array, In: Medical physics / American Association of Physicists in Medicine; American Institute of Physics. - New York, NY, Bd. 40.2013, 8, 082106, insges. 2 S. - 2. - ISSN 0094-2405, vol. 2. 2013.
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Chofor, N., Harder, D., and Poppe, B., Supplementary values of the dosimetric parameters kNR and Em for various types of detectors in 6 and 15 MV photon fields = Ergänzende Daten zu den dosimetrischen Parametern kNR und Em für verschiedene Detektortypen bei 6 und 15 MV Photonenstrahlung, Zeitschrift für medizinische Physik : offizielles Organ der Deutschen, Österreichischen und Schweizerischen Gesellschaft für Medizinische Physik, vol. 24.2013, no. 1. 2013.
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Heilemann, G., Poppe, B., and Laub, W., On the sensitivity of common gamma-index evaluation methods to MLC misalignments in RapidArc quality assurance, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 40.2013, 3, S. 031702, insges. 12 S. - S. 031702. - <12>. - ISSN 0094-2405. 2013.
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Looe, H. K., Stelljes, T. S., Foschepoth, S., Harder, D., Willborn, K. C., and Poppe, B., The dose response functions of ionization chambers in photon dosimetry - Gaussian or non-Gaussian?, Zeitschrift für medizinische Physik : Zeitschrift der DGMP; ÖGMP und SGSMP / Hrsg.: Deutsche Gesellschaft für Medizinische Physik; Österreichische Gesellschaft für Medizinische Physik; Schweizerische Gesellschaft für Strahlenbiologie und Medizinische Physik, vol. 23.2013, no. 2. 2013.
Abstract
Looe, H. K., Harder, D., and Poppe, B., SU-E-T-70: are the dose response functions of ionization chambers Gaussian or nonGaussian?, In: Medical physics / American Association of Physicists in Medicine; American Institute of Physics. - New York, NY 0094-2405, 40.2013. - S. 219. 2013.
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Schönfeld, A. A., Crilly, R., Poppe, B., and Laub, W., SU-E-I-39: Experimental study on the performance of the OMAR CT artifact correction algorithm near titanium and stainless steel, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
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Stelljes, T. S., Poppe, B., Looe, H. K., Harder, D., and Willborn, K. C., SU-E-T-62 : dosimetric properties of the octavius 1000SRS liquid filled ionization chamber array, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
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Schönfeld, A. A., Poppinga, D., Harder, D., and Poppe, B., SU-E-I-87 : experimental study of anisotropic light scattering and polarization effects of EBT3films, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
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Poppinga, D., Schönfeld, A. A., Blanck, O., Harder, D., and Poppe, B., SU-E-T-24 : a new method correcting the parabola effect of flatbed scanners used in radiochromic film dosimetry ; [abstract], Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
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Stelljes, T. S., Looe, H. K., Willborn, K. C., and Poppe, B., SU-E-T-332 : verification of prostate VMAT treatment plans using the octavius 4D system, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
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Chofor, N., Lohmann, N., Lüthjens, S., Harder, D., and Poppe, B., SU-E-T-54 : dosimetric verification of Monte Carlo dose calculations for a GammaMed HDR 192Ir brachytherapy source using various detector types, and nonreference condition correction factors KNR, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
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Stelljes, T. S., Goethem, M. van, Brandenburg, S., Willborn, K. C., and Poppe, B., SU-E-T-60 : evaluation of a twodimensional ionization chamber array for proton beam dosimetry, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
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Markovic, M., Stathakis, S., Ha, C., Poppe, B., Gutierrez, A., and Papanikolaou, N., SU-E-T-382 : investigation of the characteristics of the OCTAVIUS detector 1000 SRS for verification of the small field size IMRT and SRS beams, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
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Markovic, M., Stathakis, S., Ha, C., Poppe, B., Gutierrez, A., and Papanikolaou, N., SU-E-T-323 : characterization of the twodimensional liquid field ion chamber detector array used for the verification of the treatments in radiation therapy, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Looe, H. K., Chofor, N., Harmeyer, A., Poppinga, D., Schönfeld, A. A., Grabowski, D., Willborn, K. C., Harder, D., and Poppe, B., SU-E-T-65 : on the dose response function and the energy dependence of a novel synthetic single crystal diamond detector, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Looe, H. K., Harder, D., and Poppe, B., The volume dependent correction factor kV of photon dosimetry, In: Medizinische Physik 2013 : Abstractband ; [44. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik, Köln, 18. - 21. September 2013] / hrsg. von Harald Treuer. - [Berlin], 2013. - ISBN 978-3-9816002-1-6. 2013.
Abstract
Becker, J. -N., Muru, A., Looe, H. K., Chofor, N., and Poppe, B., Merging CT images for the treatment planning of total-body irradiations, In: Medizinische Physik 2013 : Abstractband ; [44. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik, Köln, 18. - 21. September 2013] / hrsg. von Harald Treuer. - [Berlin], 2013. - ISBN 978-3-9816002-1-6. 2013.
Abstract
Poppe, B., Willborn, K. C., Looe, H. K., and Chorfor, N., Auf der Suche nach der richtigen Dosis = Looking for the right dose, Einblicke : Forschungsmagazin der Carl-von-Ossietzky-Universität Oldenburg, vol. 28.2013, no. 57. 2013.
Abstract
Govor, L. V., Bauer, G. H., Reiter, G., and Parisi, J., Charge transport in nanoparticle chains influenced by stabilizer molecules, Physica status solidi : pss. *A*Applications and materials science, vol. 210.2013, no. 6. 2013.
Full Text
Huber, R., Witt, F., Borchert, H., Hauff, E. von, Heun, S., Buchholz, H., and Parisi, J., Charge transport properties in electrically aged organic light-emitting diodes, In: Journal of applied physics / publ. of the American Institute of Physics, AIP. Elmer Hutchisson, ed. - Melville, NY, Bd. 113.2013, Art.-Nr. 023104, insges. 5 S. - 5. - ISSN 0021-8979, vol. 5. 2013.
AbstractFull Text
Scheunemann, D., Wilken, S., Parisi, J., and Borchert, H., Towards depleted heterojunction solar cells with CuInS2 and ZnO nanocrystals, In: Applied physics letters / publ. by the American Institute of Physics. - Melville, NY, Bd. 103, 2013, 13, Art.-Nr. 133902, insges. ca. 11 S. - 11. - ISSN 0003-6951, vol. 11. 2013.
Abstract
Augustin, M., Yezerska, O., Derendorf, J., Knipper, M., Fenske, D., Plaggenborg, T., and Parisi, J., Colloidal manganese oxide nanoparticles as bifunctional catalysts for oxygen reduction and evolution reactions in lithium/air batteries, ECS transactions : ECST / Electrochemical Society, vol. 45.2013, no. 27. 2013.
Abstract DOIFull Text
Altmann, L., Wang, X., Stöver, J., Klink, M., Zielasek, V., Thiel, K., Kolny-Olesiak, J., Shamery, K. A. -, Borchert, H., and Parisi, J., Impact of organic ligands on the structure and hydrogenation performance of colloidally prepared bimetallic PtSn nanoparticles, ChemCatChem, vol. 5.2013, no. 7. 2013.
Abstract DOIFull Text
Wang, X., Altmann, L., Stöver, J., Zielasek, V., Bäumer, M., Shamery, K. A. -, Borchert, H., Parisi, J., and Kolny-Olesiak, J., Pt/Sn intermetallic, core/shell and alloy nanoparticles : colloidal synthesis and structural control, Chemistry of materials / American Chemical Society, vol. 25.2013, no. 8. 2013.
Abstract DOIFull Text
Keller, J., Schlesiger, R., Riedel, I., Parisi, J., Schmitz, G., Avellan, A., and Dalibor, T., Grain boundary investigations on sulfurized Cu(In,Ga)(S,Se)2 solar cells using atom probe tomography, Solar energy materials & solar cells : an international journal devoted to photovoltaic, photothermal, and photochemical solar energy conversion, vol. 117.2013. 2013.
Abstract DOIFull Text
Knecht, R., Hammer, M. S., Parisi, J., and Riedel, I., Impact of varied sulfur incorporation on the device performance of sequentially processed Cu(In,Ga)(Se,S)2 thin film solar cells, In: Physica status solidi. *A* Applied research [Elektronische Ressource]. - Weinheim, 210.2013 (Juli). - S. 1392-1399. - ISSN 1521-396X. 2013.
Abstract DOIFull Text
Richter, M., Schubbert, C., Eraerds, P., Riedel, I., Keller, J., Parisi, J., Dalibor, T., and Avellán-Hampe, A., Optical characterization and modeling of Cu(In,Ga)(Se,S)2 solar cells with spectroscopic ellipsometry and coherent numerical simulation, Thin solid films : international journal on the science and technology of condensed matter films, vol. 535.2013, no. 15. (Mai). 2013.
Abstract DOIFull Text
Huber, R., Borchert, H., Hauff, E. von, Heun, S., Buchholz, H., and Parisi, J., Incident photon-to-current efficiency measurements as a helpful tool to analyze luminescence loss mechanisms in organic light-emitting diodes, In: Applied physics letters / publ. by the American Institute of Physics. - Melville, NY, 103.2013. - S. 043311-1-043311-4. - <4>. - ISSN 1077-3118. 2013.
Abstract DOIFull Text
Jin, X., Parisi, J., and Kolny-Olesiak, J., Shape control of CdTe nanocrystals : influence of the solvent composition and ligand effects, In: Journal of nanoparticles. - (2013), Article ID 243831, S. 1-7. - ISSN 2314-484X, vol. (2013). 2013.
AbstractFull Text
Govor, L. V. and Parisi, J., Conductance fluctuations in chains of particles arising from conformational changes of stabilizer molecules, Zeitschrift für Naturforschung. *Section A*a journal of physical sciences, vol. 68.2013. 2013.
Abstract
Kullmann, L., Schlüter, T., Wagner, H., and Nothwang, H. G., Evolutionary conservation of K v 3.1 in the barn owl Tyto alba, Brain, behavior and evolution : official journal of the J. B. Johnston Club, vol. 81.2013, no. 3. 2013.
AbstractFull Text
Zuccotti, A., Lee, S. C., Campanelli, D., Singer, W., Somisetty, V. S., Patriarchi, T., Geisler, H. -S., Köpschall, I., Rohbock, K., and Nothwang, H. G., L-type CaV1.2 deletion in the cochlea but not in the brainstem reduces noise vulnerability : implication for CaV1.2-mediated control of cochlear BDNF expression, In: Frontiers in molecular neuroscience / Frontiers Research Foundation. - Lausanne, Bd. 6. 2013, Art. 20, insges. 12 S. - 12. - ISSN 1662-5099, vol. 12. 2013.
Abstract DOIFull Text
Schindler, J., Ye, J., Jensen, O. N., and Nothwang, H. G., Monitoring the native phosphorylation state of plasma membrane proteins from a single mouse cerebellum, In: Journal of neuroscience methods. - Amsterdam [u.a.], 213.2013, 2. - S. 153-164. - ISSN 1872-678X. 2013.
AbstractFull Text
Wong, M. B., Goodwin, J., Norazit, A., Meedeniya, A. C. B., Richter-Landsberg, C., Gai, W. P., and Pountney, D. L., SUMO-1 is associated with a subset of lysosomes in glial protein aggregate diseases, Neurotoxicity research : neurodegeneration, neuroregeneration, neurotrophic action, neuroprotection ; official journal of the Neurotoxicity Society, vol. 23.2013, no. 1. 2013.
Abstract
Richter-Landsberg, C. and Leyk, J., Inclusion body formation, macroautophagy, and the role of HDAC6 in neurodegeneration, Acta neuropathologica, vol. 126.2013, no. 6. 2013.
Abstract DOIFull Text
Seiberlich, V., Borchert, J., Zhukareva, V., and Richter-Landsberg, C., Inhibition of protein deubiquitination by PR-619 activates the autophagic pathway in OLN-t40 oligodendroglial cells, Cell biochemistry and biophysics, vol. 67.2013, no. 1 (Sep.). 2013.
Abstract DOIFull Text
Kragh, C. L., Fillon, G., Gysbers, A., Hansen, H. D., Neumann, M., Richter-Landsberg, C., Haass, C., Zalc, B., Lubetzki, C., and Gai, W. P., FAS-dependent cell death in æ-synuclein transgenic oligodendrocyte models of multiple system atrophy, In: PLoS one / Public Library of Science. - Lawrence, Kan, Bd. 8.2013, 1, S. e55243, insges. 9 S. - 9. - ISSN 1932-6203, vol. 9. 2013.
Abstract DOIFull Text
Poppe, B., Stelljes, T. S., Looe, H. K., Chofor, N., Harder, D., and Willborn, K. C., Performance parameters of a liquid filled ionization chamber array, In: Medical physics / American Association of Physicists in Medicine; American Institute of Physics. - New York, NY, Bd. 40.2013, 8, 082106, insges. 2 S. - 2. - ISSN 0094-2405, vol. 2. 2013.
Abstract DOIFull Text
Chofor, N., Harder, D., and Poppe, B., Supplementary values of the dosimetric parameters kNR and Em for various types of detectors in 6 and 15 MV photon fields = Ergänzende Daten zu den dosimetrischen Parametern kNR und Em für verschiedene Detektortypen bei 6 und 15 MV Photonenstrahlung, Zeitschrift für medizinische Physik : offizielles Organ der Deutschen, Österreichischen und Schweizerischen Gesellschaft für Medizinische Physik, vol. 24.2013, no. 1. 2013.
Abstract DOIFull Text
Heilemann, G., Poppe, B., and Laub, W., On the sensitivity of common gamma-index evaluation methods to MLC misalignments in RapidArc quality assurance, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 40.2013, 3, S. 031702, insges. 12 S. - S. 031702. - <12>. - ISSN 0094-2405. 2013.
AbstractFull Text
Looe, H. K., Stelljes, T. S., Foschepoth, S., Harder, D., Willborn, K. C., and Poppe, B., The dose response functions of ionization chambers in photon dosimetry - Gaussian or non-Gaussian?, Zeitschrift für medizinische Physik : Zeitschrift der DGMP; ÖGMP und SGSMP / Hrsg.: Deutsche Gesellschaft für Medizinische Physik; Österreichische Gesellschaft für Medizinische Physik; Schweizerische Gesellschaft für Strahlenbiologie und Medizinische Physik, vol. 23.2013, no. 2. 2013.
Abstract
Looe, H. K., Harder, D., and Poppe, B., SU-E-T-70: are the dose response functions of ionization chambers Gaussian or nonGaussian?, In: Medical physics / American Association of Physicists in Medicine; American Institute of Physics. - New York, NY 0094-2405, 40.2013. - S. 219. 2013.
Abstract DOIFull Text
Schönfeld, A. A., Crilly, R., Poppe, B., and Laub, W., SU-E-I-39: Experimental study on the performance of the OMAR CT artifact correction algorithm near titanium and stainless steel, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Stelljes, T. S., Poppe, B., Looe, H. K., Harder, D., and Willborn, K. C., SU-E-T-62 : dosimetric properties of the octavius 1000SRS liquid filled ionization chamber array, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Schönfeld, A. A., Poppinga, D., Harder, D., and Poppe, B., SU-E-I-87 : experimental study of anisotropic light scattering and polarization effects of EBT3films, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Poppinga, D., Schönfeld, A. A., Blanck, O., Harder, D., and Poppe, B., SU-E-T-24 : a new method correcting the parabola effect of flatbed scanners used in radiochromic film dosimetry ; [abstract], Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Stelljes, T. S., Looe, H. K., Willborn, K. C., and Poppe, B., SU-E-T-332 : verification of prostate VMAT treatment plans using the octavius 4D system, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Chofor, N., Lohmann, N., Lüthjens, S., Harder, D., and Poppe, B., SU-E-T-54 : dosimetric verification of Monte Carlo dose calculations for a GammaMed HDR 192Ir brachytherapy source using various detector types, and nonreference condition correction factors KNR, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Stelljes, T. S., Goethem, M. van, Brandenburg, S., Willborn, K. C., and Poppe, B., SU-E-T-60 : evaluation of a twodimensional ionization chamber array for proton beam dosimetry, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Markovic, M., Stathakis, S., Ha, C., Poppe, B., Gutierrez, A., and Papanikolaou, N., SU-E-T-382 : investigation of the characteristics of the OCTAVIUS detector 1000 SRS for verification of the small field size IMRT and SRS beams, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Markovic, M., Stathakis, S., Ha, C., Poppe, B., Gutierrez, A., and Papanikolaou, N., SU-E-T-323 : characterization of the twodimensional liquid field ion chamber detector array used for the verification of the treatments in radiation therapy, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Looe, H. K., Chofor, N., Harmeyer, A., Poppinga, D., Schönfeld, A. A., Grabowski, D., Willborn, K. C., Harder, D., and Poppe, B., SU-E-T-65 : on the dose response function and the energy dependence of a novel synthetic single crystal diamond detector, Medical physics / American Association of Physicists in Medicine; American Institute of Physics, vol. 40.2013. 2013.
Abstract DOIFull Text
Looe, H. K., Harder, D., and Poppe, B., The volume dependent correction factor kV of photon dosimetry, In: Medizinische Physik 2013 : Abstractband ; [44. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik, Köln, 18. - 21. September 2013] / hrsg. von Harald Treuer. - [Berlin], 2013. - ISBN 978-3-9816002-1-6. 2013.
Abstract
Becker, J. -N., Muru, A., Looe, H. K., Chofor, N., and Poppe, B., Merging CT images for the treatment planning of total-body irradiations, In: Medizinische Physik 2013 : Abstractband ; [44. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik, Köln, 18. - 21. September 2013] / hrsg. von Harald Treuer. - [Berlin], 2013. - ISBN 978-3-9816002-1-6. 2013.
Abstract
Poppe, B., Willborn, K. C., Looe, H. K., and Chorfor, N., Auf der Suche nach der richtigen Dosis = Looking for the right dose, Einblicke : Forschungsmagazin der Carl-von-Ossietzky-Universität Oldenburg, vol. 28.2013, no. 57. 2013.
Abstract
Govor, L. V., Bauer, G. H., Reiter, G., and Parisi, J., Charge transport in nanoparticle chains influenced by stabilizer molecules, Physica status solidi : pss. *A*Applications and materials science, vol. 210.2013, no. 6. 2013.
AbstractFull Text
Huber, R., Witt, F., Borchert, H., Hauff, E. von, Heun, S., Buchholz, H., and Parisi, J., Charge transport properties in electrically aged organic light-emitting diodes, In: Journal of applied physics / publ. of the American Institute of Physics, AIP. Elmer Hutchisson, ed. - Melville, NY, Bd. 113.2013, Art.-Nr. 023104, insges. 5 S. - 5. - ISSN 0021-8979, vol. 5. 2013.
AbstractFull Text
Scheunemann, D., Wilken, S., Parisi, J., and Borchert, H., Towards depleted heterojunction solar cells with CuInS2 and ZnO nanocrystals, In: Applied physics letters / publ. by the American Institute of Physics. - Melville, NY, Bd. 103, 2013, 13, Art.-Nr. 133902, insges. ca. 11 S. - 11. - ISSN 0003-6951, vol. 11. 2013.
Abstract
Augustin, M., Yezerska, O., Derendorf, J., Knipper, M., Fenske, D., Plaggenborg, T., and Parisi, J., Colloidal manganese oxide nanoparticles as bifunctional catalysts for oxygen reduction and evolution reactions in lithium/air batteries, ECS transactions : ECST / Electrochemical Society, vol. 45.2013, no. 27. 2013.
Abstract DOIFull Text
Altmann, L., Wang, X., Stöver, J., Klink, M., Zielasek, V., Thiel, K., Kolny-Olesiak, J., Shamery, K. A. -, Borchert, H., and Parisi, J., Impact of organic ligands on the structure and hydrogenation performance of colloidally prepared bimetallic PtSn nanoparticles, ChemCatChem, vol. 5.2013, no. 7. 2013.
Abstract DOIFull Text
Wang, X., Altmann, L., Stöver, J., Zielasek, V., Bäumer, M., Shamery, K. A. -, Borchert, H., Parisi, J., and Kolny-Olesiak, J., Pt/Sn intermetallic, core/shell and alloy nanoparticles : colloidal synthesis and structural control, Chemistry of materials / American Chemical Society, vol. 25.2013, no. 8. 2013.
Abstract DOIFull Text
Keller, J., Schlesiger, R., Riedel, I., Parisi, J., Schmitz, G., Avellan, A., and Dalibor, T., Grain boundary investigations on sulfurized Cu(In,Ga)(S,Se)2 solar cells using atom probe tomography, Solar energy materials & solar cells : an international journal devoted to photovoltaic, photothermal, and photochemical solar energy conversion, vol. 117.2013. 2013.
Abstract DOIFull Text
Knecht, R., Hammer, M. S., Parisi, J., and Riedel, I., Impact of varied sulfur incorporation on the device performance of sequentially processed Cu(In,Ga)(Se,S)2 thin film solar cells, In: Physica status solidi. *A* Applied research [Elektronische Ressource]. - Weinheim, 210.2013 (Juli). - S. 1392-1399. - ISSN 1521-396X. 2013.
Abstract DOIFull Text
Richter, M., Schubbert, C., Eraerds, P., Riedel, I., Keller, J., Parisi, J., Dalibor, T., and Avellán-Hampe, A., Optical characterization and modeling of Cu(In,Ga)(Se,S)2 solar cells with spectroscopic ellipsometry and coherent numerical simulation, Thin solid films : international journal on the science and technology of condensed matter films, vol. 535.2013, no. 15. (Mai). 2013.
Abstract DOIFull Text
Huber, R., Borchert, H., Hauff, E. von, Heun, S., Buchholz, H., and Parisi, J., Incident photon-to-current efficiency measurements as a helpful tool to analyze luminescence loss mechanisms in organic light-emitting diodes, In: Applied physics letters / publ. by the American Institute of Physics. - Melville, NY, 103.2013. - S. 043311-1-043311-4. - <4>. - ISSN 1077-3118. 2013.
Abstract DOIFull Text
Jin, X., Parisi, J., and Kolny-Olesiak, J., Shape control of CdTe nanocrystals : influence of the solvent composition and ligand effects, In: Journal of nanoparticles. - (2013), Article ID 243831, S. 1-7. - ISSN 2314-484X, vol. (2013). 2013.
AbstractFull Text
Govor, L. V. and Parisi, J., Conductance fluctuations in chains of particles arising from conformational changes of stabilizer molecules, Zeitschrift für Naturforschung. *Section A*a journal of physical sciences, vol. 68.2013. 2013.
Abstract
Kullmann, L., Schlüter, T., Wagner, H., and Nothwang, H. G., Evolutionary conservation of K v 3.1 in the barn owl Tyto alba, Brain, behavior and evolution : official journal of the J. B. Johnston Club, vol. 81.2013, no. 3. 2013.
AbstractFull Text
Zuccotti, A., Lee, S. C., Campanelli, D., Singer, W., Somisetty, V. S., Patriarchi, T., Geisler, H. -S., Köpschall, I., Rohbock, K., and Nothwang, H. G., L-type CaV1.2 deletion in the cochlea but not in the brainstem reduces noise vulnerability : implication for CaV1.2-mediated control of cochlear BDNF expression, In: Frontiers in molecular neuroscience / Frontiers Research Foundation. - Lausanne, Bd. 6. 2013, Art. 20, insges. 12 S. - 12. - ISSN 1662-5099, vol. 12. 2013.
Abstract DOIFull Text
Schindler, J., Ye, J., Jensen, O. N., and Nothwang, H. G., Monitoring the native phosphorylation state of plasma membrane proteins from a single mouse cerebellum, In: Journal of neuroscience methods. - Amsterdam [u.a.], 213.2013, 2. - S. 153-164. - ISSN 1872-678X. 2013.
AbstractFull Text
Mauermann, M., Improving the usability of the distortion product otoacoustic emisssions-sweep method : an alternative artifact rejection and noise-floor estimation ; [abstract], The journal of the Acoustical Society of America : JASA-O, vol. 133.2013, no. 5. 2013.
Abstract DOIFull Text
Dai, Z., Exarchakis, G., and Lücke, J., What are the invariant occlusive components of image patches? : a probabilistic generative approach, Advances in neural information processing systems : .. proceedings of the .. conference, vol. 26.2013. 2013.
Abstract
Bornschein, J., Henniges, M., and Lücke, J., Are V1 simple cells optimized for visual occlusions? : a comparative study, In: PLoS Computational Biology : a new community journal / publ. by the Public Library of Science (PLoS) in association with the International Society for Computational Biology (ISCB). - San Francisco, Calif, Bd. 9.2013 (Jun.), Art.-Nr e1003062, insges. 16 S. - 16. - ISSN 1553-7358, vol. 16. 2013.
Abstract DOIFull Text
Pohl, N. U., Slabbekoorn, H., Neubauer, H., Heil, P., Klump, G. M., and Langemann, U., Why longer song elements are easier to detect : threshold level-duration functions in the Great Tit and comparison with human data, Journal of comparative physiology. *A*Neuroethology, sensory, neural, and behavioral physiology [Elektronische Ressource], vol. 199.2013, no. 3. 2013.
DOIFull Text
Langemann, U., Beutelmann, R., and Klump, G. M., Mechanisms of auditory spatial selectivity in barn owls, Abstracts of the .. midwinter research meeting / Association for Research in Otolaryngology, vol. 36.2013. 2013.
Kretschmer, F., Kretschmer, V., Kunze, V. P., and Kretzberg, J., OMR-arena : automated measurement and stimulation system to determine mouse visual thresholds based on optomotor responses, In: PLoS one / Public Library of Science. - Lawrence, Kan, Bd. 8.2013, 11, Art.-Nr. e78058, insges. 12 S. - 12. - ISSN 1932-6203, vol. 12. 2013.
AbstractFull Text
Fathiazar, E., Hilgen, G., and Kretzberg, J., Removing bleaching artifacts from voltage sensitive dye recordings with ICA, In: BMC neuroscience. - London ; Berlin ; Heidelberg, Bd. 14.2013, Suppl. 1, insges. 2 S. - 2. - ISSN 1471-2202, vol. 2. 2013.
Abstract DOIFull Text
Pirschel, F. and Kretzberg, J., Coding of touch properties by three types of mechanosensory cells of the leech hirudo medicinalis, In: BMC neuroscience. - London ; Berlin ; Heidelberg, Bd. 14.2013, Suppl. 1, P224, insges. 2 S. - 2. - ISSN 1471-2202, vol. 2. 2013.
Abstract DOIFull Text
Koepcke, L. and Kretzberg, J., Change point detection for neuronal data with CUSUM and classification methods, In: BMC neuroscience. - London ; Berlin ; Heidelberg, Bd. 14.2013, Suppl. 1, insges. 2 S. - 2. - ISSN 1471-2202, vol. 2. 2013.
Abstract DOIFull Text
Kretschmer, T., Comment [on] Lingtong Liu [et al.], Sylvian fissure arteriovenous malformations: long-term prognosis and riskfactors, Neurosurgical review, vol. 36.2013, no. 4. 2013.
Abstract DOIFull Text
Kretschmer, T. and Heinen, C., Die operative Behandlung von peripheren Nervenverletzungen, In: Zeitschrift für Handtherapie : offizielles Organ der Deutschen Arbeitsgemeinschaft für Handtherapie e.V. / DAHTH. - Sendenhorst, 16.2013, 2. - 2. - ISSN 1436-705X, vol. 2. 2013.
Abstract
Heinen, C., Kretschmer, T., Pedro, M. T., and Schmidt, T., Sind Nerventransfers der autologen Rekonstruktion bei traumatischen Armplexusläsionen überlegen? : [Abstract], In: Kongreß der Deutschen Gesellschaft für Chirurgie. - Berlin ; Heidelberg, Bd. 130.2013, insges. 1 S. - 1, vol. 1. 2013.
Abstract DOIFull Text
Oberhoffer, J., Antoniadis, G., König, R. W., Heinen, C., Kretschmer, T., Wirtz, C. R., and Pedro, M. T., 10-year experience with nerve transfers for restoration of elbow function in patients with traumatic brachial plexus injuries : [abstract], In: Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC). - [Berlin], Bd. 64.2013, insges. 1 S. - 1. - ISSN 0945-0890, vol. 1. 2013.
AbstractFull Text
Dhinakaran, J., De Vos, M., Thorne, J. D., Braun, N., Janson, J., and Kranczioch, C., Tough doughnuts : affect and the modulation of attention, In: Frontiers in human neuroscience / Frontiers Research Foundation. - Lausanne, Bd. 7.2013, Article 876, insges. 8 S. - 8. - ISSN 1662-5161, vol. 8. 2013.
Abstract DOIFull Text
Felten, A., Montag, C., Kranczioch, C., Markett, S., Walter, N. T., and Reuter, M., The DRD2 C957T polymorphism and the Attentional Blink : a genetic association study, European neuropsychopharmacology : ENP ; the journal of the European College of Neuropsychopharmacology, vol. 23.2013, no. 8. 2013.
Abstract DOIFull Text
Götz, T., Huonker, R., Kranczioch, C., Reuken, P., Witte, O. W., Günther, A., and Debener, S., Impaired evoked and resting-state brain oscillations in patients with liver cirrhosis as revealed by magnetoencephalography, NeuroImage: Clinical : a journal of diseases affecting the nervous system ; open access journal, vol. 13.2013, no. 2. 2013.
Abstract DOIFull Text
Kranczioch, C. and Dhinakaran, J., The role of temporal context and expectancy in resource allocation to and perception of rapid serial events, Brain and cognition : a journal of clinical, experimental, and theoretical research, vol. 81.2013, no. 3. 2013.
Abstract DOIFull Text
Kranczioch, C. and Thorne, J. D., Simultaneous and preceding sounds enhance rapid visual targets : evidence from the attentional blink, Advances in cognitive psychology / University of Finance and Management, vol. 9.2013, no. 3. 2013.
AbstractFull Text
Sukowski, H., Wagener, K. C., Thiele, C., Uppenkamp, S., and Kollmeier, B., Der Einsatz neuer Testverfahren zur Erfassung des Sprachverstehens in Ruhe bei der Begutachtung erworbener Schwerhörigkeiten, HNO, vol. 61.2013, no. 1. 2013.
AbstractFull Text
Ernst, S. M. A., Grimm, G., and Kollmeier, B., Evaluation of a binaurally synchronized dynamic-range compression algorithms for hearing aids : abstract, The journal of the Acoustical Society of America : JASA / American Institute of Physics, vol. 133.2013, no. 5. 2013.
AbstractFull Text
Ernst, S. M. A., Grimm, G., and Kollmeier, B., Evaluation of binaurally-synchronized dynamic-range compression algorithms for hearing aids, In: Proceedings of Meetings on Acoustics : POMA / Acoustical Society of America. - Lancaster, Pa, Bd. 19.2013, Art. 050085, insges. 6 S. - 6, vol. 6. 2013.
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Hochmuth, S., Jürgens, T., Brand, T., and Kollmeier, B., Der Einfluss unterschiedlicher Störgeräuschsituationen auf die Sprachverständlichkeit in verschiedenen Sprachen, In: 16. Jahrestagung / Deutsche Gesellschaft für Audiologie : Rostock, 27.02. - 02.03.2013 ; Tagungs-CD / in Zusammenarb. mit der Arbeitsgemeinschaft Deutschsprachiger Audiologen und Neurootologen, der Universitätsmedizin Rostock und der Universität Rostock. - Oldenburg, 2013, insges. 4 S. - 4. - ISBN 978-3-9813141-3-7, vol. 4. 2013.
Abstract
Kortlang, S., Mauermann, M. D., Kollmeier, B., and Ewert, S. D., Quantifizierung und Modellierung zeitlicher Verarbeitungsstörungen im Rauschen bei Normal- und Schwerhörenden, In: 16. Jahrestagung / Deutsche Gesellschaft für Audiologie : Rostock, 27.02. - 02.03.2013 ; Tagungs-CD / in Zusammenarb. mit der Arbeitsgemeinschaft Deutschsprachiger Audiologen und Neurootologen, der Universitätsmedizin Rostock und der Universität Rostock. - Oldenburg, 2013, insges. 4 S. - 4. - ISBN 978-3-9813141-3-7, vol. 4. 2013.
Abstract
Schulte, M., Meis, M., Vormann, M., Wagener, K. C., and Kollmeier, B., Alltagsrelevante Messung der Höranstrengung im Labor, In: 16. Jahrestagung / Deutsche Gesellschaft für Audiologie : Rostock, 27.02. - 02.03.2013 ; Tagungs-CD / in Zusammenarb. mit der Arbeitsgemeinschaft Deutschsprachiger Audiologen und Neurootologen, der Universitätsmedizin Rostock und der Universität Rostock. - Oldenburg, 2013, insges. 5 S. - 5. - ISBN 978-3-9813141-3-7, vol. 5. 2013.
Abstract
Uslar, V. N., Kollmeier, B., and Brand, T., Sprachverständlichkeitsmessungen mit Sätzen und Satzfragmenten mit unterschiedlicher linguistischer Komplexität, In: 16. Jahrestagung / Deutsche Gesellschaft für Audiologie : Rostock, 27.02. - 02.03.2013 ; Tagungs-CD / in Zusammenarb. mit der Arbeitsgemeinschaft Deutschsprachiger Audiologen und Neurootologen, der Universitätsmedizin Rostock und der Universität Rostock. - Oldenburg, 2013, insges. 4 S. - 4. - ISBN 978-3-9813141-3-7, vol. 4. 2013.
Abstract
Moritz, N., Schädler, M. R., Adiloglu, K., Meyer, B. T., Jürgens, T., Gerkmann, T., Kollmeier, B., and Doclo, S., Noise robust distant automatic speech recognition utilizing NMF based source separation and auditory feature extraction, In: Chime Workshop : 1st June 2013, Vancouver, Canada (in conjunction with ICASSP 2013) / Chime Workshop. - Vancouver, 2013, insges. 6 S. - 6, vol. 6. 2013.
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Schröder, J., Moritz, N., Schädler, M. R., Cauchi, B., Adiloglu, K., Anemüller, J., Doclo, S., Kollmeier, B., and Goetze, S., On the use of spectro-temporal features for the IEEE AASP challenge 'Detection and Classification of Acoustic Scenes and Events', In: IEEE Workshop on Applications of Signal Processing to Audio and Acoustics (WASPAA 2013) : Proceedings of a meeting held 20-23 October 2013, New Paltz, New York, USA, 2013. - S. 197-200. - ISBN 978-1-4799-0970-4. 2013.
Abstract
Diekmann, R. and Bauer, J. M., Proteinbedarf älterer Menschen, Schweizer Zeitschrift für Ernährungsmedizin, vol. 2013, no. 5. 2013.
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Kosse, N. M., Dutmer, A. L., Dasenbrock, L., Bauer, J. M., and Lamoth, C. J. C., Effectiveness and feasibility of early physical rehabilitation programs for geriatric hospitalized patients : a systematic review, In: BMC geriatrics. - London, Bd. 13.2013, Art. 107, insges. 16 S. - <16>. - ISSN 1471-2318, vol. 16. 2013.
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Diekmann, R., Winning, K., Bauer, J. M., Uter, W., Stehle, P., Lesser, S., Bertsch, T., Sieber, C. C., and Volkert, D., Vitamin D status and physical function in nursing home residents : a 1-year observational study, Zeitschrift für Gerontologie und Geriatrie : Organ der Deutschen Gesellschaft für Gerontologie und Geriatrie, vol. 46.2013, no. 5. 2013.
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Morley, J. E., Vellas, B. J., Abellan van Kan, G., Anker, S. D., Bauer, J. M., Bernabei, R., Cesari, M., Chumlea, W. C., Döhner, W., and Evans, J., Frailty consensus : a call to action, Journal of the American Medical Directors Association : JAMDA, vol. 14.2013, no. 6. 2013.
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Szalárdy, O., Winkler, I., Schröger, E., Widmann, A., and Bendixen, A., Foreground-background discrimination indicated by event-related brain potentials in a new auditory multistability paradigm, Psychophysiology / publ. for the Society for Psychophysiological Research, vol. 50.2013, no. 12. 2013.
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Bendixen, A., Böhm, T. M., Szalárdy, O., Mill, R., Denham, S. L., and Winkler, I., Different roles of similarity and predictability in auditory stream segregation, In: Learning & perception. - Budapest, Bd. 5.2013 (19. Jun.), Suppl.2, S. 37-54. - S. 37-54. - ISSN 2060-9175. 2013.
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Böhm, T. M., Shestopalova, L., Bendixen, A., Andreou, A. G., Georgiou, J., Garreau, G., Pouliquen, P., Cassidy, A., Denham, S. L., and Winkler, I., The role of perceived source location in auditory stream segregation : separation affects sound organization, common fate does not, In: Learning & perception. - Budapest, Bd. 5.2013 (19. Jun.), Suppl.2, S. 55-72. - S. 55-72. - ISSN 2060-9175. 2013.
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Szalárdy, O., Bendixen, A., Tóth, D., Denham, S. L., and Winkler, I., Modulation-frequency acts as a primary cue for auditory stream segregation, In: Learning & perception. - Budapest, Bd. 5.2013, Suppl. 2, S. 149-161. - S. 149-161. - ISSN 2060-9175. 2013.
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Dolležal, L. -V. I. E., Tolnai, S., Beutelmann, R., and Klump, G. M., Auditory stream segregation abolishes informational masking : [abstract], Abstracts of the .. midwinter research meeting / Association for Research in Otolaryngology, vol. 36.2013. 2013.
Enriquez Geppert, S., Huster, R. J., and Herrmann, C. S., Boosting brain functions : improving executive functions with behavioral training, neurostimulation, and neurofeedback, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 88.2013, no. 1. 2013.
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Huster, R. J., Enriquez Geppert, S., Lavallee, C. F., Falkenstein, M., and Herrmann, C. S., Electroencephalography of response inhibition tasks : functional networks and cognitive contributions, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 87.2013, no. 3. 2013.
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Enriquez Geppert, S., Huster, R. J., Scharfenort, R., Mokom, Z. N., Vosskuhl, J., Figge, C., Zimmermann, J., and Herrmann, C. S., The morphology of midcingulate cortex predicts frontal-midline theta neurofeedback success, In: Frontiers in human neuroscience / Frontiers Research Foundation. - Lausanne, Bd. 7, 2013, Art. 453, insges. 10 S. - 10. - ISSN 1662-5161. 2013.
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Herrmann, C. S., Rach, S., Neuling, T., and Strüber, D., Transcranial alternating current stimulation : a review of the underlying mechanisms and modulation of cognitive processes, In: Frontiers in human neuroscience / Frontiers Research Foundation. - Lausanne, Bd. 7.2013,Artikel-Nr. 279, insges. 13 S. - 13. - ISSN 1662-5161, vol. 13. 2013.
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Enriquez Geppert, S., Huster, R. J., Scharfenort, R., Mokom, Z. N., Zimmermann, J., and Herrmann, C. S., Modulation of frontal-midline theta by neurofeedback, In: Biological psychology. - Amsterdam [u.a.], 95.2014 (Jan.). - S. 59-69. - ISSN 1873-6246. 2013.
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Sætrevik, B., Huster, R. J., and Herrmann, C. S., Proactive and reactive sequential effects on selective attention, Brain and cognition : a journal of clinical, experimental, and theoretical research, vol. 83.2013, no. 1. 2013.
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Neuling, T., Rach, S., and Herrmann, C. S., Orchestrating neuronal networks : sustained after-effects of transcranial alternating current stimulation depend upon brain states, In: Frontiers in human neuroscience / Frontiers Research Foundation. - Lausanne, Bd. 7.2013, Artikel 161, inges. 12 S. - 12. - ISSN 1662-5161, vol. 12. 2013.
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Neuling, T., Rach, S., and Herrmann, C. S., P 12 : transcranial alternating current stimulation enhances endogenous alpha for 30 min only for moderate alpha levels, In: Clinical neurophysiology. - Amsterdam [u.a.], Bd. 124.2013, 10, e69-e70, insges. 2 S. - 2. - ISSN 1872-8952, vol. 2. 2013.
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Murray, M. M. and Herrmann, C. S., llusory contours : a window onto the neurophysiology of constructing perception, In: Trends in cognitive sciences. - Amsterdam [u.a.], 17.2013, 9. - S. 471-481. - ISSN 1879-307X. 2013.
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Trautmann-Lengsfeld, S. A. and Herrmann, C. S., EEG reveals an early influence of social conformity on visual processing in group pressure situations, Social neuroscience, vol. 8.2013, no. 1. 2013.
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Ott, C. G. M., Stier, C., Herrmann, C. S., and Jäncke, L., Musical expertise affects attention as reflected by auditory-evoked gamma-band activity in human EEG, In: Neuroreport. - London, 24.2013, 9. - S. 445-450. - ISSN 1473-558X. 2013.
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Koch, K. -W., The guanylate cyclase signaling system in zebrafish photoreceptors, FEBS letters, vol. 587, no. 13. Jun.-2013.
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Karbasi, S., Koch, K. -W., and Mafi, A., Multiple-beam propagation in an Anderson localized optical fiber, Optics express, vol. 21, no. 1. Jan.-2013.
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Koch, K. -W. and Dell'orco, D., A calcium-relay mechanism in vertebrate phototransduction, ACS chemical neuroscience, vol. 4, no. 6. Jun.-2013.
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Zägel, P., Dell'Orco, D., and Koch, K. -W., The dimerization domain in outer segment guanylate cyclase is a Ca²⁺-sensitive control switch module, Biochemistry, vol. 52, no. 30. Jul.-2013.
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Fries, R., Scholten, A., Säftel, W., and Koch, K. -W., Zebrafish guanylate cyclase type 3 signaling in cone photoreceptors, PloS one, vol. 8, no. 8. 2013.
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Aquila, M., Benedusi, M., Koch, K. -W., Dell'Orco, D., and Rispoli, G., Divalent cations modulate membrane binding and pore formation of a potent antibiotic peptide analog of alamethicin, Cell calcium, vol. 53, no. 3. Mar.-2013.
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Invergo, B. M., Montanucci, L., Koch, K. -W., Bertranpetit, J., and Dell'orco, D., Exploring the rate-limiting steps in visual phototransduction recovery by bottom-up kinetic modeling, Cell communication and signaling : CCS, vol. 11, no. 1. 2013.
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Beste, K. Y., Spangler, C. M., Burhenne, H., Koch, K. -W., Shen, Y., Tang, W. -J., Kaever, V., and Seifert, R., Nucleotidyl cyclase activity of particulate guanylyl cyclase A: comparison with particulate guanylyl cyclases E and F, soluble guanylyl cyclase and bacterial adenylyl cyclases CyaA and edema factor, PloS one, vol. 8, no. 7. 2013.
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Karbasi, S., Frazier, R. J., Mirr, C. R., Koch, K. -W., and Mafi, A., Fabrication and characterization of disordered polymer optical fibers for transverse Anderson localization of light, Journal of visualized experiments : JoVE, no. 77. 2013.
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Kretschmer, F., Kretschmer, V., Kunze, V. P., and Kretzberg, J., OMR-arena: automated measurement and stimulation system to determine mouse visual thresholds based on optomotor responses, PloS one, vol. 8, no. 11. p. e78058, 2013.
Abstract DOI
Measurement of the optomotor response is a common way to determine thresholds of the visual system in animals. Particularly in mice, it is frequently used to characterize the visual performance of different genetically modified strains or to test the effect of various drugs on visual performance. Several methods have been developed to facilitate the presentation of stimuli using computer screens or projectors. Common methods are either based on the measurement of eye movement during optokinetic reflex behavior or rely on the measurement of head and/or body-movements during optomotor responses. Eye-movements can easily and objectively be quantified, but their measurement requires invasive fixation of the animals. Head movements can be observed in freely moving animals, but until now depended on the judgment of a human observer who reported the counted tracking movements of the animal during an experiment. In this study we present a novel measurement and stimulation system based on open source building plans and software. This system presents appropriate 360° stimuli while simultaneously video-tracking the animal's head-movements without fixation. The on-line determined head gaze is used to adjust the stimulus to the head position, as well as to automatically calculate visual acuity. Exemplary, we show that automatically measured visual response curves of mice match the results obtained by a human observer very well. The spatial acuity thresholds yielded by the automatic analysis are also consistent with the human observer approach and with published results. Hence, OMR-arena provides an affordable, convenient and objective way to measure mouse visual performance
Kranz, K., Dorgau, B., Pottek, M., Herrling, R., Schultz, K., Bolte, P., Monyer, H., Penuela, S., Laird, D. W., Dedek, K., Weiler, R., and Janssen-Bienhold, U., Expression of Pannexin1 in the outer plexiform layer of the mouse retina and physiological impact of its knockout, J. Comp. Neurol., vol. 521, no. 5. Wiley-Blackwell, pp. 1119-1135, 29-Jan.-2013.
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Knop, G. C., Pottek, M., Monyer, H., Weiler, R., and Dedek, K., Morphological and physiological properties of enhanced green fluorescent protein (EGFP)-expressing wide-field amacrine cells in the ChAT-EGFP mouse line, Eur J Neurosci, vol. 39, no. 5. Wiley-Blackwell, pp. 800-810, 3-Dec.-2013.
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Ströh, S., Sonntag, S., Janssen-Bienhold, U., Schultz, K., Cimiotti, K., Weiler, R., Willecke, K., and Dedek, K., Cell-Specific Cre Recombinase Expression Allows Selective Ablation of Glutamate Receptors from Mouse Horizontal Cells, PLoS ONE, vol. 8, no. 12. Public Library of Science (PLoS), p. e83076, 12-Dec.-2013.
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Kranz, K., Paquet-Durand, F., Weiler, R., Janssen-Bienhold, U., and Dedek, K., Testing for a Gap Junction-Mediated Bystander Effect in Retinitis Pigmentosa: Secondary Cone Death Is Not Altered by Deletion of Connexin36 from Cones, PLoS ONE, vol. 8, no. 2. Public Library of Science (PLoS), p. e57163, 27-Feb.-2013.
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Schmid, F., Hiller, T., Korner, G., Glaus, E., Berger, W., and Neidhardt, J., A Gene Therapeutic Approach to Correct Splice Defects with Modified U1 and U6 snRNPs, Human Gene Therapy, vol. 24, no. 1. Mary Ann Liebert Inc, pp. 97-104, Jan.-2013.
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Sienknecht, U. J., Developmental origin and fate of middle ear structures, Hearing Research, vol. 301. Elsevier BV, pp. 19-26, Jul.-2013.
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Bendixen, A. and Andersen, S. K., Measuring target detection performance in paradigms with high event rates, Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, vol. 124, no. 5. pp. 928-940, May-2013.
Abstract DOI
OBJECTIVES: Combining behavioral and neurophysiological measurements inevitably implies mutual constraints, such as when the neurophysiological measurement requires fast-paced stimulus presentation and hence the attribution of a behavioral response to a particular preceding stimulus becomes ambiguous. We develop and test a method for validly assessing behavioral detection performance in spite of this ambiguity. METHODS: We examine four approaches taken in the literature to treat such situations. We analytically derive a new variant of computing the classical parameters of signal detection theory, hit and false alarm rates, adapted to fast-paced paradigms. RESULTS: Each of the previous approaches shows specific shortcomings (susceptibility towards response window choice, biased estimates of behavioral detection performance). Superior performance of our new approach is demonstrated for both simulated and empirical behavioral data. Further evidence is provided by reliable correspondence between behavioral performance and the N2b component as an electrophysiological indicator of target detection. CONCLUSIONS: The appropriateness of our approach is substantiated by both theoretical and empirical arguments. SIGNIFICANCE: We demonstrate an easy-to-implement solution for measuring target detection performance independent of the rate of event presentation. Thus overcoming the measurement bias of previous approaches, our method will help to clarify the behavioral relevance of different measures of cortical activation
SanMiguel, I., Widmann, A., Bendixen, A., Trujillo-Barreto, N., and Schröger, E., Hearing silences: human auditory processing relies on preactivation of sound-specific brain activity patterns, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 33, no. 20. pp. 8633-8639, May-2013.
Abstract DOI
The remarkable capabilities displayed by humans in making sense of an overwhelming amount of sensory information cannot be explained easily if perception is viewed as a passive process. Current theoretical and computational models assume that to achieve meaningful and coherent perception, the human brain must anticipate upcoming stimulation. But how are upcoming stimuli predicted in the brain? We unmasked the neural representation of a prediction by omitting the predicted sensory input. Electrophysiological brain signals showed that when a clear prediction can be formulated, the brain activates a template of its response to the predicted stimulus before it arrives to our senses
Mill, R. W., Bőhm, T. M., Bendixen, A., Winkler, I., and Denham, S. L., Modelling the emergence and dynamics of perceptual organisation in auditory streaming, PLoS computational biology, vol. 9, no. 3. p. e1002925, 2013.
Abstract DOI
Many sound sources can only be recognised from the pattern of sounds they emit, and not from the individual sound events that make up their emission sequences. Auditory scene analysis addresses the difficult task of interpreting the sound world in terms of an unknown number of discrete sound sources (causes) with possibly overlapping signals, and therefore of associating each event with the appropriate source. There are potentially many different ways in which incoming events can be assigned to different causes, which means that the auditory system has to choose between them. This problem has been studied for many years using the auditory streaming paradigm, and recently it has become apparent that instead of making one fixed perceptual decision, given sufficient time, auditory perception switches back and forth between the alternatives-a phenomenon known as perceptual bi- or multi-stability. We propose a new model of auditory scene analysis at the core of which is a process that seeks to discover predictable patterns in the ongoing sound sequence. Representations of predictable fragments are created on the fly, and are maintained, strengthened or weakened on the basis of their predictive success, and conflict with other representations. Auditory perceptual organisation emerges spontaneously from the nature of the competition between these representations. We present detailed comparisons between the model simulations and data from an auditory streaming experiment, and show that the model accounts for many important findings, including: the emergence of, and switching between, alternative organisations; the influence of stimulus parameters on perceptual dominance, switching rate and perceptual phase durations; and the build-up of auditory streaming. The principal contribution of the model is to show that a two-stage process of pattern discovery and competition between incompatible patterns can account for both the contents (perceptual organisations) and the dynamics of human perception in auditory streaming
Ruigendijk, E., Boekbespreking: Zwart, Jan Wouter, The syntax of Dutch - (Cambridge Syntax Guides.), Internationale Neerlandistiek, vol. 51, no. 1. Amsterdam University Press, pp. 82-84, 1-Feb.-2013.
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Hauthal, N., Sandmann, P., Debener, S., and Thorne, J. D., Visual movement perception in deaf and hearing individuals, Advances in cognitive psychology / University of Finance and Management in Warsaw, vol. 9, no. 2. pp. 53-61, 2013.
Abstract DOI
A number of studies have investigated changes in the perception of visual motion as a result of altered sensory experiences. An animal study has shown that auditory-deprived cats exhibit enhanced performance in a visual movement detection task compared to hearing cats (Lomber, Meredith, & Kral, 2010). In humans, the behavioural evidence regarding the perception of motion is less clear. The present study investigated deaf and hearing adult participants using a movement localization task and a direction of motion task employing coherently-moving and static visual dot patterns. Overall, deaf and hearing participants did not differ in their movement localization performance, although within the deaf group, a left visual field advantage was found. When discriminating the direction of motion, however, deaf participants responded faster and tended to be more accurate when detecting small differences in direction compared with the hearing controls. These results conform to the view that visual abilities are enhanced after auditory deprivation and extend previous findings regarding visual motion processing in deaf individuals.
Kranczioch, C. and Thorne, J., Simultaneous and preceding sounds enhance rapid visual targets: Evidence from the attentional blink, ACP, vol. 9, no. 3. University of Finance and Management in Warsaw, pp. 130-142, 30-Sep.-2013.
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Suesskind, D., Schrader, M., Foerster, M. H., Ernemann, U., and Aisenbrey, S., Cataract formation: a possible complication of intra-arterial chemotherapy for retinoblastoma, European Journal of Ophthalmology, vol. 24, no. 3. Wichtig Publishing, SRL, pp. 449-453, 7-Nov.-2013.
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Januschowski, K., Schnichels, S., Hagemann, U., Koch, V., Hofmann, J., Spitzer, M. S., Bartz-Schmidt, K. -U., Szurman, P., Lüke, M., and Aisenbrey, S., Electrophysiological toxicity testing of VEGF Trap-Eye in an isolated perfused vertebrate retina organ culture model, Acta Ophthalmologica, vol. 92, no. 4. Wiley-Blackwell, pp. e305-e311, 8-Nov.-2013.
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Suesskind, D., Altpeter, E., Schrader, M., Bartz-Schmidt, K. U., and Aisenbrey, S., Pars plana vitrectomy for treatment of advanced Coats’ disease—presentation of a modified surgical technique and long-term follow-up, Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 252, no. 6. Springer Science + Business Media, pp. 873-879, 12-Nov.-2013.
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Schnichels, S., Hagemann, U., Januschowski, K., Hofmann, J., Bartz-Schmidt, K. -U., Szurman, P., Spitzer, M. S., and Aisenbrey, S., Comparative toxicity and proliferation testing of aflibercept, bevacizumab and ranibizumab on different ocular cells, Br J Ophthalmol, vol. 97, no. 7. BMJ, pp. 917-923, 17-May-2013.
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Laycock, H., Valente, J., Bantel, C., and Nagy, I., Peripheral mechanisms of burn injury-associated pain, European Journal of Pharmacology, vol. 716, no. 1-3. Elsevier BV, pp. 169-178, Sep.-2013.
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Laycock, H. C. and Bantel, C., The value of pupillary dilation in pre-emptive analgesia: is there more to this than meets the eye?, Crit Care, vol. 17, no. 5. Springer Nature, p. 178, 2013.
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Meyer, J. and Hein, A., Live Long and Prosper: Potentials of Low-Cost Consumer Devices for the Prevention of Cardiovascular Diseases, Med 2.0, vol. 2, no. 2. JMIR Publications Inc., p. e7, 12-Aug.-2013.
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Bubl, E., Dörr, M., Philipsen, A., Ebert, D., Bach, M., and van Elst, L. T., Retinal Contrast Transfer Functions in Adults with and without ADHD, PLoS ONE, vol. 8, no. 5. Public Library of Science (PLoS), p. e61728, 2-May-2013.
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Jacob, G., Zvonik, K., Kamphausen, S., Sebastian, A., Maier, S., Philipsen, A., Tebartz van Elst, L., Lieb, K., and Tüscher, O., Emotional modulation of motor response inhibition in women with borderline personality disorder: an fMRI study, J Psychiatry Neurosci, vol. 38, no. 3. 8872147 Canada, Inc., pp. 164-172, 1-May-2013.
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Wilbertz, G., Trueg, A., Sonuga-Barke, E. J. S., Blechert, J., Philipsen, A., and Tebartz van Elst, L., Neural and psychophysiological markers of delay aversion in attention-deficit hyperactivity disorder., Journal of Abnormal Psychology, vol. 122, no. 2. American Psychological Association (APA), pp. 566-572, 2013.
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Hinz, J., Molder, J. M., Hanekop, G. -G., Weyland, A., Popov, A. -F., Bauer, M., and Kazmaier, S., Reduced sevoflurane loss during cardiopulmonary bypass when using a polymethylpentane versus a polypropylene oxygenator, The International Journal of Artificial Organs. Wichtig Publishing, SRL, pp. 0-0, 18-Mar.-2013.
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Pielawa, L., Frenken, M., and Hein, A., A workflow for design and evaluation of embedded control systems in medical devices, International Journal of Biomedical Engineering and Technology, vol. 13, no. 3. Inderscience Publishers, p. 257, 2013.
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Epp, B., Mauermann, M., and Verhey, J. L., Temporal integration near threshold fine structure–The role of cochlear processing, J. Acoust. Soc. Am., vol. 133, no. 5. Acoustical Society of America (ASA), p. 3428, 2013.
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Leipold, D., Silies, M., Mascheck, M., Lienau, C., and Runge, E., Ultrafast dynamics of localized light modes, Annalen der Physik, vol. 525, no. 1-2. Wiley-Blackwell, pp. 199-204, 24-Jan.-2013.
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Esmann, M., Becker, S. F., Cunha, B. B., Brauer, J. H., Vogelgesang, R., Groß, P., and Lienau, C., k-space imaging of the eigenmodes of sharp gold tapers for scanning near-field optical microscopy, Beilstein journal of nanotechnology, vol. 4. pp. 603-610, 2013.
Abstract DOI
We investigate the radiation patterns of sharp conical gold tapers, which were designed as adiabatic nanofocusing probes for scanning near-field optical microscopy (SNOM). Field calculations show that only the lowest order eigenmode of such a taper can reach the very apex and thus induce the generation of strongly enhanced near-field signals. Higher-order modes are coupled into the far field at finite distances from the apex. Here, we demonstrate experimentally how to distinguish and separate between the lowest and higher-order eigenmodes of such a metallic taper by filtering in the spatial frequency domain. Our approach has the potential to considerably improve the signal-to-background ratio in spectroscopic experiments at the nanoscale.
Schmidt, S., Engelke, P., Piglosiewicz, B., Esmann, M., Becker, S. F., Yoo, K., Park, N., Lienau, C., and Groß, P., Wave front adaptation using a deformable mirror for adiabatic nanofocusing along an ultrasharp gold taper, Optics express, vol. 21, no. 22. pp. 26564-26577, Nov.-2013.
Abstract DOI
We describe and demonstrate the use of an adaptive wave front optimization scheme for enhancing the efficiency of adiabatic nanofocusing of surface plasmon polariton (SPP) waves along an ultrasharp conical gold taper. Adiabatic nanofocusing is an emerging and promising scheme for controlled focusing of far field light into nanometric volumes. It comprises three essential steps: SPP excitation by coupling far field light to an SPP waveguide, SPP propagation along the waveguide and adiabatic SPP nanofocusing towards a geometric singularity. For commonly used complex waveguide geometries, such as, e.g., conical metal tapers, a realistic modeling and efficiency optimization is challenging. Here, we use a deformable mirror to adaptively control the wave front of the incident far field light. We demonstrate an eight-fold enhancement in nanofocusing efficiency and analyze the shape of the resulting optimized wave front. The introduced wave front optimization scheme is of general interest for guiding and controlling light on the nanoscale
Rozzi, C. A., Falke, S. M., Spallanzani, N., Rubio, A., Molinari, E., Brida, D., Maiuri, M., Cerullo, G., Schramm, H., Christoffers, J., and Lienau, C., Quantum coherence controls the charge separation in a prototypical artificial light-harvesting system, Nature communications, vol. 4. p. 1602, 2013.
Abstract DOI
The efficient conversion of light into electricity or chemical fuels is a fundamental challenge. In artificial photosynthetic and photovoltaic devices, this conversion is generally thought to happen on ultrafast, femto-to-picosecond timescales and to involve an incoherent electron transfer process. In some biological systems, however, there is growing evidence that the coherent motion of electronic wavepackets is an essential primary step, raising questions about the role of quantum coherence in artificial devices. Here we investigate the primary charge-transfer process in a supramolecular triad, a prototypical artificial reaction centre. Combining high time-resolution femtosecond spectroscopy and time-dependent density functional theory, we provide compelling evidence that the driving mechanism of the photoinduced current generation cycle is a correlated wavelike motion of electrons and nuclei on a timescale of few tens of femtoseconds. We highlight the fundamental role of the interface between chromophore and charge acceptor in triggering the coherent wavelike electron-hole splitting
Colonius, H. and Diederich, A., Response time variability and stage dependence in the time-window-of-integration model, Multisensory Research, vol. 26. Brill Academic Publishers, pp. 129-129, 16-May-2013.
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Salzmann, D. and Diederich, A., Setting priorities in preventative services, Journal of Public Health, vol. 21, no. 6. Springer Science + Business Media, pp. 515-522, 19-Jul.-2013.
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Breckel, T. P. K., Thiel, C. M., and Gießing, C., The efficiency of functional brain networks does not differ between smokers and non-smokers, Psychiatry Research: Neuroimaging, vol. 214, no. 3. Elsevier BV, pp. 349-356, Dec.-2013.
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Breckel, T. P. K., Thiel, C. M., Bullmore, E. T., Zalesky, A., Patel, A. X., and Gießing, C., Long-Term Effects of Attentional Performance on Functional Brain Network Topology, PLoS ONE, vol. 8, no. 9. Public Library of Science (PLoS), p. e74125, 9-Sep.-2013.
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Gießing, C., Thiel, C. M., Alexander-Bloch, A. F., Patel, A. X., and Bullmore, E. T., Human brain functional network changes associated with enhanced and impaired attentional task performance, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 33, no. 14. pp. 5903-5914, Apr.-2013.
Abstract DOI
How is the cognitive performance of the human brain related to its topological and spatial organization as a complex network embedded in anatomical space? To address this question, we used nicotine replacement and duration of attentionally demanding task performance (time-on-task), as experimental factors expected, respectively, to enhance and impair cognitive function. We measured resting-state fMRI data, performance and brain activation on a go/no-go task demanding sustained attention, and subjective fatigue in n = 18 healthy, briefly abstinent, cigarette smokers scanned repeatedly in a placebo-controlled, crossover design. We tested the main effects of drug (placebo vs Nicorette gum) and time-on-task on behavioral performance and brain functional network metrics measured in binary graphs of 477 regional nodes (efficiency, measure of integrative topology; clustering, a measure of segregated topology; and the Euclidean physical distance between connected nodes, a proxy marker of wiring cost). Nicotine enhanced attentional task performance behaviorally and increased efficiency, decreased clustering, and increased connection distance of brain networks. Greater behavioral benefits of nicotine were correlated with stronger drug effects on integrative and distributed network configuration and with greater frequency of cigarette smoking. Greater time-on-task had opposite effects: it impaired attentional accuracy, decreased efficiency, increased clustering, and decreased connection distance of networks. These results are consistent with hypothetical predictions that superior cognitive performance should be supported by more efficient, integrated (high capacity) brain network topology at greater connection distance (high cost). They also demonstrate that brain network analysis can provide novel and theoretically principled pharmacodynamic biomarkers of pro-cognitive drug effects in humans
Herrmann, C. S., Rach, S., Vosskuhl, J., and Strüber, D., Time–Frequency Analysis of Event-Related Potentials: A Brief Tutorial, Brain Topography, vol. 27, no. 4. Springer Science + Business Media, pp. 438-450, 6-Nov.-2013.
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Quirin, M., Meyer, F., Heise, N., Kuhl, J., Küstermann, E., Strüber, D., and Cacioppo, J. T., Neural correlates of social motivation: An fMRI study on power versus affiliation, International Journal of Psychophysiology, vol. 88, no. 3. Elsevier BV, pp. 289-295, Jun.-2013.
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Ansmann, G., Karnatak, R., Lehnertz, K., and Feudel, U., Extreme events in excitable systems and mechanisms of their generation, Phys. Rev. E, vol. 88, no. 5. American Physical Society (APS), 18-Nov.-2013.
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Guseva, K., Feudel, U., and Tél, T., Influence of the history force on inertial particle advection: Gravitational effects and horizontal diffusion, Phys. Rev. E, vol. 88, no. 4. American Physical Society (APS), 17-Oct.-2013.
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Hinz, C., Namekawa, ri, Behrmann-Godel, J., Oppelt, C., Jaeschke, A., Müller, A., Friedrich, R. W., and Gerlach, G., Olfactory imprinting is triggered by MHC peptide ligands, Scientific Reports, vol. 3. Nature Publishing Group, 30-Sep.-2013.
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Hinz, C., Kobbenbring, S., Kress, S., Sigman, L., Müller, A., and Gerlach, G., Kin recognition in zebrafish, Danio rerio, is based on imprinting on olfactory and visual stimuli, Animal Behaviour, vol. 85, no. 5. Elsevier BV, pp. 925-930, May-2013.
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Mouritsen, H., Atema, J., Kingsford, M. J., and Gerlach, G., Sun Compass Orientation Helps Coral Reef Fish Larvae Return to Their Natal Reef, PloS one, vol. 8, no. 6. p. e66039, 2013.
Abstract DOI
Reef fish sustain populations on isolated reefs and show genetic diversity between nearby reefs even though larvae of many species are swept away from the natal site during pelagic dispersal. Retention or recruitment to natal reefs requires orientation capabilities that enable larvae to find their way. Although olfactory and acoustically based orientation has been implicated in homing when larvae are in the reef's vicinity, it is still unclear how they cope with greater distances. Here we show evidence for a sun compass mechanism that can bring the larvae to the vicinity of their natal reef. In a circular arena, pre-settlement larvae and early settlers (<24 hours) of the cardinal fish, Ostorhinchus doederleini, showed a strong SSE directional swimming response, which most likely has evolved to compensate for the locally prevailing large scale NNW current drift. When fish were clock-shifted 6 hours, they changed their orientation by ca. 180° as predicted by the tropical sun curve at One Tree Island, i.e. they used a time-compensated sun compass. Furthermore, the fish oriented most consistently at times of the day when the sun azimuth is easy to determine. Microsatellite markers showed that the larvae that had just arrived at One Tree Island genetically belonged to either the local reef population or to Fitzroy Reef located 12 kilometers to the SSE. The use of a sun compass adds a missing long-distance link to the hierarchy of other sensory abilities that can direct larvae to the region of origin, including their natal reef. Predominant local recruitment, in turn, can contribute to genetic isolation and potential speciation
Paris, C. B., Atema, J., Irisson, J. -O., Kingsford, M., Gerlach, G., and Guigand, C. M., Reef odor: a wake up call for navigation in reef fish larvae, PloS one, vol. 8, no. 8. p. e72808, 2013.
Abstract DOI
The behavior of reef fish larvae, equipped with a complex toolbox of sensory apparatus, has become a central issue in understanding their transport in the ocean. In this study pelagic reef fish larvae were monitored using an unmanned open-ocean tracking device, the drifting in-situ chamber (DISC), deployed sequentially in oceanic waters and in reef-born odor plumes propagating offshore with the ebb flow. A total of 83 larvae of two taxonomic groups of the families Pomacentridae and Apogonidae were observed in the two water masses around One Tree Island, southern Great Barrier Reef. The study provides the first in-situ evidence that pelagic reef fish larvae discriminate reef odor and respond by changing their swimming speed and direction. It concludes that reef fish larvae smell the presence of coral reefs from several kilometers offshore and this odor is a primary component of their navigational system and activates other directional sensory cues. The two families expressed differences in their response that could be adapted to maintain a position close to the reef. In particular, damselfish larvae embedded in the odor plume detected the location of the reef crest and swam westward and parallel to shore on both sides of the island. This study underlines the critical importance of in situ Lagrangian observations to provide unique information on larval fish behavioral decisions. From an ecological perspective the central role of olfactory signals in marine population connectivity raises concerns about the effects of pollution and acidification of oceans, which can alter chemical cues and olfactory responses
Kishkinev, D., Chernetsov, N., Heyers, D., and Mouritsen, H., Migratory Reed Warblers Need Intact Trigeminal Nerves to Correct for a 1,000 km Eastward Displacement, PloS one, vol. 8, no. 6. p. e65847, 2013.
Abstract DOI
Several studies have shown that experienced night-migratory songbirds can determine their position, but it has remained a mystery which cues and sensory mechanisms they use, in particular, those used to determine longitude (east-west position). One potential solution would be to use a magnetic map or signpost mechanism like the one documented in sea turtles. Night-migratory songbirds have a magnetic compass in their eyes and a second magnetic sense with unknown biological function involving the ophthalmic branch of the trigeminal nerve (V1). Could V1 be involved in determining east-west position? We displaced 57 Eurasian reed warblers (Acrocephalus scirpaceus) with or without sectioned V1. Sham operated birds corrected their orientation towards the breeding area after displacement like the untreated controls did. In contrast, V1-sectioned birds did not correct for the displacement. They oriented in the same direction after the displacement as they had done at the capture site. Thus, an intact ophthalmic branch of the trigeminal nerve is necessary for detecting the 1,000 km eastward displacement in this night-migratory songbird. Our results suggest that V1 carries map-related information used in a large-scale map or signpost sense that the reed warblers needed to determine their approximate geographical position and/or an east-west coordinate
Mouritsen, H., Derbyshire, R., Stalleicken, J., Mouritsen, O. Ø., Frost, B. J., and Norris, D. R., An experimental displacement and over 50 years of tag-recoveries show that monarch butterflies are not true navigators, Proceedings of the National Academy of Sciences of the United States of America, vol. 110, no. 18. pp. 7348-7353, Apr.-2013.
Abstract DOI
Monarch butterflies (Danaus plexippus) breeding in eastern North America are famous for their annual fall migration to their overwintering grounds in Mexico. However, the mechanisms they use to successfully reach these sites remain poorly understood. Here, we test whether monarchs are true navigators who can determine their location relative to their final destination using both a "compass" and a "map". Using flight simulators, we recorded the orientation of wild-caught monarchs in southwestern Ontario and found that individuals generally flew in a southwest direction toward the wintering grounds. When displaced 2,500 km to the west, the same individuals continued to fly in a general southwest direction, suggesting that monarchs use a simple vector-navigation strategy (i.e., use a specific compass bearing without compensating for displacement). Using over 5 decades of field data, we also show that the directional concentration and the angular SD of recoveries from tagged monarchs largely conformed to two mathematical models describing the directional distribution of migrants expected under a vector-navigation strategy. A third analysis of tagged recoveries shows that the increasing directionality of migration from north to south is largely because of the presence of geographic barriers that guide individuals toward overwintering sites. Our work suggests that monarchs breeding in eastern North America likely combine simple orientation mechanisms with geographic features that funnel them toward Mexican overwintering sites, a remarkable achievement considering that these butterflies weigh less than a gram and travel thousands of kilometers to a site they have never seen
Jarvis, E. D., Yu, J., Rivas, M. V., Horita, H., Feenders, G., Whitney, O., Jarvis, S. C., Jarvis, E. R., Kubikova, L., Puck, A. E. P., Siang-Bakshi, C., Martin, S., McElroy, M., Hara, E., Howard, J., Pfenning, A., Mouritsen, H., Chen, C. -C., and Wada, K., Global view of the functional molecular organization of the avian cerebrum: mirror images and functional columns, The Journal of comparative neurology, vol. 521, no. 16. pp. 3614-3665, Nov.-2013.
Abstract DOI
Based on quantitative cluster analyses of 52 constitutively expressed or behaviorally regulated genes in 23 brain regions, we present a global view of telencephalic organization of birds. The patterns of constitutively expressed genes revealed a partial mirror image organization of three major cell populations that wrap above, around, and below the ventricle and adjacent lamina through the mesopallium. The patterns of behaviorally regulated genes revealed functional columns of activation across boundaries of these cell populations, reminiscent of columns through layers of the mammalian cortex. The avian functionally regulated columns were of two types: those above the ventricle and associated mesopallial lamina, formed by our revised dorsal mesopallium, hyperpallium, and intercalated hyperpallium; and those below the ventricle, formed by our revised ventral mesopallium, nidopallium, and intercalated nidopallium. Based on these findings and known connectivity, we propose that the avian pallium has four major cell populations similar to those in mammalian cortex and some parts of the amygdala: 1) a primary sensory input population (intercalated pallium); 2) a secondary intrapallial population (nidopallium/hyperpallium); 3) a tertiary intrapallial population (mesopallium); and 4) a quaternary output population (the arcopallium). Each population contributes portions to columns that control different sensory or motor systems. We suggest that this organization of cell groups forms by expansion of contiguous developmental cell domains that wrap around the lateral ventricle and its extension through the middle of the mesopallium. We believe that the position of the lateral ventricle and its associated mesopallium lamina has resulted in a conceptual barrier to recognizing related cell groups across its border, thereby confounding our understanding of homologies with mammals
Spielmann, M., Schröger, E., Kotz, S. A., Pechmann, T., and Bendixen, A., Using a staircase procedure for the objective measurement of auditory stream integration and segregation thresholds., Front. Psychol., vol. 4, no. August. 2013.
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Auditory scene analysis describes the ability to segregate relevant sounds out from the environment and to integrate them into a single sound stream using the characteristics of the sounds to determine whether or not they are related. This study aims to contrast task performances in objective threshold measurements of segregation and integration using identical stimuli, manipulating two variables known to influence streaming, inter-stimulus-interval (ISI) and frequency difference ($\\Delta$f). For each measurement, one parameter (either ISI or $\\Delta$f) was held constant while the other was altered in a staircase procedure. By using this paradigm, it is possible to test within-subject across multiple conditions, covering a wide $\\Delta$f and ISI range in one testing session. The objective tasks were based on across-stream temporal judgments (facilitated by integration) and within-stream deviance detection (facilitated by segregation). Results show the objective integration task is well suited for combination with the staircase procedure, as it yields consistent threshold measurements for separate variations of ISI and $\\Delta$f, as well as being significantly related to the subjective thresholds. The objective segregation task appears less suited to the staircase procedure. With the integration-based staircase paradigm, a comprehensive assessment of streaming thresholds can be obtained in a relatively short space of time. This permits efficient threshold measurements particularly in groups for which there is little prior knowledge on the relevant parameter space for streaming perception.
Puschmann, S., Sandmann, P., Ahrens, J., Thorne, J., Weerda, R., Klump, G. M., Debener, S., and Thiel, C. M., Electrophysiological correlates of auditory change detection and change deafness in complex auditory scenes, NeuroImage, vol. 75. 2013.
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Change deafness describes the failure to perceive even intense changes within complex auditory input, if the listener does not attend to the changing sound. Remarkably, previous psychophysical data provide evidence that this effect occurs independently of successful stimulus encoding, indicating that undetected changes are processed to some extent in auditory cortex. Here we investigated cortical representations of detected and undetected auditory changes using electroencephalographic (EEG) recordings and a change deafness paradigm. We applied a one-shot change detection task, in which participants listened successively to three complex auditory scenes, each of them consisting of six simultaneously presented auditory streams. Listeners had to decide whether all scenes were identical or whether the pitch of one stream was changed between the last two presentations. Our data show significantly increased middle-latency Nb responses for both detected and undetected changes as compared to no-change trials. In contrast, only successfully detected changes were associated with a later mismatch response in auditory cortex, followed by increased N2, P3a and P3b responses, originating from hierarchically higher non-sensory brain regions. These results strengthen the view that undetected changes are successfully encoded at sensory level in auditory cortex, but fail to trigger later change-related cortical responses that lead to conscious perception of change.
Weis, T., Brechmann, A., Puschmann, S., and Thiel, C. M., Feedback that confirms reward expectation triggers auditory cortex activity., J. Neurophysiol., vol. 110, no. 8. 2013.
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Associative learning studies have shown that the anticipation of reward and punishment shapes the representation of sensory stimuli, which is further modulated by dopamine. Less is known about whether and how reward delivery activates sensory cortices and the role of dopamine at that time point of learning. We used an appetitive instrumental learning task in which participants had to learn that a specific class of frequency-modulated tones predicted a monetary reward following fast and correct responses in a succeeding reaction time task. These fMRI data were previously analyzed regarding the effect of reward anticipation, but here we focused on neural activity to the reward outcome relative to the reward expectation and tested whether such activation in the reward reception phase is modulated by L-DOPA. We analyzed neural responses at the time point of reward outcome under three different conditions: 1) when a reward was expected and received, 2) when a reward was expected but not received, and 3) when a reward was not expected and not received. Neural activity in auditory cortex was enhanced during feedback delivery either when an expected reward was received or when the expectation of obtaining no reward was correct. This differential neural activity in auditory cortex was only seen in subjects who learned the reward association and not under dopaminergic modulation. Our data provide evidence that auditory cortices are active at the time point of reward outcome. However, responses are not dependent on the reward itself but on whether the outcome confirmed the subject\'s expectations.
Puschmann, S., ÖZyurt, J., Uppenkamp, S., and Thiel, C. M., Pitch-induced responses in the right auditory cortex correlate with musical ability in normal listeners., Neuroreport, vol. 24, no. 15. 2013.
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Previous work compellingly shows the existence of functional and structural differences in human auditory cortex related to superior musical abilities observed in professional musicians. In this study, we investigated the relationship between musical abilities and auditory cortex activity in normal listeners who had not received a professional musical education. We used functional MRI to measure auditory cortex responses related to auditory stimulation per se and the processing of pitch and pitch changes, which represents a prerequisite for the perception of musical sequences. Pitch-evoked responses in the right lateral portion of Heschl\'s gyrus were correlated positively with the listeners\' musical abilities, which were assessed using a musical aptitude test. In contrast, no significant relationship was found for noise stimuli, lacking any musical information, and for responses induced by pitch changes. Our results suggest that superior musical abilities in normal listeners are reflected by enhanced neural encoding of pitch information in the auditory system.
Weis, T., Puschmann, S., Brechmann, A., and Thiel, C. M., Positive and negative reinforcement activate human auditory cortex., Front. Hum. Neurosci., vol. 7. 2013.
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hPrior studies suggest that reward modulates neural activity in sensory cortices, but less is known about punishment. We used functional magnetic resonance imaging and an auditory discrimination task, where participants had to judge the duration of frequency modulated tones. In one session correct performance resulted in financial gains at the end of the trial, in a second session incorrect performance resulted in financial loss. Incorrect performance in the rewarded as well as correct performance in the punishment condition resulted in a neutral outcome. The size of gains and losses was either low or high (10 or 50 Euro cent) depending on the direction of frequency modulation. We analyzed neural activity at the end of the trial, during reinforcement, and found increased neural activity in auditory cortex when gaining a financial reward as compared to gaining no reward and when avoiding financial loss as compared to receiving a financial loss. This was independent on the size of gains and losses. A similar pattern of neural activity for both gaining a reward and avoiding a loss was also seen in right middle temporal gyrus, bilateral insula and pre-supplemental motor area, here however neural activity was lower after correct responses compared to incorrect responses. To summarize, this study shows that the activation of sensory cortices, as previously shown for gaining a reward is also seen during avoiding a loss.
Puschmann, S., Weerda, R., Klump, G. M., and Thiel, C. M., Segregating the neural correlates of physical and perceived change in auditory input using the change deafness effect., J. Cogn. Neurosci., vol. 25, no. 5. 2013.
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Psychophysical experiments show that auditory change detection can be disturbed in situations in which listeners have to monitor complex auditory input. We made use of this change deafness effect to segregate the neural correlates of physical change in auditory input from brain responses related to conscious change perception in an fMRI experiment. Participants listened to two successively presented complex auditory scenes, which consisted of six auditory streams, and had to decide whether scenes were identical or whether the frequency of one stream was changed between presentations. Our results show that physical changes in auditory input, independent of successful change detection, are represented at the level of auditory cortex. Activations related to conscious change perception, independent of physical change, were found in the insula and the ACC. Moreover, our data provide evidence for significant effective connectivity between auditory cortex and the insula in the case of correctly detected auditory changes, but not for missed changes. This underlines the importance of the insula/anterior cingulate network for conscious change detection.
Herrmann, C. S. and Murray, M. M., Seeing things that are not there: Illusions reveal how our brain constructs what we see, Front. Neurosci. Young Minds, vol. 1, no. 6. 2013.
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Uslar, V. N., Carroll, R., Hanke, M., Hamann, C., Ruigendijk, E., Brand, T., and Kollmeier, B., Development and evaluation of a linguistically and audiologically controlled sentence intelligibility test., J. Acoust. Soc. Am., vol. 134, no. 4. 2013.
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To allow for a systematic variation of linguistic complexity of sentences while acoustically controlling for intelligibility of sentence fragments, a German corpus, Oldenburg linguistically and audiologically controlled sentences (OLACS), was designed, implemented, and evaluated. Sentences were controlled for plausibility with a questionnaire survey. Verification of the speech material was performed in three listening conditions (quiet, stationary, and fluctuating noise) by collecting speech reception thresholds (SRTs) and response latencies as well as individual cognitive measures for 20 young listeners with normal hearing. Consistent differences in response latencies across sentence types verified the effect of linguistic complexity on processing speed. The addition of noise decreased response latencies, giving evidence for different response strategies for measurements in noise. Linguistic complexity had a significant effect on SRT. In fluctuating noise, this effect was more pronounced, indicating that fluctuating noise correlates with stronger cognitive contributions. SRTs in quiet correlated with hearing thresholds, whereas cognitive measures explained up to 40% of the variance in SRTs in noise. In conclusion, OLACS appears to be a suitable tool for assessing the interaction between aspects of speech understanding (including cognitive processing) and speech intelligibility in German.
Feinkohl, A., Borzeszkowski, K., and Klump, G. M., Effect of head turns on the localization accuracy of sounds in the European starling (Sturnus vulgaris), Behav. Brain Res., vol. 256. 2013.
Abstract DOI
Long signal durations that represent closed-loop conditions permit responses based on the sensory feedback during the presentation of the stimulus, while short stimulus durations that represent open-loop conditions do not allow for directed head turns during signal presentation. A previous study showed that for broadband noise stimuli, the minimum audible angle (MAA) of the European starling (Sturnus vulgaris) is smaller under closed-loop compared to open-loop conditions (Feinkohl & Klump, 2013). Head turns represent a possible strategy to improve sound localization cues under closed-loop conditions. In this study, we analyze the influence of head turns on the starling MAA for broadband noise and 2 kHz tones under closed-loop and open-loop conditions. The starlings made more head turns under closed-loop conditions compared to open-loop conditions. Under closed-loop conditions, their sensitivity for discriminating sound source positions was best if they turned their head once or more per stimulus presentation. We discuss potential cues generated from head turns under closed-loop conditions.
Kodrasi, I., Goetze, S., and Doclo, S., Regularization for Partial Multichannel Equalization for Speech Dereverberation, IEEE Trans. Aud. Sp. Lang. Proc., vol. 21, no. 9. 2013.
Abstract
Acoustic multichannel equalization techniques such as the multiple-input/output inverse theorem (MINT), which aim to equalize the room impulse responses (RIRs) between the source and the microphone array, are known to be highly sensitive to RIR estimation errors. To increase robustness, it has been proposed to incorporate regularization in order to decrease the energy of the equalization filters. In addition, more robust partial multichannel equalization techniques such as relaxed multichannel least-squares (RMCLS) and channel shortening (CS) have recently been proposed. In this paper, we propose a partial multichannel equalization technique based on MINT (P-MINT) which aims to shorten the RIR. Furthermore, we investigate the effectiveness of incorporating regularization to further increase the robustness of P-MINT and the aforementioned partial multichannel equalization techniques, i.e., RMCLS and CS. In addition, we introduce an automatic non-intrusive procedure for determining the regularization parameter based on the L-curve. Simulation results using measured RIRs show that incorporating regularization in P-MINT yields a significant performance improvement in the presence of RIR estimation errors, whereas a smaller performance improvement is observed when incorporating regularization in RMCLS and CS. Furthermore, it is shown that the intrusively regularized P-MINT technique outperforms all other investigated intrusively regularized multichannel equalization techniques in terms of perceptual speech quality (PESQ). Finally, it is shown that the automatic non-intrusive regularization parameter in regularized P-MINT leads to a very similar performance as the intrusively determined optimal regularization parameter, making regularized P-MINT a robust, perceptually advantageous, and practically applicable multichannel equalization technique for speech dereverberation.
Wouters, J., Doclo, S., Koning, R., and Francart, T., Sound Processing for Better Coding of Monaural and Binaural Cues in Auditory Prostheses, Proc. IEEE, vol. 101, no. 9. 2013.
Abstract DOIFull Text
Despite many considerable technical advances in the field of hearing aids and cochlear implants, people using auditory prostheses still have major problems with speech understanding in the presence of interfering sounds and with directional hearing. Both abilities are dependent on sound stream segregation in real-world listening environments. In this paper, two timely and important issues related to sound stream segregation in auditory prostheses are addressed, namely, the coding of monaural and binaural cues. Several state-of-the-art signal processing algorithms used in cochlear implants (CIs) and in hearing aids (HAs) are introduced. A review is given of some recent proposals to improve temporal coding in monaural CIs, and of recent work to improve the transmission of binaural cues in both HAs, CIs, and combined acoustic and electric hearing (bimodal hearing). The ultimate aim is to improve speech and music perception, and, additionally, the preservation of binaural cues to preserve directional hearing.
Gerkmann, T. and Krawczyk, M., MMSE-Optimal Spectral Amplitude Estimation Given the STFT-Phase, IEEE Signal Process. Lett., vol. 20, no. 2. 2013.
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Heeren, W., Hohmann, V., Appell, J. E., and Verhey, J. L., Relation between loudness in categorical units and loudness in phons and sones., J. Acoust. Soc. Am., vol. 133, no. 4. 2013.
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Data are presented on the relation between loudness measured in categorical units (CUs) using a standardized loudness scaling method (ISO 16832, 2006) and loudness expressed as the classical standardized measures phon and sone. Based on loudness scaling of narrowband noise signals by 31 normal-hearing subjects, sound pressure levels eliciting the same categorical loudness were derived for various center frequencies. The results were comparable to the standardized equal-loudness level contours. A comparison between the loudness function in CUs at 1000 Hz and the standardized loudness function in sones indicates a cubic relation between the two loudness measures.
Jürgens, T., Brand, T., Clark, N. R., Meddis, R., and Brown, G. J., The robustness of speech representations obtained from simulated auditory nerve fibers under different noise conditions., J. Acoust. Soc. Am., vol. 134, no. 3. 2013.
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Different methods of extracting speech features from an auditory model were systematically investigated in terms of their robustness to different noises. The methods either computed the average firing rate within frequency channels (spectral features) or inter-spike-intervals (timing features) from the simulated auditory nerve response. When used as the front-end for an automatic speech recognizer, timing features outperformed spectral features in Gaussian noise. However, this advantage was lost in babble, because timing features extracted the spectro-temporal structure of babble noise, which is similar to the target speaker. This suggests that different feature extraction methods are optimal depending on the background noise.
Warzybok, A., Rennies, J., Brand, T., Doclo, S., and Kollmeier, B., Effects of spatial and temporal integration of a single early reflection on speech intelligibility, J. Acoust. Soc. Am., vol. 133, no. 1. 2013.
Abstract
In order to study the interaction between the intelligibility advantage in rooms due to the presence of early reflections and due to binaural unmasking, a series of speech reception threshold experiments was performed employing a single reflection of the frontal target speech source as a function of its delay ranging from 0 to 200 ms. The direction of the reflection and the spatial characteristic of the interfering noise (diotic, diffuse, or laterally localized) were varied in the experiments. For the frontal reflection, full temporal integration was observed for all three noise types up to a delay of at least 25 ms followed by gradual intelligibility decay at longer delays. At 200 ms delay the reflection introduced additional intelligibility deterioration. For short delays, intelligibility was not reduced when the reflection was spatially separated from the direct sound in the diffuse and lateral noise conditions. A release from the deterioration effect at 200 ms delay was found for all spatially separated reflections. The suppression of a detrimental reflection was symmetrical in diffuse noise, but azimuth-dependent in lateral noise. This indicates an interaction of spatial and temporal processing of speech reflections which challenges existing binaural speech intelligibility models.
Papakonstantinou, A., Kollmeier, B., and Riedel, H., Ipsi- and contralateral interaction in the 40 Hz auditory steady state responses (ASSRs) with two carriers at 60 dB SPL., Int. J. Audiol., vol. 52, no. 9. 2013.
Abstract DOIFull Text
OBJECTIVE: Auditory steady state responses have been suggested for simultaneous threshold assessment using the multiple ASSR (MASSR) technique. However, at least at high stimulation levels, strong interactions reduce response amplitudes. The present study investigates ASSR interaction at a moderate stimulus level. DESIGN: Sinusoidal carriers modulated at rates near 40 Hz were used as probe. Unmodulated and modulated interferers were presented ipsi- or contralaterally. STUDY SAMPLE: Twenty normal-hearing subjects participated. RESULTS: Unmodulated interferers did not significantly change ASSR amplitudes. Modulated interferers, presented ipsilaterally or contralaterally, both significantly reduced the ASSR SNR by 13% and 8%, respectively. CONCLUSIONS: To compensate for the average SNR reduction would require a 32% and 18% longer measurement time for ipsi- and contralateral interferers, respectively, far less than the doubling of measurement time for two single measurements, emphasizing the MASSR technique advantage. However, the largest reduction for a single subject was 22% for the amplitude and 28% for the SNR, almost completely undoing the benefit in measurement time in MASSR. The individually varying interaction effects even at 60 dB SPL clearly limits the advantage of using the MASSR for modulation rates near 40 Hz over corresponding single ASSR measurements, at least for two simultaneous carriers.
Zokoll, M. A., Hochmuth, S., Warzybok, A., Wagener, K. C., Buschermöhle, M., and Kollmeier, B., Speech-in-Noise Tests for Multilingual Hearing Screening and Diagnostics 1, Am. J. Audiol., vol. 22, no. 1. 2013.
Abstract
PurposeNew complementary multilingual speech-in-noise tests in Russian, Turkish, and Spanish for hearing self-screening purposes and follow-up hearing diagnostics are compared to the speech tests of the European project, HearCom (Hearing in the Communication Society). MethodThe tests consist of spoken numbers (Digit Triplet Test; Smits, Kapteyn, & Houtgast, 2004) or sentences (Matrix Test; e.g., Hagerman, 1982) presented in a background noise and estimate the speech reception threshold, which is the signal-to-noise ratio that yields 50% speech intelligibility. All tests were developed according to the HearCom minimum quality standards for speech intelligibility tests. This report presents a cross-language comparison of reference speech intelligibility functions for monaural headphone measurements with normal-hearing listeners. The same model function was employed to describe the speech intelligibility functions for all of the tests. ResultsReference speech intelligibility functions of the new versions of the Digit Triplet Test and Matrix Test show high comparability to the HearCom tests. In order to achieve the highest possible comparability across languages, language- and speaker-dependent factors in speech intelligibility should be compensated for. ConclusionTo date, several complementary tests for screening and diagnostics have been developed in several languages. Adhering to the HearCom standards, the tests are highly comparable across languages. For the Matrix Test, equal syntax and linguistic complexity were maintained across languages due to common methodological standards.
Uslar, V. N., Carroll, R., Hanke, M., Hamann, C., Ruigendijk, E., Brand, T., and Kollmeier, B., Development and evaluation of a linguistically and audiologically controlled sentence intelligibility test., J. Acoust. Soc. Am., vol. 134, no. 4. 2013.
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To allow for a systematic variation of linguistic complexity of sentences while acoustically controlling for intelligibility of sentence fragments, a German corpus, Oldenburg linguistically and audiologically controlled sentences (OLACS), was designed, implemented, and evaluated. Sentences were controlled for plausibility with a questionnaire survey. Verification of the speech material was performed in three listening conditions (quiet, stationary, and fluctuating noise) by collecting speech reception thresholds (SRTs) and response latencies as well as individual cognitive measures for 20 young listeners with normal hearing. Consistent differences in response latencies across sentence types verified the effect of linguistic complexity on processing speed. The addition of noise decreased response latencies, giving evidence for different response strategies for measurements in noise. Linguistic complexity had a significant effect on SRT. In fluctuating noise, this effect was more pronounced, indicating that fluctuating noise correlates with stronger cognitive contributions. SRTs in quiet correlated with hearing thresholds, whereas cognitive measures explained up to 40% of the variance in SRTs in noise. In conclusion, OLACS appears to be a suitable tool for assessing the interaction between aspects of speech understanding (including cognitive processing) and speech intelligibility in German.
van Esch, T. E. M., Kollmeier, B., Vormann, M., Lyzenga, J., Houtgast, T., Hällgren, M., Larsby, B., Athalye, S. P., Lutman, M. E., and Dreschler, W. a, Evaluation of the preliminary auditory profile test battery in an international multi-centre study., Int. J. Audiol., vol. 52, no. 5. 2013.
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OBJECTIVE: This paper describes the composition and international multi-centre evaluation of a battery of tests termed the preliminary auditory profile. It includes measures of loudness perception, listening effort, speech perception, spectral and temporal resolution, spatial hearing, self-reported disability and handicap, and cognition. Clinical applicability and comparability across different centres are investigated. DESIGN: Headphone tests were conducted in five centres divided over four countries. Effects of test-retest, ear, and centre were investigated. Results for normally-hearing (NH) and hearing-impaired (HI) listeners are presented. STUDY SAMPLE: Thirty NH listeners aged 19-39 years, and 72 HI listeners aged 22-91 years with a broad range of hearing losses were included. RESULTS: Test-retest reliability was generally good and there were very few right/left ear effects. Results of all tests were comparable across centres for NH listeners after baseline correction to account for necessary differences between test materials. For HI listeners, results were comparable across centres for the language-independent tests. CONCLUSIONS: The auditory profile forms a clinical test battery that is applicable in four different languages. Even after baseline correction, differences between test materials have to be taken into account when interpreting results of language-dependent tests in HI listeners.
Bianchi, F., Verhulst, S., and Dau, T., Experimental evidence for a cochlear source of the precedence effect, J. Assoc. Res. Otolaryngol., vol. 14. 2013.
Abstract
The precedence effect (PE) refers to the dominance of directional information carried by a direct sound (lead) over the spatial information contained in its multiple reflections (lags) in sound localization. Although the processes underlying the PE have been largely investigated, the extent to which peripheral versus central auditory processes contribute to this perceptual phenomenon has remained unclear. The present study investigated the contribution of peripheral processing to the PE through a comparison of physiological and psychoacoustical data in the same human listeners. The psychoacoustical experiments, comprising a fusion task, an interaural time difference detection task and a lateralization task, demonstrated a time range from 1 to 4.6–5 ms, in which the PE operated (precedence window). Click-evoked otoacoustic emissions (CEOAEs) were recorded in both ears to investigate the lead–lag interactions at the level of the basilar membrane (BM) in the cochlea. The CEOAE-derived peripheral and monaural lag suppression was largest for ICIs of 1–4 ms. Auditory-evoked brainstem responses (ABRs) were used to investigate monaural and binaural lag suppression at the brainstem level. The responses to monaural stimulation reflected the peripheral lag suppression observed in the CEOAE results, while the binaural brainstem responses did not show any substantial contribution of binaural processes to monaural lag suppression. The results demonstrated that the lag suppression occurring at the BM in a time range from 1 to 4 ms, as indicated by the suppression of the lag-CEOAE, was the source of the reduction in the lag-ABRs and a possible peripheral contributor to the PE for click stimuli.
Ehmann, H., Hartwich, H., Salzig, C., Hartmann, N., Clément-Ziza, M., Ushakov, K., Avraham, K. B., Bininda-Emonds, O. R. P., Hartmann, A. K., Lang, P., Friauf, E., and Nothwang, H. G., Time-dependent gene expression analysis of the developing superior olivary complex., J. Biol. Chem., vol. 288, no. 36. 2013.
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The superior olivary complex (SOC) is an essential auditory brainstem relay involved in sound localization. To identify the genetic program underlying its maturation, we profiled the rat SOC transcriptome at postnatal days 0, 4, 16, and 25 (P0, P4, P16, and P25, respectively), using genome-wide microarrays (41,012 oligonucleotides (oligos)). Differences in gene expression between two consecutive stages were highest between P4 and P16 (3.6%) and dropped to 0.06% between P16 and P25. To identify SOC-related genetic programs, we also profiled the entire brain at P4 and P25. The number of differentially expressed oligonucleotides between SOC and brain almost doubled from P4 to P25 (4.4% versus 7.6%). These data demonstrate considerable molecular specification around hearing onset, which is rapidly finalized. Prior to hearing onset, several transcription factors associated with the peripheral auditory system were up-regulated, probably coordinating the development of the auditory system. Additionally, crystallin-$\\\\\\\\gamma$ subunits and serotonin-related genes were highly expressed. The molecular repertoire of mature neurons was sculpted by SOC-related up- and down-regulation of voltage-gated channels and G-proteins. Comparison with the brain revealed a significant enrichment of hearing impairment-related oligos in the SOC (26 in the SOC, only 11 in the brain). Furthermore, 29 of 453 SOC-related oligos mapped within 19 genetic intervals associated with hearing impairment. Together, we identified sequential genetic programs in the SOC, thereby pinpointing candidates that may guide its development and ensure proper function. The enrichment of hearing impairment-related genes in the SOC may have implications for restoring hearing because central auditory structures might be more severely affected than previously appreciated.
Kullmann, L., Schlüter, T., Wagner, H., and Nothwang, H. G., Evolutionary conservation of Kv3.1 in the barn owl Tyto alba., Brain. Behav. Evol., vol. 81, no. 3. 2013.
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For prey capture in the dark, the barn owl Tyto alba has evolved into an auditory specialist with an exquisite capability of sound localization. Adaptations include asymmetrical ears, enlarged auditory processing centers, the utilization of minute interaural time differences, and phase locking along the entire hearing range up to 10 kHz. Adaptations on the molecular level have not yet been investigated. Here, we tested the hypothesis that divergence in the amino acid sequence of the voltage-gated K(+) channel Kv3.1 contributes to the accuracy and high firing rates of auditory neurons in the barn owl. We therefore cloned both splice variants of Kcnc1, the gene encoding Kv3.1. Both splice variants, Kcnc1a and Kcnc1b, encode amino acids identical to those of the chicken, an auditory generalist. Expression analyses confirmed neural-restricted expression of the channel. In summary, our data reveal strong evolutionary conservation of Kcnc1 in the barn owl and point to other genes involved in auditory specializations of this animal. The data also demonstrate the feasibility to address neuroethological questions in organisms with no reference genome by molecular approaches. This will open new avenues for neuroethologists working in these organisms.
Van Den Heuvel, I. M., Cherry, M. I., and Klump, G. M., Land or lover? Territorial defence and mutual mate guarding in the crimson-breasted shrike, Behav Ecol Sociobiol, vol. 68, no. 3. Springer Science + Business Media, pp. 373-381, 19-Nov.-2013.
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Wissel, T., Pfeiffer, T., Frysch, R., Knight, R. T., Chang, E. F., Hinrichs, H., Rieger, J. W., and Rose, G., Hidden Markov model and support vector machine based decoding of finger movements using electrocorticography, Journal of Neural Engineering, vol. 10, no. 5. IOP Publishing, p. 056020, 18-Sep.-2013.
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Rieger, J. W., Gegenfurtner, K. R., Schalk, F., Koechy, N., Heinze, H. -jochen, and Grueschow, M., BOLD responses in human V1 to local structure in natural scenes: Implications for theories of visual coding, Journal of vision, vol. 13, no. 2. p. 19, 2013.
Abstract DOI
In this study we tested predictions of two important theories of visual coding, contrast energy and sparse coding theory, on the dependence of population activity level and metabolic demands on spatial structure of the visual input. With carefully calibrated displays we find that in humans neither the V1 blood oxygenation level dependent (BOLD) response nor the initial visually evoked fields in magnetoencephalography (MEG) are sensitive to phase perturbations in photographs of natural scenes. As a control, we quantitatively show that the applied phase perturbations decrease sparseness (kurtosis) of our stimuli but preserve their root mean square (RMS) contrast. Importantly, we show that the lack of sensitivity of the V1 population response level to phase perturbations is not due to a lack of sensitivity of our methods because V1 responses were highly sensitive to variations of image RMS contrast. Our results suggest that the transition from a sparse to a distributed neural code in the early visual system induced by reducing image sparseness has negligible consequences for population metabolic cost. This result imposes a novel and important empirical constraint on quantitative models of sparse coding: Population metabolic rate and population activation level is sensitive to second order statistics (RMS contrast) of the input but not to its spatial phase and fourth order statistics (kurtosis)
Enriquez-Geppert, S., Huster, R. J., and Herrmann, C. S., Boosting brain functions: Improving executive functions with behavioral training, neurostimulation, and neurofeedback, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 88, no. 1. pp. 1-16, Apr.-2013.
Abstract DOI
Cognitive enhancement is a popular topic, attracting attention both from the general public and the scientific research community. Higher cognitive functions are involved in various aspects of everyday life and have been associated with manifest behavioral and psychiatric mental impairments when deteriorated. The improvement of these so-called executive functions (EFs) is of high individual, social, and economic relevances. This review provides a synopsis of two lines of research, investigating the enhancement of capabilities in executive functioning: a) computerized behavioral trainings, and b) approaches for direct neuromodulation (neurofeedback and transcranial electrostimulation). Task switching, memory updating, response inhibition, and dual task performance are addressed in terms of cognitive functions. It has been shown that behavioral cognitive training leads to enhanced performance in task switching, memory updating, and dual tasks. Similarly, direct neurocognitive modulation of brain regions that are crucially involved in specific EFs also leads to behavioral benefits in response inhibition, task switching, and memory updating. Response inhibition performance has been shown to be improved by neurostimulation of the right inferior frontal cortex, whereas neurostimulation of the dorsolateral prefrontal cortex exerts effects on task switching and memory updating. Due to a lack of consistency in experimental methods and findings, a comparison of different training approaches concerning their effectiveness is not yet possible. So far, current data suggest that training gains may indeed generalize to untrained tasks aiming at the same cognitive process, as well as across cognitive domains within executive control
Huster, R. J., Enriquez-Geppert, S., Lavallee, C. F., Falkenstein, M., and Herrmann, C. S., Electroencephalography of response inhibition tasks: functional networks and cognitive contributions, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 87, no. 3. pp. 217-233, Mar.-2013.
Abstract DOI
Response inhibition paradigms, as for example stop signal and go/no-go tasks, are often used to study cognitive control processes. Because of the apparent demand to stop a motor reaction, the electrophysiological responses evoked by stop and no-go trials have sometimes likewise been interpreted as indicators of inhibitory processes. Recent research, however, suggests a richer conceptual background. Evidence denotes an association of a frontal-midline N200/theta oscillations with premotor cognitive processes such as conflict monitoring or response program updating, and an anterior P300/delta oscillations with response-related, evaluative processing stages, probably the evaluation of motor inhibition. However, the data are still insufficient to unambiguously relate these electroencephalographic measures to specific inhibitory functions. Beta band activity only recently has become a focus of attention in this task context because of its association with the motor system and regions involved in inhibitory control. Its functional role in response inhibition tasks needs further exploration though. Hence, as things stand, any deduction of differences regarding actual inhibitory capabilities or loads between subject groups or conditions based on electroencephalographic measures has to be treated with caution
Hartmann, A. -M., Abraham Fraunce's Use of Giovanni Andrea dell'Anguillara'sMetamorfosi, Translation and Literature, vol. 22, no. 1. Edinburgh University Press, pp. 103-110, Mar.-2013.
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Schepers, I. M., Schneider, T. R., Hipp, J. F., Engel, A. K., and Senkowski, D., Noise alters beta-band activity in superior temporal cortex during audiovisual speech processing, NeuroImage, vol. 70. Elsevier BV, pp. 101-112, Apr.-2013.
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Hawellek, D. J., Schepers, I. M., Roeder, B., Engel, A. K., Siegel, M., and Hipp, J. F., Altered Intrinsic Neuronal Interactions in the Visual Cortex of the Blind, Journal of Neuroscience, vol. 33, no. 43. Society for Neuroscience, pp. 17072-17080, 23-Oct.-2013.
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Kishkinev, D., Chernetsov, N., Heyers, D., and Mouritsen, H., Migratory Reed Warblers Need Intact Trigeminal Nerves to Correct for a 1,000 km Eastward Displacement, PLOS ONE, vol. 8, no. 6. PUBLIC LIBRARY SCIENCE, Jun.-2013.
Abstract
Several studies have shown that experienced night-migratory songbirds can determine their position, but it has remained a mystery which cues and sensory mechanisms they use, in particular, those used to determine longitude (east-west position). One potential solution would be to use a magnetic map or signpost mechanism like the one documented in sea turtles. Night-migratory songbirds have a magnetic compass in their eyes and a second magnetic sense with unknown biological function involving the ophthalmic branch of the trigeminal nerve (V1). Could V1 be involved in determining east-west position? We displaced 57 Eurasian reed warblers (Acrocephalus scirpaceus) with or without sectioned V1. Sham operated birds corrected their orientation towards the breeding area after displacement like the untreated controls did. In contrast, V1-sectioned birds did not correct for the displacement. They oriented in the same direction after the displacement as they had done at the capture site. Thus, an intact ophthalmic branch of the trigeminal nerve is necessary for detecting the 1,000 km eastward displacement in this night-migratory songbird. Our results suggest that V1 carries map-related information used in a large-scale map or signpost sense that the reed warblers needed to determine their approximate geographical position and/or an east-west coordinate.
Lauwers, M., Pichler, P., Edelman, N. B., Resch, G. P., Ushakova, L., Salzer, M. C., Heyers, D., Saunders, M., Shaw, J., and Keays, D. A., An Iron-Rich Organelle in the Cuticular Plate of Avian Hair Cells, CURRENT BIOLOGY, vol. 23, no. 10. CELL PRESS, May-2013.
Abstract
Hair cells reside in specialized epithelia in the inner ear of vertebrates, mediating the detection of sound, motion, and gravity. The transduction of these stimuli into a neuronal impulse requires the deflection of stereocilia, which are stabilized by the actin-rich cuticular plate. Recent electrophysiological studies have implicated the vestibular system in pigeon magnetosensation {[}1]. Here we report the discovery of a single iron-rich organelle that resides in the cuticular plate of cochlear and vestibular hair cells in the pigeon. Transmission electron microscopy, coupled with elemental analysis, has shown that this structure is composed of ferritin-like granules, is approximately 300-600 nm in diameter, is spherical, and in some instances is membrane-bound and/or organized in a paracrystalline array. This organelle is found in hair cells in a wide variety of avian species, but not in rodents or in humans. This structure may function as (1) a store of excess iron, (2) a stabilizer of stereocilia, or (3) a mediator of magnetic detection. Given the specific subcellular location, elemental composition, and evolutionary conservation, we propose that this structure is an integral component of the sensory apparatus in birds.
Velmans, T., Battefeld, A., Geist, B., Farres, A. S., Strauss, U., and Braeuer, A. U., Plasticity-related gene 3 promotes neurite shaft protrusion, BMC NEUROSCIENCE, vol. 14. BIOMED CENTRAL LTD, Mar.-2013.
Abstract
Background: Recently, we and others proposed plasticity-related gene 3 (PRG3) as a novel molecule in neuritogenesis based on PRG3 overexpression experiments in neuronal and non-neuronal cell lines. However, direct information on PRG3 effects in neuronal development and, in particular, its putative spatio-temporal distribution and conditions of action, is sparse. Results: We demonstrate here that PRG3 induces filopodia formation in HEK293 cells depending on its N-glycosylation status. The PRG3 protein was strongly expressed during mouse brain development in vivo from embryonic day 16 to postnatal day 5 (E16 - P5). From P5 on, expression declined. Furthermore, in early, not yet polarized hippocampal cultured neurons, PRG3 was expressed along the neurite shaft. Knock-down of PRG3 in these neurons led to a decreased number of neurites. This phenotype is rescued by expression of an shRNA-resistant PRG3 construct in PRG3 knock-down neurons. After polarization, endogenous PRG3 expression shifted mainly to axons, specifically to the plasma membrane along the neurite shaft. These PRG3 pattern changes appeared temporally and spatially related to ongoing synaptogenesis. Therefore we tested (i) whether dendritic PRG3 re-enhancement influences synaptic currents and (ii) whether synaptic inputs contribute to the PRG3 shift. Our results rendered both scenarios unlikely: (i) PRG3 over-expression had no influence on miniature excitatory postsynaptic currents (mEPSC) and (ii) blocking of incoming signals did not alter PRG3 distribution dynamics. In addition, PRG3 levels did not interfere with intrinsic neuronal properties. Conclusion: Taken together, our data indicate that endogenous PRG3 promotes neurite shaft protrusion and therefore contributes to regulating filopodia formation in immature neurons. PRG3 expression in more mature neurons, however, is predominantly localized in the axon. Changes in PRG3 levels did not influence intrinsic or synaptic neuronal properties.
Witt, K., Granert, O., Daniels, C., Volkmann, J., Falk, D., van Eimeren, T., and Deuschl, G., Relation of lead trajectory and electrode position to neuropsychological outcomes of subthalamic neurostimulation in Parkinson's disease: results from a randomized trial, BRAIN, vol. 136, no. 7. OXFORD UNIV PRESS, Jul.-2013.
Abstract
Deep brain stimulation of the subthalamic nucleus improves motor functions in patients suffering from advanced Parkinson's disease but in some patients, it is also associated with a mild decline in cognitive functioning about one standard deviation from the preoperative state. We assessed the impact of the cortical lead entry point, the subcortical electrode path and the position of the active electrode contacts on neuropsychological changes after subthalamic nucleus-deep brain stimulation compared to a control group of patients receiving best medical treatment. Sixty-eight patients with advanced Parkinson's disease were randomly assigned to have subthalamic nucleus-deep brain stimulation or best medical treatment for Parkinson's disease. All patients had a blinded standardized neuropsychological exam (Mattis Dementia Rating scale, backward digit span, verbal fluency and Stroop task performance) at baseline and after 6 months of treatment. Patients with subthalamic nucleus-deep brain stimulation were defined as impaired according to a mild decline of one or more standard deviations compared to patients in the best medical treatment group. The cortical entry point of the electrodes, the electrode trajectories and the position of the active electrode contact were transferred into a normalized brain volume by an automated, non-linear registration algorithm to allow accurate statistical group analysis using pre- and postoperative magnetic resonance imaging data. Data of 31 patients of the subthalamic nucleus-deep brain stimulation group and 31 patients of the best medical treatment group were analysed. The subthalamic nucleus-deep brain stimulation group showed impaired semantic fluency compared with the best medical treatment group 6 months after surgery (P = 0.02). Electrode trajectories intersecting with caudate nuclei increased the risk of a decline in global cognition and working memory performance. Statistically, for every 0.1 ml overlap with a caudate nucleus, the odds for a decline > 1 standard deviation increased by a factor of 37.4 (odds ratio, confidence interval 2.1-371.8) for the Mattis Dementia Rating Scale and by a factor of 8.8 (odds ratio, confidence interval 1.0-70.9) for the backward digit span task. Patients with subthalamic nucleus-deep brain stimulation who declined in semantic verbal fluency, Stroop task and the backward digit span task performance showed a position of the active electrode outside the volume built by the active electrodes of stable performers. Passage of the chronic stimulation lead through the head of the caudate increases the risk of global cognitive decline and working memory performance after subthalamic nucleus-deep brain stimulation in Parkinson's disease. Therefore the electrode path should be planned outside the caudate nuclei, whenever possible. This study also stresses the importance of precise positioning of the active stimulating contact within the subthalamic volume to avoid adverse effects on semantic verbal fluency and response inhibition.
Witt, E., Parisi, J., and Kolny-Olesiak, J., Selective growth of gold onto copper indium sulfide selenide nanoparticles. 2013.
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Hartwich, H., Erzeugung und Analyse transgener Mausmodelle für das zentrale auditorische System. 2013.
Abstract
Witt, E., Parisi, J., and Kolny-Olesiak, J., Selective growth of gold onto copper indium sulfide selenide nanoparticles. 2013.
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Hartwich, H., Erzeugung und Analyse transgener Mausmodelle für das zentrale auditorische System. 2013.
Abstract
Assmus, H. ; K., S3-Leitlinie: Versorgung peripherer Nervenverletzungen : AWMF-Registernummer: 005-010, Stand: 06/2013th ed. [Düsseldorf] : [Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften e.V. (AWMF)], 2013.
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Schabas, W. A., Kein Frieden ohne Gerechtigkeit? : Die Rolle der internationalen Strafjustiz, 1. Aufl.st ed. Hamburg : Hamburger Ed., 2013.
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Manley, G. A. and Sienknecht, U. J., The Evolution and Development of Middle Ears in Land Vertebrates, Springer Handbook of Auditory Research. Springer Science + Business Media, pp. 7-30, 2013.
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Sienknecht, U. J., Origin and Development of Hair Cell Orientation in the Inner Ear, Springer Handbook of Auditory Research. Springer Science + Business Media, pp. 69-109, 2013.
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Manley, G. A., Köppl, C., and Sienknecht, U. J., The Remarkable Ears of Geckos and Pygopods, Springer Handbook of Auditory Research. Springer Science + Business Media, pp. 111-131, 2013.
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Thomas, B., Bantel, C., Stone, L., and Wilcox, G. L., Alpha(α) 2-Adrenergic Agonists in Pain Treatment, Encyclopedia of Pain. Springer Science + Business Media, pp. 96-101, 2013.
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Klinge-Strahl, A., Parnitzke, T., Beutelmann, R., and Klump, G. M., Phase Discrimination Ability in Mongolian Gerbils Provides Evidence for Possible Processing Mechanism of Mistuning Detection, Basic Aspects of Hearing. Springer Science + Business Media, pp. 399-407, 2013.
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Steen, E. -E., Frenken, T., Frenken, M., and Hein, A., Functional Assessment in Elderlies’ Homes: Early Results from a Field Trial, Advanced Technologies and Societal Change. Springer Science + Business Media, pp. 3-17, 22-Nov.-2013.
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Wallbaum, T., Frenken, M., Meyer, J., Hein, A., and Giehoff, C., Mneme: Telemonitoring for Medical Treatment-Support in Dementia, Advanced Technologies and Societal Change. Springer Science + Business Media, pp. 93-107, 22-Nov.-2013.
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Volkening, N., Hein, A., Isken, M., Frenken, T., and Brell, M., Housing Enabling: Detection of Imminent Risk Areas in Domestic Environments Using Mobile Service Robots, Advanced Technologies and Societal Change. Springer Science + Business Media, pp. 301-314, 22-Nov.-2013.
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Müller, F., Hoffmann, P., Frenken, M., Hein, A., and Herzog, O., LsW: Networked Home Automation in Living Environments, Advanced Technologies and Societal Change. Springer Science + Business Media, pp. 19-34, 22-Nov.-2013.
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Diederich, A. and Schreier, M., Priorisierungskriterien in der gesundheitlichen Versorgung – Was meinen die Bürger?, Priorisierung in der Medizin. Springer Science + Business Media, pp. 265-298, 2013.
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Mouritsen, H., The Magnetic Senses, Neurosciences - From Molecule to Behavior: a university textbook. Springer Science + Business Media, pp. 427-443, 2013.
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Strüber, D., Hirnforschung, Gewalt. Ein interdisziplinäres Handbuch. Metzler, pp. 332-339, 2013.
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Strüber, D., Hirnforschung, Gewalt. Ein interdisziplinäres Handbuch. Metzler, pp. 332-339, 2013.
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Strüber, D., Lück, M., and Roth, G., Tatort Gehirn, Profiler & Co. Schattauer, und Heidelberg: Spektrum der Wissenschaft Verlagsgesellschaft mbH, pp. 97-108, 2013.
Abstract
Kodrasi, I. and Doclo, S., Regularized subspace-based acoustic multichannel equalization for speech dereverberation, Eur. Signal Process. Conf. (EUSIPCO), no. 1. EURASIP, 2013.
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Acoustic multichannel equalization techniques aim at designing robust reshaping filters which reduce the reverberant energy and preserve the perceptual speech quality. Although the recently proposed channel shortening (CS) technique can achieve reverberant energy suppression, its optimization criterion results in a subspace of solutions where each solution yields a different perceptual speech quality. In this paper, we propose a perceptually advantageous subspace-based equalization technique, where the reshaping filter is constrained to lie in the subspace of the multiple CS solutions. Since it has been shown that regularization increases the robustness of equalization techniques to errors in the estimated room impulse responses (RIRs), a regularization term is incorporated in order to control the energy of the reshaping filter. Simulation results for erroneously estimated RIRs demonstrate the advantages of the proposed approach.
Dalga, D. and Doclo, S., Influence of secondary path estimation errors on the performance of ANC-motivated noise reduction algorithms for hearing aids, IEEE Work. Appl. Signal Process. to Audio Acoust. (WASPAA). 2013.
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Lawin-Ore, T. and Doclo, S., Average output SNR of the multichannel Wiener filter using statistical room acoustics, IEEE Work. Appl. Signal Process. to Audio Acoust. (WASPAA). IEEE, 2013.
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Schepker, H., Rennies, J., and Doclo, S., Improving speech intelligibility in noise by SII-dependent preprocessing using frequency dependent amplification and dynamic range compression, Conf. Int. Speech Comm. Assoc. (Interspeech). 2013.
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Krawczyk, M., Rehr, R., and Gerkmann, T., Phase-Sensitive Real-Time Capable Speech Enhancement Under Voiced-Unvoiced Uncertainty, Eur. Signal Process. Conf. (EUSIPCO). EURASIP, 2013.
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In many short-time Fourier transform (STFT)-based single channel speech enhancement algorithms, the clean speech spectral amplitude is estimated from a noisy observation to suppress additive noise. For the estimation, only the noisy amplitudes and functions thereof, like the a priori or a pos- teriori signal-to-noise ratio (SNR), are utilized. Information about the clean speech spectral phase is mostly not employed. In this work we present a comprehensive speech enhancement setup that combines phase-sensitive and phase-insensitive amplitude estimation, improving the perceptual speech qual- ity of the enhanced signal in terms of PESQ compared to phase-insensitive amplitude estimation alone. The proposed algorithm is real-time capable in the sense that it is imple- mented in a causal block-wise manner and the computational complexity is feasible.
Oetting, D., Ewert, S. D., Hohmann, V., and Appell, J. -E., Model-based loudness compensation for broad- and narrow-band signals, Int. Symp. Auditory Audiol. Res. (ISAAR). 2013.
Abstract
Moritz, N., Schädler, M. R., Adiloglu, K., Meyer, B. T., Jürgens, T., Gerkmann, T., Kollmeier, B., Doclo, S., and Goetze, S., Noise robust distant automatic speech recognition utilizing NMF based source separation and auditory feature extraction, Int. Work. Mach. Listening Multisource Env. (CHiME). IEEE, 2013.
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This paper describes our contribution to the 2nd CHiME challenge and focuses on the small vocabulary task, i.e. track one. We present a robust system combination that involves source separation, auditory feature extraction and a modified automatic speech recognition back-end. The source separation code is based on a non-negative matrix factorization approach and the presented auditory feature extraction method uses 2D Gabor filter functions to extract spectral, temporal and spectro-temporal information of the speech signals. In addition we describe the modifications to our classification back-end and discuss the achieved results. On the final CHiME test set the proposed system achieves a maximum keyword recognition rate improvement of 50.25 % for the -6 dB SNR condition, for instance.
Dai, Z., Exarchakis, G., and Lücke, J., What Are the Invariant Occlusive Components of Image Patches? A Probabilistic Generative Approach, Adv. in Neural Inf. Proc. Sys. (NIPS), vol. 26. 2013.
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We study optimal image encoding based on a generative approach with non-linear feature combinations and explicit position encoding. By far most approaches to unsupervised learning of visual features, such as sparse coding or ICA, account for translations by representing the same features at different positions. Some earlier models used a separate encoding of features and their positions to facil- itate invariant data encoding and recognition. All probabilistic generative mod- els with explicit position encoding have so far assumed a linear superposition of components to encode image patches. Here, we for the first time apply a model with non-linear feature superposition and explicit position encoding for patches. By avoiding linear superpositions, the studied model represents a closer match to component occlusions which are ubiquitous in natural images. In order to account for occlusions, the non-linear model encodes patches qualitatively very different from linear models by using component representations separated into mask and feature parameters. We first investigated encodings learned by the model using ar- tificial data with mutually occluding components. We find that the model extracts the components, and that it can correctly identify the occlusive components with the hidden variables of the model. On natural image patches, the model learns component masks and features for typical image components. By using reverse correlation, we estimate the receptive fields associated with the model’s hidden units. We find many Gabor-like or globular receptive fields as well as fields sen- sitive to more complex structures. Our results show that probabilistic models that capture occlusions and invariances can be trained efficiently on image patches, and that the resulting encoding represents an alternative model for the neural encoding of images in the primary visual cortex.
Kisos, H., Pukaß, K., Ben-Hur, T., Richter-Landsberg, C., and Sharon, R., Increased neuronal alpha-synuclein pathology associates with its accumulation in oligodendrocytes in mice modeling alpha-synucleinopathies, In: PLoS one / Public Library of Science. - Lawrence, Kan, Bd. 7.2012, 10, Art. e46817, insges. 13 S. - 13. - ISSN 1932-6203, vol. 13. 2012.
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Schwarz, L., Goldbaum, O., Bergmann, M., Probst-Cousin, S., and Richter-Landsberg, C., Involvement of macroautophagy in multiple system atrophy and protein aggregate formation in oligodendrocytes, Journal of molecular neuroscience : MN, vol. 47.2012, no. 2. 2012.
Abstract
Fernández-Gamba, A., Leal, M. C., Maarouf, C. L., Richter-Landsberg, C., Wu, T., Morelli, L., Roher, A. E., and Castaño, E. M., Collapsin response mediator protein-2 phosphorylation promotes the reversible retraction of oligodendrocyte processes in response to non-lethal oxidative stress, Journal of neurochemistry : JNC ; official journal of the International Society for Neurochemistry / chief ed. A.N. Davison, vol. 121.2012, no. 6. 2012.
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Seiberlich, V., Goldbaum, O., Zhukareva, V., and Richter-Landsberg, C., The small molecule inhibitor PR-619 of deubiquitinating enzymes affects the microtubule network and causes protein aggregate formation in neural cells : implications for neurodegenerative diseases, Biochimica et biophysica acta : BBA ; international journal of biochemistry, biophysics and molecular biology, vol. 1823.2012, no. 11. 2012.
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Tulpule, K., Schmidt, M. M., Boecker, K., Goldbaum, O., Richter-Landsberg, C., and Dringen, R., Formaldehyde induces rapid glutathione export from viable oligodendroglial OLN-93 cells, Neurochemistry international : the internat. journal for the rapid publ. of critical reviews, preliminary and original research communications in neurochemistry, vol. 61.2012, no. 8. 2012.
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Richter-Landsberg, C., Recycling-Strategien der Zellen = The recycling strategies of cells, Einblicke : Forschungsmagazin der Carl-von-Ossietzky-Universität Oldenburg, vol. 27.2012, no. 56. 2012.
Abstract
Liebmann, M., Lüllau, T., Feltes, M., Poppe, B., and Boetticher, H. von, Comparision of different methods for measuring CT dose profiles with a new dosimetry phantom, In: The 13th International Radiation Protection Association (IRPA) Meeting in Glasgow, Scotland during 12-16 May 2012 has at its theme "Living with Radiation-Engaging with Society" / [Joseph C. McDonald, ed.-in-chief]. - Oxford, 2012. 2012.
Abstract
Looe, H. K., Chofor, N., Harder, D., and Poppe, B., The EPOM shift cylindrical ionization chambers : a status report, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 202-208. 2012.
Abstract
Looe, H. K., Stelljes, T. S., Harder, D., and Poppe, B., Correction of the limited spatial resolution of ionization chambers by iterative deconvolution, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 131-133. 2012.
Abstract
Chofor, N., Harder, D., and Poppe, B., Local mean photon energy determines TLD detector response in telegraphy and brachytherapy photon fields, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 222-224. 2012.
Abstract
Lüllau, T., Liebmann, M., Poppe, B., and Boetticher, H. von, Messung der Strahlbreite und der geometrischen Effizienz bei Mehrschicht-CT mit radiochemischen Filmen, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 482-483. 2012.
Abstract
Looe, H. K., Stelljes, T. S., Harder, D., and Poppe, B., The Gaussian line spread functions of single and array-type ionization chambers, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 515-519. 2012.
Abstract
Chofor, N., Harder, D., and Poppe, B., Dose pertubation factors due to secondary electron transport near the surface of a titanium implant in megavoltage radiotherapy, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 522-523. 2012.
Abstract
Poppinga, D., Schönfeld, A. A., Poppe, B., and Chofor, N., Hochauflösende Filmdosimetrie parallel zur Strahlausbreitung mittels radiochromischen EBT2-Filmen, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 533-535. 2012.
Abstract
Schönfeld, A. A., Poppinga, D., Chofor, N., Looe, H. K., and Poppe, B., Bestimmung der optimalen Scanauflösung für radiochromische EBT2- und EBT3-Filme mit einem Epson 10000-XL-Flachbettscanner, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 522-523. 2012.
Abstract
Schönfeld, A. A., Poppinga, D., Chofor, N., Looe, H. K., and Poppe, B., Vermessung der Dosiserhöhungen an dentalen Materialien ,it radiochromischen EBT-2-Filmen, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 540-541. 2012.
Abstract
Poppinga, D., Schönfeld, A. A., Chofor, N., Poppe, B., and Willborn, K. C., Dosimetrische Vermessung eines Speiseröhrenstens in Wasser mittels radiochromischer Filmdosimetrie, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 452-544. 2012.
Abstract
Liebmann, M., Poppe, B., and Boetticher, H. von, Strahlentherapy-Dosimetriesysteme in der CT-Dosimetrie : Energieabhängigkeit und Einsatzgebiete, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 557-560. 2012.
Abstract
Chofor, N., Harder, D., and Poppe, B., Non-reference condition correction factor KNR of typical radiation detectors for the dosimetry of high-energy photons, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 520-521. 2012.
Abstract
Stelljes, T. S., Alber, M., Poppe, B., and Laub, W., Vergleich des XVMC Monte Carlo Codes mit dem Eclipse AAA Algorithmus in der Dosisberechnung für RapidArc, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 592-594. 2012.
Abstract
Fischer, J., Uphoff, Y., Looe, H. K., Welzel, J., Poppe, B., and Willborn, K. C., Evaluierung der klinischen Implementierung von Goldmarkern bei Strahlentherapie des Prostatakarzinoms, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 622-624. 2012.
Abstract
Chofor, N., Oberacker, E., Harder, D., Poppe, B., and Willborn, K. C., Dose to lung during megavoltage beam radiotherapy with photon beams of different energy, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 631-633. 2012.
Abstract
Looe, H. K., Uphoff, Y., Harder, D., Poppe, B., and Willborn, K. C., Numerical deconvolution to enhance sharpness and contrast of portal images for radiotherapy patient positioning verification, Strahlentherapie und Onkologie : journal of radiation oncology, biology, physics ; official journal of the German Society of Radiation Oncology, Austrian Society of Radiation Oncology, Scientific Association of Swiss Radiation Oncology, Hungarian Society of Radiation Oncology, Working Group Radiation Oncology of the German Cancer Society, German Roentgen Society, German Society of Medical Physics, Hellenic Society of Radiation Oncology, Romanian Society of Radiation Oncology, vol. 188.2012, no. 2. 2012.
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Kareem, R. H., Liebmann, M., Chofor, N., Lüllau, T., and Poppe, B., SU-E-I-106: Description of energy dose deposition kernel for the diagnostic beam, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Chofor, N., Poppe, B., and Harder, D., SU-E-T-126: Non-reference condition correction factor KNR of typical radiation detectors for the dosimetry of high-energy photons, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Poppe, B., Looe, H. K., Heilemann, G., and Harder, D., SU-E-T-129: Rescaling of IMRT verification deviations from detector arrays into the patient, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 39.2012, 6, S. 3732, insges. 2 S. - S. 3732. - <2>. - ISSN 0094-2405. 2012.
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Poppe, B., Looe, H. K., Stelljes, T. S., and Harder, D., SU-E-T-177: Deconvolution of line dose profiles with ionization chambers : experiences with the first software implementation in Mephisto 3.0, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 39.2012, 6, S. 3743, insges. 2 S. - S. 3743. - <2>. - ISSN 0094-2405. 2012.
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Poppinga, D., Schönfeld, A. A., Chofor, N., and Poppe, B., SU-E-T-224: Dose distribution of oesophagus stents measured by EBT2 film dosimetry, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Foong, P., Looe, H. K., and Poppe, B., SU-E-T-544: Commissioning and clinical evaluation of a secondary check software for 3D conformal and IMRT treatment plans, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 39.2012, 6, S. 3830, insges. 2 S. - S. 3830. - <2>. - ISSN 0094-2405. 2012.
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Poppinga, D., Schönfeld, A. A., Poppe, B., and Chofor, N., SU-E-T-244: High spatial resolution EBT2 film dosimetry, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Looe, H. K., Stelljes, T. S., Harder, D., and Poppe, B., SU-E-T-114: Characterization of the spatial response functions of ionization chambers for photon beam dosimetry, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Poppe, B., Looe, H. K., and Harder, D., WE-G-BRB-03: On the detectability of jaw decalibrations with the DAVID system, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Harder, D., Looe, H. K., and Poppe, B., SU-E-T-174: Synopsis of the experimental and Monte Carlo calculated values of the radial EPOM shift of cylindrical ionization chambers for photon-beam dosimetry, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Stelljes, T. S., Alber, M., Poppe, B., and Laub, W., SU-E-T-490: Comparison of XVMC Monte Carlo dose calculations with eclipse AAA calculations for RapidArc plans, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Lüllau, T., Liebmann, M., Boetticher, H. von, and Poppe, B., SU-E-I-42: Measurement of x-ray beam width and geometric efficiency in MDCT using radiochromic films, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Chofor, N., Poppe, B., and Harder, D., SU-E-T-502: Dose perturbation effects near implant surfaces caused by secondary electron transport in photon-beam therapy, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 39.2012, 6, S. 3820, insges. 2 S. - S. 3820. - <2>. - ISSN 0094-2405. 2012.
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Looe, H. K., Stelljes, T. S., Harder, D., and Poppe, B., SU-E-T-113: Volume effect correction factor KV for small-field photon dosimetry with ionization chambers, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Schönfeld, A. A., Poppinga, D., Poppe, B., and Chofor, N., SU-E-T-65: Dose enhancement measurements at high-Z dental materials using radiochromic EBT-2 films, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Schönfeld, A. A., Poppinga, D., Chofor, N., and Poppe, B., SU-E-T-121: Investigating the optimal scanning resolution for radiochromic EBT-2 films using an Epson 10000XL flatbed scanner, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Liebmann, M., Poppe, B., and Boetticher, H. von, SU-E-I-107: Suitability of various radiation detectors used in radiation therapy for x-ray dosimetry in computed tomography, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 39.2012, 6, S. 3649, insges. 2 S. - S. 3649. - <2>. - ISSN 0094-2405. 2012.
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Chofor, N., Harder, D., and Poppe, B., Non-reference condition correction factor kNR of typical radiation detectors applied for the dosimetry of high-energy photon fields in radiotherapy, Zeitschrift für medizinische Physik : Zeitschrift der DGMP; ÖGMP und SGSMP / Hrsg.: Deutsche Gesellschaft für Medizinische Physik; Österreichische Gesellschaft für Medizinische Physik; Schweizerische Gesellschaft für Strahlenbiologie und Medizinische Physik, vol. 22.2012, no. 3. 2012.
Abstract
Chofor, N., Fischer, J., Danpullo, M. S., Looe, H. K., Rühmann, A., Willborn, K. C., Harder, D., and Poppe, B., Implications of source aging on radiation quality and dose distribution around an electronic brachytherapy source : [poster], In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 554-556. 2012.
Abstract
Poppe, B., Rühmann, A., Kollhoff, R., Chofor, N., Looe, H. K., Bauer, S., Kunth, W., Ritter, H., Böhne, P., and Wilde, R. L. de, Einführung der Xoft Electronic Brachytherapy als intraoperativer Boost beim Mamma-Karzinom, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 104-107. 2012.
Abstract
Poppinga, D., Schönfeld, A. A., Chofor, N., and Poppe, B., Eigenschaften des radiochromischen EBT3 Films, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 131-133. 2012.
Abstract
Chofor, N., Harder, D., and Poppe, B., EP-1326 Photon beam quality correction factors under non-reference conditions, In: Radiotherapy & oncology : journal of the European Society for Therapeutic Radiology and Oncology. - Amsterdam, Bd. 103.2012, Suppl. 1, S. S503-S504. - S. 503-504. - ISSN 0167-8140. 2012.
Abstract
Poppinga, D., Schönfeld, A. A., Chofor, N., Looe, H. K., Willborn, K. C., and Poppe, B., Eine innovative Messmethode der radiochromischen Filmdosimetrie zur Messung von dosiseffekten an Grenzflächen : eine Vorstudie, Strahlentherapie und Onkologie : journal of radiation oncology, biology, physics ; official journal of the German Society of Radiation Oncology, Austrian Society of Radiation Oncology, Scientific Association of Swiss Radiation Oncology, Hungarian Society of Radiation Oncology, Hellenic Society of Radiation Oncology, Romanian Society of Radiation Oncology, Slovak Society of Radiation Oncology, vol. 188.2012. 2012.
Abstract
Poppinga, D., Schönfeld, A. A., Chofor, N., Looe, H. K., Oberacker, E., Poppe, B., and Willborn, K. C., Dosiserhöhungen an Zahnimplantaten : eine Untersuchung verschiedener Materialien mittels EBT2 Filmdosimetrie, Strahlentherapie und Onkologie : journal of radiation oncology, biology, physics ; official journal of the German Society of Radiation Oncology, Austrian Society of Radiation Oncology, Scientific Association of Swiss Radiation Oncology, Hungarian Society of Radiation Oncology, Hellenic Society of Radiation Oncology, Romanian Society of Radiation Oncology, Slovak Society of Radiation Oncology, vol. 188.2012. 2012.
Abstract
Uphoff, Y., Looe, H. K., Thomas, A., Poppe, B., and Willborn, K. C., IGRT-Technik in der Prostatabestrahlung : Evaluierung verschiedener Goldmarker, Strahlentherapie und Onkologie : journal of radiation oncology, biology, physics ; official journal of the German Society of Radiation Oncology, Austrian Society of Radiation Oncology, Scientific Association of Swiss Radiation Oncology, Hungarian Society of Radiation Oncology, Hellenic Society of Radiation Oncology, Romanian Society of Radiation Oncology, Slovak Society of Radiation Oncology, vol. 188.2012. 2012.
Abstract
Schönfeld, A. A., Poppinga, D., Chofor, N., Looe, H. K., Willborn, K. C., and Poppe, B., Bestimmung der optimalen Scanauflösung für radiochromische EBT-Filme mit einem Epson 10000XL-Flachbettscanner, Strahlentherapie und Onkologie : journal of radiation oncology, biology, physics ; official journal of the German Society of Radiation Oncology, Austrian Society of Radiation Oncology, Scientific Association of Swiss Radiation Oncology, Hungarian Society of Radiation Oncology, Hellenic Society of Radiation Oncology, Romanian Society of Radiation Oncology, Slovak Society of Radiation Oncology, vol. 188.2012. 2012.
Abstract
Witt, E., Witt, F., Trautwein, N., Fenske, D., Neumann, J., Bochert, H., Parisi, J., and Kolny-Olesiak, J., Synthesis of lead chalcogenide nanocrystals and study of charge transfer in blends of PbSe nanocrystals and poly(3-hexylthiophene), Physical chemistry, chemical physics : PCCP ; a journal of European Chemical Societies, vol. 14.2012, no. 33. 2012.
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Knecht, R., Parisi, J., Riedel, I., Schäffler, R., and Dimmler, B., Investigation of Cu(In,Ga)Se2 solar cell performance deviations in nominally equal absorbers, In: Japanese journal of applied physics / publ. with the coop. of the Physical Society of Japan and the Japan Society of Applied Physics. - Tokyo, Bd. 51.2012, insges. 4 S. - 4. - ISSN 0021-4922, vol. 4. 2012.
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Selishcheva, E., Parisi, J., and Kolny-Olesiak, J., Copper-assisted shape control in colloidal synthesis of indium oxide nanoparticles, Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology, vol. 14.2012, no. 4. 2012.
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Wilken, S., Hoffmann, T., Hauff, E. von, Borchert, H., and Parisi, J., ITO-free inverted polymer/fullerene solar cells : interface effects and comparison of different semi-transparent front contacts, Solar energy materials & solar cells : an international journal devoted to photovoltaic, photothermal, and photochemical solar energy conversion, vol. 96.2012. 2012.
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Tunc, A. V., De Sio, A., Riedel, D., Deschler, F., Como, E. D., Parisi, J., and Hauff, E. von, Molecular doping of low-bandgap-polymer.fullerene solar cells : effects on transport and solar cells, Organic electronics : materials, physics, chemistry, applications, vol. 13.2012, no. 2. 2012.
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De Sio, A., Tunc, A. V., Parisi, J., Como, E. D., and Hauff, E. von, Improving the photocurrent in low bandgap polymer : fullerene solar cells with molecular doping, In: Organic photonics V : 16 - 18 April 2012, Brussels, Belgium ; [part of SPIE Photonics Europe] / sponsored by SPIE. Barry P. Rand .., ed. - Bellingham, Wash., 2012, insges. 11 S. - 11. - ISBN 978-0-8194-9127-5, vol. 11. 2012.
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Ecker, B., Egelhaaf, H. -J., Steim, R., Parisi, J., and Hauff, E. von, Understanding S-shaped current-voltage characteristics in organic solar cells containing a TiOx interlayer with impedance spectroscopy and equivalent circuit analysis, The journal of physical chemistry / publ. weekly by the American Chemical Society. C, Nanomaterials and interfaces, vol. 116.2012, no. 31. 2012.
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Kruszynska, M., Borchert, H., Bachmatiuk, A., Rümmeli, M. H., Büchner, B., Parisi, J., and Kolny-Olesiak, J., Size and shape control of colloidal copper(I) sulfide nanorods, ACS nano, vol. 6.2012, no. 7. 2012.
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Wilken, S., Scheunemann, D., Wilkens, V., Parisi, J., and Borchert, H., Improvement of ITO-free inverted polymer-based solar cells by using colloidal zinc oxide nanocrystals as electron-selective buffer layer, Organic electronics : materials, physics, chemistry, applications, vol. 13.2012, no. 11. 2012.
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Chory, J., Synthesis and characterization of organically linked ZnO nanoparticles, Physica status solidi : pss. *A*Applications and materials science, vol. 209.2012, no. 11. 2012.
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Radychev, N., Scheunemann, D., Kruszynska, M., Frevert, K., Miranti, R., Kolny-Olesiak, J., Borchert, H., and Parisi, J., Investigation of the morphology and electrical characteristics of hybrid blends based on poly(3-hexylthiophene) and colloidal CuInS2 nanocrystals of different shapes, Organic electronics : materials, physics, chemistry, applications, vol. 13.2012, no. 12. 2012.
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Tunc, A. V., Ecker, B., Dogruyol, Z., Jüchter, S., Ugur, A. L., Erdogmus, A., San, S. E., Parisi, J., and Hauff, E. von, Influence of molecular weight on the short-channel effect in polymer-based field-effect transistors, Journal of polymer science. B, Polymer physics, vol. 50.2012, no. 2. 2012.
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De Sio, A., Chakanga, K., Sergeev, O., Maydell, K. von, Parisi, J., and Hauff, E. von, ITO-free inverted polymer solar cells with ZnO : Al cathodes and stable top anodes, Solar energy materials & solar cells : an international journal devoted to photovoltaic, photothermal, and photochemical solar energy conversion, vol. 98.2012. 2012.
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Parisi, J., Vertically oriented carbon nanostructures and their application potential for polymer-based solar cells, The journal of physical chemistry, vol. 116.2012, no. 1. 2012.
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Govor, L. V., Bauer, G. H., Lüdtke, T., Haug, R., and Parisi, J., Charge transport in one-dimensional chains of nanoparticles, Physica status solidi. Rapid research letters, vol. 6.2012, no. 1. 2012.
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Chiguvare, Z. and Parisi, J., Current conduction in poly(3-hexylthiophene) and in poly(3-hexylthiophene) doped [6,6]-phenyl C61-butyric acid methylester composite thin film devices, Zeitschrift für Naturforschung. *Section A*a journal of physical sciences, vol. 67.2012. 2012.
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Rosengauer, E., Hartwich, H., Hartmann, A. -M., Rudnicki, A., Somisetty, V. S., Avraham, K. B., and Nothwang, H. G., Egr2::Cre mediated conditional ablation of dicer disrupts histogenesis of mammalian central auditory nuclei, In: PLoS one / Public Library of Science. - Lawrence, Kan, Bd. 7.2012, 11, Art. e49503, insges. 13 S. - 13. - ISSN 1932-6203, vol. 13. 2012.
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Hartwich, H. and Nothwang, H. G., An easy and versatile 2-step protocol for targeted modification and subcloning of DNA from bacterial artificial chromosomes using noncommercial plasmids, In: BMC Research Notes / Biomed Central. - London, Bd. 5.2012, Art. 156, insges. 6 S. - 6. - ISSN 1756-0500, vol. 6. 2012.
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Hartwich, H., Somisetty, V. S., and Nothwang, H. G., A pink mouse reports the switch from red to green fluorescence upon Cre-mediated recombination, In: BMC Research Notes / Biomed Central. - London, Bd. 5.2012, Art. 296, insges. 7 S. - 7. - ISSN 1756-0500, vol. 7. 2012.
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Somisetty, V. S., Kunert, K., Rüttiger, L., Zuccotti, A., Schönig, K., Friauf, E., Knipper, M., Bartsch, D., and Nothwang, H. G., Retrocochlear function of the peripheral deafness gene Cacna1d, Human molecular genetics, vol. 21.2012. 2012.
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Kisos, H., Pukaß, K., Ben-Hur, T., Richter-Landsberg, C., and Sharon, R., Increased neuronal alpha-synuclein pathology associates with its accumulation in oligodendrocytes in mice modeling alpha-synucleinopathies, In: PLoS one / Public Library of Science. - Lawrence, Kan, Bd. 7.2012, 10, Art. e46817, insges. 13 S. - 13. - ISSN 1932-6203, vol. 13. 2012.
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Schwarz, L., Goldbaum, O., Bergmann, M., Probst-Cousin, S., and Richter-Landsberg, C., Involvement of macroautophagy in multiple system atrophy and protein aggregate formation in oligodendrocytes, Journal of molecular neuroscience : MN, vol. 47.2012, no. 2. 2012.
Abstract
Fernández-Gamba, A., Leal, M. C., Maarouf, C. L., Richter-Landsberg, C., Wu, T., Morelli, L., Roher, A. E., and Castaño, E. M., Collapsin response mediator protein-2 phosphorylation promotes the reversible retraction of oligodendrocyte processes in response to non-lethal oxidative stress, Journal of neurochemistry : JNC ; official journal of the International Society for Neurochemistry / chief ed. A.N. Davison, vol. 121.2012, no. 6. 2012.
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Seiberlich, V., Goldbaum, O., Zhukareva, V., and Richter-Landsberg, C., The small molecule inhibitor PR-619 of deubiquitinating enzymes affects the microtubule network and causes protein aggregate formation in neural cells : implications for neurodegenerative diseases, Biochimica et biophysica acta : BBA ; international journal of biochemistry, biophysics and molecular biology, vol. 1823.2012, no. 11. 2012.
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Richter-Landsberg, C., Recycling-Strategien der Zellen = The recycling strategies of cells, Einblicke : Forschungsmagazin der Carl-von-Ossietzky-Universität Oldenburg, vol. 27.2012, no. 56. 2012.
Abstract
Liebmann, M., Lüllau, T., Feltes, M., Poppe, B., and Boetticher, H. von, Comparision of different methods for measuring CT dose profiles with a new dosimetry phantom, In: The 13th International Radiation Protection Association (IRPA) Meeting in Glasgow, Scotland during 12-16 May 2012 has at its theme "Living with Radiation-Engaging with Society" / [Joseph C. McDonald, ed.-in-chief]. - Oxford, 2012. 2012.
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Looe, H. K., Chofor, N., Harder, D., and Poppe, B., The EPOM shift cylindrical ionization chambers : a status report, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 202-208. 2012.
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Looe, H. K., Stelljes, T. S., Harder, D., and Poppe, B., Correction of the limited spatial resolution of ionization chambers by iterative deconvolution, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 131-133. 2012.
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Chofor, N., Harder, D., and Poppe, B., Local mean photon energy determines TLD detector response in telegraphy and brachytherapy photon fields, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 222-224. 2012.
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Lüllau, T., Liebmann, M., Poppe, B., and Boetticher, H. von, Messung der Strahlbreite und der geometrischen Effizienz bei Mehrschicht-CT mit radiochemischen Filmen, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 482-483. 2012.
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Looe, H. K., Stelljes, T. S., Harder, D., and Poppe, B., The Gaussian line spread functions of single and array-type ionization chambers, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 515-519. 2012.
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Chofor, N., Harder, D., and Poppe, B., Dose pertubation factors due to secondary electron transport near the surface of a titanium implant in megavoltage radiotherapy, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 522-523. 2012.
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Poppinga, D., Schönfeld, A. A., Poppe, B., and Chofor, N., Hochauflösende Filmdosimetrie parallel zur Strahlausbreitung mittels radiochromischen EBT2-Filmen, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 533-535. 2012.
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Schönfeld, A. A., Poppinga, D., Chofor, N., Looe, H. K., and Poppe, B., Bestimmung der optimalen Scanauflösung für radiochromische EBT2- und EBT3-Filme mit einem Epson 10000-XL-Flachbettscanner, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 522-523. 2012.
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Schönfeld, A. A., Poppinga, D., Chofor, N., Looe, H. K., and Poppe, B., Vermessung der Dosiserhöhungen an dentalen Materialien ,it radiochromischen EBT-2-Filmen, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 540-541. 2012.
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Poppinga, D., Schönfeld, A. A., Chofor, N., Poppe, B., and Willborn, K. C., Dosimetrische Vermessung eines Speiseröhrenstens in Wasser mittels radiochromischer Filmdosimetrie, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 452-544. 2012.
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Liebmann, M., Poppe, B., and Boetticher, H. von, Strahlentherapy-Dosimetriesysteme in der CT-Dosimetrie : Energieabhängigkeit und Einsatzgebiete, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 557-560. 2012.
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Chofor, N., Harder, D., and Poppe, B., Non-reference condition correction factor KNR of typical radiation detectors for the dosimetry of high-energy photons, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 520-521. 2012.
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Stelljes, T. S., Alber, M., Poppe, B., and Laub, W., Vergleich des XVMC Monte Carlo Codes mit dem Eclipse AAA Algorithmus in der Dosisberechnung für RapidArc, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 592-594. 2012.
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Fischer, J., Uphoff, Y., Looe, H. K., Welzel, J., Poppe, B., and Willborn, K. C., Evaluierung der klinischen Implementierung von Goldmarkern bei Strahlentherapie des Prostatakarzinoms, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 622-624. 2012.
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Chofor, N., Oberacker, E., Harder, D., Poppe, B., and Willborn, K. C., Dose to lung during megavoltage beam radiotherapy with photon beams of different energy, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 631-633. 2012.
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Looe, H. K., Uphoff, Y., Harder, D., Poppe, B., and Willborn, K. C., Numerical deconvolution to enhance sharpness and contrast of portal images for radiotherapy patient positioning verification, Strahlentherapie und Onkologie : journal of radiation oncology, biology, physics ; official journal of the German Society of Radiation Oncology, Austrian Society of Radiation Oncology, Scientific Association of Swiss Radiation Oncology, Hungarian Society of Radiation Oncology, Working Group Radiation Oncology of the German Cancer Society, German Roentgen Society, German Society of Medical Physics, Hellenic Society of Radiation Oncology, Romanian Society of Radiation Oncology, vol. 188.2012, no. 2. 2012.
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Kareem, R. H., Liebmann, M., Chofor, N., Lüllau, T., and Poppe, B., SU-E-I-106: Description of energy dose deposition kernel for the diagnostic beam, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Chofor, N., Poppe, B., and Harder, D., SU-E-T-126: Non-reference condition correction factor KNR of typical radiation detectors for the dosimetry of high-energy photons, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Poppe, B., Looe, H. K., Heilemann, G., and Harder, D., SU-E-T-129: Rescaling of IMRT verification deviations from detector arrays into the patient, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 39.2012, 6, S. 3732, insges. 2 S. - S. 3732. - <2>. - ISSN 0094-2405. 2012.
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Poppe, B., Looe, H. K., Stelljes, T. S., and Harder, D., SU-E-T-177: Deconvolution of line dose profiles with ionization chambers : experiences with the first software implementation in Mephisto 3.0, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 39.2012, 6, S. 3743, insges. 2 S. - S. 3743. - <2>. - ISSN 0094-2405. 2012.
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Poppinga, D., Schönfeld, A. A., Chofor, N., and Poppe, B., SU-E-T-224: Dose distribution of oesophagus stents measured by EBT2 film dosimetry, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Foong, P., Looe, H. K., and Poppe, B., SU-E-T-544: Commissioning and clinical evaluation of a secondary check software for 3D conformal and IMRT treatment plans, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 39.2012, 6, S. 3830, insges. 2 S. - S. 3830. - <2>. - ISSN 0094-2405. 2012.
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Poppinga, D., Schönfeld, A. A., Poppe, B., and Chofor, N., SU-E-T-244: High spatial resolution EBT2 film dosimetry, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Looe, H. K., Stelljes, T. S., Harder, D., and Poppe, B., SU-E-T-114: Characterization of the spatial response functions of ionization chambers for photon beam dosimetry, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Poppe, B., Looe, H. K., and Harder, D., WE-G-BRB-03: On the detectability of jaw decalibrations with the DAVID system, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Harder, D., Looe, H. K., and Poppe, B., SU-E-T-174: Synopsis of the experimental and Monte Carlo calculated values of the radial EPOM shift of cylindrical ionization chambers for photon-beam dosimetry, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Stelljes, T. S., Alber, M., Poppe, B., and Laub, W., SU-E-T-490: Comparison of XVMC Monte Carlo dose calculations with eclipse AAA calculations for RapidArc plans, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Lüllau, T., Liebmann, M., Boetticher, H. von, and Poppe, B., SU-E-I-42: Measurement of x-ray beam width and geometric efficiency in MDCT using radiochromic films, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Chofor, N., Poppe, B., and Harder, D., SU-E-T-502: Dose perturbation effects near implant surfaces caused by secondary electron transport in photon-beam therapy, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 39.2012, 6, S. 3820, insges. 2 S. - S. 3820. - <2>. - ISSN 0094-2405. 2012.
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Looe, H. K., Stelljes, T. S., Harder, D., and Poppe, B., SU-E-T-113: Volume effect correction factor KV for small-field photon dosimetry with ionization chambers, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Schönfeld, A. A., Poppinga, D., Poppe, B., and Chofor, N., SU-E-T-65: Dose enhancement measurements at high-Z dental materials using radiochromic EBT-2 films, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Schönfeld, A. A., Poppinga, D., Chofor, N., and Poppe, B., SU-E-T-121: Investigating the optimal scanning resolution for radiochromic EBT-2 films using an Epson 10000XL flatbed scanner, Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics, vol. 39.2012, no. 6. 2012.
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Liebmann, M., Poppe, B., and Boetticher, H. von, SU-E-I-107: Suitability of various radiation detectors used in radiation therapy for x-ray dosimetry in computed tomography, In: Medical physics : the international journal of medical physics research and practice / American Association of Physicists in Medicine; American Institute of Physics. - College Park, Md, Bd. 39.2012, 6, S. 3649, insges. 2 S. - S. 3649. - <2>. - ISSN 0094-2405. 2012.
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Chofor, N., Harder, D., and Poppe, B., Non-reference condition correction factor kNR of typical radiation detectors applied for the dosimetry of high-energy photon fields in radiotherapy, Zeitschrift für medizinische Physik : Zeitschrift der DGMP; ÖGMP und SGSMP / Hrsg.: Deutsche Gesellschaft für Medizinische Physik; Österreichische Gesellschaft für Medizinische Physik; Schweizerische Gesellschaft für Strahlenbiologie und Medizinische Physik, vol. 22.2012, no. 3. 2012.
Abstract
Chofor, N., Fischer, J., Danpullo, M. S., Looe, H. K., Rühmann, A., Willborn, K. C., Harder, D., and Poppe, B., Implications of source aging on radiation quality and dose distribution around an electronic brachytherapy source : [poster], In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 554-556. 2012.
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Poppe, B., Rühmann, A., Kollhoff, R., Chofor, N., Looe, H. K., Bauer, S., Kunth, W., Ritter, H., Böhne, P., and Wilde, R. L. de, Einführung der Xoft Electronic Brachytherapy als intraoperativer Boost beim Mamma-Karzinom, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 104-107. 2012.
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Poppinga, D., Schönfeld, A. A., Chofor, N., and Poppe, B., Eigenschaften des radiochromischen EBT3 Films, In: 43. Jahrestagung der Deutschen Gesellschaft für Medizinische Physik : 26. - 29. September 2012 .. an der Friedrich-Schiller-Universität Jena ; Abstractband. - [Jena], 2012. - S. 131-133. 2012.
Abstract
Chofor, N., Harder, D., and Poppe, B., EP-1326 Photon beam quality correction factors under non-reference conditions, In: Radiotherapy & oncology : journal of the European Society for Therapeutic Radiology and Oncology. - Amsterdam, Bd. 103.2012, Suppl. 1, S. S503-S504. - S. 503-504. - ISSN 0167-8140. 2012.
Abstract
Poppinga, D., Schönfeld, A. A., Chofor, N., Looe, H. K., Willborn, K. C., and Poppe, B., Eine innovative Messmethode der radiochromischen Filmdosimetrie zur Messung von dosiseffekten an Grenzflächen : eine Vorstudie, Strahlentherapie und Onkologie : journal of radiation oncology, biology, physics ; official journal of the German Society of Radiation Oncology, Austrian Society of Radiation Oncology, Scientific Association of Swiss Radiation Oncology, Hungarian Society of Radiation Oncology, Hellenic Society of Radiation Oncology, Romanian Society of Radiation Oncology, Slovak Society of Radiation Oncology, vol. 188.2012. 2012.
Abstract
Poppinga, D., Schönfeld, A. A., Chofor, N., Looe, H. K., Oberacker, E., Poppe, B., and Willborn, K. C., Dosiserhöhungen an Zahnimplantaten : eine Untersuchung verschiedener Materialien mittels EBT2 Filmdosimetrie, Strahlentherapie und Onkologie : journal of radiation oncology, biology, physics ; official journal of the German Society of Radiation Oncology, Austrian Society of Radiation Oncology, Scientific Association of Swiss Radiation Oncology, Hungarian Society of Radiation Oncology, Hellenic Society of Radiation Oncology, Romanian Society of Radiation Oncology, Slovak Society of Radiation Oncology, vol. 188.2012. 2012.
Abstract
Uphoff, Y., Looe, H. K., Thomas, A., Poppe, B., and Willborn, K. C., IGRT-Technik in der Prostatabestrahlung : Evaluierung verschiedener Goldmarker, Strahlentherapie und Onkologie : journal of radiation oncology, biology, physics ; official journal of the German Society of Radiation Oncology, Austrian Society of Radiation Oncology, Scientific Association of Swiss Radiation Oncology, Hungarian Society of Radiation Oncology, Hellenic Society of Radiation Oncology, Romanian Society of Radiation Oncology, Slovak Society of Radiation Oncology, vol. 188.2012. 2012.
Abstract
Schönfeld, A. A., Poppinga, D., Chofor, N., Looe, H. K., Willborn, K. C., and Poppe, B., Bestimmung der optimalen Scanauflösung für radiochromische EBT-Filme mit einem Epson 10000XL-Flachbettscanner, Strahlentherapie und Onkologie : journal of radiation oncology, biology, physics ; official journal of the German Society of Radiation Oncology, Austrian Society of Radiation Oncology, Scientific Association of Swiss Radiation Oncology, Hungarian Society of Radiation Oncology, Hellenic Society of Radiation Oncology, Romanian Society of Radiation Oncology, Slovak Society of Radiation Oncology, vol. 188.2012. 2012.
Abstract
Witt, E., Witt, F., Trautwein, N., Fenske, D., Neumann, J., Bochert, H., Parisi, J., and Kolny-Olesiak, J., Synthesis of lead chalcogenide nanocrystals and study of charge transfer in blends of PbSe nanocrystals and poly(3-hexylthiophene), Physical chemistry, chemical physics : PCCP ; a journal of European Chemical Societies, vol. 14.2012, no. 33. 2012.
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Knecht, R., Parisi, J., Riedel, I., Schäffler, R., and Dimmler, B., Investigation of Cu(In,Ga)Se2 solar cell performance deviations in nominally equal absorbers, In: Japanese journal of applied physics / publ. with the coop. of the Physical Society of Japan and the Japan Society of Applied Physics. - Tokyo, Bd. 51.2012, insges. 4 S. - 4. - ISSN 0021-4922, vol. 4. 2012.
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Selishcheva, E., Parisi, J., and Kolny-Olesiak, J., Copper-assisted shape control in colloidal synthesis of indium oxide nanoparticles, Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology, vol. 14.2012, no. 4. 2012.
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Wilken, S., Hoffmann, T., Hauff, E. von, Borchert, H., and Parisi, J., ITO-free inverted polymer/fullerene solar cells : interface effects and comparison of different semi-transparent front contacts, Solar energy materials & solar cells : an international journal devoted to photovoltaic, photothermal, and photochemical solar energy conversion, vol. 96.2012. 2012.
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Tunc, A. V., De Sio, A., Riedel, D., Deschler, F., Como, E. D., Parisi, J., and Hauff, E. von, Molecular doping of low-bandgap-polymer.fullerene solar cells : effects on transport and solar cells, Organic electronics : materials, physics, chemistry, applications, vol. 13.2012, no. 2. 2012.
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De Sio, A., Tunc, A. V., Parisi, J., Como, E. D., and Hauff, E. von, Improving the photocurrent in low bandgap polymer : fullerene solar cells with molecular doping, In: Organic photonics V : 16 - 18 April 2012, Brussels, Belgium ; [part of SPIE Photonics Europe] / sponsored by SPIE. Barry P. Rand .., ed. - Bellingham, Wash., 2012, insges. 11 S. - 11. - ISBN 978-0-8194-9127-5, vol. 11. 2012.
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Ecker, B., Egelhaaf, H. -J., Steim, R., Parisi, J., and Hauff, E. von, Understanding S-shaped current-voltage characteristics in organic solar cells containing a TiOx interlayer with impedance spectroscopy and equivalent circuit analysis, The journal of physical chemistry / publ. weekly by the American Chemical Society. C, Nanomaterials and interfaces, vol. 116.2012, no. 31. 2012.
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Kruszynska, M., Borchert, H., Bachmatiuk, A., Rümmeli, M. H., Büchner, B., Parisi, J., and Kolny-Olesiak, J., Size and shape control of colloidal copper(I) sulfide nanorods, ACS nano, vol. 6.2012, no. 7. 2012.
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Wilken, S., Scheunemann, D., Wilkens, V., Parisi, J., and Borchert, H., Improvement of ITO-free inverted polymer-based solar cells by using colloidal zinc oxide nanocrystals as electron-selective buffer layer, Organic electronics : materials, physics, chemistry, applications, vol. 13.2012, no. 11. 2012.
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Chory, J., Synthesis and characterization of organically linked ZnO nanoparticles, Physica status solidi : pss. *A*Applications and materials science, vol. 209.2012, no. 11. 2012.
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Radychev, N., Scheunemann, D., Kruszynska, M., Frevert, K., Miranti, R., Kolny-Olesiak, J., Borchert, H., and Parisi, J., Investigation of the morphology and electrical characteristics of hybrid blends based on poly(3-hexylthiophene) and colloidal CuInS2 nanocrystals of different shapes, Organic electronics : materials, physics, chemistry, applications, vol. 13.2012, no. 12. 2012.
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Tunc, A. V., Ecker, B., Dogruyol, Z., Jüchter, S., Ugur, A. L., Erdogmus, A., San, S. E., Parisi, J., and Hauff, E. von, Influence of molecular weight on the short-channel effect in polymer-based field-effect transistors, Journal of polymer science. B, Polymer physics, vol. 50.2012, no. 2. 2012.
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De Sio, A., Chakanga, K., Sergeev, O., Maydell, K. von, Parisi, J., and Hauff, E. von, ITO-free inverted polymer solar cells with ZnO : Al cathodes and stable top anodes, Solar energy materials & solar cells : an international journal devoted to photovoltaic, photothermal, and photochemical solar energy conversion, vol. 98.2012. 2012.
AbstractFull Text
Parisi, J., Vertically oriented carbon nanostructures and their application potential for polymer-based solar cells, The journal of physical chemistry, vol. 116.2012, no. 1. 2012.
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Govor, L. V., Bauer, G. H., Lüdtke, T., Haug, R., and Parisi, J., Charge transport in one-dimensional chains of nanoparticles, Physica status solidi. Rapid research letters, vol. 6.2012, no. 1. 2012.
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Chiguvare, Z. and Parisi, J., Current conduction in poly(3-hexylthiophene) and in poly(3-hexylthiophene) doped [6,6]-phenyl C61-butyric acid methylester composite thin film devices, Zeitschrift für Naturforschung. *Section A*a journal of physical sciences, vol. 67.2012. 2012.
AbstractFull Text
Rosengauer, E., Hartwich, H., Hartmann, A. -M., Rudnicki, A., Somisetty, V. S., Avraham, K. B., and Nothwang, H. G., Egr2::Cre mediated conditional ablation of dicer disrupts histogenesis of mammalian central auditory nuclei, In: PLoS one / Public Library of Science. - Lawrence, Kan, Bd. 7.2012, 11, Art. e49503, insges. 13 S. - 13. - ISSN 1932-6203, vol. 13. 2012.
Abstract DOIFull Text
Hartwich, H. and Nothwang, H. G., An easy and versatile 2-step protocol for targeted modification and subcloning of DNA from bacterial artificial chromosomes using noncommercial plasmids, In: BMC Research Notes / Biomed Central. - London, Bd. 5.2012, Art. 156, insges. 6 S. - 6. - ISSN 1756-0500, vol. 6. 2012.
AbstractFull Text
Hartwich, H., Somisetty, V. S., and Nothwang, H. G., A pink mouse reports the switch from red to green fluorescence upon Cre-mediated recombination, In: BMC Research Notes / Biomed Central. - London, Bd. 5.2012, Art. 296, insges. 7 S. - 7. - ISSN 1756-0500, vol. 7. 2012.
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Somisetty, V. S., Kunert, K., Rüttiger, L., Zuccotti, A., Schönig, K., Friauf, E., Knipper, M., Bartsch, D., and Nothwang, H. G., Retrocochlear function of the peripheral deafness gene Cacna1d, Human molecular genetics, vol. 21.2012. 2012.
AbstractFull Text
Mauermann, M., Fast method for online registration of single source DPOAE input/output-functions : [abstract], Abstracts of the .. midwinter research meeting / Association for Research in Otolaryngology, vol. 35.2012. 2012.
Abstract
Kretschmer, F., Ahlers, M. T., Ammermüller, J., and Kretzberg, J., Automated measurement of spectral sensitivity of motion vision during optokinetic behavior, Neurocomputing : an international journal, vol. 84.2012, no. 1. 2012.
AbstractFull Text
Braun, N., Sölle, A., Hildebrandt, H., Kranczioch, C., and Debener, S., Sustained top-down control after biofeedback-based self alert training : [poster abstract], In: Zeitschrift für Neuropsychologie : ZNP ; zugleich Organ der Gesellschaft für Neuropsychologie ; mit Mitteilungen der Deutschen Gesellschaft für Neurotraumatologie und Klinische Neuropsychologie. - Bern ; Göttingen [u.a.], 23.2012, 3. - S. 179. - ISSN 1016-264X. 2012.
Abstract
Köppl, C., Auditory neuroscience : how to encode microsecond differences, In: Current biology : CB. - Cambridge, Mass., Bd. 22.2012, 2, S. R56 - R58. - 3. - ISSN 0960-9822, vol. 3. 2012.
AbstractFull Text
Corfield, J. R., Kubke, F., Parsons, S., and Köppl, C., Inner-ear morphology of the New Zealand Kiwi (Apteryx mantelli) suggests high-frequency specialization, Journal of the Association for Research in Otolaryngology : JARO, vol. 13.2012, no. 5. 2012.
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Schmidt, K., Brand, T., and Kollmeier, B., Adaptive Bestimmung der Frequenzgewichtung für die Sprachverständlichkeitsvorhersage mit dem Speech-Intelligibility-Index, In: 15. Jahrestagung / Deutsche Gesellschaft für Audiologie : Erlangen, 7. -10. März 2012 ; Tagungs-CD / In Zusammenarbeit mit der Arbeitsgemeinschaft Deutschsprachiger Audiologen und Neurootologen (ADANO), dem Universitätsklinikum Erlangen .. - Oldenburg, 2012, insges. 5 S. - 5. - ISBN 978-3-9813141-2-0, vol. 5. 2012.
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Uslar, V. N., Brand, T., and Kollmeier, B., Über den Zusammenhang zwischen linguistischer Komplexität, Hörsituation und kognitiven Fähigkeiten bei Sprachverständlichkeitstests, In: 15. Jahrestagung / Deutsche Gesellschaft für Audiologie : Erlangen, 7. -10. März 2012 ; Tagungs-CD / In Zusammenarbeit mit der Arbeitsgemeinschaft Deutschsprachiger Audiologen und Neurootologen (ADANO), dem Universitätsklinikum Erlangen .. - Oldenburg, 2012, insges. 5 S. - 5. - ISBN 978-3-9813141-2-0, vol. 5. 2012.
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Zokoll, M. A., Hochmuth, S., Fidan, D., Wagener, K. C., Ergenc, I., and Kollmeier, B., Speech intelligibility tests for the Turkish language, In: 15. Jahrestagung / Deutsche Gesellschaft für Audiologie : Erlangen, 7. -10. März 2012 ; Tagungs-CD / In Zusammenarbeit mit der Arbeitsgemeinschaft Deutschsprachiger Audiologen und Neurootologen (ADANO), dem Universitätsklinikum Erlangen .. - Oldenburg, 2012, insges. 5 S. - 5. - ISBN 978-3-9813141-2-0, vol. 5. 2012.
Abstract
Meyer, B. T., Spille, C., Kollmeier, B., and Morgan, N., Hooking up spectro-temporal filters with auditory-inspired representations for robust automatic speech recognition, In: Proceedings of the 13th Annual Conference of the International Speech Communication Association ; Interspeech 2012, Spoken Language Processing and Biomedicine : September 9-13, 2012, Portland, Oregon. - ISCA, 2012, paper identifier: TueP5c.08, insges. 4 S. - 4, vol. 4. 2012.
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Bisitz, T., Madhu, N., Spriet, A., Wouters, J., Moonen, M., Kollmeier, B., and Hohmann, V., Relation between different measures of feedback in hearing aids and gain measures derived from percentile analysis, Acta acustica united with Acustica : the journal of the European Acoustics Association (EAA) ; international journal on acoustics, vol. 98.2012, no. 4. 2012.
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Schädler, M. R., Meyer, B. T., and Kollmeier, B., Spectro-temporal modulation subspace-spanning filter bank features for robust automatic speech recognition, The journal of the Acoustical Society of America : JASA / American Institute of Physics, vol. 131.2012, no. 5. 2012.
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Hochmuth, S., Brand, T., Zokoll, M. A., Zenker Castro, F., Wardenga, N., and Kollmeier, B., A Spanish matrix sentence test for assessing speech reception thresholds in noise, International journal of audiology : the official journal of owner societies, The British Society of Audiology, The International Society of Audiology, the Nordic Audiological Society, vol. 51.2012, no. 7. 2012.
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Huster, R. J., Debener, S., Eichele, T., and Herrmann, C. S., Methods for simultaneous EEG-fMRI : an introductory review, The journal of neuroscience : the official journal of the Society for Neuroscience, vol. 32.2012, no. 18. 2012.
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Neuling, T., Rach, S., Wagner, S., Wolters, C. H., and Herrmann, C. S., Good vibrations : oscillatory phase shapes perception, NeuroImage, vol. 63.2012, no. 2. 2012.
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Neuling, T., Wagner, S., Wolters, C. H., Zaehle, T., and Herrmann, C. S., Finite-element model predicts current density distribution for clinical applications of tDCS and tACS, In: Frontiers in psychiatry / Frontiers Research Foundation. - Lausanne, Bd. 3.2012, Art.-Nr. 83, insges. 10 S. - 10. - ISSN 1664-0640, vol. 10. 2012.
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Neuling, T., Rach, S., and Herrmann, C. S., Oscillatory phase shapes auditory perception : [abstract], In: Journal of cognitive neuroscience / publ. with the Cognitive Neuroscience Institute. - Cambridge, Mass, Bd.24.2012, Suppl., S. 27-28. - 2. - ISSN 1530-8898, vol. 2. 2012.
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Enriquez Geppert, S., Huster, R. J., Scharfenort, R., Mokom, Z. N., Zimmermann, J., and Herrmann, C. S., Modulation of frontal-midline theta by neurofeedback : [abstract], In: New directions in brain training : effectiveness, methodology, and application of cognitive interventions ; workshop, October 11-13 2012, Humboldt University, Berlin ; program and abstracts / Humboldt-Universität .. Organization .. Torsten Schubert .. - Berlin [u.a.], 2012. - S. 23. 2012.
Abstract
Enriquez Geppert, S., Huster, R. J., and Herrmann, C. S., Modulation von EEG-Frequenzbändern durch Neurofeedback : fm-Theta und exekutive Funktionsleistungen, In: Psychologie und Gehirn 2012 : 38. gemeinsame Jahrestagung der Deutschen Gesellschaft für Psychophysiologie und ihre Anwendung (DGPA) und der Fachgruppe Biologische Psychologie und Neuropsychologie der Deutschen Gesellschaft für Psychologie (DGPs), 8. - 10. Juni 2012, Friedrich-Schiller-Universität Jena ; Tagungsband / Wolfgang H. R. Miltner .. - Jena, 2012. - S. 159-160. 2012.
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Herrmann, C. S., Neuling, T., Rach, S., and Strüber, D., Modulation of EEG oscillations via transcranial alternating current stimulation, In: Biomedizinische Technik / Deutsche Gesellschaft für Biomedizinische Technik; Österreichische Gesellschaft für Biomedizinische Technik; Schweizerische Gesellschaft für Biomedizinische Technik. - Berlin [u.a.], Bd. 57.2012, Suppl. 1, S. 318. - 1. - ISSN 0013-5585, vol. 1. 2012.
Strüber, D., Rach, S., Trautmann-Lengsfeld, S. A., Engel, A. K., and Herrmann, C. S., Transcranial alternating current stimulation modulates the perception of bistable apparent motion, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 85.2012, no. 3. 2012.
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Trautmann, S. A., Strüber, D., Rach, S., Engel, A. K., and Herrmann, C. S., Transcranial alternating current stimulation of 40Hz influences bistable motion perception by interhemispheric functional decoupling, In: ASSC 16 : 2nd - 6th July 2012, Brighton, UK : conference handbook / Association for the Scientific Study of Consciousness, hosted by the Sackler Centre for Consciousness Science. - Brighton, 2012. - S. 162-163. 2012.
Ford, J. M., Dierks, T., Fisher, D. J., Herrmann, C. S., Hubl, D., Kindler, J., König, T., Mathalon, D. H., Spencer, K. M., and Strik, W., Neurophysiological studies of auditory verbal hallucinations, Schizophrenia bulletin / MPRC, Maryland Psychiatric Research Center, vol. 38.2012, no. 4. 2012.
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Wagner, S., Rampersad, S., Aydin, Ü., Vorwerk, J., Neuling, T., Herrmann, C. S., Stegeman, D., and Wolter, C. H., Volume conduction effects in tDCS using a 1mm geometry-adapted hexahedral finite element head model, In: Biomedizinische Technik / Deutsche Gesellschaft für Biomedizinische Technik; Österreichische Gesellschaft für Biomedizinische Technik; Schweizerische Gesellschaft für Biomedizinische Technik. - Berlin [u.a.], Bd. 57.2012, Suppl. 1, S. 329. - 1. - ISSN 0013-5585, vol. 1. 2012.
Abstract
Koch, K. -W., Biophysical investigation of retinal calcium sensor function, Biochimica et biophysica acta, vol. 1820, no. 8. Aug.-2012.
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Fries, R., Scholten, A., Säftel, W., and Koch, K. -W., Operation profile of zebrafish guanylate cyclase-activating protein 3, Journal of neurochemistry, vol. 121, no. 1. Apr.-2012.
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Dell'Orco, D., Sulmann, S., Linse, S., and Koch, K. -W., Dynamics of conformational Ca2+-switches in signaling networks detected by a planar plasmonic device, Analytical chemistry, vol. 84, no. 6. Mar.-2012.
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Wache, N., Schröder, C., Koch, K. -W., and Christoffers, J., Diaminoterephthalate turn-on fluorescence probes for thiols--tagging of recoverin and tracking of its conformational change, Chembiochem : a European journal of chemical biology, vol. 13, no. 7. May-2012.
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Karbasi, S., Mirr, C. R., Yarandi, P. G., Frazier, R. J., Koch, K. -W., and Mafi, A., Observation of transverse Anderson localization in an optical fiber, Optics letters, vol. 37, no. 12. Jun.-2012.
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Karbasi, S., Mirr, C. R., Frazier, R. J., Yarandi, P. G., Koch, K. -W., and Mafi, A., Detailed investigation of the impact of the fiber design parameters on the transverse Anderson localization of light in disordered optical fibers, Optics express, vol. 20, no. 17. Aug.-2012.
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Kollmann, H., Becker, S. F., Shirdel, J., Scholten, A., Ostendorp, A., Lienau, C., and Koch, K. -W., Probing the Ca(2+) switch of the neuronal Ca(2+) sensor GCAP2 by time-resolved fluorescence spectroscopy, ACS chemical biology, vol. 7, no. 6. Jun.-2012.
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Duda, T., Pertzev, A., Koch, K. -W., and Sharma, R. K., Antithetical modes of and the Ca(2+) sensors targeting in ANF-RGC and ROS-GC1 membrane guanylate cyclases, Frontiers in molecular neuroscience, vol. 5. 2012.
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Kreutz, M. R., Naranjo, J. R., Koch, K. -W., and Schwaller, B., The Neuronal Functions of EF-Hand Ca2+-Binding Proteins, Frontiers in molecular neuroscience, vol. 5. 2012.
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Grigoriev, I. I., Senin, I. I., Tikhomirova, N. K., Komolov, K. E., Permyakov, S. E., Zernii, E. Y., Koch, K. -W., and Philippov, P. P., Synergetic effect of recoverin and calmodulin on regulation of rhodopsin kinase, Frontiers in molecular neuroscience, vol. 5. 2012.
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Landgraf, I., Mühlhans, J., Dedek, K., Reim, K., Brandstätter, J. H., and Ammermüller, J., The absence of Complexin 3 and Complexin 4 differentially impacts the ON and OFF pathways in mouse retina, European Journal of Neuroscience, vol. 36, no. 4. Wiley-Blackwell, pp. 2470-2481, 14-Jun.-2012.
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Hilgen, G., Huebner, A. K., Tanimoto, N., Sothilingam, V., Seide, C., Garrido, M. G., Schmidt, K. -F., Seeliger, M. W., Löwel, S., Weiler, R., Hübner, C. A., and Dedek, K., Lack of the Sodium-Driven Chloride Bicarbonate Exchanger NCBE Impairs Visual Function in the Mouse Retina, PLoS ONE, vol. 7, no. 10. Public Library of Science (PLoS), p. e46155, 9-Oct.-2012.
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Kloeckener-Gruissem, B., Neidhardt, J., Magyar, I., Plauchu, H., Zech, J. -C., Morlé, L., Palmer-Smith, S. M., MacDonald, M. J., Nas, V., Fry, A. E., and Berger, W., Novel VCAN mutations and evidence for unbalanced alternative splicing in the pathogenesis of Wagner syndrome, European Journal of Human Genetics, vol. 21, no. 3. Nature Publishing Group, pp. 352-356, 27-Jun.-2012.
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Keil, C., Müntze, F., Schiek, M., Lützen, A., and Schlettwein, D., Influence of an Applied Electric Field on the Conduction Characteristics of a Bithienyl-Capped Biphenylene and Biphenyl-Capped Oligothiophenes in Organic Field-Effect Transistor Structures, MRS Proceedings, vol. 1402. Cambridge University Press (CUP), Jan.-2012.
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Becker, K., Jährling, N., Saghafi, S., Weiler, R., and Dodt, H. -U., Chemical Clearing and Dehydration of GFP Expressing Mouse Brains, PLoS ONE, vol. 7, no. 3. Public Library of Science (PLoS), p. e33916, 30-Mar.-2012.
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Manley, G. A., Evolutionary paths to mammalian cochleae, Journal of the Association for Research in Otolaryngology : JARO, vol. 13, no. 6. pp. 733-743, Dec.-2012.
Abstract DOI
Evolution of the cochlea and high-frequency hearing (>20 kHz; ultrasonic to humans) in mammals has been a subject of research for many years. Recent advances in paleontological techniques, especially the use of micro-CT scans, now provide important new insights that are here reviewed. True mammals arose more than 200 million years (Ma) ago. Of these, three lineages survived into recent geological times. These animals uniquely developed three middle ear ossicles, but these ossicles were not initially freely suspended as in modern mammals. The earliest mammalian cochleae were only about 2 mm long and contained a lagena macula. In the multituberculate and monotreme mammalian lineages, the cochlea remained relatively short and did not coil, even in modern representatives. In the lineage leading to modern therians (placental and marsupial mammals), cochlear coiling did develop, but only after a period of at least 60 Ma. Even Late Jurassic mammals show only a 270 ° cochlear coil and a cochlear canal length of merely 3 mm. Comparisons of modern organisms, mammalian ancestors, and the state of the middle ear strongly suggest that high-frequency hearing (>20 kHz) was not realized until the early Cretaceous (~125 Ma). At that time, therian mammals arose and possessed a fully coiled cochlea. The evolution of modern features of the middle ear and cochlea in the many later lineages of therians was, however, a mosaic and different features arose at different times. In parallel with cochlear structural evolution, prestins in therian mammals evolved into effective components of a new motor system. Ultrasonic hearing developed quite late-the earliest bat cochleae (~60 Ma) did not show features characteristic of those of modern bats that are sensitive to high ultrasonic frequencies
Becker, K., Jährling, N., Saghafi, S., Weiler, R., and Dodt, H. -U., Correction: Chemical Clearing and Dehydration of GFP Expressing Mouse Brains, PLoS ONE, vol. 7, no. 8. Public Library of Science (PLoS), 7-Aug.-2012.
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Sonntag, S., Dedek, K., Dorgau, B., Schultz, K., Schmidt, K. -F., Cimiotti, K., Weiler, R., Lowel, S., Willecke, K., and Janssen-Bienhold, U., Ablation of Retinal Horizontal Cells from Adult Mice Leads to Rod Degeneration and Remodeling in the Outer Retina, Journal of Neuroscience, vol. 32, no. 31. Society for Neuroscience, pp. 10713-10724, 1-Aug.-2012.
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Rimmele, J., Schröger, E., and Bendixen, A., Age-related changes in the use of regular patterns for auditory scene analysis, Hearing research, vol. 289, no. 1-2. pp. 98-107, Jul.-2012.
Abstract DOI
A recent approach to auditory processing suggests a close relationship of regularity processing in auditory sensory memory (ASM) and stream segregation, such that within-stream regularities can be used to stabilize stream segregation. The present study investigates age-related changes in how regular patterns are used for auditory scene analysis (ASA), when the stream containing the regularity is attended or unattended. In order to accomplish an intensity level deviant detection task, participants had to segregate the task-relevant pure tone sequence from an irrelevant distractor pure tone sequence, which randomly varied in level. In three conditions a simple spectro-temporal regularity ("Isochronous"), a more complex spectro-temporal regularity ("Rhythmic"), or no regularity ("Random") was embedded in either the attended target sequence (Experiment 1), or the unattended distractor sequence (Experiment 2). When the sequence containing the regularity was attended, older participants showed a similar increase of performance to younger adults in the conditions with regular patterns ("Isochronous" and "Rhythmic") compared to the "Random" condition. In contrast, when the sequence containing the regularity was unattended, older adults showed a specific performance decline compared to younger adults in the "Isochronous" condition. Results suggest a link between impaired automatic processing of regularities in ASM, and age-related deficits in the use of regular patterns for ASA
Horváth, J. and Bendixen, A., Preventing distraction by probabilistic cueing, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 83, no. 3. pp. 342-347, Mar.-2012.
Abstract DOI
Involuntary attention switches triggered by infrequent, unpredictably occurring sensory events (distraction) can be prevented when participants are made aware of the forthcoming distractor. Previous studies exploring this phenomenon presented visual cues before each stimulus in an auditory oddball sequence. In one condition, cues were completely reliable in predicting the forthcoming distractor or standard sound, in another, separate condition, they were completely unreliable. These studies found that in the condition with reliable cues, distraction was reduced compared to that with unreliable cues, as signaled by decreased reaction time delay as well as reduced P3a and reorienting negativity event-related potentials. Whereas these results are generally interpreted as the results of preparatory processes initiated by the cues, it could be argued that the preventive effect is a byproduct of increased information processing load in the condition with informative cues compared to that in the condition with uninformative ones. In the present study, using 80% reliable visual cues preceding tones in an oddball sequence, it was demonstrated that distraction can be prevented when the trials with valid and invalid cues were presented within a single experimental condition, as shown by reduced reaction time delay and P3a amplitude. These results are compatible with the notion that the distraction is prevented by means of preparatory processes initiated by the cues
Weise, A., Schröger, E., and Bendixen, A., The processing of concurrent sounds based on inharmonicity and asynchronous onsets: an object-related negativity (ORN) study, Brain research, vol. 1439. pp. 73-81, Feb.-2012.
Abstract DOI
This study addresses the processing of concurrent sounds based on inharmonicity and onset asynchrony cues. We used harmonic complex sounds with one component starting marginally (40 ms) or considerably (500 ms) earlier than the complex and being slightly (3%) or strongly (13%) inharmonic. To index sound segregation of concurrent events, we measured the object-related negativity (ORN) component of the event-related potential. We contrasted two hypotheses: According to the concurrent-segregation hypothesis, increased onset asynchrony is assumed to promote segregation of the leading partial from the harmonic complex, which should be reflected in increased ORN amplitudes. That is, even with large onset asynchronies concurrent events would be processed by a simultaneous sound segregation mechanism. According to the sequential-integration hypothesis, however, with increased onset asynchrony concurrent cues are assumed to be less considered by simultaneous grouping processes, which should be reflected in attenuated ORN amplitudes for long onset asynchronies. This assumption is based on the notion that due to sequential integration, a stable percept of the leading partial has been developed within ~350 ms after sound onset, thus less processing is required from scene analysis mechanisms based on concurrent cues. Indeed, with increased onset asynchrony ORN was found to decrease, which supports the sequential-integration hypothesis. In line with previous data, ORN was also found to increase with increased inharmonicity. The absence of an inharmonicity×onset asynchrony interaction further supports the assumption that both cues are used in different ways for simultaneous sound segregation
Bendixen, A., SanMiguel, I., and Schröger, E., Early electrophysiological indicators for predictive processing in audition: a review, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 83, no. 2. pp. 120-131, Feb.-2012.
Abstract DOI
The auditory system essentially deals with sequential type of input and thus requires processing that is particularly suited to extract stimulus relations within a sequence. Evidence from a variety of paradigms converges to show that the auditory system automatically uses stimulus predictability for facilitating its sequential processing. This type of predictive processing does not require attentional processing of the sounds or cognitive control of the predictions, nor does it involve the preparation of motor responses to the auditory stimuli. We will present a taxonomy of paradigms and resulting electrophysiological indicators for such automatic predictive processing in terms of event-related potential components and oscillatory activity. These indicators will include signals of fulfilled predictions (match signals such as N1 attenuation, repetition positivity, and early evoked gamma band response enhancement) as well as signals of violated predictions (mismatch signals such as the mismatch negativity and stimulus omission responses). We will show how recent approaches have revealed particularly early indicators of predictive processing down to the level of the auditory middle-latency responses. We will discuss the strength of the various indicators in terms of a truly predictive account of auditory processing (as opposed to, e.g., a retrospective verification of predictions). Finally, we will discuss the benefits of a predictive system within and beyond auditory processing. In conclusion, we argue in favor of the overwhelming evidence for predictions in audition, flexibly instantiated on different levels and timescales, and we aim to provide guidance along a variety of research paradigms illustrating the existence of these predictions
Bendixen, A., Schröger, E., Ritter, W., and Winkler, I., Regularity extraction from non-adjacent sounds, Frontiers in psychology, vol. 3. p. 143, 2012.
Abstract DOI
The regular behavior of sound sources helps us to make sense of the auditory environment. Regular patterns may, for instance, convey information on the identity of a sound source (such as the acoustic signature of a train moving on the rails). Yet typically, this signature overlaps in time with signals emitted from other sound sources. It is generally assumed that auditory regularity extraction cannot operate upon this mixture of signals because it only finds regularities between adjacent sounds. In this view, the auditory environment would be grouped into separate entities by means of readily available acoustic cues such as separation in frequency and location. Regularity extraction processes would then operate upon the resulting groups. Our new experimental evidence challenges this view. We presented two interleaved sound sequences which overlapped in frequency range and shared all acoustic parameters. The sequences only differed in their underlying regular patterns. We inserted deviants into one of the sequences to probe whether the regularity was extracted. In the first experiment, we found that these deviants elicited the mismatch negativity (MMN) component. Thus the auditory system was able to find the regularity between the non-adjacent sounds. Regularity extraction was not influenced by sequence cohesiveness as manipulated by the relative duration of tones and silent inter-tone-intervals. In the second experiment, we showed that a regularity connecting non-adjacent sounds was discovered only when the intervening sequence also contained a regular pattern, but not when the intervening sounds were randomly varying. This suggests that separate regular patterns are available to the auditory system as a cue for identifying signals coming from distinct sound sources. Thus auditory regularity extraction is not necessarily confined to a processing stage after initial sound grouping, but may precede grouping when other acoustic cues are unavailable
Weise, A., Bendixen, A., Müller, D., and Schröger, E., Which kind of transition is important for sound representation? An event-related potential study, Brain research, vol. 1464. pp. 30-42, Jun.-2012.
Abstract DOI
Auditory transients (such as sound onset or a frequency transition within a continuous sound) are assumed to parse the auditory input into smaller units enabling the formation of unitary sound representations separately for each segment. This was discovered by using the mismatch negativity (MMN) component of the event-related potential (ERP) that taps into auditory sensory memory representations. For unstructured sounds, MMN amplitude decreased or even vanished with increasing the temporal distance of an irregular feature (deviance, e.g. duration decrement) relative to the onset of an otherwise regularly occurring sound, whereas for sounds that were segmented by a transient, MMN persisted. It has been speculated that the P1-N1-P2 complex, indexing the sensory encoding of the transient, determines the temporal units of the acoustic input that are represented by the information processing system. To test this hypothesis, we utilized a previously reported asymmetry in the sensory encoding of physically identical but time-reversed transitions between segments of constant and gliding frequency. In separate blocks, we regularly presented 1400-ms sounds with a centered constant-to-glide or glide-to-constant transition. Occasionally and unpredictably, one of the regularly occurring sounds was shortened in duration to 910 ms. We found larger transition-related P1-N1-P2 potentials accompanied by larger deviance-related MMN amplitudes for sounds with constant-to-glide transition than for sounds with glide-to-constant transition. This provides evidence that it is the precise sensory encoding of the transition which is crucial for automatically parsing the auditory input into smaller units, thus enabling the formation of unitary sound representations even for late segments
Scharinger, M., Bendixen, A., Trujillo-Barreto, N. J., and Obleser, J., A sparse neural code for some speech sounds but not for others, PloS one, vol. 7, no. 7. p. e40953, 2012.
Abstract DOI
The precise neural mechanisms underlying speech sound representations are still a matter of debate. Proponents of 'sparse representations' assume that on the level of speech sounds, only contrastive or otherwise not predictable information is stored in long-term memory. Here, in a passive oddball paradigm, we challenge the neural foundations of such a 'sparse' representation; we use words that differ only in their penultimate consonant ("coronal" [t] vs. "dorsal" [k] place of articulation) and for example distinguish between the German nouns Latz ([lats]; bib) and Lachs ([laks]; salmon). Changes from standard [t] to deviant [k] and vice versa elicited a discernible Mismatch Negativity (MMN) response. Crucially, however, the MMN for the deviant [lats] was stronger than the MMN for the deviant [laks]. Source localization showed this difference to be due to enhanced brain activity in right superior temporal cortex. These findings reflect a difference in phonological 'sparsity': Coronal [t] segments, but not dorsal [k] segments, are based on more sparse representations and elicit less specific neural predictions; sensory deviations from this prediction are more readily 'tolerated' and accordingly trigger weaker MMNs. The results foster the neurocomputational reality of 'representationally sparse' models of speech perception that are compatible with more general predictive mechanisms in auditory perception
Denham, S., Bendixen, A., Mill, R., Tóth, D., Wennekers, T., Coath, M., Bőhm, T., Szalardy, O., and Winkler, I., Characterising switching behaviour in perceptual multi-stability, Journal of neuroscience methods, vol. 210, no. 1. pp. 79-92, Sep.-2012.
Abstract DOI
When people experience an unchanging sensory input for a long period of time, their perception tends to switch stochastically and unavoidably between alternative interpretations of the sensation; a phenomenon known as perceptual bi-stability or multi-stability. The huge variability in the experimental data obtained in such paradigms makes it difficult to distinguish typical patterns of behaviour, or to identify differences between switching patterns. Here we propose a new approach to characterising switching behaviour based upon the extraction of transition matrices from the data, which provide a compact representation that is well-understood mathematically. On the basis of this representation we can characterise patterns of perceptual switching, visualise and simulate typical switching patterns, and calculate the likelihood of observing a particular switching pattern. The proposed method can support comparisons between different observers, experimental conditions and even experiments. We demonstrate the insights offered by this approach using examples from our experiments investigating multi-stability in auditory streaming. However, the methodology is generic and thus widely applicable in studies of multi-stability in any domain
Winkler, I., Denham, S., Mill, R., Bohm, T. M., and Bendixen, A., Multistability in auditory stream segregation: a predictive coding view, Philosophical transactions of the Royal Society of London. Series B, Biological sciences, vol. 367, no. 1591. pp. 1001-1012, Apr.-2012.
Abstract DOI
Auditory stream segregation involves linking temporally separate acoustic events into one or more coherent sequences. For any non-trivial sequence of sounds, many alternative descriptions can be formed, only one or very few of which emerge in awareness at any time. Evidence from studies showing bi-/multistability in auditory streaming suggest that some, perhaps many of the alternative descriptions are represented in the brain in parallel and that they continuously vie for conscious perception. Here, based on a predictive coding view, we consider the nature of these sound representations and how they compete with each other. Predictive processing helps to maintain perceptual stability by signalling the continuation of previously established patterns as well as the emergence of new sound sources. It also provides a measure of how well each of the competing representations describes the current acoustic scene. This account of auditory stream segregation has been tested on perceptual data obtained in the auditory streaming paradigm
Carroll, R. and Ruigendijk, E., The Effects of Syntactic Complexity on Processing Sentences in Noise, Journal of Psycholinguistic Research, vol. 42, no. 2. Springer Science + Business Media, pp. 139-159, 30-Mar.-2012.
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Ruigendijk, E., 1975 - Jan Koster: ‘Dutch as an SOV language’. Linguistic analysis 1, pp. 111-136, Internationale Neerlandistiek, vol. 50, no. 1. Amsterdam University Press, pp. 42-44, 1-Jan.-2012.
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Pohl, N. U., Leadbeater, E., Slabbekoorn, H., Klump, G. M., and Langemann, U., Great tits in urban noise benefit from high frequencies in song detection and discrimination, Animal Behaviour, vol. 83, no. 3. Elsevier BV, pp. 711-721, Mar.-2012.
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Mansour, A. M., Schwartz, S. G., Gregori, N. Z., Yehoshua, Z., Freund, K. B., Dellatorre, K., Aisenbrey, S., Hosseini, H., Huang, J. Y., Bodla, A. A., and Bhatti, M. T., Insight Into 8 Patients With Nonarteritic Anterior Ischemic Optic Neuropathy Following Anti-VEGF Injections, Journal of Neuro-Ophthalmology, vol. 32, no. 2. Ovid Technologies (Wolters Kluwer Health), p. 193, Jun.-2012.
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Schramm, C., Rohrbach, J. M., Reinert, S., Mau-Holzmann, U. A., Aisenbrey, S., Bartz-Schmidt, K. -U., and Besch, D., Amniotic bands as a cause of congenital anterior staphyloma, Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 251, no. 3. Springer Science + Business Media, pp. 959-965, 13-Nov.-2012.
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Bantel, C., Laycock, H., and Nagy, I., The potential use of biomarkers and new diagnostic tools in the management of acute pain, Pain Management, vol. 2, no. 3. Future Medicine Ltd, pp. 187-190, May-2012.
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CONDAT, H., HEIN, A., and STROBEL, C., 4.5.2 Model-based automatic generation and selection of safe architectures, INCOSE International Symposium, vol. 22, no. 1. Wiley-Blackwell, pp. 612-632, Jul.-2012.
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Svaldi, J., Philipsen, A., and Matthies, S., Risky decision-making in borderline personality disorder, Psychiatry Research, vol. 197, no. 1-2. Elsevier BV, pp. 112-118, May-2012.
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Svaldi, J., Dorn, C., Matthies, S., and Philipsen, A., Effects of suppression and acceptance of sadness on the urge for non-suicidal self-injury and self-punishment, Psychiatry Research, vol. 200, no. 2-3. Elsevier BV, pp. 404-416, Dec.-2012.
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Wuendrich, M. S., Nissen, C., Feige, B., Philipsen, A. S., and Voderholzer, U., Portrayal of Psychiatric Disorders: Are Simulated Patients Authentic?, Academic Psychiatry, vol. 36, no. 6. Springer Science + Business Media, p. 501, 1-Nov.-2012.
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Philipsen, A., Psychotherapy in adult attention deficit hyperactivity disorder: implications for treatment and research, Expert Review of Neurotherapeutics, vol. 12, no. 10. Informa Healthcare, pp. 1217-1225, Oct.-2012.
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Sebastian, A., Gerdes, B., Feige, B., Klöppel, S., Lange, T., Philipsen, A., Tebartz van Elst, L., Lieb, K., and Tüscher, O., Neural correlates of interference inhibition, action withholding and action cancelation in adult ADHD, Psychiatry Research: Neuroimaging, vol. 202, no. 2. Elsevier BV, pp. 132-141, May-2012.
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Wilbertz, G., Tebartz van Elst, L., Delgado, M. R., Maier, S., Feige, B., Philipsen, A., and Blechert, J., Orbitofrontal reward sensitivity and impulsivity in adult attention deficit hyperactivity disorder, NeuroImage, vol. 60, no. 1. Elsevier BV, pp. 353-361, Mar.-2012.
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Weyland, A. and Scheeren, T., Hämodynamisches Monitoring - Verbessertes Outcome durch erweitertes perioperatives hämodynamisches Monitoring, Anästhesiol Intensivmed Notfallmed Schmerzther, vol. 47, no. 02. Thieme Publishing Group, pp. 92-100, Feb.-2012.
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Brunkhorst, F. M., Oppert, M., Marx, G., Bloos, F., Ludewig, K., Putensen, C., Nierhaus, A., Jaschinski, U., Meier-Hellmann, A., Weyland, A., Gründling, M., Moerer, O., Riessen, R., Seibel, A., Ragaller, M., Büchler, M. W., John, S., Bach, F., Spies, C., Reill, L., Fritz, H., Kiehntopf, M., Kuhnt, E., Bogatsch, H., Engel, C., Loeffler, M., Kollef, M. H., Reinhart, K., and Welte, T., Effect of empirical treatment with moxifloxacin and meropenem vs meropenem on sepsis-related organ dysfunction in patients with severe sepsis: a randomized trial, JAMA, vol. 307, no. 22. pp. 2390-2399, Jun.-2012.
Abstract DOI
CONTEXT: Early appropriate antimicrobial therapy leads to lower mortality rates associated with severe sepsis. The role of empirical combination therapy comprising at least 2 antibiotics of different mechanisms remains controversial. OBJECTIVE: To compare the effect of moxifloxacin and meropenem with the effect of meropenem alone on sepsis-related organ dysfunction. DESIGN, SETTING, AND PATIENTS: A randomized, open-label, parallel-group trial of 600 patients who fulfilled criteria for severe sepsis or septic shock (n = 298 for monotherapy and n = 302 for combination therapy). The trial was performed at 44 intensive care units in Germany from October 16, 2007, to March 23, 2010. The number of evaluable patients was 273 in the monotherapy group and 278 in the combination therapy group. INTERVENTIONS: Intravenous meropenem (1 g every 8 hours) and moxifloxacin (400 mg every 24 hours) or meropenem alone. The intervention was recommended for 7 days and up to a maximum of 14 days after randomization or until discharge from the intensive care unit or death, whichever occurred first. MAIN OUTCOME MEASURE: Degree of organ failure (mean of daily total Sequential Organ Failure Assessment [SOFA] scores over 14 days; score range: 0-24 points with higher scores indicating worse organ failure); secondary outcome: 28-day and 90-day all-cause mortality. Survivors were followed up for 90 days. RESULTS: Among 551 evaluable patients, there was no statistically significant difference in mean SOFA score between the meropenem and moxifloxacin group (8.3 points; 95% CI, 7.8-8.8 points) and the meropenem alone group (7.9 points; 95% CI, 7.5-8.4 points) (P = .36). The rates for 28-day and 90-day mortality also were not statistically significantly different. By day 28, there were 66 deaths (23.9%; 95% CI, 19.0%-29.4%) in the combination therapy group compared with 59 deaths (21.9%; 95% CI, 17.1%-27.4%) in the monotherapy group (P = .58). By day 90, there were 96 deaths (35.3%; 95% CI, 29.6%-41.3%) in the combination therapy group compared with 84 deaths (32.1%; 95% CI, 26.5%-38.1%) in the monotherapy group (P = .43). CONCLUSION: Among adult patients with severe sepsis, treatment with combined meropenem and moxifloxacin compared with meropenem alone did not result in less organ failure. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00534287
Richter-Landsberg, C., Autophagie als Überlebensstrategie, Biologie in unserer Zeit, vol. 42, no. 6. Wiley-Blackwell, pp. 374-379, Dec.-2012.
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Seiberlich, V., Goldbaum, O., Zhukareva, V., and Richter-Landsberg, C., The small molecule inhibitor PR-619 of deubiquitinating enzymes affects the microtubule network and causes protein aggregate formation in neural cells: implications for neurodegenerative diseases, Biochimica et biophysica acta, vol. 1823, no. 11. pp. 2057-2068, Nov.-2012.
Abstract DOI
A pathological hallmark of many neurodegenerative diseases is the aggregation of proteins. Protein aggregate formation may be linked to a failure of the ubiquitin proteasome system (UPS) and/or the autophagy pathway. The UPS involves the ubiquitination of proteins followed by proteasomal degradation. Deubiquitination of target proteins is performed by proteases called deubiquitinating proteins (DUBs). Inhibition of DUBs may lead to the dysregulation of homeostasis and have pathological consequences. To assess the effects of DUB-inhibition, we have used the oligodendroglial cell line, OLN-t40, stably expressing the longest human tau isoform. Cells were incubated with PR-619, a broad-range, reversible inhibitor of ubiquitin isopeptidases. Incubation with PR-619 led to morphological changes, the upregulation of heat shock proteins (HSP), including HSP70 and αB-crystallin, and to protein aggregates near the MTOC, containing ubiquitin, HSPs, and the ubiquitin binding protein p62, which may provide a link between the UPS and autophagy. Thus, inhibition of DUB activity caused stress responses and the formation of protein aggregates resembling pathological inclusions observed in aggregopathies. Furthermore, PR-619 led to the stabilization of the microtubule network, possibly through the modulation of tau phosphorylation, and small tau deposits assembled near the MTOC. Hence, organization and integrity of the cytoskeleton were affected, which is particularly important for the maintenance of the cellular architecture and intracellular transport processes, and essential for the functionality and survival of neural cells. Our data demonstrate that DUB inhibitors provide a useful tool to elucidate the manifold mechanisms of DUB functions in cells and their dysregulation in neurodegenerative diseases. This article is part of a Special Issue entitled: Ubiquitin Drug Discovery and Diagnostics
Wache, N., Scholten, A., Klüner, T., Koch, K. -W., and Christoffers, J., Turning On Fluorescence with Thiols - Synthetic and Computational Studies on Diaminoterephthalates and Monitoring the Switch of the Ca 2+ Sensor Recoverin , Eur. J. Org. Chem., vol. 2012, no. 29. Wiley-Blackwell, pp. 5712-5722, 29-Aug.-2012.
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Dolležal, L. -V., Beutelmann, R., and Klump, G. M., Stream Segregation in the Perception of Sinusoidally Amplitude-Modulated Tones, PLoS ONE, vol. 7, no. 9. Public Library of Science (PLoS), p. e43615, 12-Sep.-2012.
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Brand, T., Rennies, J., Beutelmann, R., Warzybok, A., and Kollmeier, B., Modeling binaural speech intelligibility in spatial listening conditions, The Journal of the Acoustical Society of America, vol. 131, no. 4. Acoustical Society of America (ASA), pp. 3316-3316, Apr.-2012.
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Frenken, T., Brell, M., Gövercin, M., Wegel, S., and Hein, A., aTUG: technical apparatus for gait and balance analysis within component-based Timed Up & Go using mutual ambient sensors, Journal of Ambient Intelligence and Humanized Computing, vol. 4, no. 6. Springer Science + Business Media, pp. 759-778, 18-Jul.-2012.
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Gimperlein, H., Krötz, B., and Lienau, C., Analytic factorization of Lie group representations, Journal of Functional Analysis, vol. 262, no. 2. Elsevier BV, pp. 667-681, Jan.-2012.
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Park, D. J., Piglosiewicz, B., Schmidt, S., Kollmann, H., Mascheck, M., and Lienau, C., Strong Field Acceleration and Steering of Ultrafast Electron Pulses from a Sharp Metallic Nanotip, Physical Review Letters, vol. 109, no. 24. American Physical Society (APS), 11-Dec.-2012.
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Schmidt, S., Piglosiewicz, B., Sadiq, D., Shirdel, J., Lee, J. S., Vasa, P., Park, N., Kim, D. -S., and Lienau, C., Adiabatic nanofocusing on ultrasmooth single-crystalline gold tapers creates a 10-nm-sized light source with few-cycle time resolution, ACS nano, vol. 6, no. 7. pp. 6040-6048, Jul.-2012.
Abstract DOI
We demonstrate adiabatic nanofocusing of few-cycle light pulses using ultrasharp and ultrasmooth single-crystalline gold tapers. We show that the grating-induced launching of spectrally broad-band surface plasmon polariton wavepackets onto the shaft of such a taper generates isolated, point-like light spots with 10 fs duration and 10 nm diameter spatial extent at its very apex. This nanofocusing is so efficient that nanolocalized electric fields inducing strong optical nonlinearities at the tip end are reached with conventional high repetition rate laser oscillators. We use here the resulting second harmonic to fully characterize the time structure of the localized electric field in frequency-resolved interferometric autocorrelation measurements. Our results strongly suggest that these nanometer-sized ultrafast light spots will enable new experiments probing the dynamics of optical excitations of individual metallic, semiconducting, and magnetic nanostructures
Mazur, Y. I., Dorogan, V. G., Ware, M. E., Marega, E., Benamara, M., Zhuchenko, Z. Y., Tarasov, G. G., Lienau, C., and Salamo, G. J., State filling dependent luminescence in hybrid tunnel coupled dot-well structures, Nanoscale, vol. 4, no. 23. pp. 7509-7516, Dec.-2012.
Abstract DOI
A strong dependence of quantum dot (QD)-quantum well (QW) tunnel coupling on the energy band alignment is established in hybrid InAs/GaAs-In(x)Ga(1-x)As/GaAs dot-well structures by changing the QW composition to shift the QW energy through the QD wetting layer (WL) energy. Due to this coupling a rapid carrier transfer from the QW to the QD excited states takes place. As a result, the QW photoluminescence (PL) completely quenches at low excitation intensities. The threshold intensities for the appearance of the QW PL strongly depend on the relative position of the QW excitonic energy with respect to the WL ground state and the QD ground state energies. These intensities decrease by orders of magnitude as the energy of the QW increases to approach that of the WL due to the increased efficiency for carrier tunneling into the WL states as compared to the less dense QD states below the QW energy
Wollschläger, L. M. and Diederich, A., The 2N-ary Choice Tree Model for N-Alternative Preferential Choice, Front. Psychology, vol. 3. Frontiers Media SA, 2012.
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Colonius, H. and Diederich, A., Focused attention vs. crossmodal signals paradigm: deriving predictions from the time-window-of-integration model, Frontiers in integrative neuroscience, vol. 6. p. 62, 2012.
Abstract DOI
In the crossmodal signals paradigm (CSP) participants are instructed to respond to a set of stimuli from different modalities, presented more or less simultaneously, as soon as a stimulus from any modality has been detected. In the focused attention paradigm (FAP), on the other hand, responses should only be made to a stimulus from a pre-defined target modality and stimuli from non-target modalities should be ignored. Whichever paradigm is being applied, a typical result is that responses tend to be faster to crossmodal stimuli than to unimodal stimuli, a phenomenon often referred to as "crossmodal interaction." Here, we investigate predictions of the time-window-of-integration (TWIN) modeling framework previously proposed by the authors. It is shown that TWIN makes specific qualitative and quantitative predictions on how the two paradigms differ with respect to the probability of multisensory integration and the amount of response enhancement, including the effect of stimulus intensity ("inverse effectiveness"). Introducing a decision-theoretic framework for TWIN further allows comparing the two paradigms with respect to the predicted optimal time window size and its dependence on the prior probability that the crossmodal stimulus information refers to the same event. In order to test these predictions, experimental studies that systematically compare crossmodal effects under stimulus conditions that are identical except for the CSP-FAP instruction should be performed in the future
Winkelhage, J. and Diederich, A., The relevance of personal characteristics in allocating health care resources-controversial preferences of laypersons with different educational backgrounds, International journal of environmental research and public health, vol. 9, no. 1. pp. 223-243, Jan.-2012.
Abstract DOI
In all industrial countries publicly funded health care systems are confronted with budget constraints. Therefore, priority setting in resource allocation seems inevitable. This paper examines whether personal characteristics could be taken into consideration when allocating health services in Germany, and whether attitudes towards prioritizing health care vary among individuals with different levels of education. Using a conjoint analysis approach, hypothetical patients described in terms of 'lifestyle', 'age', 'severity of illness', 'type of illness', 'improvement in health', and 'treatment costs' were constructed, and the importance weights for these personal characteristics were elicited from 120 members of the general public. Participants were selected according to a sampling guide including educational background, age, chronic illness and gender. Results are reported for groups with different levels of education (low, middle, high) only. The findings show that the patients' age is the most important criterion for the allocation of health care resources, followed by 'severity of illness' and 'improvement in health'. Preferences vary among participants with different educational backgrounds, which refer to different attitudes towards distributive justice and might represent different socialization experiences
Diederich, A., Schomburg, A., and Colonius, H., Saccadic reaction times to audiovisual stimuli show effects of oscillatory phase reset, PloS one, vol. 7, no. 10. p. e44910, 2012.
Abstract DOI
Initiating an eye movement towards a suddenly appearing visual target is faster when an accessory auditory stimulus occurs in close spatiotemporal vicinity. Such facilitation of saccadic reaction time (SRT) is well-documented, but the exact neural mechanisms underlying the crossmodal effect remain to be elucidated. From EEG/MEG studies it has been hypothesized that coupled oscillatory activity in primary sensory cortices regulates multisensory processing. Specifically, it is assumed that the phase of an ongoing neural oscillation is shifted due to the occurrence of a sensory stimulus so that, across trials, phase values become highly consistent (phase reset). If one can identify the phase an oscillation is reset to, it is possible to predict when temporal windows of high and low excitability will occur. However, in behavioral experiments the pre-stimulus phase will be different on successive repetitions of the experimental trial, and average performance over many trials will show no signs of the modulation. Here we circumvent this problem by repeatedly presenting an auditory accessory stimulus followed by a visual target stimulus with a temporal delay varied in steps of 2 ms. Performing a discrete time series analysis on SRT as a function of the delay, we provide statistical evidence for the existence of distinct peak spectral components in the power spectrum. These frequencies, although varying across participants, fall within the beta and gamma range (20 to 40 Hz) of neural oscillatory activity observed in neurophysiological studies of multisensory integration. Some evidence for high-theta/alpha activity was found as well. Our results are consistent with the phase reset hypothesis and demonstrate that it is amenable to testing by purely psychophysical methods. Thus, any theory of multisensory processes that connects specific brain states with patterns of saccadic responses should be able to account for traces of oscillatory activity in observable behavior
Diederich, A., Swait, J., and Wirsik, N., Citizen participation in patient prioritization policy decisions: an empirical and experimental study on patients' characteristics, PloS one, vol. 7, no. 5. p. e36824, 2012.
Abstract DOI
Health systems worldwide are grappling with the need to control costs to maintain system viability. With the combination of worsening economic conditions, an aging population and reductions in tax revenues, the pressures to make structural changes are expected to continue growing. Common cost control mechanisms, e.g. curtailment of patient access and treatment prioritization, are likely to be adversely viewed by citizens. It seems therefore wise to include them in the decision making processes that lead up to policy changes. In the context of a multilevel iterative mixed-method design a quantitative survey representative of the German population (N = 2031) was conducted to probe the acceptance of priority setting in medicine and to explore the practicability of direct public involvement. Here we focus on preferences for patients' characteristics (medical aspects, lifestyle and socio-economic status) as possible criteria for prioritizing medical services. A questionnaire with closed response options was fielded to gain insight into attitudes toward broad prioritization criteria of patient groups. Furthermore, a discrete choice experiment was used as a rigorous approach to investigate citizens' preferences toward specific criteria level in context of other criteria. Both the questionnaire and the discrete choice experiment were performed with the same sample. The citizens' own health and social situation are included as explanatory variables. Data were evaluated using corresponding analysis, contingency analysis, logistic regression and a multinomial exploded logit model. The results show that some medical criteria are highly accepted for prioritizing patients whereas socio-economic criteria are rejected
Gießing, C. and Thiel, C. M., Pro-cognitive drug effects modulate functional brain network organization, Frontiers in Behavioral Neuroscience, vol. 6. Frontiers Media SA, 2012.
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Gießing, C., Neber, T., and Thiel, C. M., Genetic variation in nicotinic receptors affects brain networks involved in reorienting attention, NeuroImage, vol. 59, no. 1. Elsevier BV, pp. 831-839, Jan.-2012.
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Doi, E., Gauthier, J. L., Field, G. D., Shlens, J., Sher, A., Greschner, M., Machado, T. A., Jepson, L. H., Mathieson, K., Gunning, D. E., Litke, A. M., Paninski, L., Chichilnisky, E. J., and Simoncelli, E. P., Efficient coding of spatial information in the primate retina, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 32, no. 46. pp. 16256-16264, Nov.-2012.
Abstract DOI
Sensory neurons have been hypothesized to efficiently encode signals from the natural environment subject to resource constraints. The predictions of this efficient coding hypothesis regarding the spatial filtering properties of the visual system have been found consistent with human perception, but they have not been compared directly with neural responses. Here, we analyze the information that retinal ganglion cells transmit to the brain about the spatial information in natural images subject to three resource constraints: the number of retinal ganglion cells, their total response variances, and their total synaptic strengths. We derive a model that optimizes the transmitted information and compare it directly with measurements of complete functional connectivity between cone photoreceptors and the four major types of ganglion cells in the primate retina, obtained at single-cell resolution. We find that the ganglion cell population exhibited 80% efficiency in transmitting spatial information relative to the model. Both the retina and the model exhibited high redundancy (~30%) among ganglion cells of the same cell type. A novel and unique prediction of efficient coding, the relationships between projection patterns of individual cones to all ganglion cells, was consistent with the observed projection patterns in the retina. These results indicate a high level of efficiency with near-optimal redundancy in visual signaling by the retina
Zech, A., Drey, M., Freiberger, E., Hentschke, C., Bauer, J. M., Sieber, C. C., and Pfeifer, K., Residual effects of muscle strength and muscle power training and detraining on physical function in community-dwelling prefrail older adults: a randomized controlled trial, BMC geriatrics, vol. 12. p. 68, 2012.
Abstract DOI
BACKGROUND: Although resistance exercise interventions have been shown to be beneficial in prefrail or frail older adults it remains unclear whether there are residual effects when the training is followed by a period of detraining. The aim of this study was to establish the sustainability of a muscle power or muscle strength training effect in prefrail older adults following training and detraining. METHODS: 69 prefrail community-dwelling older adults, aged 65-94 years were randomly assigned into three groups: muscle strength training (ST), muscle power training (PT) or controls. The exercise interventions were performed for 60 minutes, twice a week over 12 weeks. Physical function (Short Physical Performance Battery=SPPB), muscle power (sit-to-stand transfer=STS), self-reported function (SF-LLFDI) and appendicular lean mass (aLM) were measured at baseline and at 12, 24 and 36 weeks after the start of the intervention. RESULTS: For the SPPB, significant intervention effects were found at 12 weeks in both exercise groups (ST: p = 0.0047; PT: p = 0.0043). There were no statistically significant effects at 24 and 36 weeks. In the ST group, the SPPB declined continuously after stop of exercising whereas the PT group and controls remained unchanged. No effects were found for muscle power, SF-LLFDI and aLM. CONCLUSIONS: The results showed that both intervention types are equally effective at 12 weeks but did not result in statistically significant residual effects when the training is followed by a period of detraining. The unchanged SPPB score at 24 and 36 weeks in the PT group indicates that muscle power training might be more beneficial than muscle strength training. However, more research is needed on the residual effects of both interventions. Taken the drop-out rates (PT: 33%, ST: 21%) into account, muscle power training should also be used more carefully in prefrail older adults. TRIAL REGISTRATION: This trial has been registered with clinicaltrials.gov (NCT00783159)
Drey, M., Zech, A., Freiberger, E., Bertsch, T., Uter, W., Sieber, C. C., Pfeifer, K., and Bauer, J. M., Effects of strength training versus power training on physical performance in prefrail community-dwelling older adults, Gerontology, vol. 58, no. 3. pp. 197-204, 2012.
Abstract DOI
It has been unclear which training mode is most effective and feasible for improving physical performance in the risk group of prefrail community-dwelling older adults.The purpose of the present study was to compare the effects of strength training (ST) versus power training (PT) on functional performance in prefrail older adults. This study was registered at clinicaltrials.gov as NCT00783159.69 community-dwelling older adults (>65 years) who were prefrail according to the definition of Fried were included in a 12-week exercise program. The participants were randomized into an ST group, a PT group and a control group. All participants were supplemented with vitamin D(3) orally before entering the intervention period. The primary outcome was the global score on the Short Physical Performance Battery (SPPB). Secondary outcomes were muscle power, appendicular lean mass (aLM) measured by dual energy X-ray absorptiometry and self-reported functional deficits (Short Form of the Late-Life Function and Disability Instrument, SF-LLFDI).Regarding changes in the SPPB score during the intervention, significant heterogeneity between the groups was observed (p = 0.023). In pair-wise comparisons, participants in both training groups significantly (PT: p = 0.012, ST: 0.009) increased their SPPB score (PT: Δ(mean) = 0.8, ST: Δ(mean) = 1.0) compared to the control group, with no statistical difference among training groups (p = 0.301). No statistical differences were found in changes in aLM (p = 0.769), muscle power (p = 0.308) and SF-LLFDI (p = 0.623) between the groups. Muscle power significantly increased (p = 0.017) under vitamin D(3) intake.In prefrail community-dwelling adults, PT is not superior to ST, although both training modes resulted in significant improvements in physical performance. With regard to dropout rates, ST appears to be advantageous compared to PT. The high prevalence of vitamin D(3) deficiency and the slight improvement of physical performance under vitamin D(3) supplementation among study participants underline the relevance of this approach in physical exercise interventions
Wirth, R., Voss, C., Smoliner, C., Sieber, C. C., Bauer, J. M., and Volkert, D., Complications and mortality after percutaneous endoscopic gastrostomy in geriatrics: a prospective multicenter observational trial, Journal of the American Medical Directors Association, vol. 13, no. 3. pp. 228-233, Mar.-2012.
Abstract DOI
BACKGROUND: Generally, the high short-term mortality after percutaneous endoscopic gastrostomy (PEG) in geriatric patients is attributed to the severity of their underlying diseases. However, the procedure-related mortality in this group is unknown. METHODS: This prospective multicenter observational study gathered information about 197 geriatric patients treated with PEG insertion, including the indication for PEG insertion and the prevalence of postprocedure complications and analyzed how these factors related to mortality. RESULTS: Dysphagia (64%) and insufficient food intake (76%) were the most frequent indications for PEG insertion. Severe complications after PEG insertion occurred in 9.6% of patients. Mortality was 9.6% in hospital, as well as 18.4% at 1 month. Six months after PEG placement, with 81 patients lost to follow-up, mortality was 51.9%. Hospital mortality was significantly higher in patients with severe complications caused by PEG insertion (47.4% vs 5.6%; P < .001). A regression analysis that corrected for confounding factors revealed that severe complications in general (HR 6.9; 95% CI: 2.6-18.1; P < .001), peritonitis (HR 33.1; 95% CI: 3.7-293.2; P = .002), and severe wound infections (HR 6.9; 95% CI: 1.9-24.9; P = .003) were each independently associated with hospital mortality. Considering the prevalence of procedure-related complications and their association with early mortality after PEG insertion, the procedure-related mortality rate in geriatric patients was at least 2% in this study. CONCLUSION: Although the prevalence of complications after PEG in this study of multimorbid geriatric patients is within the expected range, the procedure-related mortality is higher than expected
Hinz, C., Gebhardt, K., Hartmann, A. K., Sigman, L., and Gerlach, G., Influence of kinship and MHC class II genotype on visual traits in zebrafish larvae (Danio rerio), PloS one, vol. 7, no. 12. p. e51182, 2012.
Abstract DOI
Kin recognition can drive kin selection and the evolution of social behaviour. In zebrafish (Danio rerio, Hamilton 1822), kin recognition is based on olfactory and visual imprinting processes. If larvae are exposed to visual and chemical cues of kin at day 5 and 6 post fertilization they will recognize kin throughout life, while exposure to non-kin fails to trigger any recognition. Chemical imprinting signals are transcribed by polymorphic genes of the major histocompatibility complex (MHC) code; however, the underlying mechanism for visual imprinting remains unclear. Here we provide evidence for the existence of family-specific differences in morphometry and pigmentation pattern of six day old zebrafish larvae. While rump, tail and body pigmentation were dependent on relatedness, iris pigmentation and morphometry were also influenced by MHC class II genotype. Our study revealed that the MHC not only influences the chemical signature of individuals, but also their visual appearance
Schmidt-Roach, S., Miller, K. J., Woolsey, E., Gerlach, G., and Baird, A. H., Broadcast spawning by Pocillopora species on the Great Barrier Reef, PloS one, vol. 7, no. 12. p. e50847, 2012.
Abstract DOI
The coral genus Pocillopora is one of the few to include some species that broadcast spawn gametes and some species that brood larvae, although reports of reproductive mode and timing vary within and among species across their range. Notably, the ubiquitous Pocillopora damicornis has been described as both a brooder and spawner, although evidence of broadcast spawning is rare. Here, we report observations of broadcast-spawning in four species of Pocillopora on the Great Barrier Reef (GBR), including P. damicornis. All species spawned predictably during the early morning, two days following the full moon, and spawning was observed in multiple months over the summer period (November to February). Eggs and sperm were free-spawned concurrently. Eggs were negatively buoyant and contained Symbiodinium. This newfound knowledge on the mode, timing and regularity of broadcast spawning in Pocillopora spp. on the GBR brings us one step closer to elucidating the complex reproductive ecology of these species
Engels, S., Hein, C. M., Lefeldt, N., Prior, H., and Mouritsen, H., Night-migratory songbirds possess a magnetic compass in both eyes, PloS one, vol. 7, no. 9. p. e43271, 2012.
Abstract DOI
Previous studies on European robins, Erithacus rubecula, and Australian silvereyes, Zosterops lateralis, had suggested that magnetic compass information is being processed only in the right eye and left brain hemisphere of migratory birds. However, recently it was demonstrated that both garden warblers, Sylvia borin, and European robins have a magnetic compass in both eyes. These results raise the question if the strong lateralization effect observed in earlier experiments might have arisen from artifacts or from differences in experimental conditions rather than reflecting a true all-or-none lateralization of the magnetic compass in European robins. Here we show that (1) European robins having only their left eye open can orient in their seasonally appropriate direction both during autumn and spring, i.e. there are no strong lateralization differences between the outward journey and the way home, that (2) their directional choices are based on the standard inclination compass as they are turned 180° when the inclination is reversed, and that (3) the capability to use the magnetic compass does not depend on monocular learning or intraocular transfer as it is already present in the first tests of the birds with only one eye open
Mouritsen, H. and Hore, P. J., The magnetic retina: light-dependent and trigeminal magnetoreception in migratory birds, Current opinion in neurobiology, vol. 22, no. 2. pp. 343-352, Apr.-2012.
Abstract DOI
Recent advances have brought much new insight into the physiological mechanisms and required characteristics of the sensory molecules that enable birds to use magnetic fields for orientation. European robins almost certainly have two magnetodetection senses, one associated with the ophthalmic branch of the trigeminal nerve, and one based on light-dependent radical-pair processes in both eyes. The first brain areas processing magnetic information from each of these two senses have been identified. It has been experimentally verified that Earth-strength magnetic fields can affect photo-induced chemical reactions and that these reactions can respond to magnetic field direction. Diagnostic behavioural experiments have provided clues to identify putative magnetoreceptive molecules in the retina. We discuss the implications of these and other recent findings and outline crucial open questions with an emphasis on the light-dependent mechanism
Mouritsen, H., Sensory biology: Search for the compass needles, Nature, vol. 484, no. 7394. Nature Publishing Group, pp. 320-321, 18-Apr.-2012.
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Haumann, S., Hohmann, V., Meis, M., Herzke, T., Lenarz, T., and Büchner, A., Indication criteria for cochlear implants and hearing aids: impact of audiological and non-audiological findings, Audiol. Res., vol. 2, no. 1. 2012.
Abstract DOIFull Text
Owing to technological progress and a growing body of clinical experience, indication criteria for cochlear implants (CI) are being extended to less severe hearing impairments. It is, therefore, worth reconsidering these indication criteria by introducing novel testing procedures. The diagnostic evidence collected will be evaluated. The investigation includes postlingually deafened adults seeking a CI. Prior to surgery, speech perception tests [Freiburg Speech Test and Oldenburg sentence (OLSA) test] were performed unaided and aided using the Oldenburg Master Hearing Aid (MHA) system. Linguistic skills were assessed with the visual Text Reception Threshold (TRT) test, and general state of health, socio-economic status (SES) and subjective hearing were evaluated through questionnaires. After surgery, the speech tests were repeated aided with a CI. To date, 97 complete data sets are available for evaluation. Statistical analyses showed significant correlations between postsurgical speech reception threshold (SRT) measured with the adaptive OLSA test and pre-surgical data such as the TRT test (r=−0.29), SES (r=−0.22) and (if available) aided SRT (r=0.53). The results suggest that new measures and setups such as the TRT test, SES and speech perception with the MHA provide valuable extra information regarding indication for CI.
Zokoll, M. A., Wagener, K. C., Brand, T., Buschermöhle, M., and Kollmeier, B., Internationally comparable screening tests for listening in noise in several European languages: the German digit triplet test as an optimization prototype, Int. J. Audiol., vol. 51, no. 9. 2012.
Abstract
Objective: A review is given of internationally comparable speech-in-noise tests for hearing screening purposes that were part of the European HearCom project. This report describes the development, optimization, and evaluation of such tests for headphone and telephone presentation, using the example of the German digit triplet test. In order to achieve the highest possible comparability, language- and speaker-dependent factors in speech intelligibility should be compensated for. Materials and methods: The tests comprise spoken numbers in background noise and estimate the speech reception threshold (SRT), i.e. the signal-to-noise ratio (SNR) yielding 50% speech intelligibility. Results: The respective reference speech intelligibility functions for headphone and telephone presentation of the German version for 15 and 10 normal-hearing listeners are described by a SRT of −9.3 ± 0.2 and −6.5 ± 0.4 dB SNR, and slopes of 19.6 and 17.9%/dB, respectively. Reference speech intelligibility functions of all digit triplet tests optimized within the HearCom project allow for investigation of the comparability due to language specificities. Conclusions: The optimization criteria established here should be used for similar screening tests in other languages.
Klein-Hennig, M., Dietz, M., Klinge-Strahl, A., Klump, G. M., and Hohmann, V., Effect of Mistuning on the Detection of a Tone Masked by a Harmonic Tone Complex, PLoS ONE, vol. 7, no. 11. Public Library of Science (PLoS), p. e48419, 5-Nov.-2012.
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Ritaccio, A., Beauchamp, M., Bosman, C., Brunner, P., Chang, E., Crone, N., Gunduz, A., Gupta, D., Knight, R., Leuthardt, E., Litt, B., Moran, D., Ojemann, J., Parvizi, J., Ramsey, N., Rieger, J. W., Viventi, J., Voytek, B., Williams, J., and Schalk, G., Proceedings of the Third International Workshop on Advances in Electrocorticography, Epilepsy & behavior : E&B, vol. 25, no. 4. pp. 605-613, Dec.-2012.
Abstract DOI
The Third International Workshop on Advances in Electrocorticography (ECoG) was convened in Washington, DC, on November 10-11, 2011. As in prior meetings, a true multidisciplinary fusion of clinicians, scientists, and engineers from many disciplines gathered to summarize contemporary experiences in brain surface recordings. The proceedings of this meeting serve as evidence of a very robust and transformative field but will yet again require revision to incorporate the advances that the following year will surely bring
Quandt, F., Reichert, C., Schneider, B., Dürschmid, S., Richter, D., Hinrichs, H., and Rieger, J. W., Fundamentals and Application of Brain-Machine Interfaces (BMI), Klinische Neurophysiologie, vol. 43, no. 02. Thieme, 2012.
Abstract
Döding, A., Hartmann, A. -M., Beyer, T., and Nothwang, H. G., KCC2 transport activity requires the highly conserved L675 in the C-terminal β1 strand, Biochemical and Biophysical Research Communications, vol. 420, no. 3. Elsevier BV, pp. 492-497, Apr.-2012.
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Schepers, I. M., Hipp, J. F., Schneider, T. R., Roder, B., and Engel, A. K., Functionally specific oscillatory activity correlates between visual and auditory cortex in the blind, Brain, vol. 135, no. 3. Oxford University Press (OUP), pp. 922-934, 24-Feb.-2012.
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Soeroes, P. and Stanton, S. G., On variability and genes: inter-individual differences in auditory brain function, FRONTIERS IN HUMAN NEUROSCIENCE, vol. 6. Jun.-2012.
Abstract
Soeroes, P. and Hachinski, V., Cardiovascular and neurological causes of sudden death after ischaemic stroke, LANCET NEUROLOGY, vol. 11, no. 2. Feb.-2012.
Abstract
Sudden death is an important but widely under-recognised consequence of stroke. Acute stroke can disturb central autonomic control, resulting in myocardial injury, electrocardiographic abnormalities, cardiac arrhythmias, and ultimately sudden death. Experimental and clinical evidence suggests that autonomic imbalance is more frequent after infarcts involving the insular cortex, a crucial region for the control of sympathetic and parasympathetic autonomic functions. Cardiovascular comorbidities increase the risk of cardiac morbidity and mortality after stroke. Thus, many sudden deaths and serious non-fatal cardiac events after stroke are probably due to an interaction between cardiovascular and neurological causes. The exact mechanisms leading to sudden death remain incompletely understood. Further research is needed to investigate the autonomic consequences of acute stroke and to identify patients at high risk of sudden death.
Rupprecht, A., Braeuer, A. U., Smorodchenko, A., Goyn, J., Hilse, K. E., Shabalina, I. G., Infante-Duarte, C., and Pohl, E. E., Quantification of Uncoupling Protein 2 Reveals Its Main Expression in Immune Cells and Selective Up-Regulation during T-Cell Proliferation, PLOS ONE, vol. 7, no. 8. PUBLIC LIBRARY SCIENCE, Aug.-2012.
Abstract
Uncoupling protein 2 (UCP2) is an inner mitochondrial membrane protein. Although the protein was discovered in 1997, its function and even its tissue distribution are still under debate. Here we present a quantitative analysis of mRNA and protein expression in various mice tissues, revealing that UCP2 is mainly expressed in organs and cells associated with the immune system. Although the UCP2 gene is present in the brain, as demonstrated using quantitative RT-PCR, the protein was not detectable in neurons under physiological conditions. Instead, we could detect UCP2 in microglia, which act in the immune defense of the central nervous system. In lymphocytes, activation led to a ten-fold increase of UCP2 protein expression simultaneously to the increase in levels of other mitochondrial proteins, whereas lymphocyte re-stimulation resulted in the selective increase of UCP2. The highest detected level of UCP2 expression in stimulated T-cells (0.54 ng/(mg total cellular protein)) was approximately 200 times lower than the level of UCP1 in brown adipose tissue from room temperature acclimated mice. Both the UCP2 expression pattern and the time course of up-regulation in stimulated T-cells imply UCP2's involvement in the immune response, probably by controlling the metabolism during cell proliferation.
Battefeld, A., Rocha, N., Stadler, K., Braeuer, A. U., and Strauss, U., Distinct perinatal features of the hyperpolarization-activated non-selective cation current I-h in the rat cortical plate, NEURAL DEVELOPMENT, vol. 7. BIOMED CENTRAL LTD, Jun.-2012.
Abstract
Background: During neocortical development, multiple voltage- and ligand-gated ion channels are differentially expressed in neurons thereby shaping their intrinsic electrical properties. One of these voltage- gated ion channels, the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel and its current I-h, is an important regulator of neuronal excitability. Thus far, studies on an early I-h appearance in rodent neocortex are missing or conflicting. Therefore, we focused our study on perinatal neocortical I-h and its properties. Results: In the perinatal rat neocortex we observed a rapid increase in the number of neurons exhibiting I-h. Perinatal I-h had unique properties: first, a pronounced cAMP sensitivity resulting in a marked shift of the voltage sufficient for half-maximum activation of the current towards depolarized voltages and second, an up to 10 times slower deactivation at physiological membrane potentials when compared to the one at postnatal day 30. The combination of these features was sufficient to suppress membrane resonance in our in silico and in vitro experiments. Although all four HCN subunits were present on the mRNA level we only detected HCN4, HCN3 and HCN1 on the protein level at P0. HCN1 protein at P0, however, appeared incompletely processed. At P30 glycosilated HCN1 and HCN2 dominated. By in silico simulations and heterologous co-expression experiments of a `slow' and a `fast' I-h conducting HCN channel subunit in HEK293 cells, we mimicked most characteristics of the native current, pointing to a functional combination of subunit homo- or heteromeres. Conclusion: Taken together, these data indicate a HCN subunit shift initiated in the first 24 hours after birth and implicate a prominent perinatal role of the phylogenetically older HCN3 and/or HCN4 subunits in the developing neocortex.
Weinshall, D., Zweig, A., Hermansky, H., Kombrink, S., Ohl, F. W., Anemueller, J., Bach, J. -H., Van Gool, L., Nater, F., Pajdla, T., Havlena, M., and Pavel, M., Beyond Novelty Detection: Incongruent Events, When General and Specific Classifiers Disagree, IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE, vol. 34, no. 10. IEEE COMPUTER SOC, Oct.-2012.
Abstract
Unexpected stimuli are a challenge to any machine learning algorithm. Here, we identify distinct types of unexpected events when general-level and specific-level classifiers give conflicting predictions. We define a formal framework for the representation and processing of incongruent events: Starting from the notion of label hierarchy, we show how partial order on labels can be deduced from such hierarchies. For each event, we compute its probability in different ways, based on adjacent levels in the label hierarchy. An incongruent event is an event where the probability computed based on some more specific level is much smaller than the probability computed based on some more general level, leading to conflicting predictions. Algorithms are derived to detect incongruent events from different types of hierarchies, different applications, and a variety of data types. We present promising results for the detection of novel visual and audio objects, and new patterns of motion in video. We also discuss the detection of Out-Of-Vocabulary words in speech recognition, and the detection of incongruent events in a multimodal audiovisual scenario.
Döding, A., Immunhistochemische und funktionelle Analyse der Interaktion des neuronalen K + Cl - -Kotransporters KCC2 mit dem GEF-Protein BetaPIX. 2012.
AbstractFull Text
Somisetty, V. S., Role of L-type calcium channels during development of the central auditory system. 2012.
Abstract
Döding, A., Immunhistochemische und funktionelle Analyse der Interaktion des neuronalen K + Cl - -Kotransporters KCC2 mit dem GEF-Protein BetaPIX. 2012.
AbstractFull Text
Somisetty, V. S., Role of L-type calcium channels during development of the central auditory system. 2012.
Abstract
Neuling, T., Probing brain oscillations with oscillating transcranial electrical stimulation. 2012.
Abstract
Richter-Landsberg, C., Microtubules and Associated Proteins in Oligodendrocytes, the Myelin Forming Cells of the Central Nervous System, Neuromethods. Springer Science + Business Media, pp. 323-333, 3-Nov.-2012.
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Frenken, T., Isken, M., Volkening, N., Brell, M., and Hein, A., Criteria for Quality and Safety while Performing Unobtrusive Domestic Mobility Assessments Using Mobile Service Robots, Advanced Technologies and Societal Change. Springer Science + Business Media, pp. 61-76, 2012.
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Hellrung, N., Ludwig, W., Frenken, T., Lipprandt, M., Steen, E. -E., Helmer, A., Veltin, B., von Bargen, T., Gövercin, M., Wegel, S., Brell, M., Thoben, W., Steinhagen-Thiessen, E., Haux, R., and Hein, A., Einbettung assistierender Technologien in Gesundheitsnetzwerke – von der Wohnung zum Arzt, Technologiegestützte Dienstleistungsinnovation in der Gesundheitswirtschaft. Springer Science + Business Media, pp. 241-262, 2012.
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Gerlach, G. and Hinz, C., Chemical signals and kin biased behaviour, Chemical Ecology in Aquatic Systems. Oxford University Press (OUP), pp. 57-71, 1-Mar.-2012.
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Gerlach, G. and Atema, J., The use of chemical cues in habitat recognition and settlement, Chemical Ecology in Aquatic Systems. Oxford University Press (OUP), pp. 72-81, 1-Mar.-2012.
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Dell'Orco, D. and Koch, K. -W., A dynamic scaffolding mechanism for rhodopsin and transducin interaction in vertebrate vision, The Biochemical journal, vol. 440, no. 2. Dec.-2011.
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Scholten, A. and Koch, K. -W., Differential calcium signaling by cone specific guanylate cyclase-activating proteins from the zebrafish retina, PloS one, vol. 6, no. 8. 2011.
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Nullmeier, M., Koliwer-Brandl, H., Kelm, S., Zägel, P., Koch, K. -W., and Brand, I., Impact of strong and weak lipid-protein interactions on the structure of a lipid bilayer on a gold electrode surface, Chemphyschem : a European journal of chemical physics and physical chemistry, vol. 12, no. 6. Apr.-2011.
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Zernii, E. Y., Komolov, K. E., Permyakov, S. E., Kolpakova, T., Dell'orco, D., Poetzsch, A., Knyazeva, E. L., Grigoriev, I. I., Permyakov, E. A., Senin, I. I., Philippov, P. P., and Koch, K. -W., Involvement of the recoverin C-terminal segment in recognition of the target enzyme rhodopsin kinase, The Biochemical journal, vol. 435, no. 2. Apr.-2011.
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Glaus, E., Schmid, F., Da Costa, R., Berger, W., and Neidhardt, J., Gene Therapeutic Approach Using Mutation-adapted U1 snRNA to Correct a RPGR Splice Defect in Patient-derived Cells, Molecular Therapy, vol. 19, no. 5. Nature Publishing Group, pp. 936-941, 15-Feb.-2011.
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Schmid, F., Glaus, E., Barthelmes, D., Fliegauf, M., Gaspar, H., Nürnberg, G., Nürnberg, P., Omran, H., Berger, W., and Neidhardt, J., U1 snRNA-mediated gene therapeutic correction of splice defects caused by an exceptionally mild BBS mutation, Hum. Mutat., vol. 32, no. 7. Wiley-Blackwell, pp. 815-824, 27-Jun.-2011.
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Bordo, K., Schiek, M., Ghazal, A., Wallmann, I., Lützen, A., Balzer, F., and Rubahn, H. -G., Parallelly and Normally Surface-Aligned Organic Nanofiber Arrays, The Journal of Physical Chemistry C, vol. 115, no. 43. American Chemical Society (ACS), pp. 20882-20887, 3-Nov.-2011.
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Sienknecht, U. J., Anderson, B. K., Parodi, R. M., Fantetti, K. N., and Fekete, D. M., Non-cell-autonomous planar cell polarity propagation in the auditory sensory epithelium of vertebrates, Developmental Biology, vol. 352, no. 1. Elsevier BV, pp. 27-39, Apr.-2011.
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Seeliger, M. W., Brombas, A., Weiler, R., Humphries, P., Knop, G., Tanimoto, N., and Müller, F., Modulation of rod photoreceptor output by HCN1 channels is essential for regular mesopic cone vision, Nat Comms, vol. 2. Nature Publishing Group, p. 532, 8-Nov.-2011.
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Klaassen, L. J., Sun, Z., Steijaert, M. N., Bolte, P., Fahrenfort, I., Sjoerdsma, T., Klooster, J., Claassen, Y., Shields, C. R., Ten Eikelder, H. M. M., Janssen-Bienhold, U., Zoidl, G., McMahon, D. G., and Kamermans, M., Synaptic Transmission from Horizontal Cells to Cones Is Impaired by Loss of Connexin Hemichannels, PLoS Biol, vol. 9, no. 7. Public Library of Science (PLoS), p. e1001107, 19-Jul.-2011.
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Ziemann, H., Weerman, F., and Ruigendijk, E., Nederlands later geleerd: gebruik van lidwoorden en flexie van bijvoeglijke naamwoorden door Duitstalige kinderen en volwassenen, Internationale Neerlandistiek, vol. 49, no. 3. Amsterdam University Press, pp. 183-207, 1-Oct.-2011.
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Kranczioch, C. and Bryant, D., Attentional awakening, resource allocation and the focus of temporal attention, NeuroReport, vol. 22, no. 4. Ovid Technologies (Wolters Kluwer Health), pp. 161-165, Mar.-2011.
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Schwartzman, D. J. and Kranczioch, C., In the blink of an eye: The contribution of microsaccadic activity to the induced gamma band response, International Journal of Psychophysiology, vol. 79, no. 1. Elsevier BV, pp. 73-82, Jan.-2011.
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Mungwe, S. A. and Hein, A., Fuzzy Controller for Positioning Tasks in Tactile Surgical Navigation, Advanced Materials Research, vol. 403-408. Trans Tech Publications, pp. 4794-4799, Nov.-2011.
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Perlov, E., Philipsen, A., Maier, S., Buechert, M., Hesslinger, B., Ebert, D., and Elst, L. T. van, Depressive Cognitions May Affect Cingulate Neurochemistry in ADHD Patients, JBBS, vol. 01, no. 01. Scientific Research Publishing, Inc, pp. 6-11, 2011.
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de Zwaan, M., Gruß, B., Müller, A., Graap, H., Martin, A., Glaesmer, H., Hilbert, A., and Philipsen, A., The estimated prevalence and correlates of adult ADHD in a German community sample, European Archives of Psychiatry and Clinical Neuroscience, vol. 262, no. 1. Springer Science + Business Media, pp. 79-86, 17-Apr.-2011.
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de Zwaan, M., Gruß, B., Müller, A., Philipsen, A., Graap, H., Martin, A., Glaesmer, H., and Hilbert, A., Association between Obesity and Adult Attention-Deficit/Hyperactivity Disorder in a German Community-Based Sample, Obes Facts, vol. 4, no. 3. S. Karger AG, pp. 204-211, 2011.
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Matthies, S., van Elst, L. T., Feige, B., Fischer, D., Scheel, C., Krogmann, E., Perlov, E., Ebert, D., and Philipsen, A., Severity of Childhood Attention-Deficit Hyperactivity Disorder—A Risk Factor for Personality Disorders in Adult Life?, Journal of Personality Disorders, vol. 25, no. 1. Guilford Publications, pp. 101-114, Feb.-2011.
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Riedel, M., Goldbaum, O., Wille, M., and Richter-Landsberg, C., Membrane lipid modification by docosahexaenoic acid (DHA) promotes the formation of α-synuclein inclusion bodies immunopositive for SUMO-1 in oligodendroglial cells after oxidative stress, Journal of molecular neuroscience : MN, vol. 43, no. 3. pp. 290-302, Mar.-2011.
Abstract DOI
α-Synuclein (α-syn) is the major constituent of Lewy bodies and glial cytoplasmic inclusions which are pathological hallmarks of neurodegenerative disorders like Parkinson's disease or multiple system atrophy (MSA), respectively. It accumulates and aggregates during the pathogenic process, and missense mutations, such as A53T, are increasing its probability of aggregate formation. Furthermore, α-syn interacts with polyunsaturated fatty acids, and this interaction may promote the oligomerization process. To investigate whether membrane lipid modification by docosahexaenoic acid (DHA) modifies the aggregation process of α-syn in oligodendroglial cells, we have used OLN-93 cells stably expressing the human α-syn A53T mutation. Cells were supplemented with DHA (25 μM) for 3 days and then subjected to oxidative stress (OS) exerted by hydrogen peroxide. The data show that modification of the oligodendroglial cell membranes by DHA followed by OS caused the formation of fibrillary α-syn inclusions, a decrease in α-syn solubility, and an increase in phosphorylation at serine 129, which has been suggested to play a proaggregatory role. The aggregates contain αB-crystallin and ubiquitinated proteins and SUMO-1 immunoreactivity. SUMO-1 has been implicated in protein aggregation and identified as a constituent in inclusion bodies in MSA. Hence, membrane lipid modification in oligodendroglial cells promotes the formation of α-syn inclusion bodies resembling protein aggregates in neurodegenerative disease. This effect is not only attributable to the A53T mutation but also is observable in OLN cells expressing wild-type α-syn
Klinge, A., Beutelmann, R., and Klump, G. M., Effect of Harmonicity on the Detection of a Signal in a Complex Masker and on Spatial Release from Masking, PLoS ONE, vol. 6, no. 10. Public Library of Science (PLoS), p. e26124, 18-Oct.-2011.
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Rauh, A. and Parisi, J., Quantum mechanics of hyperbolic orbits in the Kepler problem, Physical Review A, vol. 83, no. 4. American Physical Society (APS), 12-Apr.-2011.
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Kruszynska, M., Borchert, H., Parisi, J., and Kolny-Olesiak, J., Morphology control of copper indium disulfide nanocrystals, MRS Proceedings, vol. 1324. Cambridge University Press (CUP), Jan.-2011.
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Wang, X., Stöver, J., Zielasek, V., Altmann, L., Thiel, K., Al-Shamery, K., Bäumer, M., Borchert, H., Parisi, J., and Kolny-Olesiak, J., Colloidal synthesis and structural control of PtSn bimetallic nanoparticles, Langmuir : the ACS journal of surfaces and colloids, vol. 27, no. 17. pp. 11052-11061, Sep.-2011.
Abstract DOI
PtSn bimetallic nanoparticles with different particle sizes (1-9 nm), metal compositions (Sn content of 10-80 mol %), and organic capping agents (e.g., amine, thiol, carboxylic acid and polymer) were synthesized by colloidal chemistry methods. Transmission electron microscopy (TEM) measurements show that, depending on the particle size, the as-prepared bimetallic nanocrystals have quasi-spherical or faceted shapes. Energy-dispersive X-ray (EDX) analyses indicate that for all samples the signals of both Pt and Sn can be detected from single nanoparticles, confirming that the products are actually bimetallic but not only a physical mixture of pure Pt and Sn metal nanoparticles. X-ray diffraction (XRD) measurements were also conducted on the bimetallic particle systems. When compared with the diffraction patterns of monometallic Pt nanoparticles, the bimetallic samples show distinct shifts of the Bragg reflections to lower degrees, which gives clear proof of the alloying of Pt with Sn. However, a quantitative analysis of the lattice parameter shifts indicates that only part of the Sn atoms are incorporated into the alloy nanocrystals. This is consistent with X-ray photoelectron spectroscopy (XPS) measurements that reveal the segregation of Sn at the surfaces of the nanocrystals. Moreover, short PtSn bimetallic nanowires were synthesized by a seed-mediated growth method with amine-capped bimetallic particles as precursors. The resulting nanowires have an average width of 2.3 nm and lengths ranging from 5 to 20 nm
Sadiq, D., Shirdel, J., Lee, J. S., Selishcheva, E., Park, N., and Lienau, C., Adiabatic Nanofocusing Scattering-Type Optical Nanoscopy of Individual Gold Nanoparticles, Nano Lett., vol. 11, no. 4. American Chemical Society (ACS), pp. 1609-1613, 13-Apr.-2011.
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Lee, J. S., Han, S., Shirdel, J., Koo, S., Sadiq, D., Lienau, C., and Park, N., Superfocusing of electric or magnetic fields using conical metal tips: effect of mode symmetry on the plasmon excitation method, Optics express, vol. 19, no. 13. pp. 12342-12347, Jun.-2011.
Abstract DOI
We compare single- and double-sided excitation methods of adiabatic surface plasmon polariton (SPP) wave superfocusing for scattering-type metallic near-field scanning optical microscopy (s-NSOM). Using the results of full 3D finite difference time domain analyses, the differences in field enhancement factors are explained and reveal the mode selectivity of a conical NSOM tip for adiabatic SPP superfocusing. Exploiting the mode-symmetric nature of the tip further, we also show that it is possible to selectively confine either the electric or magnetic field at the NSOM tip apex, by simply adjusting the relative phase between the SPP waves in the double-sided excitation approach
Colonius, H. and Diederich, A., Optimal Time Windows of Integration, i-Perception, vol. 2, no. 8. Pion Ltd, pp. 816-816, Oct.-2011.
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Diederich, A. and Colonius, H., Modeling Multisensory Integration across Different Experimental Paradigms, i-Perception, vol. 2, no. 8. Pion Ltd, pp. 817-817, Oct.-2011.
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Diederich, A. and Schreier, M., Wer was bekommen soll - und wer was nicht, forschung, vol. 36, no. S1. Wiley-Blackwell, pp. 66-69, Jun.-2011.
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Colonius, H. and Diederich, A., Computing an optimal time window of audiovisual integration in focused attention tasks: illustrated by studies on effect of age and prior knowledge, Experimental brain research, vol. 212, no. 3. pp. 327-337, Jul.-2011.
Abstract DOI
The concept of a "time window of integration" holds that information from different sensory modalities must not be perceived too far apart in time in order to be integrated into a multisensory perceptual event. Empirical estimates of window width differ widely, however, ranging from 40 to 600 ms depending on context and experimental paradigm. Searching for theoretical derivation of window width, Colonius and Diederich (Front Integr Neurosci 2010) developed a decision-theoretic framework using a decision rule that is based on the prior probability of a common source, the likelihood of temporal disparities between the unimodal signals, and the payoff for making right or wrong decisions. Here, this framework is extended to the focused attention task where subjects are asked to respond to signals from a target modality only. Evoking the framework of the time-window-of-integration (TWIN) model, an explicit expression for optimal window width is obtained. The approach is probed on two published focused attention studies. The first is a saccadic reaction time study assessing the efficiency with which multisensory integration varies as a function of aging. Although the window widths for young and older adults differ by nearly 200 ms, presumably due to their different peripheral processing speeds, neither of them deviates significantly from the optimal values. In the second study, head saccadic reactions times to a perfectly aligned audiovisual stimulus pair had been shown to depend on the prior probability of spatial alignment. Intriguingly, they reflected the magnitude of the time-window widths predicted by our decision-theoretic framework, i.e., a larger time window is associated with a higher prior probability
Breckel, T. Pk., Gießing, C., and Thiel, C. M., Impact of brain networks involved in vigilance on processing irrelevant visual motion, NeuroImage, vol. 55, no. 4. Elsevier BV, pp. 1754-1762, Apr.-2011.
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Ala-Laurila, P., Greschner, M., Chichilnisky, E. J., and Rieke, F., Cone photoreceptor contributions to noise and correlations in the retinal output, Nature neuroscience, vol. 14, no. 10. pp. 1309-1316, Oct.-2011.
Abstract DOI
Transduction and synaptic noise generated in retinal cone photoreceptors determine the fidelity with which light inputs are encoded, and the readout of cone signals by downstream circuits determines whether this fidelity is used for vision. We examined the effect of cone noise on visual signals by measuring its contribution to correlated noise in primate retinal ganglion cells. Correlated noise was strong in the responses of dissimilar cell types with shared cone inputs. The dynamics of cone noise could account for rapid correlations in ganglion cell activity, and the extent of shared cone input could explain correlation strength. Furthermore, correlated noise limited the fidelity with which visual signals were encoded by populations of ganglion cells. Thus, a simple picture emerges: cone noise, traversing the retina through diverse pathways, accounts for most of the noise and correlations in the retinal output and constrains how higher centers exploit signals carried by parallel visual pathways
Greschner, M., Shlens, J., Bakolitsa, C., Field, G. D., Gauthier, J. L., Jepson, L. H., Sher, A., Litke, A. M., and Chichilnisky, E. J., Correlated firing among major ganglion cell types in primate retina, The Journal of physiology, vol. 589, no. Pt 1. pp. 75-86, Jan.-2011.
Abstract DOI
Retinal ganglion cells exhibit substantial correlated firing: a tendency to fire nearly synchronously at rates different from those expected by chance. These correlations suggest that network interactions significantly shape the visual signal transmitted from the eye to the brain. This study describes the degree and structure of correlated firing among the major ganglion cell types in primate retina. Correlated firing among ON and OFF parasol, ON and OFF midget, and small bistratified cells, which together constitute roughly 75% of the input to higher visual areas, was studied using large-scale multi-electrode recordings. Correlated firing in the presence of constant, spatially uniform illumination exhibited characteristic strength, time course and polarity within and across cell types. Pairs of nearby cells with the same light response polarity were positively correlated; cells with the opposite polarity were negatively correlated. The strength of correlated firing declined systematically with distance for each cell type, in proportion to the degree of receptive field overlap. The pattern of correlated firing across cell types was similar at photopic and scotopic light levels, although additional slow correlations were present at scotopic light levels. Similar results were also observed in two other retinal ganglion cell types. Most of these observations are consistent with the hypothesis that shared noise from photoreceptors is the dominant cause of correlated firing. Surprisingly, small bistratified cells, which receive ON input from S cones, fired synchronously with ON parasol and midget cells, which receive ON input primarily from L and M cones. Collectively, these results provide an overview of correlated firing across cell types in the primate retina, and constraints on the underlying mechanisms
Kreuz, T., Chicharro, D., Greschner, M., and Andrzejak, R. G., Time-resolved and time-scale adaptive measures of spike train synchrony, Journal of neuroscience methods, vol. 195, no. 1. pp. 92-106, Jan.-2011.
Abstract DOI
A wide variety of approaches to estimate the degree of synchrony between two or more spike trains have been proposed. One of the most recent methods is the ISI-distance which extracts information from the interspike intervals (ISIs) by evaluating the ratio of the instantaneous firing rates. In contrast to most previously proposed measures it is parameter free and time-scale independent. However, it is not well suited to track changes in synchrony that are based on spike coincidences. Here we propose the SPIKE-distance, a complementary measure which is sensitive to spike coincidences but still shares the fundamental advantages of the ISI-distance. In particular, it is easy to visualize in a time-resolved manner and can be extended to a method that is also applicable to larger sets of spike trains. We show the merit of the SPIKE-distance using both simulated and real data
Naue, N., Strüber, D., Fründ, I., Schadow, J., Lenz, D., Rach, S., Körner, U., and Herrmann, C. S., Gamma in motion: Pattern reversal elicits stronger gamma-band responses than motion, NeuroImage, vol. 55, no. 2. Elsevier BV, pp. 808-817, Mar.-2011.
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Wiswede, D., Taubner, S., Münte, T. F., Roth, G., Strüber, D., Wahl, K., and Krämer, U. M., Neurophysiological Correlates of Laboratory-Induced Aggression in Young Men with and without a History of Violence, PLoS ONE, vol. 6, no. 7. Public Library of Science (PLoS), p. e22599, 2011.
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Naue, N., Rach, S., Strüber, D., Huster, R. J., Zaehle, T., Körner, U., and Herrmann, C. S., Auditory event-related response in visual cortex modulates subsequent visual responses in humans, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 31, no. 21. pp. 7729-7736, May-2011.
Abstract DOI
Growing evidence from electrophysiological data in animal and human studies suggests that multisensory interaction is not exclusively a higher-order process, but also takes place in primary sensory cortices. Such early multisensory interaction is thought to be mediated by means of phase resetting. The presentation of a stimulus to one sensory modality resets the phase of ongoing oscillations in another modality such that processing in the latter modality is modulated. In humans, evidence for such a mechanism is still sparse. In the current study, the influence of an auditory stimulus on visual processing was investigated by measuring the electroencephalogram (EEG) and behavioral responses of humans to visual, auditory, and audiovisual stimulation with varying stimulus-onset asynchrony (SOA). We observed three distinct oscillatory EEG responses in our data. An initial gamma-band response around 50 Hz was followed by a beta-band response around 25 Hz, and a theta response around 6 Hz. The latter was enhanced in response to cross-modal stimuli as compared to either unimodal stimuli. Interestingly, the beta response to unimodal auditory stimuli was dominant in electrodes over visual areas. The SOA between auditory and visual stimuli--albeit not consciously perceived--had a modulatory impact on the multisensory evoked beta-band responses; i.e., the amplitude depended on SOA in a sinusoidal fashion, suggesting a phase reset. These findings further support the notion that parameters of brain oscillations such as amplitude and phase are essential predictors of subsequent brain responses and might be one of the mechanisms underlying multisensory integration
Sharma, A., Shrimali, M. D., Prasad, A., Ramaswamy, R., and Feudel, U., Phase-flip transition in relay-coupled nonlinear oscillators, Phys. Rev. E, vol. 84, no. 1. American Physical Society (APS), 27-Jul.-2011.
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Ngonghala, C. N., Feudel, U., and Showalter, K., Extreme multistability in a chemical model system, Phys. Rev. E, vol. 83, no. 5. American Physical Society (APS), May-2011.
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Finke, C., Freund, J. A., Rosa, E., Bryant, P. H., Braun, H. A., and Feudel, U., Temperature-dependent stochastic dynamics of the Huber-Braun neuron model, Chaos (Woodbury, N.Y.), vol. 21, no. 4. p. 047510, Dec.-2011.
Abstract DOI
The response of a four-dimensional mammalian cold receptor model to different implementations of noise is studied across a wide temperature range. It is observed that for noisy activation kinetics, the parameter range decomposes into two regions in which the system reacts qualitatively completely different to small perturbations through noise, and these regions are separated by a homoclinic bifurcation. Noise implemented as an additional current yields a substantially different system response at low temperature values, while the response at high temperatures is comparable to activation-kinetic noise. We elucidate how this phenomenon can be understood in terms of state space dynamics and gives quantitative results on the statistics of interspike interval distributions across the relevant parameter range
Braun, H. A., Schwabedal, J., Dewald, M., Finke, C., Postnova, S., Huber, M. T., Wollweber, B., Schneider, H., Hirsch, M. C., Voigt, K., Feudel, U., and Moss, F., Noise-induced precursors of tonic-to-bursting transitions in hypothalamic neurons and in a conductance-based model, Chaos (Woodbury, N.Y.), vol. 21, no. 4. p. 047509, Dec.-2011.
Abstract DOI
The dynamics of neurons is characterized by a variety of different spiking patterns in response to external stimuli. One of the most important transitions in neuronal response patterns is the transition from tonic firing to burst discharges, i.e., when the neuronal activity changes from single spikes to the grouping of spikes. An increased number of interspike-interval sequences of specific temporal correlations was detected in anticipation of temperature induced tonic-to-bursting transitions in both, experimental impulse recordings from hypothalamic brain slices and numerical simulations of a stochastic model. Analysis of the modelling data elucidates that the appearance of such patterns can be related to particular system dynamics in the vicinity of the period-doubling bifurcation. It leads to a nonlinear response on de- and hyperpolarizing perturbations introduced by noise. This explains why such particular patterns can be found as reliable precursors of the neurons' transition to burst discharges
Cederholm, T. E., Bauer, J. M., Boirie, Y., Schneider, S. M., Sieber, C. C., and Rolland, Y., Toward a definition of sarcopenia, Clinics in geriatric medicine, vol. 27, no. 3. pp. 341-353, Aug.-2011.
Abstract DOI
The definition of sarcopenia has been thoroughly discussed by scientific stakeholders and industry representatives to increase the clinical applicability of the concept. The pooled consensus from 3 of 5 recent and parallel processes, of which 2 are pending, is that sarcopenia is mainly, but not only, an age-related condition defined by the combined presence of reduced muscle mass and muscle function. Contributing factors to sarcopenia are senescence, chronic disease, physical inactivity, and poor food intake. Cachexia may be considered as one etiologic pathway of an accelerated sarcopenia. The adjusted and extended definitions of sarcopenia promote the clinical use of the concept
Rosenthal, G. G., Fitzsimmons, J. N., Woods, K. U., Gerlach, G., and Fisher, H. S., Tactical release of a sexually-selected pheromone in a swordtail fish, PloS one, vol. 6, no. 2. p. e16994, 2011.
Abstract DOI
BACKGROUND: Chemical communication plays a critical role in sexual selection and speciation in fishes; however, it is generally assumed that most fish pheromones are passively released since most fishes lack specialized scent glands or scent-marking behavior. Swordtails (genus Xiphophorus) are widely used in studies of female mate choice, and female response to male chemical cues is important to sexual selection, reproductive isolation, and hybridization. However, it is unclear whether females are attending to passively produced cues, or to pheromones produced in the context of communication. METHODOLOGY/PRINCIPAL FINDINGS: We used fluorescein dye injections to visualize pulsed urine release in male sheepshead swordtails, Xiphophorus birchmanni. Simultaneous-choice assays of mating preference showed that females attend to species- and sex-specific chemical cues emitted in male urine. Males urinated more frequently in the presence and proximity of an audience (conspecific females). In the wild, males preferentially courted upstream of females, facilitating transmission of pheromone cues. CONCLUSIONS/SIGNIFICANCE: Males in a teleost fish have evolved sophisticated temporal and spatial control of pheromone release, comparable to that found in terrestrial animals. Pheromones are released specifically in a communicative context, and the timing and positioning of release favors efficient signal transmission
Tagay, S., Düllmann, S., Schlegl, S., Nater-Mewes, R., Repic, N., Hampke, C., Brähler, E., Gerlach, G., and Senf, W., [Effects of inpatient treatment on eating disorder symptoms, health-related quality of life and personal resources in anorexia and bulimia nervosa], Psychotherapie, Psychosomatik, medizinische Psychologie, vol. 61, no. 7. pp. 319-327, Jul.-2011.
Abstract DOI
The aim of the present prospective-naturalistic study was the evaluation of psychosomatic inpatient treatment for anorexia nervosa (AN) and bulimia nervosa (BN). 128 patients with eating disorders (n=59 AN and n=69 BN) were investigated on admission and discharge using the following standardized questionnaires: eating disorder symptoms (EDI), general psychopathology (BSI), quality of life (SF-12), and personal resources (SOC-13, SWE). Moderate to large effect sizes were achieved for the eating disorder symptoms; in addition, general psychopathology was substantially reduced at the end of treatment, and quality of life as well as personal resources were enhanced. Personal resources were found to be the strongest predictors for therapy outcome. Based on our data, important insights and recommendations may be gained for the inpatient treatment of eating disorders, especially with regard to the potential influence of personal resources
Hein, C. M., Engels, S., Kishkinev, D., and Mouritsen, H., Robins have a magnetic compass in both eyes, Nature, vol. 471, no. 7340. pp. E11-2; discussion E12-3, Mar.-2011.
Abstract DOI
Arising from W. Wiltschko et al. 419, 467-470 (2002); Wiltschko et al. replyThe magnetic compass of migratory birds is embedded in the visual system and it has been reported by Wiltschko et al. that European Robins, Erithacus rubecula, cannot show magnetic compass orientation using their left eye only. This has led to the notion that the magnetic compass should be located only in the right eye of birds. However, a complete right lateralization of the magnetic compass would be very surprising, and functional neuroanatomical data have questioned this notion. Here we show that the results of Wiltschko et al. could not be independently confirmed using double-blind protocols. European Robins can perform magnetic compass orientation with both eyes open, with the left eye open only, and with the right eye open only. No clear lateralization is observed
Guilford, T., Åkesson, S., Gagliardo, A., Holland, R. A., Mouritsen, H., Muheim, R., Wiltschko, R., Wiltschko, W., and Bingman, V. P., Migratory navigation in birds: new opportunities in an era of fast-developing tracking technology, The Journal of experimental biology, vol. 214, no. Pt 22. pp. 3705-3712, Nov.-2011.
Abstract DOI
Birds have remained the dominant model for studying the mechanisms of animal navigation for decades, with much of what has been discovered coming from laboratory studies or model systems. The miniaturisation of tracking technology in recent years now promises opportunities for studying navigation during migration itself (migratory navigation) on an unprecedented scale. Even if migration tracking studies are principally being designed for other purposes, we argue that attention to salient environmental variables during the design or analysis of a study may enable a host of navigational questions to be addressed, greatly enriching the field. We explore candidate variables in the form of a series of contrasts (e.g. land vs ocean or night vs day migration), which may vary naturally between migratory species, populations or even within the life span of a migrating individual. We discuss how these contrasts might help address questions of sensory mechanisms, spatiotemporal representational strategies and adaptive variation in navigational ability. We suggest that this comparative approach may help enrich our knowledge about the natural history of migratory navigation in birds
Jansen, S., Luts, H., Wagener, K. C., Kollmeier, B., and Rio, M. D., Comparison of three types of French speech-in-noise tests: A multi-center study, Int. J. Audiol., vol. 51, no. 3. 2011.
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Objective: To compare results on the everyday sentence test ‘FIST’, the new closed-set sentence test ‘FrMatrix’, and the digit triplet screening test ‘FrDigit3’. Design: First, the FrMatrix was developed and normative values were obtained. Subsequently, speech reception thresholds (SRTs) for the three types of tests were gathered at four study centers representing different geographic regions in Belgium and France. Study sample: Fifty-seven normal-hearing listeners took part in the normative study of the FrMatrix, and 118 subjects, with a wide range of hearing thresholds, participated in the comparative study. Results: Homogenizing the individual words of the FrMatrix with regard to their intelligibility resulted in a reference SRT of −6.0 (±0.6) dB SNR and slope at the SRT of 14.0 %/dB. The within-subject variability was only 0.4 dB. Comparison of the three tests showed high correlations between the SRTs mutually (>0.81). The FrMatrix had the highest discriminative power, both in stationary and in fluctuating noise. For all three tests, differences across the participating study centers were small and not significant. Conclusions: The FIST, the FrMatrix, and the FrDigit3 provide similar results and reliably evaluate speech recognition performance in noise both in normal-hearing and hearing-impaired listeners.
Hollmann, M., Rieger, J. W., Baecke, S., Lützkendorf, R., Müller, C., Adolf, D., and Bernarding, J., Predicting Decisions in Human Social Interactions Using Real-Time fMRI and Pattern Classification, PLoS ONE, vol. 6, no. 10. Public Library of Science (PLoS), p. e25304, 7-Oct.-2011.
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Zaehle, T., Sandmann, P., Thorne, J. D., Jäncke, L., and Herrmann, C. S., Transcranial direct current stimulation of the prefrontal cortex modulates working memory performance: combined behavioural and electrophysiological evidence, BMC neuroscience, vol. 12. p. 2, 2011.
Abstract DOI
BACKGROUND: Transcranial direct current stimulation (tDCS) is a technique that can systematically modify behaviour by inducing changes in the underlying brain function. In order to better understand the neuromodulatory effect of tDCS, the present study examined the impact of tDCS on performance in a working memory (WM) task and its underlying neural activity. In two experimental sessions, participants performed a letter two-back WM task after sham and either anodal or cathodal tDCS over the left dorsolateral prefrontal cortex (DLPFC). RESULTS: Results showed that tDCS modulated WM performance by altering the underlying oscillatory brain activity in a polarity-specific way. We observed an increase in WM performance and amplified oscillatory power in the theta and alpha bands after anodal tDCS whereas cathodal tDCS interfered with WM performance and decreased oscillatory power in the theta and alpha bands under posterior electrode sides. CONCLUSIONS: The present study demonstrates that tDCS can alter WM performance by modulating the underlying neural oscillations. This result can be considered an important step towards a better understanding of the mechanisms involved in tDCS-induced modulations of WM performance, which is of particular importance, given the proposal to use electrical brain stimulation for the therapeutic treatment of memory deficits in clinical settings
Zoefel, B., Huster, R. J., and Herrmann, C. S., Neurofeedback training of the upper alpha frequency band in EEG improves cognitive performance, NeuroImage, vol. 54, no. 2. pp. 1427-1431, Jan.-2011.
Abstract DOI
In this study, the individually determined upper alpha frequency band in EEG (electroencephalogram) was investigated as a neurofeedback parameter. Fourteen subjects were trained on five sessions within 1 week by means of feedback dependent on the current upper alpha amplitude. On the first and fifth session, cognitive ability was tested by a mental rotation test. As a result, eleven of the fourteen subjects showed significant training success. Individually determined upper alpha was increased independently of other frequency bands. The enhancement of cognitive performance was significantly larger for the neurofeedback group than for a control group who did not receive feedback. Thus, enhanced cognitive control went along with an increased upper alpha amplitude that was found in the neurofeedback group only
Zaehle, T. and Herrmann, C. S., Neural synchrony and white matter variations in the human brain--relation between evoked γ frequency and corpus callosum morphology, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 79, no. 1. pp. 49-54, Jan.-2011.
Abstract DOI
Synchronous gamma oscillations frame a general principle of functional connectivity and communication in the cortex. Efficient communication and coordination across neural networks rely upon the temporal precision of neural signals, which depends on the structural properties of the fibre bundles serving neural signal transmission. Therefore a direct relation between the geometry of cortical connections and the formation of stimulus-driven synchronous neural activity can be assumed. The aim of the present study was to identify the neuroanatomical correspondents of individual gamma frequency variations. For that purpose we used voxel-based morphometry (VBM) to correlate the frequency of visually evoked gamma band responses (eGBR) with local inter-individual variations in white matter (WM) density across a group of 17 individuals. Analyses demonstrate an association of eGBR frequency and white matter density in the individual human brain. Individuals with a higher eGBR frequency demonstrate increased white matter in fibres of the corpus callosum, whereas participants with low-density callosal WM show lower eGBR frequencies. The observed positive correlation between callosal white matter measure and frequency of visually evoked GBR may indicate that additional or better-myelinated callosal pathways facilitate a more efficient inter-hemispheric information transfer, which is likely to benefit the integration and processing of information and consequently to facilitate more efficient synchronization of neural activity between the two hemispheres
Lenz, D., Fischer, S., Schadow, J., Bogerts, B., and Herrmann, C. S., Altered evoked γ-band responses as a neurophysiological marker of schizophrenia?, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 79, no. 1. pp. 25-31, Jan.-2011.
Abstract DOI
Evoked gamma-band responses (GBRs) were shown to be involved in different aspects of human cognition and behavior. They have been linked to the integration and processing of incoming information leading to an adequate behavioral outcome. Consequently, altered evoked GBRs have been associated with impaired cognitive and behavioral states present in a variety of psychiatric disorders. However, to the best of our knowledge, there are no reports directly comparing evoked GBRs of different clinical groups in the same experimental setting. Thus, the purpose of the present study was to shed light on the question, whether evoked GBRs, as a kind of a neurophysiological biomarker of pathological states, might serve for characterization and distinguishing of groups suffering from diverse psychiatric disorders. We measured EEG during a passive auditory oddball-paradigm. Participants were patients diagnosed with schizophrenia, mood disorder, and personality disorders as well as a fourth group consisting of healthy participants. Our results indicate that evoked GBRs significantly differed from healthy participants only in schizophrenic patients whereas no difference could be observed for the other clinical groups. Our findings support the notion that early evoked GBRs could be indeed a trait variable of schizophrenia and are not a general marker of pathological brain states
Zaehle, T., Beretta, M., Jäncke, L., Herrmann, C. S., and Sandmann, P., Excitability changes induced in the human auditory cortex by transcranial direct current stimulation: direct electrophysiological evidence, Experimental brain research, vol. 215, no. 2. pp. 135-140, Nov.-2011.
Abstract DOI
Transcranial direct current stimulation (tDCS) can systematically modify behavior by inducing changes in the underlying brain function. Objective electrophysiological evidence for tDCS-induced excitability changes has been demonstrated for the visual and somatosensory cortex, while evidence for excitability changes in the auditory cortex is lacking. In the present study, we applied tDCS over the left temporal as well as the left temporo-parietal cortex and investigated tDCS-induced effects on auditory evoked potentials after anodal, cathodal, and sham stimulation. Results show that anodal and cathodal tDCS can modify auditory cortex reactivity. Moreover, auditory evoked potentials were differentially modulated as a function of site of stimulation. While anodal tDCS over the temporal cortex increased auditory P50 amplitudes, cathodal tDCS over the temporo-parietal cortex induced larger N1 amplitudes. The results directly demonstrate excitability changes in the auditory cortex induced by active tDCS over the temporal and temporo-parietal cortex and might contribute to the understanding of mechanisms involved in the successful treatment of auditory disorders like tinnitus via tDCS
Hartmann, A. -maria and Nothwang, H. G., Opposite temperature effect on transport activity of KCC2/KCC4 and N(K)CCs in HEK-293 cells, BMC Res Notes, vol. 4, no. 1. Springer Nature, p. 526, 2011.
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Endler, P. C., Matzer, W., Reich, C., Reischl, T., Hartmann, A. -maria, Thieves, K., Pfleger, A., Hofäcker, J., Lothaller, H., and Scherer-pongratz, W., Seasonal Variation of the Effect of Extremely Diluted Agitated Gibberellic Acid (10e-30) on Wheat Stalk Growth: A Multiresearcher Study, The Scientific World JOURNAL, vol. 11. Hindawi Publishing Corporation, pp. 1667-1678, 2011.
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Hartmann, A. -M., Abarzua, S., Schlichting, A., Richter, D. -U., Leinweber, P., and Briese, V., Effects of elm bark extracts from Ulmus laevis on human chorion carcinoma cell lines, Archives of Gynecology and Obstetrics, vol. 284, no. 5. Springer Nature, pp. 1265-1269, 12-Jan.-2011.
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Soeroes, P., Bose, A., Sokoloff, L. G., Graham, S. J., and Stuss, D. T., Age-related changes in the functional neuroanatomy of overt speech production, NEUROBIOLOGY OF AGING, vol. 32, no. 8. Aug.-2011.
Abstract
Alterations of existing neural networks during healthy aging, resulting in behavioral deficits and changes in brain activity, have been described for cognitive, motor, and sensory functions. To investigate age-related changes in the neural circuitry underlying overt non-lexical speech production, functional MRI was performed in 14 healthy younger (21-32years) and 14 healthy older individuals (62-84years). The experimental task involved the acoustically cued overt production of the vowel /a/ and the polysyllabic utterance /pataka/. In younger and older individuals, overt speech production was associated with the activation of a widespread articulo-phonological network, including the primary motor cortex, the supplementary motor area, the cingulate motor areas, and the posterior superior temporal cortex, similar in the /a/ and /pataka/ condition. An analysis of variance with the factors age and condition revealed a significant main effect of age. Irrespective of the experimental condition, significantly greater activation was found in the bilateral posterior superior temporal cortex, the posterior temporal plane, and the transverse temporal gyri in younger compared to older individuals. Significantly greater activation was found in the bilateral middle temporal gyri, medial frontal gyri, middle frontal gyri, and inferior frontal gyri in older vs. younger individuals. The analysis of variance did not reveal a significant main effect of condition and no significant interaction of age and condition. These results suggest a complex reorganization of neural networks dedicated to the production of speech during healthy aging. (C) 2009 Elsevier Inc. All rights reserved.
Soeroes, P., Al-Otaibi, F., Wong, S. W. H., Shoemaker, J. K., Mirsattari, S. M., Hachinski, V., and Martin, R. E., Stuttered swallowing: Electric stimulation of the right insula interferes with water swallowing. A case report, BMC NEUROLOGY, vol. 11. Feb.-2011.
Abstract
Background: Various functional resonance imaging, magnetoencephalographic and lesion studies suggest the involvement of the insular cortex in the control of swallowing. However, the exact location of insular activation during swallowing and its functional significance remain unclear. Case presentation: Invasive electroencephalographic monitoring was performed in a 24-year-old man with medically intractable stereotyped nocturnal hypermotor seizures due to a ganglioglioma. During stimulation of the right inferior posterior insular cortex with depth electrodes the patient spontaneously reported a perception of a ``stutter in swallowing{''}. Stimulation of the inferior posterior insular cortex at highest intensity (4 mA) was also associated with irregular and delayed swallows. Swallowing was not impaired during stimulation of the superior posterior insular cortex, regardless of stimulation intensity. Conclusions: These results indicate that the right inferior posterior insular cortex is involved in the neural circuitry underlying the control of swallowing.
Braun, D., Kinne, A., Braeuer, A. U., Sapin, R., Klein, M. O., Koehrle, J., Wirth, E. K., and Schweizer, U., Developmental and Cell Type-Specific Expression of Thyroid Hormone Transporters in the Mouse Brain and in Primary Brain Cells, GLIA, vol. 59, no. 3. WILEY-LISS, Mar.-2011.
Abstract
Cellular thyroid hormone uptake and efflux are mediated by transmembrane transport proteins. One of these, monocarboxylate transporter 8 (MCT8) is mutated in Allan-Herndon-Dudley syndrome, a severe mental retardation associated with abnormal thyroid hormone constellations. Since mice deficient in Mct8 exhibit a milder neurological phenotype than patients, we hypothesized that alternative thyroid hormone transporters may compensate in murine brain cells for the lack of Mct8. Using qPCR, Western Blot, and immunocytochemistry, we investigated the expression of three different thyroid hormone transporters, i.e., Mct8 and L-type amino acid transporters Lat1 and Lat2, in mouse brain. All three thyroid hormone transporters are expressed from corticogenesis and peak around birth. Primary cultures of neurons and astrocytes express Mct8, Lat1, and Lat2. Microglia specifically expresses Met10 and Slco4a1 in addition to high levels of Lat2 mRNA and protein. As in vivo, a brain microvascular endothelial cell line expressed Mct8 and Lat1. 158N, an oligodendroglial cell line expressed Mct8 protein, consistent with delayed myelination in MCT8-deficient patients. Functional T(3)- and T(4)-transport assays into primary astrocytes showed K(M) values of 4.2 and 3.7 mu M for T(3) and T(4). Pharmacological inhibition of L-type amino acid transporters by BCH and genetic inactivation of Lat2 reduced astrocytic T(3) uptake to the same extent. BSP, a broad spectrum inhibitor, including Mct8, reduced T(3) uptake further suggesting the cooperative activity of several T(3) transporters in astrocytes. (C)2010 Wiley-Liss, Inc.
Bach, J. -H., Anemueller, J., and Kollmeier, B., Robust speech detection in real acoustic backgrounds with perceptually motivated features, SPEECH COMMUNICATION, vol. 53, no. 5, SI. ELSEVIER SCIENCE BV, Jan.-2011.
Abstract
The current study presents an analysis of the robustness of a speech detector in real background sounds. One of the most important aspects of automatic speech/nonspeech classification is robustness in the presence of strongly varying external conditions. These include variations of the signal-to-noise ratio as well as fluctuations of the background noise. These variations are systematically evaluated by choosing different mismatched conditions between training and testing of the speech/nonspeech classifiers. The detection performance of the classifier with respect to these mismatched conditions is used as a measure of robustness and generalisation. The generalisation towards un-trained SNR conditions and unknown background noises is evaluated and compared to a matched baseline condition. The classifier consists of a feature front-end, which computes amplitude modulation spectral features (AMS), and a support vector machine (SVM) back-end. The AMS features are based on Fourier decomposition over time of short-term spectrograms. Mel-frequency cepstral coefficients (MFCC) as well as relative spectral features (RASTA) based on perceptual linear prediction (PLP) serve as baseline. The results show that RASTA-filtered PLP features perform best in the matched task. In the generalisation tasks however, the AMS features emerge as more robust in most cases, while MFCC features are outperformed by both other feature types. In a second set of experiments, a hierarchical approach is analysed which employs a background classification step prior to the speech/nonspeech classifier in order to improve the robustness of the detection scores in novel backgrounds. The background sounds used are recorded in typical everyday scenarios. The hierarchy provides a benefit in overall performance if the robust AMS features are employed. The generalisation capabilities of the hierarchy towards novel backgrounds and SNRs is found to be optimal when a limited number of training backgrounds is used (compared to the inclusion of all available background data). The best backgrounds in terms of generalisation capabilities are found to be backgrounds in which some component of speech (such as unintelligible background babble) is present, which corroborates the hypothesis that the AMS features provide a decomposition of signals which is by itself very suitable for training very general speech/nonspeech detectors. This is also supported by the finding that the SVMs combined with RASTA-PLPs require nonlinear kernels to reach a similar performance as the AMS patterns with linear kernels. (C) 2010 Elsevier B.V. All rights reserved.
Daniels, C., Krack, P., Volkmann, J., Raethjen, J., Pinsker, M. O., Kloss, M., Tronnier, V., Schnitzler, A., Wojtecki, L., Boetzel, K., Danek, A., Hilker, R., Sturm, V., Kupsch, A., Karner, E., Deuschl, G., and Witt, K., Is improvement in the quality of life after subthalamic nucleus stimulation in Parkinson's disease predictable?, MOVEMENT DISORDERS, vol. 26, no. 14. WILEY-BLACKWELL, Dec.-2011.
Abstract
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) significantly improves quality of life (QoL) in PD. However, QoL fails to improve in a relevant proportion of patients. We studied clinical baseline and progression parameters associated with improvement in QoL after DBS. Data from a German randomized, controlled study comparing DBS (60 patients) with best medical treatment (59 patients) were analyzed. Changes in patients' QoL were assessed using the Parkinson's Disease Questionnaire (PDQ-39) at baseline and at the 6-month follow-up. For the STN-DBS patients, the changes in PDQ-39 were correlated with predefined clinical preoperative and progression parameters. Scores for QoL improved after STN-DBS for 57\% of the patients, and for 43\% patients, they did not improve. Patients with improvement in QoL showed significantly higher cumulative daily off time. Changes in the PDQ-39 showed a significant positive correlation with the cumulative daily off time at baseline. Logistic regression analysis revealed that 1 additional hour off time at baseline increases the odds for improvement on PDQ-39 by a factor of 1.33 (odds ratio). In the postoperative course, changes in the PDQ-39 significantly correlated with the reduction of cumulative daily off time, an improvement on the UPDRS (UPDRS III off), and positive mood changes. Among the baseline parameters, the cumulative daily off time is the strongest predictor for improvement in disease-related QoL after DBS. Improvement in QoL after STN-DBS is also correlated with changes in motor functions and changes in depression and anxiety. (c) 2011 Movement Disorder Society
Witt, K., Daniels, C., Krack, P., Volkmann, J., Pinsker, M. O., Kloss, M., Tronnier, V., Schnitzler, A., Wojtecki, L., Boetzel, K., Danek, A., Hilker, R., Sturm, V., Kupsch, A., Karner, E., and Deuschl, G., Negative impact of borderline global cognitive scores on quality of life after subthalamic nucleus stimulation in Parkinson's disease, JOURNAL OF THE NEUROLOGICAL SCIENCES, vol. 310, no. 1-2, SI. ELSEVIER SCIENCE BV, Nov.-2011.
Abstract
Deep brain stimulation (DBS) of the subthalamic nucleus (STN) significantly improves quality of life (QoL) in Parkinson's disease (PD). Dementia is considered as a contraindication for STN-DBS. However, no controlled study assessed the impact of STN-DBS on the QoL and motor outcome in PD patients with a borderline global cognitive impairment. We studied clinical baseline and progression parameters in a cohort of STN-DBS patients with a global cognitive score still in the non-demented range but scoring in the lowest quartile of the Mattis Dementia Rating Scale (MDRS), a measure of global cognitive functioning. Data from a German randomised controlled study comparing DBS (60 patients) with best medical treatment (BMT, 59 patients) were analysed. Changes in patients' QoL scores were assessed using the Parkinson's disease questionnaire (PDQ-39) at baseline and at the 6 months follow up. Patients were split into four groups according to their MDRS performance at baseline and these groups were compared in the context of motor outcome and QoL Twelve out of sixty patients of the STN-DBS group scored in the lowest quartile of the MDRS (range between one hundred thirty and one hundred thirty seven points). An individual analysis revealed that 3 of 12 patients showed a clinical relevant improvement in QoL whereas the group statistics did not reveal any significant improvement in QoL measures after STN-DBS compared to the BMT group. Since this failure to improve in QoL cannot be explained by a failure to improve in motor functions, stimulation settings and psychiatric scales after STN-DBS, the failure to improve in QoL in patients with a borderline global cognitive score might be specifically related to lower cognitive functioning. (C) 2011 Elsevier B.V. All rights reserved.
Reiff, J., Schmidt, N., Riebe, B., Breternitz, R., Aldenhoff, J., Deuschl, G., and Witt, K., Subthreshold Depression in Parkinson's Disease, MOVEMENT DISORDERS, vol. 26, no. 9. WILEY-BLACKWELL, Aug.-2011.
Abstract
Background: Quality of life in Parkinson patients with subthreshold depression could be improved if the prevalence and symptom profile were better understood. Methods: Our study used standard DSM-IV and Judd criteria as well as motor, depression, and quality-of-life scales to investigate a sample of 110 nondemented Parkinson patients. This led to formation of nondepressed (48.2\%), subthreshold depressed (25.5\%), and depressed (26.4\%) groups. Results: Quality of life was seen to be significantly lower in subthreshold depressed patients than in the nondepressed, and there were differences in the frequency of depressive symptoms that partially overlapped with nonmotor symptoms of vegetative origin in Parkinson's disease (appetite, sleep disorders). Key measures of depression (diminished interest/pleasure) were more frequent in the depressed group compared with the subthreshold depressed, although the motor functions of these 2 groups did not differ significantly. Conclusions: The Beck Depression Inventory score ranging from 9 to 15 points differentiates subthreshold depressed from nondepressed and depressed patients best. (C) 2011 Movement Disorder Society
Balzer-Geldsetzer, M., da Costa, A. S. F. B., Kronenbuerger, M., Schulz, J. B., Roeske, S., Spottke, A., Wuellner, U., Klockgether, T., Storch, A., Schneider, C., Riedel, O., Wittchen, H. -U., Seifried, C., Hilker, R., Schmidt, N., Witt, K., Deuschl, G., Mollenhauer, B., Trenkwalder, C., Liepelt-Scarfone, I., Graeber-Sultan, S., Berg, D., Gasser, T., Kalbe, E., Bodden, M., Oertel, W. H., and Dodel, R., Parkinson's Disease and Dementia: A Longitudinal Study (DEMPARK), NEUROEPIDEMIOLOGY, vol. 37, no. 3-4. KARGER, 2011.
Abstract
Background: Parkinson's disease (PD) is a progressive neurodegenerative motor disorder. However, non-motor complications frequently alter the course of the disease. A particularly disabling non-motor symptom is dementia. Methods/Design: The study is designed as a multicentre prospective, observational cohort study of about 700 PD patients aged 45-80 years with or without dementia and PD-mild cognitive impairment (MCI). The patients will be recruited in eight specialized movement disorder clinics and will be followed for 36 months. Information about the patients' functional status will be assessed at baseline and 6-/12-month intervals. In addition, 120 patients with dementia with Lewy bodies (DLB) will be included. Well-established standardized questionnaires/tests will be applied for detailed neuropsychological assessment. In addition, patients will be asked to participate in modules including volumetric MRI, genetic parameters, and neuropsychology to detect risk factors, early diagnostic biomarkers and predictors for dementia in PD. Results: The study included 604 PD patients by March 2011; 56.3\% were classified as having PD alone, with 30.6\% of patients suffering from PD-MCI and 13.1\% from PD with dementia. The mean age of the cohort was 68.6 +/- 7.9 years, with a mean disease duration of 6.8 +/- 5.4 years. There was a prepon derance of patients in the earlier Hoehn and Yahr stages. Conclusion: The main aim of the study is to characterize the natural progression of cognitive impairment in PD and to identify factors which contribute to the evolution and/or progression of the cognitive impairment. To accomplish this aim we established a large cohort of PD patients without cognitive dysfunction, PD patients with MCI, and PD patients with dementia, to characterize these patients in a standardized manner, using imaging (serial structural MRI), genetic and proteomic methods in order to improve our understanding of the course of the PD process and the development of cognitive dysfunction and dementia in this disease. The inclusion of the DLB patients will start in the second quarter of 2011 in the BMBF-funded follow-up project LANDSCAPE. Copyright (C) 2011 S. Karger AG, Basel
Hein, A., Strauß, M., and Lüth, T., Navigated Control: Leistungsregelung chirurgischer Instrumente, Computerassistierte Chirurgie. Elsevier BV, pp. 259-266, 2011.
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Gaefke, C., Baumgartner, H., Brell, M., Simon, S., and Hein, A., System Architecture for Palliative Care in the Home Environment, Ambient Assisted Living. Springer Science + Business Media, pp. 103-115, 2011.
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Kretschmer, T. and Heros, R. C., Microsurgical Management of Arteriovenous Malformations, Youmans Neurological Surgery. Elsevier BV, pp. 4072-4087, 2011.
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Kretschmer, T. and Birch, R., Management of Acute Peripheral Nerve Injuries, Youmans Neurological Surgery. Elsevier BV, pp. 2465-2483, 2011.
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Farhat, H., Kretschmer, T., and Morcos, J. J., Nonlesional Spontaneous Intracerebral Hemorrhage, Youmans Neurological Surgery. Elsevier BV, pp. 3706-3729, 2011.
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Weyland, A., Geleitwort, Leitfaden Rettungsdienst. Elsevier BV, p. v, 2011.
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Isken, M., Vester, B., Frenken, T., Steen, E. -E., Brell, M., and Hein, A., Enhancing Mobile Robots’ Navigation through Mobility Assessments in Domestic Environments, Ambient Assisted Living. Springer Science + Business Media, pp. 223-238, 2011.
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Rössler, O. E., Kuypers, H., and Parisi, J., Gravitational slowing down of clocks implies proportional size increase, Lecture Notes in Physics. Springer Science + Business Media, pp. 370-372, 2011.
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Diederich, A., Einstellungen zu Priorisierungen in der medizinischen Versorgung, Priorisierte Medizin. Springer Science + Business Media, pp. 13-38, 2011.
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Colonius, H. and Diederich, A., The Multisensory Driver: Contributions from the Time-Window-of-Integration Model, Human Modelling in Assisted Transportation. Springer Science + Business Media, pp. 363-371, 2011.
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Roth, G., Lück, M., and Strüber, D., Cerveau, libre arbitre et droit pénal, Ethique et droit - Culpabilité et retribution. Editions Schwabe, pp. 59-70, 2011.
Abstract
Dell'Orco, D. and Koch, K. -W., Systems biochemistry approaches to vertebrate phototransduction: towards a molecular understanding of disease, Biochemical Society transactions, vol. 38, no. 5. Oct.-2010.
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Komolov, K. E. and Koch, K. -W., Application of surface plasmon resonance spectroscopy to study G-protein coupled receptor signalling, Methods in molecular biology (Clifton, N.J.), vol. 627. 2010.
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Behnen, P., Dell'Orco, D., and Koch, K. -W., Involvement of the calcium sensor GCAP1 in hereditary cone dystrophies, Biological chemistry, vol. 391, no. 6. Jun.-2010.
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Koch, K. -W., Duda, T., and Sharma, R. K., Ca(2+)-modulated vision-linked ROS-GC guanylate cyclase transduction machinery, Molecular and cellular biochemistry, vol. 334, no. 1-2. Jan.-2010.
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Rätscho, N., Scholten, A., and Koch, K. -W., Diversity of sensory guanylate cyclases in teleost fishes, Molecular and cellular biochemistry, vol. 334, no. 1-2. Jan.-2010.
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Dell'Orco, D., Müller, M., and Koch, K. -W., Quantitative detection of conformational transitions in a calcium sensor protein by surface plasmon resonance, Chemical communications (Cambridge, England), vol. 46, no. 39. Oct.-2010.
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Dell'Orco, D., Behnen, P., Linse, S., and Koch, K. -W., Calcium binding, structural stability and guanylate cyclase activation in GCAP1 variants associated with human cone dystrophy, Cellular and molecular life sciences : CMLS, vol. 67, no. 6. Mar.-2010.
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Komolov, K. E., Aguilà, M., Toledo, D., Manyosa, J., Garriga, P., and Koch, K. -W., On-chip photoactivation of heterologously expressed rhodopsin allows kinetic analysis of G-protein signaling by surface plasmon resonance spectroscopy, Analytical and bioanalytical chemistry, vol. 397, no. 7. Aug.-2010.
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Fries, R., Reddy, P. P., Mikhaylova, M., Haverkamp, S., Wei, T., Müller, M., Kreutz, M. R., and Koch, K. -W., Dynamic cellular translocation of caldendrin is facilitated by the Ca2+-myristoyl switch of recoverin, Journal of neurochemistry, vol. 113, no. 5. Jun.-2010.
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Broaddus, D. H., Foster, M. A., Kuzucu, O., Turner-Foster, A. C., Koch, K. -W., Lipson, M., and Gaeta, A. L., Temporal-imaging system with simple external-clock triggering, Optics express, vol. 18, no. 13. Jun.-2010.
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Hilgen, G., von Maltzahn, J., Willecke, K., Weiler, R., and Dedek, K., Subcellular distribution of connexin45 in OFF bipolar cells of the mouse retina, J. Comp. Neurol., vol. 519, no. 3. Wiley-Blackwell, pp. 433-450, Dec.-2010.
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Feigenspan, A., Dedek, K., Schlich, K., Weiler, R., and Thanos, S., Expression and Biophysical Characterization of Voltage-Gated Sodium Channels in Axons and Growth Cones of the Regenerating Optic Nerve, Invest. Ophthalmol. Vis. Sci., vol. 51, no. 3. Association for Research in Vision and Ophthalmology (ARVO), p. 1789, 1-Mar.-2010.
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Pérez De Sevilla Müller, L., Dedek, K., Janssen-Bienhold, U., Meyer, A., Kreuzberg, M. M., Lorenz, S., Willecke, K., and Weiler, R., Expression and modulation of connexin30.2, a novel gap junction protein in the mouse retina, Visual Neuroscience, vol. 27, no. 3-4. Cambridge University Press (CUP), pp. 91-101, 11-Jun.-2010.
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Poloschek, C. M., Bach, M., Lagrèze, W. A., Glaus, E., Lemke, J. R., Berger, W., and Neidhardt, J., ABCA4 and ROM1: Implications for Modification of the PRPH2 -Associated Macular Dystrophy Phenotype , Invest. Ophthalmol. Vis. Sci., vol. 51, no. 8. Association for Research in Vision and Ophthalmology (ARVO), p. 4253, 1-Aug.-2010.
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Brunner, S., Skosyrski, S., Kirschner-Schwabe, R., Knobeloch, K. -P., Neidhardt, J., Feil, S., Glaus, E., Luhmann, U. F. O., Rüther, K., and Berger, W., Cone versus Rod Disease in a Mutant Rpgr Mouse Caused by Different Genetic Backgrounds , Invest. Ophthalmol. Vis. Sci., vol. 51, no. 2. Association for Research in Vision and Ophthalmology (ARVO), p. 1106, 1-Feb.-2010.
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Zuercher, J., Neidhardt, J., Magyar, I., Labs, S., Moore, A. T., Tanner, F. C., Waseem, N., Schorderet, D. F., Munier, F. L., Bhattacharya, S., Berger, W., and Kloeckener-Gruissem, B., Alterations of the 5′Untranslated Region of SLC16A12 Lead to Age-Related Cataract , Invest. Ophthalmol. Vis. Sci., vol. 51, no. 7. Association for Research in Vision and Ophthalmology (ARVO), p. 3354, 1-Jul.-2010.
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Schmid, F., Glaus, E., Cremers, F. P. M., Kloeckener-Gruissem, B., Berger, W., and Neidhardt, J., Mutation- and Tissue-Specific Alterations of RPGR Transcripts , Invest. Ophthalmol. Vis. Sci., vol. 51, no. 3. Association for Research in Vision and Ophthalmology (ARVO), p. 1628, 1-Mar.-2010.
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Berger, W., Kloeckener-Gruissem, B., and Neidhardt, J., The molecular basis of human retinal and vitreoretinal diseases, Progress in Retinal and Eye Research, vol. 29, no. 5. Elsevier BV, pp. 335-375, Sep.-2010.
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Liu, X., Wallmann, I., Boudinov, H., Kjelstrup-Hansen, J., Schiek, M., Lützen, A., and Rubahn, H. -G., AC-biased organic light-emitting field-effect transistors from naphthyl end-capped oligothiophenes, Organic Electronics, vol. 11, no. 6. Elsevier BV, pp. 1096-1102, Jun.-2010.
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Frank, M., Eiberger, B., Janssen-Bienhold, U., De Sevilla Muller, L. P., Tjarks, A., Kim, J. -S., Maschke, S., Dobrowolski, R., Sasse, P., Weiler, R., Fleischmann, B. K., and Willecke, K., Neuronal connexin-36 can functionally replace connexin-45 in mouse retina but not in the developing heart, Journal of Cell Science, vol. 123, no. 20. The Company of Biologists, pp. 3605-3615, 7-Oct.-2010.
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Ruigendijk, E., Determiner Omission in Dutch Agrammatic Aphasia: Different from German, Similar to English?, Journal of Germanic Linguistics, vol. 22, no. 04. Cambridge University Press (CUP), pp. 445-459, Dec.-2010.
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Kranczioch, C., Mathews, S., Dean, P., and Sterr, A., Task Complexity Differentially Affects Executed and Imagined Movement Preparation: Evidence from Movement-Related Potentials, PLoS ONE, vol. 5, no. 2. Public Library of Science (PLoS), p. e9284, 19-Feb.-2010.
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Bantel, C., Maze, M., and Trapp, S., Noble Gas Xenon Is a Novel Adenosine Triphosphate-sensitive Potassium Channel Opener, Anesthesiology, vol. 112, no. 3. Ovid Technologies (Wolters Kluwer Health), pp. 623-630, Mar.-2010.
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Jänen, S. B., Chaachouay, H., and Richter-Landsberg, C., Autophagy is activated by proteasomal inhibition and involved in aggresome clearance in cultured astrocytes, Glia, vol. 58, no. 14. Wiley-Blackwell, pp. 1766-1774, 19-Jul.-2010.
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Bolhuis, S. and Richter-Landsberg, C., Effect of proteasome inhibition by MG-132 on HSP27 oligomerization, phosphorylation, and aggresome formation in the OLN-93 oligodendroglia cell line, Journal of Neurochemistry. Wiley-Blackwell, Feb.-2010.
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Schwarz, L., Vollmer, G., and Richter-Landsberg, C., The Small Heat Shock Protein HSP25/27 (HspB1) Is Abundant in Cultured Astrocytes and Associated with Astrocytic Pathology in Progressive Supranuclear Palsy and Corticobasal Degeneration, International journal of cell biology, vol. 2010. p. 717520, 2010.
Abstract DOI
Filamentous tau-positive protein inclusions in neurons and glia are prominent features of a number of neurodegenerative disorders termed tauopathies. These inclusions are further characterized by the presence of heat shock proteins (HSPs). The group of small HSPs, namely, HSP27 and alphaB-crystallin, interact with the cytoskeleton, bind to nonnative proteins, and prevent their aggregation after stress. To further investigate their contribution to neurodegenerative diseases, we have analyzed the association of HSP27 with pathological lesions of tauopathies. Microarray and immunoblot analysis revealed that HSP27 is enhanced at the mRNA and protein levels in affected brains, and that it is associated with astrocytic pathology. The upregulation of HSP27 in tauopathies with gial pathology implies distinct mechanisms for glial and neuronal cells. This was sustained by cell culture studies, demonstrating that the small HSPs are specifically and prominently expressed in unstressed astrocytes and not in neurons and in neurons remained at a rather low level even after stress situations
Riedel, M., Goldbaum, O., Schwarz, L., Schmitt, S., and Richter-Landsberg, C., 17-AAG induces cytoplasmic alpha-synuclein aggregate clearance by induction of autophagy, PloS one, vol. 5, no. 1. p. e8753, 2010.
Abstract DOI
BACKGROUND: The accumulation and aggregation of alpha-synuclein in nerve cells and glia are characteristic features of a number of neurodegenerative diseases termed synucleinopathies. alpha-Synuclein is a highly soluble protein which in a nucleation dependent process is capable of self-aggregation. The causes underlying aggregate formation are not yet understood, impairment of the proteolytic degradation systems might be involved. METHODOLOGY/PRINCIPAL FINDINGS: In the present study the possible aggregate clearing effects of the geldanamycin analogue 17-AAG (17-(Allylamino)-17-demethoxygeldanamycin) was investigated. Towards this, an oligodendroglial cell line (OLN-93 cells), stably expressing human alpha-synuclein (A53T mutation) was used. In these cells small punctate aggregates, not staining with thioflavine S, representing prefibrillary aggregates, occur characteristically. Our data demonstrate that 17-AAG attenuated the formation of alpha-synuclein aggregates by stimulating macroautophagy. By blocking the lysosomal compartment with NH(4)Cl the aggregate clearing effects of 17-AAG were abolished and alpha-synuclein deposits were enlarged. Analysis of LC3-II immunoreactivity, which is an indicator of autophagosome formation, further revealed that 17-AAG led to the recruitment of LC3-II and to the formation of LC3 positive puncta. This effect was also observed in cultured oligodendrocytes derived from the brains of newborn rats. Inhibition of macroautophagy by 3-methyladenine prevented 17-AAG induced occurrence of LC3 positive puncta as well as the removal of alpha-synuclein aggregates in OLN-A53T cells. CONCLUSIONS: Our data demonstrate for the first time that 17-AAG not only causes the upregulation of heat shock proteins, but also is an effective inducer of the autophagic pathway by which alpha-synuclein can be removed. Hence geldanamycin derivatives may provide a means to modulate autophagy in neural cells, thereby ameliorating pathogenic aggregate formation and protecting the cells during disease and aging
Brand, A., Bauer, N. G., Hallott, A., Goldbaum, O., Ghebremeskel, K., Reifen, R., and Richter-Landsberg, C., Membrane lipid modification by polyunsaturated fatty acids sensitizes oligodendroglial OLN-93 cells against oxidative stress and promotes up-regulation of heme oxygenase-1 (HSP32), Journal of neurochemistry, vol. 113, no. 2. pp. 465-476, Apr.-2010.
Abstract DOI
Polyunsaturated fatty acids (PUFA) are highly abundant in brain tissue, and docosahexaenoic acid (DHA) might protect cells from oxidative stress (OS) during inflammation and demyelinating disorders, but also might exert pro-oxidant effects. Here we investigated if PUFA supplements lead to heat shock protein induction, altered cell survival properties and stress responses to OS exerted by hydrogen peroxide in oligodendroglial OLN-93 cells. The data show that supplements of various fatty acids (FA) with 18-22 carbons chain length and 2-6 double bonds led to PUFA enrichment in cellular membranes. Depending on the degree of desaturation, FA-supplements caused the up-regulation of heme oxygenase-1 (HSP32), a stress protein inducible by OS, and an increase in sensitivity to hydrogen peroxide-treatment. DHA, with the highest number of double bonds, was most effective. Co-treatment with DHA and the lipophilic vitamin E analogue alpha-tocopherol, suppressed heme oxygenase-1 up-regulation and cell survival was restored. Analysis of the lipid profile demonstrates that alpha-tocopherol not only has antioxidant capacities, but also directly modified the PUFA profile in cell membranes. Enrichment with higher omega-3, -6 and -9 PUFA and an increase in the biosynthesis rate of very long chain fatty acids, mainly changed the FA profile of ethanolamine and serine phosphoglycerides
Hoffmann, A., Grimm, C., Kraft, R., Goldbaum, O., Wrede, A., Nolte, C., Hanisch, U. -K., Richter-Landsberg, C., Brück, W., Kettenmann, H., and Harteneck, C., TRPM3 is expressed in sphingosine-responsive myelinating oligodendrocytes, Journal of neurochemistry, vol. 114, no. 3. pp. 654-665, Aug.-2010.
Abstract DOI
Oligodendrocytes are the myelin-forming cells of the CNS and guarantee proper nerve conduction. Sphingosine, one major component of myelin, has recently been identified to activate TRPM3, a member of the melastatin-related subfamily of transient receptor potential (TRP) channels. TRPM3 has been demonstrated to be expressed in brain with unknown cellular distribution. Here, we show for the first time that TRPM3 is expressed in oligodendrocytes in vitro and in vivo. TRPM3 is present during oligodendrocyte differentiation. Immunohistochemistry of adult rat brain slices revealed staining of white matter areas, which co-localized with oligodendrocyte markers. Analysis of the developmental distribution revealed that, prior to myelination, TRPM3 channels are localized on neurons. On oligodendrocytes they are found after the onset of myelination. RT-PCR studies showed that the transcription of TRPM3 splice variants is also developmentally regulated in vitro. Ca(2+) imaging approaches revealed the presence of a sphingosine-induced Ca(2+) entry mechanism in oligodendrocytes - with a pharmacological profile similar to the profile published for heterologously expressed TRPM3. These findings indicate that TRPM3 participates as a Ca(2+)-permeable and sphingosine-activated channel in oligodendrocyte differentiation and CNS myelination
Beutelmann, R., Brand, T., and Kollmeier, B., Revision, extension, and evaluation of a binaural speech intelligibility model, J. Acoust. Soc. Am., vol. 127, no. 4. Acoustical Society of America (ASA), p. 2479, 2010.
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Epp, B., Verhey, J. L., and Mauermann, M., Modeling cochlear dynamics: Interrelation between cochlea mechanics and psychoacousticsa), J. Acoust. Soc. Am., vol. 128, no. 4. Acoustical Society of America (ASA), pp. 1870-1883, Oct.-2010.
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Chory, C., Zutz, F., Witt, F., Borchert, H., and Parisi, J., Synthesis and characterization of Cu2ZnSnS4, Phys. Status Solidi (c), vol. 7, no. 6. Wiley-Blackwell, pp. 1486-1488, 31-Mar.-2010.
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Kruszynska, M., Borchert, H., Parisi, J., and Kolny-Olesiak, J., Synthesis and shape control of CuInS(2) nanoparticles, Journal of the American Chemical Society, vol. 132, no. 45. pp. 15976-15986, Nov.-2010.
Abstract DOI
Cu(2)S-CuInS(2) hybrid nanostructures as well as pure CuInS(2) (CIS) nanocrystals were synthesized by methods of colloidal chemistry. The structure, the shape and the composition of these nanomaterials were investigated with transmission electron microscopy (TEM), powder X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX). By changing the reaction conditions, CuInS(2) nanorods with different aspect ratio, dimeric nanorods as well as hexagonal discs and P-shaped particles could be synthesized. Under our reaction conditions, CIS nanoparticles crystallize in the hexagonal wurtzite structure, as confirmed by Rietveld analysis of the X-ray diffraction patterns. The formation of Cu(2)S-CuInS(2) hybrid nanostructures turned out to be an essential intermediate step in the growth of CIS nanoparticles, the copper sulphide part of the hybrid material playing an important role in the shape control of the CIS nanocrystals. By a treatment of Cu(2)S-CuInS(2) with 1,10-phenanthroline, Cu(2)S parts of the hybrid nanostructures could be removed, and pure CIS nanoparticles with shapes not accessible with other methods can be obtained. Our synthetic procedure turned out to be suitable to synthesize also other compounds, like CuInS(2)-ZnS alloys, and to modify, in this way, the optical properties of the nanocrystals
Vasa, P. and Lienau, C., Eine ungewöhnliche Vermählung: die Kopplung molekularer Exzitonen an Oberflächenplasmon-Polaritonen in Metall-Nanostrukturen, Angewandte Chemie, vol. 122, no. 14. Wiley-Blackwell, pp. 2527-2529, 1-Mar.-2010.
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Lienau, C., Analytic Dirac approximation for real linear algebraic groups, Math. Ann., vol. 351, no. 2. Springer Science + Business Media, pp. 403-410, 20-Nov.-2010.
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Parchmann, I., Lienau, C., Klüner, T., Drögemüller, S., and Al-Shamery, K., „Kann man Atome sehen?“ - Eine Reflexion aus Sicht verschiedener Wissenschaften. “Can You See Atoms?” - A Reflection from Different Scientific Perspectives, CHEMKON, vol. 17, no. 2. Wiley-Blackwell, pp. 59-65, Apr.-2010.
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Vasa, P. and Lienau, C., An Unusual Marriage: Coupling Molecular Excitons to Surface Plasmon Polaritons in Metal Nanostructures, Angew. Chem. Int. Ed., vol. 49, no. 14. Wiley-Blackwell, pp. 2476-2477, 29-Mar.-2010.
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Gütay, L., Lienau, C., and Bauer, G. H., Subgrain size inhomogeneities in the luminescence spectra of thin film chalcopyrites, Applied Physics Letters, vol. 97, no. 5. AIP Publishing, p. 052110, 2010.
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Hoyer, T., Tuszynski, W., and Lienau, C., Competing ultrafast photoinduced quenching reactions in cinnamic acid : peptide blends, Physical Chemistry Chemical Physics, vol. 12, no. 40. Royal Society of Chemistry (RSC), p. 13052, 2010.
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Rach, S., Diederich, A., and Colonius, H., On quantifying multisensory interaction effects in reaction time and detection rate, Psychological Research, vol. 75, no. 2. Springer Science + Business Media, pp. 77-94, 29-May-2010.
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Colonius, H. and Diederich, A., The optimal time window of visual-auditory integration: a reaction time analysis, Frontiers in integrative neuroscience, vol. 4. p. 11, 2010.
Abstract DOI
THE SPATIOTEMPORAL WINDOW OF INTEGRATION HAS BECOME A WIDELY ACCEPTED CONCEPT IN MULTISENSORY RESEARCH: crossmodal information falling within this window is highly likely to be integrated, whereas information falling outside is not. Here we further probe this concept in a reaction time context with redundant crossmodal targets. An infinitely large time window would lead to mandatory integration, a zero-width time window would rule out integration entirely. Making explicit assumptions about the arrival time difference between peripheral sensory processing times triggered by a crossmodal stimulus set, we derive a decision rule that determines an optimal window width as a function of (i) the prior odds in favor of a common multisensory source, (ii) the likelihood of arrival time differences, and (iii) the payoff for making correct or wrong decisions; moreover, we suggest a detailed experimental setup to test the theory. Our approach is in line with the well-established framework for modeling multisensory integration as (nearly) optimal decision making, but none of those studies, to our knowledge, has considered reaction time as observable variable. The theory can easily be extended to reaction times collected under the focused attention paradigm. Possible variants of the theory to account for judgments of crossmodal simultaneity are discussed. Finally, neural underpinnings of the theory in terms of oscillatory responses in primary sensory cortices are hypothesized
Rach, S., Diederich, A., Steenken, R., and Colonius, H., The race model inequality for censored reaction time distributions, Attention, perception & psychophysics, vol. 72, no. 3. pp. 839-847, Apr.-2010.
Abstract DOI
The race model inequality (RMI) introduced in Miller (1982) puts an upper limit on the amount of reaction time facilitation within the redundant-signals paradigm that is consistent with a race model. Here, it is shown through theoretical analysis and numerical simulation that inferences from the RMI test may become invalid when the experimenter misses a proportion of the responses by limiting the recording interval (right censoring) or excluding outliers from analysis (left and/or right censoring). Moreover, a correction of the inequality test for right-censored reaction time distributions is proposed
Anishchenko, A., Greschner, M., Elstrott, J., Sher, A., Litke, A. M., Feller, M. B., and Chichilnisky, E. J., Receptive field mosaics of retinal ganglion cells are established without visual experience, Journal of neurophysiology, vol. 103, no. 4. pp. 1856-1864, Apr.-2010.
Abstract DOI
A characteristic feature of adult retina is mosaic organization: a spatial arrangement of cells of each morphological and functional type that produces uniform sampling of visual space. How the mosaics of visual receptive fields emerge in the retina during development is not fully understood. Here we use a large-scale multielectrode array to determine the mosaic organization of retinal ganglion cells (RGCs) in rats around the time of eye opening and in the adult. At the time of eye opening, we were able to reliably distinguish two types of ON RGCs and two types of OFF RGCs in rat retina based on their light response and intrinsic firing properties. Although the light responses of individual cells were not yet mature at this age, each of the identified functional RGC types formed a receptive field mosaic, where the spacing of the receptive field centers and the overlap of the receptive field extents were similar to those observed in the retinas of adult rats. These findings suggest that, although the light response properties of RGCs may need vision to reach full maturity, extensive visual experience is not required for individual RGC types to form a regular sensory map of visual space
Field, G. D., Gauthier, J. L., Sher, A., Greschner, M., Machado, T. A., Jepson, L. H., Shlens, J., Gunning, D. E., Mathieson, K., Dabrowski, W., Paninski, L., Litke, A. M., and Chichilnisky, E. J., Functional connectivity in the retina at the resolution of photoreceptors, Nature, vol. 467, no. 7316. pp. 673-677, Oct.-2010.
Abstract DOI
To understand a neural circuit requires knowledge of its connectivity. Here we report measurements of functional connectivity between the input and ouput layers of the macaque retina at single-cell resolution and the implications of these for colour vision. Multi-electrode technology was used to record simultaneously from complete populations of the retinal ganglion cell types (midget, parasol and small bistratified) that transmit high-resolution visual signals to the brain. Fine-grained visual stimulation was used to identify the location, type and strength of the functional input of each cone photoreceptor to each ganglion cell. The populations of ON and OFF midget and parasol cells each sampled the complete population of long- and middle-wavelength-sensitive cones. However, only OFF midget cells frequently received strong input from short-wavelength-sensitive cones. ON and OFF midget cells showed a small non-random tendency to selectively sample from either long- or middle-wavelength-sensitive cones to a degree not explained by clumping in the cone mosaic. These measurements reveal computations in a neural circuit at the elementary resolution of individual neurons
Finke, C., Freund, J. A., Rosa, E., Braun, H. A., and Feudel, U., On the role of subthreshold currents in the Huber-Braun cold receptor model, Chaos (Woodbury, N.Y.), vol. 20, no. 4. p. 045107, Dec.-2010.
Abstract DOI
We study the role of the strength of subthreshold currents in a four-dimensional Hodgkin-Huxley-type model of mammalian cold receptors. Since a total diminution of subthreshold activity corresponds to a decomposition of the model into a slow, subthreshold, and a fast, spiking subsystem, we first elucidate their respective dynamics separately and draw conclusions about their role for the generation of different spiking patterns. These results motivate a numerical bifurcation analysis of the effect of varying the strength of subthreshold currents, which is done by varying a suitable control parameter. We work out the key mechanisms which can be attributed to subthreshold activity and furthermore elucidate the dynamical backbone of different activity patterns generated by this model
Stiefs, D., Voorn, G. A. K., Kooi, B. W., Feudel, U., and Gross, T., Food quality in producer-grazer models: a generalized analysis, The American naturalist, vol. 176, no. 3. pp. 367-380, Sep.-2010.
Abstract DOI
Stoichiometric constraints play a role in the dynamics of natural populations but are not explicitly considered in most mathematical models. Recent theoretical works suggest that these constraints can have a significant impact and should not be neglected. However, it is not yet resolved how stoichiometry should be integrated in population dynamical models, as different modeling approaches are found to yield qualitatively different results. Here we investigate a unifying framework that reveals the differences and commonalities between previously proposed models for producer-grazer systems. Our analysis reveals that stoichiometric constraints affect the dynamics mainly by increasing the intraspecific competition between producers and by introducing a variable biomass conversion efficiency. The intraspecific competition has a strongly stabilizing effect on the system, whereas the variable conversion efficiency resulting from a variable food quality is the main determinant for the nature of the instability once destabilization occurs. Only if the food quality is high can an oscillatory instability, as in the classical paradox of enrichment, occur. While the generalized model reveals that the generic insights remain valid in a large class of models, we show that other details such as the specific sequence of bifurcations encountered in enrichment scenarios can depend sensitively on assumptions made in modeling stoichiometric constraints
Kaiser, R., Winning, K., Uter, W., Volkert, D., Lesser, S., Stehle, P., Kaiser, M. J., Sieber, C. C., and Bauer, J. M., Functionality and mortality in obese nursing home residents: an example of 'risk factor paradox'?, Journal of the American Medical Directors Association, vol. 11, no. 6. pp. 428-435, Jul.-2010.
Abstract DOI
BACKGROUND: Although the percentage of obese nursing home residents is increasing, few longitudinal studies have reported on functionality and mortality in this subpopulation. The aim of the present study was to explore functionality and mortality in obese nursing home residents during a 1-year follow-up and to compare these results with those of residents within the normal and low BMI range. METHODS: Two hundred residents (147 female, 53 male, mean age 85.6 +/- 7.8 years) from 2 Nuremberg nursing homes were included. Body weight and height were measured in all participants. BMI was calculated and categorized as low (<20 kg/m(2)), normal (20-30 kg/m(2)), and high (>30 kg/m(2)). Handgrip strength, timed "up and go" test, and Barthel's Activities of Daily Living were applied as functional parameters. All measurements were done at baseline and after a 1-year follow-up. RESULTS: At baseline, the prevalence of obesity was 23.5%, whereas low BMI values were present in 8.5% of the residents. After 1 year, there was no significant decline of functionality in the obese group, whereas functional parameters deteriorated significantly in study participants with normal BMI. One-year mortality was lowest in the obese (12.8%), with no deaths in residents with BMI of 35 kg/m(2) or higher. Mortality was highest in residents with low BMI (58.8%). CONCLUSION: In nursing home residents, obesity is associated with increased survival and stable functionality. These observations may therefore be regarded as an expression of "risk factor paradox" in this specific population of older individuals
Bauer, J. M., Kaiser, M. J., and Sieber, C. C., Evaluation of nutritional status in older persons: nutritional screening and assessment, Current opinion in clinical nutrition and metabolic care, vol. 13, no. 1. pp. 8-13, Jan.-2010.
Abstract DOI
PURPOSE OF REVIEW: Malnutrition is highly prevalent in the older population. It is associated with declining functionality and relevant health deficits. This review presents the principles of successful nutritional screening and assessment in older persons. RECENT FINDINGS: Although no gold standard for the diagnosis of malnutrition can serve as reference, a large number of nutritional screening tools have been developed during the past two decades. For efficient screening, the most appropriate tool has to be selected based on setting and practicability. The screening intervals have to be chosen according to the population screened. Although screening has to be performed routinely and systematically in a very practical and efficient manner, nutritional assessment has to be individualized to provide information on the grade of malnutrition and its cause. The development of a local guideline that reflects local expertise and resources will prove essential for successful nutritional management. CONCLUSION: Nutritional screening and assessment should be a standard of care for older persons. It has to be considered as a clearly defined two-step procedure, which has to reflect setting and local resources. Further adaptations of the available screening tools with regard to ethnic characteristics are indicated
Gerlach, G., Impact of Social Ties on Dispersal, Reproduction and Dominance in Feral House Mice (Mus musculus domesticus), Ethology, vol. 104, no. 6. Wiley-Blackwell, pp. 487-499, 26-Apr.-2010.
DOIFull Text
Gerlach, G., Jueterbock, A., Kraemer, P., Deppermann, J., and Harmand, P., Calculations of population differentiation based on GST and D: forget GST but not all of statistics!, Molecular Ecology, vol. 19, no. 18. Wiley-Blackwell, pp. 3845-3852, 23-Aug.-2010.
DOIFull Text
Schwarz, R., Joseph, B., Gerlach, G., Schramm-Glück, A., Engelhard, K., Frosch, M., Müller, T., and Schoen, C., Evaluation of one- and two-color gene expression arrays for microbial comparative genome hybridization analyses in routine applications, Journal of clinical microbiology, vol. 48, no. 9. pp. 3105-3110, Sep.-2010.
Abstract DOI
DNA microarray technology has already revolutionized basic research in infectious diseases, and whole-genome sequencing efforts have allowed for the fabrication of tailor-made spotted microarrays for an increasing number of bacterial pathogens. However, the application of microarrays in diagnostic microbiology is currently hampered by the high costs associated with microarray experiments and the specialized equipment needed. Here, we show that a thorough bioinformatic postprocessing of the microarray design to reduce the amount of unspecific noise also allows the reliable use of spotted gene expression microarrays for gene content analyses. We further demonstrate that the use of only single-color labeling to halve the costs for dye-labeled nucleotides results in only a moderate decrease in overall specificity and sensitivity. Therefore, gene expression microarrays using only single-color labeling can also reliably be used for gene content analyses, thus reducing the costs for potential routine applications such as genome-based pathogen detection or strain typing
Gerlach, G., Anthony, M., Deadman, M., Schoen, C., Hood, D., and Reidl, J., Transposon insertion in a serine-specific minor tRNA coding sequence affects intraperitoneal survival of Haemophilus influenzae in the infant rat model, International journal of medical microbiology : IJMM, vol. 300, no. 4. pp. 218-228, Apr.-2010.
Abstract DOI
Due to its lifestyle as a commensal and occasional pathogen in the upper and lower respiratory tracts of humans, Haemophilus influenzae needs to protect itself from endogenously and exogenously generated reactive oxygen species. To better understand the oxygen radical resistance and to investigate a correlation with virulence, randomly generated paraquat-sensitive H. influenzae transposon mutants were analyzed in an infant rat model of infection. Among 25 different paraquat-sensitive mutants only one mutant harbouring a Tn-insertion within the tRNA-Ser1 gene specific for the rare serine codon UCC, was highly attenuated for intraperitoneal infectivity. Compared to the wild-type strain, the tRNA-Ser1 mutant was also more sensitive to neutrophil-mediated killing, deficient for DNA transformation but showed similar growth rates under laboratory conditions. However, by comparative analysis using an oxyR mutant strain, we could show that neutrophil-mediated killing might not be relevant for intraperitoneal infectivity. Therefore, the increased ROS sensitivity observed for tRNA-Ser1 mutant may not be directly responsible for the observed virulence deficiency in the intraperitoneal infection. We speculate that a reduced translation efficiency of several UCC containing mRNAs results in a delay of protein synthesis and consequently in the loss of cellular mechanisms which are necessary for ROS resistance and virulence
Liedvogel, M. and Mouritsen, H., Cryptochromes--a potential magnetoreceptor: what do we know and what do we want to know?, Journal of the Royal Society, Interface / the Royal Society, vol. 7 Suppl 2. pp. S147-62, Apr.-2010.
Abstract DOI
Cryptochromes have been suggested to be the primary magnetoreceptor molecules underlying light-dependent magnetic compass detection in migratory birds. Here we review and evaluate (i) what is known about these candidate magnetoreceptor molecules, (ii) what characteristics cryptochrome molecules must fulfil to possibly underlie light-dependent, radical pair based magnetoreception, (iii) what evidence supports the involvement of cryptochromes in magnetoreception, and (iv) what needs to be addressed in future research. The review focuses primarily on our knowledge of cryptochromes in the context of magnetoreception
Zapka, M., Heyers, D., Liedvogel, M., Jarvis, E. D., and Mouritsen, H., Night-time neuronal activation of Cluster N in a day- and night-migrating songbird, The European journal of neuroscience, vol. 32, no. 4. pp. 619-624, Aug.-2010.
Abstract DOI
Magnetic compass orientation in a night-migratory songbird requires that Cluster N, a cluster of forebrain regions, is functional. Cluster N, which receives input from the eyes via the thalamofugal pathway, shows high neuronal activity in night-migrants performing magnetic compass-guided behaviour at night, whereas no activation is observed during the day, and covering up the birds' eyes strongly reduces neuronal activation. These findings suggest that Cluster N processes light-dependent magnetic compass information in night-migrating songbirds. The aim of this study was to test if Cluster N is active during daytime migration. We used behavioural molecular mapping based on ZENK activation to investigate if Cluster N is active in the meadow pipit (Anthus pratensis), a day- and night-migratory species. We found that Cluster N of meadow pipits shows high neuronal activity under dim-light at night, but not under full room-light conditions during the day. These data suggest that, in day- and night-migratory meadow pipits, the light-dependent magnetic compass, which requires an active Cluster N, may only be used during night-time, whereas another magnetosensory mechanism and/or other reference system(s), like the sun or polarized light, may be used as primary orientation cues during the day
Solov'yov, I. A., Mouritsen, H., and Schulten, K., Acuity of a cryptochrome and vision-based magnetoreception system in birds, Biophysical journal, vol. 99, no. 1. pp. 40-49, Jul.-2010.
Abstract DOI
The magnetic compass of birds is embedded in the visual system and it has been hypothesized that the primary sensory mechanism is based on a radical pair reaction. Previous models of magnetoreception have assumed that the radical pair-forming molecules are rigidly fixed in space, and this assumption has been a major objection to the suggested hypothesis. In this article, we investigate theoretically how much disorder is permitted for the radical pair-forming, protein-based magnetic compass in the eye to remain functional. Our study shows that only one rotational degree of freedom of the radical pair-forming protein needs to be partially constrained, while the other two rotational degrees of freedom do not impact the magnetoreceptive properties of the protein. The result implies that any membrane-associated protein is sufficiently restricted in its motion to function as a radical pair-based magnetoreceptor. We relate our theoretical findings to the cryptochromes, currently considered the likeliest candidate to furnish radical pair-based magnetoreception
Hein, C. M., Zapka, M., Heyers, D., Kutzschbauch, S., Schneider, N. -L., and Mouritsen, H., Night-migratory garden warblers can orient with their magnetic compass using the left, the right or both eyes, Journal of the Royal Society, Interface / the Royal Society, vol. 7 Suppl 2. pp. S227-33, Apr.-2010.
Abstract DOI
Several studies have suggested that the magnetic compass of birds is located only in the right eye. However, here we show that night-migrating garden warblers (Sylvia borin) are able to perform magnetic compass orientation with both eyes open, with only the left eye open and with only the right eye open. We did not observe any clear lateralization of magnetic compass orientation behaviour in this migratory songbird, and, therefore, it seems that the suggested all-or-none lateralization of magnetic compass orientation towards the right eye only cannot be generalized to all birds, and that the answer to the question of whether magnetic compass orientation in birds is lateralized is probably not as simple as suggested previously
Ritz, T., Ahmad, M., Mouritsen, H., Wiltschko, R., and Wiltschko, W., Photoreceptor-based magnetoreception: optimal design of receptor molecules, cells, and neuronal processing, Journal of the Royal Society, Interface / the Royal Society, vol. 7 Suppl 2. pp. S135-46, Apr.-2010.
Abstract DOI
The sensory basis of magnetoreception in animals still remains a mystery. One hypothesis of magnetoreception is that photochemical radical pair reactions can transduce magnetic information in specialized photoreceptor cells, possibly involving the photoreceptor molecule cryptochrome. This hypothesis triggered a considerable amount of research in the past decade. Here, we present an updated picture of the radical-pair photoreceptor hypothesis. In our review, we will focus on insights that can assist biologists in their search for the elusive magnetoreceptors
Heyers, D., Zapka, M., Hoffmeister, M., Wild, J. M., and Mouritsen, H., Magnetic field changes activate the trigeminal brainstem complex in a migratory bird, Proceedings of the National Academy of Sciences of the United States of America, vol. 107, no. 20. pp. 9394-9399, May-2010.
Abstract DOI
The upper beak of birds, which contains putative magnetosensory ferro-magnetic structures, is innervated by the ophthalmic branch of the trigeminal nerve (V1). However, because of the absence of replicable neurobiological evidence, a general acceptance of the involvement of the trigeminal nerve in magnetoreception is lacking in birds. Using an antibody to ZENK protein to indicate neuronal activation, we here document reliable magnetic activation of neurons in and near the principal (PrV) and spinal tract (SpV) nuclei of the trigeminal brainstem complex, which represent the two brain regions known to receive primary input from the trigeminal nerve. Significantly more neurons were activated in PrV and in medial SpV when European robins (Erithacus rubecula) experienced a magnetic field changing every 30 seconds for a period of 3 h (CMF) than when robins experienced a compensated, zero magnetic field condition (ZMF). No such differences in numbers of activated neurons were found in comparison structures. Under CMF conditions, sectioning of V1 significantly reduced the number of activated neurons in and near PrV and medial SpV, but not in lateral SpV or in the optic tectum. Tract tracing of V1 showed spatial proximity and regional overlap of V1 nerve endings and ZENK-positive (activated) neurons in SpV, and partly in PrV, under CMF conditions. Together, these results suggest that magnetic field changes activate neurons in and near the trigeminal brainstem complex and that V1 is necessary for this activation. We therefore suggest that V1 transmits magnetic information to the brain in this migratory passerine bird
Falkenberg, G., Fleissner, G., Schuchardt, K., Kuehbacher, M., Thalau, P., Mouritsen, H., Heyers, D., Wellenreuther, G., and Fleissner, G., Avian magnetoreception: elaborate iron mineral containing dendrites in the upper beak seem to be a common feature of birds, PloS one, vol. 5, no. 2. p. e9231, 2010.
Abstract DOI
The magnetic field sensors enabling birds to extract orientational information from the Earth's magnetic field have remained enigmatic. Our previously published results from homing pigeons have made us suggest that the iron containing sensory dendrites in the inner dermal lining of the upper beak are a candidate structure for such an avian magnetometer system. Here we show that similar structures occur in two species of migratory birds (garden warbler, Sylvia borin and European robin, Erithacus rubecula) and a non-migratory bird, the domestic chicken (Gallus gallus). In all these bird species, histological data have revealed dendrites of similar shape and size, all containing iron minerals within distinct subcellular compartments of nervous terminals of the median branch of the Nervus ophthalmicus. We also used microscopic X-ray absorption spectroscopy analyses to identify the involved iron minerals to be almost completely Fe III-oxides. Magnetite (Fe II/III) may also occur in these structures, but not as a major Fe constituent. Our data suggest that this complex dendritic system in the beak is a common feature of birds, and that it may form an essential sensory basis for the evolution of at least certain types of magnetic field guided behavior
Bendixen, A., Jones, S. J., Klump, G. M., and Winkler, I., Probability dependence and functional separation of the object-related and mismatch negativity event-related potential components, NeuroImage, vol. 50, no. 1. Elsevier BV, pp. 285-290, Mar.-2010.
DOIFull Text
Chang, E. F., Rieger, J. W., Johnson, K., Berger, M. S., Barbaro, N. M., and Knight, R. T., Categorical speech representation in human superior temporal gyrus, Nature Neuroscience, vol. 13, no. 11. Springer Nature, pp. 1428-1432, 3-Oct.-2010.
DOIFull Text
Zaehle, T., Rach, S., and Herrmann, C. S., Transcranial alternating current stimulation enhances individual alpha activity in human EEG, PloS one, vol. 5, no. 11. p. e13766, 2010.
Abstract DOI
Non-invasive electrical stimulation of the human cortex by means of transcranial direct current stimulation (tDCS) has been instrumental in a number of important discoveries in the field of human cortical function and has become a well-established method for evaluating brain function in healthy human participants. Recently, transcranial alternating current stimulation (tACS) has been introduced to directly modulate the ongoing rhythmic brain activity by the application of oscillatory currents on the human scalp. Until now the efficiency of tACS in modulating rhythmic brain activity has been indicated only by inference from perceptual and behavioural consequences of electrical stimulation. No direct electrophysiological evidence of tACS has been reported. We delivered tACS over the occipital cortex of 10 healthy participants to entrain the neuronal oscillatory activity in their individual alpha frequency range and compared results with those from a separate group of participants receiving sham stimulation. The tACS but not the sham stimulation elevated the endogenous alpha power in parieto-central electrodes of the electroencephalogram. Additionally, in a network of spiking neurons, we simulated how tACS can be affected even after the end of stimulation. The results show that spike-timing-dependent plasticity (STDP) selectively modulates synapses depending on the resonance frequencies of the neural circuits that they belong to. Thus, tACS influences STDP which in turn results in aftereffects upon neural activity.The present findings are the first direct electrophysiological evidence of an interaction of tACS and ongoing oscillatory activity in the human cortex. The data demonstrate the ability of tACS to specifically modulate oscillatory brain activity and show its potential both at fostering knowledge on the functional significance of brain oscillations and for therapeutic application
Busch, N. A., Dürschmid, S., and Herrmann, C. S., ERP effects of change localization, change identification, and change blindness, Neuroreport, vol. 21, no. 5. pp. 371-375, Mar.-2010.
Abstract DOI
Change blindness is the failure to detect changes in visual scenes. Changes can elicit phenomenologically different perceptual experiences, possibly relating to different mechanisms: changes may be entirely missed, merely detected, located, or identified. We presented sequences of meaningful objects, one of which could change between the presentations. Changes had to be located and identified. Observers sometimes located the change without knowing which object had changed. However, effects of localization with and without identification were remarkably similar on a sequence of event-related potential components (including change-related positivity and N2pc). Only a late contralateral positivity was found exclusively for identified changes, indicating that change localization and change identification initially rely on a common processing sequence and differ only at later stages
Busch, N. A., Fründ, I., and Herrmann, C. S., Electrophysiological evidence for different types of change detection and change blindness, Journal of cognitive neuroscience, vol. 22, no. 8. pp. 1852-1869, Aug.-2010.
Abstract DOI
Numerous studies have demonstrated that observers often fail to notice large changes in visual scenes, a phenomenon known as change blindness. Some experiments have suggested that phenomenological experience in change blindness experiments is more diverse than the common distinction between change detection and change blindness allows to resolve. Recently, it has been debated whether changes in visual scenes can be detected ("sensed") without a corresponding perception of the changing object ("seeing") and whether these phenomena build on fundamentally different perceptual processes. The present study investigated whether phenomenologically different perceptual processes such as sensing and seeing rely on different or similar neural processes. We studied ERP effects of visual change processing (as compared to change blindness) when observers merely detected the presence of a change ("sensing") and when they identified the changing object in addition to detection ("seeing"). Although the visual awareness negativity (VAN)/selection negativity was similar for detection with and without identification, a change-related positivity and the N2pc contralateral to changes were found exclusively when the change was fully identified. This finding indicates that change identification requires perceptual and neural processes that are not involved in mere detection. In a second experiment, we demonstrated that the VAN and N2pc effects are similar to effects of selective attention in a visual search task. By contrast, the change-related positivity was specific for conscious processing of visual changes. The results suggest that changes can be detected ("sensed") without perception of the changing object. Furthermore, sensing and seeing seem to rely on different neural processes and seem to constitute different types of visual perception. These findings bear implications for how different categories of visual awareness are related to different stages in visual processing
Lenz, D., Krauel, K., Flechtner, H. -H., Schadow, J., Hinrichs, H., and Herrmann, C. S., Altered evoked gamma-band responses reveal impaired early visual processing in ADHD children, Neuropsychologia, vol. 48, no. 7. pp. 1985-1993, Jun.-2010.
Abstract DOI
Neurophysiological studies yield contrary results whether attentional problems of patients with attention-deficit/hyperactivity disorder (ADHD) are related to early visual processing deficits or not. Evoked gamma-band responses (GBRs), being among the first cortical responses occurring as early as 90ms after visual stimulation in human EEG, have been assigned a pivotal role in early visual processing. In particular, they are involved in memory matching processes and are enhanced when known stimuli are processed. The current study examined whether evoked GBR patterns during early memory matching processes could be indicative of an early visual processing deficit in ADHD patients. EEG was recorded from 13 young ADHD patients as well as 13 age-matched healthy participants. Both groups performed a simple forced choice reaction task employing line drawings of either known real-world items with representations in long-term memory or physically similar unknown items without such representations. Evoked GBRs of ADHD patients did not differentiate between known and unknown items. However, in healthy children, evoked GBRs were enhanced when stimuli matched a representation stored in memory. This finding indicates disadvantages at early visual processing stages in ADHD patients: In contrast to healthy participants, ADHD children lack an early memory based classification, possibly resulting in an impaired ability to rapidly reallocate attentional resources to relevant stimuli. These findings suggest that impaired early automatic stimulus classification in ADHD patients could be involved in deficits of selective and sustained attention
Herrmann, C. S., Fründ, I., and Lenz, D., Human gamma-band activity: a review on cognitive and behavioral correlates and network models, Neuroscience and biobehavioral reviews, vol. 34, no. 7. pp. 981-992, Jun.-2010.
Abstract DOI
Gamma-band oscillations (roughly 30-100 Hz) in human and animal EEG have received considerable attention in the past due to their correlations with cognitive processes. Here, we want to sketch how some of the higher cognitive functions can be explained by memory processes which are known to modulate gamma activity. Especially, the function of binding together the multiple features of a perceived object requires a comparison with contents stored in memory. In addition, we review recent findings about the actual behavioral relevance of human gamma-band activity. Interestingly, rather simple models of spiking neurons are not only able to generate oscillatory activity within the gamma-band range, but even show modulations of these oscillations in line with findings from human experiments
Zapka, M., Heyers, D., Liedvogel, M., Jarvis, E. D., and Mouritsen, H., Night-time neuronal activation of Cluster N in a day- and night-migrating songbird, EUROPEAN JOURNAL OF NEUROSCIENCE, vol. 32, no. 4. WILEY-BLACKWELL, Aug.-2010.
Abstract
Magnetic compass orientation in a night-migratory songbird requires that Cluster N, a cluster of forebrain regions, is functional. Cluster N, which receives input from the eyes via the thalamofugal pathway, shows high neuronal activity in night-migrants performing magnetic compass-guided behaviour at night, whereas no activation is observed during the day, and covering up the birds' eyes strongly reduces neuronal activation. These findings suggest that Cluster N processes light-dependent magnetic compass information in night-migrating songbirds. The aim of this study was to test if Cluster N is active during daytime migration. We used behavioural molecular mapping based on ZENK activation to investigate if Cluster N is active in the meadow pipit (Anthus pratensis), a day- and night-migratory species. We found that Cluster N of meadow pipits shows high neuronal activity under dim-light at night, but not under full room-light conditions during the day. These data suggest that, in day- and night-migratory meadow pipits, the light-dependent magnetic compass, which requires an active Cluster N, may only be used during night-time, whereas another magnetosensory mechanism and/or other reference system(s), like the sun or polarized light, may be used as primary orientation cues during the day.
Heyers, D., Zapka, M., Hoffmeister, M., Wild, J. M., and Mouritsen, H., Magnetic field changes activate the trigeminal brainstem complex in a migratory bird, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, vol. 107, no. 20. NATL ACAD SCIENCES, May-2010.
Abstract
The upper beak of birds, which contains putative magnetosensory ferro-magnetic structures, is innervated by the ophthalmic branch of the trigeminal nerve (V1). However, because of the absence of replicable neurobiological evidence, a general acceptance of the involvement of the trigeminal nerve in magnetoreception is lacking in birds. Using an antibody to ZENK protein to indicate neuronal activation, we here document reliable magnetic activation of neurons in and near the principal (PrV) and spinal tract (SpV) nuclei of the trigeminal brainstem complex, which represent the two brain regions known to receive primary input from the trigeminal nerve. Significantly more neurons were activated in PrV and in medial SpV when European robins (Erithacus rubecula) experienced a magnetic field changing every 30 seconds for a period of 3 h (CMF) than when robins experienced a compensated, zero magnetic field condition (ZMF). No such differences in numbers of activated neurons were found in comparison structures. Under CMF conditions, sectioning of V1 significantly reduced the number of activated neurons in and near PrV and medial SpV, but not in lateral SpV or in the optic tectum. Tract tracing of V1 showed spatial proximity and regional overlap of V1 nerve endings and ZENK-positive (activated) neurons in SpV, and partly in PrV, under CMF conditions. Together, these results suggest that magnetic field changes activate neurons in and near the trigeminal brainstem complex and that V1 is necessary for this activation. We therefore suggest that V1 transmits magnetic information to the brain in this migratory passerine bird.
Hein, C. M., Zapka, M., Heyers, D., Kutzschbauch, S., Schneider, N. -L., and Mouritsen, H., Night-migratory garden warblers can orient with their magnetic compass using the left, the right or both eyes, JOURNAL OF THE ROYAL SOCIETY INTERFACE, vol. 7, no. 2. ROYAL SOC, Apr.-2010.
Abstract
Several studies have suggested that the magnetic compass of birds is located only in the right eye. However, here we show that night-migrating garden warblers (Sylvia borin) are able to perform magnetic compass orientation with both eyes open, with only the left eye open and with only the right eye open. We did not observe any clear lateralization of magnetic compass orientation behaviour in this migratory songbird, and, therefore, it seems that the suggested all-or-none lateralization of magnetic compass orientation towards the right eye only cannot be generalized to all birds, and that the answer to the question of whether magnetic compass orientation in birds is lateralized is probably not as simple as suggested previously.
Falkenberg, G., Fleissner, G., Schuchardt, K., Kuehbacher, M., Thalau, P., Mouritsen, H., Heyers, D., Wellenreuther, G., and Fleissner, G., Avian Magnetoreception: Elaborate Iron Mineral Containing Dendrites in the Upper Beak Seem to Be a Common Feature of Birds, PLOS ONE, vol. 5, no. 2. PUBLIC LIBRARY SCIENCE, Feb.-2010.
Abstract
The magnetic field sensors enabling birds to extract orientational information from the Earth's magnetic field have remained enigmatic. Our previously published results from homing pigeons have made us suggest that the iron containing sensory dendrites in the inner dermal lining of the upper beak are a candidate structure for such an avian magnetometer system. Here we show that similar structures occur in two species of migratory birds (garden warbler, Sylvia borin and European robin, Erithacus rubecula) and a non-migratory bird, the domestic chicken (Gallus gallus). In all these bird species, histological data have revealed dendrites of similar shape and size, all containing iron minerals within distinct subcellular compartments of nervous terminals of the median branch of the Nervus ophthalmicus. We also used microscopic X-ray absorption spectroscopy analyses to identify the involved iron minerals to be almost completely Fe III-oxides. Magnetite (Fe II/III) may also occur in these structures, but not as a major Fe constituent. Our data suggest that this complex dendritic system in the beak is a common feature of birds, and that it may form an essential sensory basis for the evolution of at least certain types of magnetic field guided behavior.
Rochon, E., Leonard, C., Burianova, H., Laird, L., Soros, P., Graham, S., and Grady, C., Neural changes after phonological treatment for anomia: An fMRI study, BRAIN AND LANGUAGE, vol. 114, no. 3. ACADEMIC PRESS INC ELSEVIER SCIENCE, Sep.-2010.
Abstract
Functional magnetic resonance imaging (fMRI) was used to investigate the neural processing characteristics associated with word retrieval abilities after a phonologically-based treatment for anomia in two stroke patients with aphasia. Neural activity associated with a phonological and a semantic task was compared before and after treatment with fMRI. In addition to the two patients who received treatment, two patients with aphasia who did not receive treatment and 10 healthy controls were also scanned twice. In the two patients who received treatment, both of whose naming improved after treatment, results showed that activation patterns changed after treatment on the semantic task in areas that would have been expected (e.g., left hemisphere frontal and temporal areas). For one control patient, there were no significant changes in brain activation at the second scan; a second control patient showed changes in brain activation at the second scan, on the semantic task, however, these changes were not accompanied with improved performance in naming. In addition, there appeared to be bilateral, or even more right than left hemisphere brain areas activated in this patient than in the treated patients. The healthy control group showed no changes in activation at the second scan. These findings are discussed with reference to the literature on the neural underpinnings of recovery after treatment for anomia in aphasia. (C) 2010 Elsevier Inc. All rights reserved.
Soeroes, P., MacIntosh, B. J., Tam, F., and Graham, S. J., fMRI-compatible registration of jaw movements using a fiber-optic bend sensor, FRONTIERS IN HUMAN NEUROSCIENCE, vol. 4. Mar.-2010.
Abstract
A functional magnetic resonance imaging (fMRI)-compatible fiber-optic bend sensor was investigated to assess whether the device could be used effectively to monitor opening and closing of the jaw during an fMRI experiment at 3 T. In contrast to surface electromyography, a bend sensor fixed to the chin of the participant is fast and easy to use and is not affected by strong electromagnetic fields. Bend sensor recordings are characterized by high validity (compared with concurrent video recordings of mouth opening) and high reliability (comparing two independent measurements). The results of this study indicate that a bend sensor is able to record the opening and closing of the jaw associated with different overt speech conditions (producing the utterances /a/, /pa/, /pataka/) and the opening of the mouth without speech production. Data post-processing such as filtering was not necessary. There are several potential applications for bend sensor recordings of speech-related jaw movements. First, bend sensor recordings are a valuable tool to assess behavioral performance, such as response latencies, accuracies, and completion times, which is particularly important in children, seniors, or patients with various neurological or psychiatric conditions. Second, the timing information provided by bend sensor data may improve the predicted hemodynamic response that is used for fMRI analysis based on the general linear model (GLM). Third, bend sensor recordings may be included in GLM analyses not for statistical contrast purposes, but as a covariate of no interest, accounting for part of the data variance to model fMRI artifacts due to motion outside the field of view.
Wierschke, S., Gigout, S., Horn, P., Lehmann, T. -N., Dehnicke, C., Braeuer, A. U., and Deisz, R. A., Evaluating reference genes to normalize gene expression in human epileptogenic brain tissues, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, vol. 403, no. 3-4. ACADEMIC PRESS INC ELSEVIER SCIENCE, Dec.-2010.
Abstract
Several reference genes have been used to quantify gene expression in human epilepsy surgery tissue. However, their reliability has not been validated in detail, although this is crucial in interpreting epilepsy-related changes of gene expression. We evaluated 12 potential reference genes in neocortical tissues resected from patients with temporal lobe epilepsy (TLE) with either few or many seizures (n = 6 each) and post mortem controls (n = 6) using geNorm and NormFinder algorithms. For all candidate reference genes threshold cycle (C-T) values were measured. geNorm analysis revealed that the expression of e.g. glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) and hypoxanthine phosphoribosyl-transferase (HPRT) is unstable, whereas synaptophysin (SYP) and neuron-specific enolase (NSE)/mitochondrial 39S ribosomal protein L28 (MRPL) are most stably expressed. The geometric mean of SYP, NSE and MRPL levels is recommended as normalization factor (NF). NormFinder analysis, in contrast, indicated HPRT as the most stable single gene and recommended the geometric mean of TATA-box binding protein (TBP) and NSE levels as NF. Different values of upregulation of glial fibrillary protein (GFAP) expression were found in TLE tissue compared to control tissue depending on the NF used: 4.5-fold (geNorm-NF), 4.7-fold (NormFinder-NF), 4.2-fold (vs. GAPDH) and 7.8-fold (vs. HPRT). The expression of GABA(A) receptor subunit alpha 5 (GAR alpha 5) was unaltered in the TLE groups compared to controls (geNorm-NF, NormFinder-NF, vs. GAPDH). However, normalization to HPRT suggests an apparent increase of GAR alpha 5 expression. In conclusion, the geNorm-NF (SYP/NSE/MRPL) and the NormFinder-NF (TBP/NSE) are equally suitable for normalization of gene expression in the human epileptogenic neocortex. In contrast, normalization to single and probably less stably expressed genes may not deliver accurate results. (C) 2010 Elsevier Inc. All rights reserved.
Daniels, C., Krack, P., Volkmann, J., Pinsker, M. O., Krause, M., Tronnier, V., Kloss, M., Schnitzler, A., Wojtecki, L., Boetzel, K., Danek, A., Hilker, R., Sturm, V., Kupsch, A., Karner, E., Deuschl, G., and Witt, K., Risk Factors for Executive Dysfunction After Subthalamic Nucleus Stimulation in Parkinson's Disease, MOVEMENT DISORDERS, vol. 25, no. 11. WILEY-LISS, Aug.-2010.
Abstract
A slight decline in cognitive functions and especially in executive functioning after deep brain stimulation (DBS) of the nucleus subthalamicus (STN) in patients with Parkinson's disease (PD) has been described. This study evaluated baseline parameters that contribute to a deterioration of cognitive functioning after DBS. We analyzed data from the neuropsychological protocol in a randomized controlled study comparing DBS with best medical treatment (BMT). Change scores were calculated for the cognitive domains ``global cognitive functioning,{''} ``memory,{''} ``working memory,{''} ``attention,{''} and ``executive function.{''} These domain-specific change scores were correlated with previously defined preoperative parameters. Compared with the BMT group (63 patients), the STN-DBS group (60 patients) showed a significant decline only in the domain executive function 6 months after DBS, which was significantly correlated with age, levodopa-equivalence dosage (LED) and axial subscore of the UPDRS in the off-medication state at baseline. Multiple regression analysis showed that these three factors explained, however, only about 23\% of the variance. Patients with higher age, higher baseline LED, and/or higher axial subscore of the UPDRS at baseline have an increased risk for worsening of executive function alter STN-DBS. High scores of these factors might reflect an advanced stage of disease progression. As these baseline factors explained the variance of the change score executive function only to a minor proportion, other factors including the surgical procedure, the exact placement of the electrode or postsurgical management might be more relevant for a decline in executive functioning after STN-DBS. (C) 2010 Movement Disorder Society
Schiek, M., Light-Emitting Organic Nanoaggregates from Functionalized para-Quaterphenylenes, Concepts in Nanoscience, Organic Materials and Environmental Chemistry. Wiley-Blackwell, pp. 185-213, 24-Sep.-2010.
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Brand, T., Jürgens, T., Beutelmann, R., Meyer, R. M., and Kollmeier, B., Macroscopic and Microscopic Analysis of Speech Recognition in Noise: What Can Be Understood at Which Level?, The Neurophysiological Bases of Auditory Perception. Springer Science + Business Media, pp. 417-427, 2010.
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Cartwright, J. H. E., Feudel, U., Károlyi, G., de Moura, A., Piro, O., and Tél, T., Dynamics of Finite-Size Particles in Chaotic Fluid Flows, Nonlinear Dynamics and Chaos: Advances and Perspectives. Springer Science + Business Media, pp. 51-87, 2010.
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Klinge, A., Itatani, N., and Klump, G. M., A Comparative View on the Perception of Mistuning: Constraints of the Auditory Periphery, The Neurophysiological Bases of Auditory Perception. Springer Science + Business Media, pp. 465-475, 2010.
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Strüber, D. and Fehr, T., Geschlechtsunterschiede bei Aggression und ihre neurobiologischen Korrelate, Neurobiologie forensisch-relevanter Störungen. Kohlhammer, pp. 186-194, 2010.
Abstract
Strüber, D., Geschlechtsspezifisches Verhalten aus Sicht der Hirnforschung, Handbuch Mädchen-Pädagogik. Beltz, pp. 62-78, 2010.
Abstract
Rätscho, N., Scholten, A., and Koch, K. -W., Expression profiles of three novel sensory guanylate cyclases and guanylate cyclase-activating proteins in the zebrafish retina, Biochimica et biophysica acta, vol. 1793, no. 6. Jun.-2009.
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Behnen, P., Scholten, A., Rätscho, N., and Koch, K. -W., The cone-specific calcium sensor guanylate cyclase activating protein 4 from the zebrafish retina, Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry, vol. 14, no. 1. Jan.-2009.
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Ishaaya, A. A., Hensley, C. J., Shim, B., Schrauth, S., Koch, K. -W., and Gaeta, A. L., Highly-efficient coupling of linearly- and radially-polarized femtosecond pulses in hollow-core photonic band-gap fibers, Optics express, vol. 17, no. 21. Oct.-2009.
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Kitiratschky, V. B. D., Behnen, P., Kellner, U., Heckenlively, J. R., Zrenner, E., Jägle, H., Kohl, S., Wissinger, B., and Koch, K. -W., Mutations in the GUCA1A gene involved in hereditary cone dystrophies impair calcium-mediated regulation of guanylate cyclase, Human mutation, vol. 30, no. 8. Aug.-2009.
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Komolov, K. E., Senin, I. I., Kovaleva, N. A., Christoph, M. P., Churumova, V. A., Grigoriev, I. I., Akhtar, M., Philippov, P. P., and Koch, K. -W., Mechanism of rhodopsin kinase regulation by recoverin, Journal of neurochemistry, vol. 110, no. 1. Jul.-2009.
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Janssen-Bienhold, U., Trümpler, J., Hilgen, G., Schultz, K., De Sevilla Müller, L. P., Sonntag, S., Dedek, K., Dirks, P., Willecke, K., and Weiler, R., Connexin57 is expressed in dendro-dendritic and axo-axonal gap junctions of mouse horizontal cells and its distribution is modulated by light, J. Comp. Neurol., vol. 513, no. 4. Wiley-Blackwell, pp. 363-374, 1-Apr.-2009.
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Dedek, K., Breuninger, T., de Sevilla Müller, L. P., Maxeiner, S., Schultz, K., Janssen-Bienhold, U., Willecke, K., Euler, T., and Weiler, R., A novel type of interplexiform amacrine cell in the mouse retina, European Journal of Neuroscience, vol. 30, no. 2. Wiley-Blackwell, pp. 217-228, Jul.-2009.
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Tanner, G., Glaus, E., Barthelmes, D., Ader, M., Fleischhauer, J., Pagani, F., Berger, W., and Neidhardt, J., Therapeutic strategy to rescue mutation-induced exon skipping in rhodopsin by adaptation of U1 snRNA, Hum. Mutat., vol. 30, no. 2. Wiley-Blackwell, pp. 255-263, Feb.-2009.
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Balzer, F., Schiek, M., Lützen, A., and Rubahn, H. -G., Self-Organized Growth of Organic Thiophene−Phenylene Nanowires on Silicate Surfaces, Chem. Mater., vol. 21, no. 20. American Chemical Society (ACS), pp. 4759-4767, 27-Oct.-2009.
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Schiek, M., Balzer, F., Al-Shamery, K., Lützen, A., and Rubahn, H. -G., Nanoaggregates from Thiophene/Phenylene Co-Oligomers, The Journal of Physical Chemistry C, vol. 113, no. 22. American Chemical Society (ACS), pp. 9601-9608, 4-Jun.-2009.
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Nonomura, K., Loewenstein, T., Michaelis, E., Kunze, P., Schiek, M., Reemts, J., Yoshie Iwaya, M., Wark, M., Rathousky, J., Al-Shamery, K., Kittel, A., Parisi, J., Wöhrle, D., Yoshida, T., and Schlettwein, D., Nanoparticulate Dye-Semiconductor Hybrid Materials Formed by Electrochemical Self-Assembly as Electrodes in Photoelectrochemical Cells, Zeitschrift für Naturforschung A, vol. 64, no. 7-8. Walter de Gruyter GmbH, 1-Jan.-2009.
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Sienknecht, U. J. and Fekete, D. M., Mapping of Wnt, frizzled, and Wnt inhibitor gene expression domains in the avian otic primordium, J. Comp. Neurol., vol. 517, no. 6. Wiley-Blackwell, pp. 751-764, 20-Dec.-2009.
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Fuchs, K., Hauff, E. von, Parisi, J., and Weiler, R., Voltage Regulated Uptake and Release of L-Glutamate from a Molecularly Selective Switch for Physiological Applications, Zeitschrift für Naturforschung A, vol. 64, no. 12. Walter de Gruyter GmbH, 1-Jan.-2009.
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Schweda, F., Kurtz, L., de Wit, Co.r., Janssen-Bienhold, U., Kurtz, A., and Wagner, C., Substitution of connexin40 with connexin45 prevents hyperreninemia and attenuates hypertension, Kidney International, vol. 75, no. 5. Elsevier BV, pp. 482-489, Mar.-2009.
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Puller, C., De Sevilla Muller, L. P., Janssen-Bienhold, U., and Haverkamp, S., ZO-1 and the Spatial Organization of Gap Junctions and Glutamate Receptors in the Outer Plexiform Layer of the Mammalian Retina, Journal of Neuroscience, vol. 29, no. 19. Society for Neuroscience, pp. 6266-6275, 13-May-2009.
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Pohl, N. U., Slabbekoorn, H., Klump, G. M., and Langemann, U., Effects of signal features and environmental noise on signal detection in the great tit, Parus major, Animal Behaviour, vol. 78, no. 6. Elsevier BV, pp. 1293-1300, Dec.-2009.
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Sterr, A., Shen, S., Kranczioch, C., Szameitat, A. J., Hou, W., and Sorger, B., fMRI effects of task demand and feedback accuracy on grip force tracking, Neuroscience Letters, vol. 457, no. 2. Elsevier BV, pp. 61-65, Jun.-2009.
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Kranczioch, C., Mathews, S., Dean, P. J. A., and Sterr, A., On the equivalence of executed and imagined movements: Evidence from lateralized motor and nonmotor potentials, Hum. Brain Mapp., vol. 30, no. 10. Wiley-Blackwell, pp. 3275-3286, Oct.-2009.
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Ganssauge, M., Wilhelm, H., Bartz-Schmidt, K. -U., and Aisenbrey, S., Non-arteritic anterior ischemic optic neuropathy (NA-AION) after intravitreal injection of bevacizumab (Avastin®) for treatment of angoid streaks in pseudoxanthoma elasticum, Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 247, no. 12. Springer Science + Business Media, pp. 1707-1710, 10-Sep.-2009.
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PETERS, S. W. A. A. N. T. J. E., TATAR, O. L. C. A. Y., SPITZER, M. A. R. T. I. N. S., SZURMAN, P. E. T. E. R., AISENBREY, S. A. B. I. N. E., LÜKE, M. A. T. T. H. I. A. S., ADAM, A. N. N. E. M. A. R. I. E., YOERUEK, E. F. D. A. L., and GRISANTI, S. A. L. V. A. T. O. R. E., ANALYSIS OF THE NEURONAL MARKER PROTEIN GENE PRODUCT 9.5 IN INTERNAL LIMITING MEMBRANES AFTER INDOCYANINE-GREEN ASSISTED PEELING, Retina, vol. 29, no. 2. Ovid Technologies (Wolters Kluwer Health), pp. 243-247, Feb.-2009.
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Bantel, C., Maze, M., and Trapp, S., Neuronal Preconditioning by Inhalational Anesthetics, Anesthesiology, vol. 110, no. 5. Ovid Technologies (Wolters Kluwer Health), pp. 986-995, May-2009.
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Kaminsky, J., Maier, W., Ridder, G., and Löwenheim, H., Interdisciplinary Treatment of Jugular Foramen Pathologies Using a Juxtacondylar Approach, Skull Base, vol. 19, no. 01. Thieme Publishing Group, Apr.-2009.
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Wolf, M., Limberger, M. F., Kleindienst, N., Stieglitz, R. -D., Domsalla, M., Philipsen, A., Steil, R., and Bohus, M., Kurzversion der Borderline-Symptom-Liste (BSL-23): Entwicklung und Überprüfung der psychometrischen Eigenschaften, Psychother Psych Med, vol. 59, no. 08. Thieme Publishing Group, pp. 321-324, 9-Mar.-2009.
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Philipsen, A., Feige, B., Hesslinger, B., Scheel, C., Ebert, D., Matthies, S., Limberger, M. F., Kleindienst, N., Bohus, M., and Lieb, K., Borderline typical symptoms in adult patients with attention deficit/hyperactivity disorder, ADHD Atten Def Hyp Disord, vol. 1, no. 1. Springer Science + Business Media, pp. 11-18, 17-Feb.-2009.
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Koch, K. -W., Guanylate cyclase 2e, AfCS-Nature Molecule Pages. Nature Publishing Group, 6-May-2009.
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Richter-Landsberg, C., Heat Shock Proteins in Neural Cells. Springer Science + Business Media, 2009.
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Bauer, N. G., Richter-Landsberg, C., and Ffrench-Constant, C., Role of the oligodendroglial cytoskeleton in differentiation and myelination, Glia, vol. 57, no. 16. Wiley-Blackwell, pp. 1691-1705, Dec.-2009.
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Goldbaum, O., Riedel, M., Stahnke, T., and Richter-Landsberg, C., The small heat shock protein HSP25 protects astrocytes against stress induced by proteasomal inhibition, Glia, vol. 57, no. 14. Wiley-Blackwell, pp. 1566-1577, 1-Nov.-2009.
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Riedel, M., Goldbaum, O., and Richter-Landsberg, C., alpha-Synuclein promotes the recruitment of tau to protein inclusions in oligodendroglial cells: effects of oxidative and proteolytic stress, Journal of molecular neuroscience : MN, vol. 39, no. 1-2. pp. 226-234, Sep.-2009.
Abstract DOI
alpha-Synuclein is the major building block of cytoplasmic inclusions in neurodegenerative disorders named synucleinopathies. These inclusion bodies often contain the small heat shock protein alphaB-crystallin and the microtubule-associated protein tau. Oxidative modification of alpha-synuclein has been linked to fibril formation, and alpha-synuclein aggregation may induce the fibrillization of tau. To study alpha-synuclein aggregate formation, we have engineered oligodendroglial cells (OLN-93 cells) to stably express the longest human isoform of tau and wild-type alpha-synuclein or the A53T alpha-synuclein mutation. Under normal growth conditions, small punctuated alpha-synuclein aggregates were formed, which were more abundant in cells expressing the A53T mutation. After exposure to oxidative stress, protein inclusions were enlarged and were positive for thioflavin S, but the solubility of alpha-synuclein was not altered. Oxidative stress followed by proteasomal inhibition caused the occurrence of larger thioflavin S-positive inclusions, immunoreactive for tau and alphaB-crystallin, thus resembling glial cell inclusion bodies. Furthermore, this double stress situation led to a decrease in alpha-synuclein solubility, and alphaB-crystallin and HSP90 were present in the insoluble fraction. The formation and recruitment of tau to thioflavin S-positive protein aggregates in OLN-93 cells only expressing tau in the absence of alpha-synuclein, either after oxidative or proteasomal stress or both, was not observable. The data indicate that oxidatively modified alpha-synuclein is degraded by the proteasome and that it plays a pro-aggregatory role for tau in this cell culture model system
Kragh, C. L., Lund, L. B., Febbraro, F., Hansen, H. D., Gai, W. -P., El-Agnaf, O., Richter-Landsberg, C., and Jensen, P. H., Alpha-synuclein aggregation and Ser-129 phosphorylation-dependent cell death in oligodendroglial cells, The Journal of biological chemistry, vol. 284, no. 15. pp. 10211-10222, Apr.-2009.
Abstract DOI
Multiple system atrophy is a neurodegenerative disorder characterized by accumulation of aggregated Ser-129-phosphorylated alpha-synuclein in oligodendrocytes. p25alpha is an oligodendroglial protein that potently stimulates alpha-synuclein aggregation in vitro. To model multiple system atrophy, we coexpressed human p25alpha and alpha-synuclein in the rat oligodendroglial cell line OLN-93 and observed a cellular response characterized by a fast retraction of microtubules from the cellular processes to the perinuclear region followed by a protracted development of apoptosis. This response was dependent on phosphorylation at Ser-129 in alpha-synuclein as demonstrated by site-directed mutagenesis. Treatment of the cells with the kinase inhibitor 2-dimethylamino-4,5,6,7-tetrabromo-1H benzimidazole that targets kinases like casein kinase 2, and polo-like kinases abrogated the toxicity. The polo-like kinase inhibitor BI 2536 caused apoptosis in the model. Ser-129 phosphorylation was linked to the formation of phosphorylated oligomers detectable by immunoblotting, and their formation was inhibited by 2-dimethylamino-4,5,6,7-tetrabromo-1H benzimidazole. The process of microtubule retraction was also dependent on aggregation as demonstrated by the protective effect of treating the cells with the specific peptide inhibitor of alpha-synuclein aggregation ASI1D and the non-selective inhibitors Congo Red and baicalein. The fast microtubule retraction was followed by the development of the apoptotic markers: activated caspase-3, phosphatidylserine externalization, nuclear condensation, and fragmentation. These markers could all be blocked by the inhibitors of phosphorylation, aggregation, and caspase-3. Hence, the model predicts that both Ser-129 phosphorylation and aggregation control the toxic alpha-syn pathway in oligodendroglial cells and may represent therapeutic intervention points in multiple system atrophy
Klink, K. B., Dierker, H., Beutelmann, R., and Klump, G. M., Comodulation Masking Release Determined in the Mouse (Mus musculus) using a Flanking-band Paradigm, Journal of the Association for Research in Otolaryngology, vol. 11, no. 1. Springer Science + Business Media, pp. 79-88, 10-Sep.-2009.
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Beutelmann, R., Brand, T., and Kollmeier, B., Prediction of binaural speech intelligibility with frequency-dependent interaural phase differences, J. Acoust. Soc. Am., vol. 126, no. 3. Acoustical Society of America (ASA), p. 1359, 2009.
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Heise, S. J., Mauermann, M., and Verhey, J. L., Investigating possible mechanisms behind the effect of threshold fine structure on amplitude modulation perception, J. Acoust. Soc. Am., vol. 126, no. 5. Acoustical Society of America (ASA), p. 2490, 2009.
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Heise, S. J., Mauermann, M., and Verhey, J. L., Threshold fine structure affects amplitude modulation perception, J. Acoust. Soc. Am., vol. 125, no. 1. Acoustical Society of America (ASA), p. EL33, 2009.
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Rossler, O. E., Kuypers, H., Parisi, J., Fröhlich, D., and Kuske, F., Black-hole horizons cannot be reached in finite outer time, Physics Essays, vol. 22, no. 3. Physics Essays Publication, pp. 420-421, Sep.-2009.
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Diederich, A., Books received for Review, Journal of Mathematical Psychology, vol. 53, no. 4. Elsevier BV, p. 301, Aug.-2009.
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Diederich, A. and Schreier, M., [Criteria for prioritisation from a societal perspective], Zeitschrift fur Evidenz, Fortbildung und Qualitat im Gesundheitswesen, vol. 103, no. 2. pp. 111-116, 2009.
Abstract DOI
The precarious financial situation of the German public health care system requires the limitation of health care benefits. Determining priorities between groups of patients, indications, or procedures and implementing preferential treatments is one of the pressing issues in health ethics, health law, social medicine and health politics. Although a public debate on priority setting, or prioritisation, has repeatedly been called for, it was mainly the physicians' views and values as well as the interests of their sponsors that have been voiced; the perspectives of patients and the public has been deemed irrelevant. In the following, we summarise the prioritisation experiences from some foreign countries and report on preliminary results obtained from qualitative interviews with healthy German citizens concerning their views on setting priorities with respect to diseases, therapies, people's lifestyle, demographic factors, and economic and ethical aspects
Diederich, A. and Colonius, H., Crossmodal interaction in speeded responses: time window of integration model, Progress in brain research, vol. 174. pp. 119-135, 2009.
Abstract DOI
Saccadic reaction time (SRT) to a visual stimulus tends to be faster when an auditory and/or somatosensory stimulus is presented in close temporal or spatial proximity, even when participants are instructed to ignore the accessory input (focused attention task). The time course of SRT as a function of stimulus onset asynchrony (SOA) is consistent with the time-window-of-integration (TWIN) model assuming a peripheral stage of parallel processing in separate sensory channels followed by a secondary stage of multisensory integration. TWIN has been shown to account for effects of the spatial configuration of the stimuli, for the effect of increasing the number of nontargets presented together with the target, for a possible warning effect of the nontarget, for effects of increasing the intensity of the nontarget, and for the effect of background noise on multisensory integration. Moreover, it has been able to accommodate some effects of aging on multisensory integration. There is empirical support for TWIN's tenet of the separability between spatial and temporal factors on multisensory integration. Besides presenting many features of TWIN within the context of crossmodal interaction modeling efforts, some possible directions on how the TWIN framework could serve to elucidate the link between perception and action are shown
Colonius, H., Diederich, A., and Steenken, R., Time-window-of-integration (TWIN) model for saccadic reaction time: effect of auditory masker level on visual-auditory spatial interaction in elevation, Brain topography, vol. 21, no. 3-4. pp. 177-184, May-2009.
Abstract DOI
Saccadic reaction time (SRT) to a visual target tends to be shorter when auditory stimuli are presented in close temporal and spatial proximity, even when subjects are instructed to ignore the auditory non-target (focused attention paradigm). Previous studies using pairs of visual and auditory stimuli differing in both azimuth and vertical position suggest that the amount of SRT facilitation decreases not with the physical but with the perceivable distance between visual target and auditory non-target. Steenken et al. (Brain Res 1220:150-156, 2008) presented an additional white-noise masker background of three seconds duration. Increasing the masker level had a diametrical effect on SRTs in spatially coincident versus disparate stimulus configurations: saccadic responses to coincident visual-auditory stimuli are slowed down, whereas saccadic responses to disparate stimuli are speeded up. Here we show that the time-window-of-integration model accounts for this observation by variation of a perceivable-distance parameter in the second stage of the model whose value does not depend on stimulus onset asynchrony between target and non-target
DeCaro, D. A., Bar-Eli, M., Conlin, J. A., Diederich, A., Johnson, J. G., and Plessner, H., How do motoric realities shape, and become shaped by, the way people evaluate and select potential courses of action? Toward a unitary framework of embodied decision making, Progress in brain research, vol. 174. pp. 189-203, 2009.
Abstract DOI
Until recently, the constraints imposed on decision makers by the human physical condition - situated both as a physical agent and within physical space - have played only an incidental, if not entirely inconsequential, role in conceptualizations of human decision making. The act of deciding has been positioned as the quintessence of traditional decision theory, while actual enactment of the decided action within physical space by a corporal actor, with all that this entails, has been regarded as the obvious and, therefore, scientifically uninteresting result of having made up one's mind (cf. Bagozzi et al., 2003). However, recent discoveries made in the area of embodied cognition regarding the involvement of fundamentally motoric representations in long-presumed "cognitive" systems (Wilson, 2002) potentially turned conventional wisdom upside-down. In this chapter, we go beyond prominent theories of action selection and decision making to rethink the link between mind and body as it pertains to the relatively novel frontier of embodied decision making. In particular, we reconceptualize what it means to evaluate one's options in light of recent advancements in embodied cognition, motor control, and dynamic decision making. In the process, we provide a much needed account of the primary theoretical issues that any good account would seem to be impelled to address. Perhaps the greatest contribution provided by the present chapter is an organizing framework that we hope will guide future research to the eventual answer to what it means to be an embodied decision maker
Gauthier, J. L., Field, G. D., Sher, A., Shlens, J., Greschner, M., Litke, A. M., and Chichilnisky, E. J., Uniform signal redundancy of parasol and midget ganglion cells in primate retina, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 29, no. 14. pp. 4675-4680, Apr.-2009.
Abstract DOI
The collective representation of visual space in high resolution visual pathways was explored by simultaneously measuring the receptive fields of hundreds of ON and OFF midget and parasol ganglion cells in isolated primate retina. As expected, the receptive fields of all four cell types formed regular mosaics uniformly tiling the visual scene. Surprisingly, comparison of all four mosaics revealed that the overlap of neighboring receptive fields was nearly identical, for both the excitatory center and inhibitory surround components of the receptive field. These observations contrast sharply with the large differences in the dendritic overlap between the parasol and midget cell populations, revealing a surprising lack of correspondence between the anatomical and functional architecture in the dominant circuits of the primate retina
Field, G. D., Greschner, M., Gauthier, J. L., Rangel, C., Shlens, J., Sher, A., Marshak, D. W., Litke, A. M., and Chichilnisky, E. J., High-sensitivity rod photoreceptor input to the blue-yellow color opponent pathway in macaque retina, Nature neuroscience, vol. 12, no. 9. pp. 1159-1164, Sep.-2009.
Abstract DOI
Small bistratified cells (SBCs) in the primate retina carry a major blue-yellow opponent signal to the brain. We found that SBCs also carry signals from rod photoreceptors, with the same sign as S cone input. SBCs exhibited robust responses under low scotopic conditions. Physiological and anatomical experiments indicated that this rod input arose from the AII amacrine cell-mediated rod pathway. Rod and cone signals were both present in SBCs at mesopic light levels. These findings have three implications. First, more retinal circuits may multiplex rod and cone signals than were previously thought to, efficiently exploiting the limited number of optic nerve fibers. Second, signals from AII amacrine cells may diverge to most or all of the approximately 20 retinal ganglion cell types in the peripheral primate retina. Third, rod input to SBCs may be the substrate for behavioral biases toward perception of blue at mesopic light levels
Shlens, J., Field, G. D., Gauthier, J. L., Greschner, M., Sher, A., Litke, A. M., and Chichilnisky, E. J., The structure of large-scale synchronized firing in primate retina, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 29, no. 15. pp. 5022-5031, Apr.-2009.
Abstract DOI
Synchronized firing among neurons has been proposed to constitute an elementary aspect of the neural code in sensory and motor systems. However, it remains unclear how synchronized firing affects the large-scale patterns of activity and redundancy of visual signals in a complete population of neurons. We recorded simultaneously from hundreds of retinal ganglion cells in primate retina, and examined synchronized firing in completely sampled populations of approximately 50-100 ON-parasol cells, which form a major projection to the magnocellular layers of the lateral geniculate nucleus. Synchronized firing in pairs of cells was a subset of a much larger pattern of activity that exhibited local, isotropic spatial properties. However, a simple model based solely on interactions between adjacent cells reproduced 99% of the spatial structure and scale of synchronized firing. No more than 20% of the variability in firing of an individual cell was predictable from the activity of its neighbors. These results held both for spontaneous firing and in the presence of independent visual modulation of the firing of each cell. In sum, large-scale synchronized firing in the entire population of ON-parasol cells appears to reflect simple neighbor interactions, rather than a unique visual signal or a highly redundant coding scheme
Gauthier, J. L., Field, G. D., Sher, A., Greschner, M., Shlens, J., Litke, A. M., and Chichilnisky, E. J., Receptive fields in primate retina are coordinated to sample visual space more uniformly, PLoS biology, vol. 7, no. 4. p. e1000063, Apr.-2009.
Abstract DOI
In the visual system, large ensembles of neurons collectively sample visual space with receptive fields (RFs). A puzzling problem is how neural ensembles provide a uniform, high-resolution visual representation in spite of irregularities in the RFs of individual cells. This problem was approached by simultaneously mapping the RFs of hundreds of primate retinal ganglion cells. As observed in previous studies, RFs exhibited irregular shapes that deviated from standard Gaussian models. Surprisingly, these irregularities were coordinated at a fine spatial scale: RFs interlocked with their neighbors, filling in gaps and avoiding large variations in overlap. RF shapes were coordinated with high spatial precision: the observed uniformity was degraded by angular perturbations as small as 15 degrees, and the observed populations sampled visual space with more than 50% of the theoretical ideal uniformity. These results show that the primate retina encodes light with an exquisitely coordinated array of RF shapes, illustrating a higher degree of functional precision in the neural circuitry than previously appreciated
Roth, G. and Strüber, D., Neurobiologische Aspekte reaktiver und proaktiver Gewalt bei antisozialer Persönlichkeitsstörung und „Psychopathie“, Praxis der Kinderpsychologie und Kinderpsychiatrie, vol. 58, no. 8. Vandenhoeck & Ruprecht GmbH & Co, KG, pp. 587-609, Oct.-2009.
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Roth, G. and Strüber, D., [Neurobiological aspects of reactive and proactive violence in antisocial personality disorder and "psychopathy"], Praxis der Kinderpsychologie und Kinderpsychiatrie, vol. 58, no. 8. pp. 587-609, 2009.
Abstract
Impulsive-reactive violent offenders show increased autonomic activity in response to negative emotional and threatening stimuli. A volume reduction and/or activity decrease of frontal brain structures associated with impulse control and the regulation of fear and anger are likewise found in combination with a fear-related hyperactivity of the amygdala. In addition, impulsive aggression is facilitated by variants of gene polymorphisms influencing the serotonergic system. Conversely, proactive-instrumental violent offender with psychopathy, who are characterized by a lack of empathy and remorse, demonstrate an autonomic hypo-responsivity as well as dysfunctions of the amygdala and of cortical regions related to empathic and social behavior. Developmentally, aggressive children exhibit temperamental differences from early childhood on that are characteristic of a developmental pathway towards either reactive or proactive violence later in life. Exposure to negative environmental factors like ineffective parenting or childhood maltreatment has been related to a heightened risk for developing reactive violence. A developmental trajectory of proactive violence, however, has been related to a mostly genetically determined callous unemotional temperament of the child that disrupts the parental socialization efforts during childhood
Zahnow, J. C., Vilela, R. D., Feudel, U., and Tél, T., Coagulation and fragmentation dynamics of inertial particles, Phys. Rev. E, vol. 80, no. 2. American Physical Society (APS), 19-Aug.-2009.
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Stiefs, D., Venturino, E., and Feudel, U., Evidence of chaos in eco-epidemic models, Mathematical Biosciences and Engineering, vol. 6, no. 4. American Institute of Mathematical Sciences (AIMS), pp. 855-871, Sep.-2009.
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Gross, T., Edwards, A. M., and Feudel, U., The invisible niche: weakly density-dependent mortality and the coexistence of species, Journal of theoretical biology, vol. 258, no. 1. pp. 148-155, May-2009.
Abstract DOI
Weakly density-dependent effects, characterized by fractional scaling exponents close to one, are rarely studied in the ecological literature. Here, we consider the effect of an additional weakly density-dependent term on a simple competition model. Our investigation reveals that weak density-dependence opens up an "invisible niche". This niche does not constitute a new mechanism for coexistence, but is a previously unexplored consequence of known mechanisms. In the invisible niche a weaker competitor can survive at very low density. Coexistence thus requires large habitat size. Such niches, if found in nature, would have a direct impact on species-area laws and species-abundance curves and should therefore receive more attention
Erim, Y., Beckmann, M., Gerlach, G., Kümmel, S., Oberhoff, C., Senf, W., and Kimmig, R., [Screening for distress in women with breast cancer diagnosed for the first time: employment of HADS-D and PO-Bado], Zeitschrift fur Psychosomatische Medizin und Psychotherapie, vol. 55, no. 3. pp. 248-262, 2009.
Abstract
OBJECTIVES: In the context of an intensification of efforts to ensure sufficient psychooncological care for breast-cancer patients, the discussion concerning valid psychometric screening instruments gains a special relevance. METHODS: The discriminant and diagnostic validity of HADS-D and PO-Bado were investigated in a sample of 123 women with breast cancer diagnosed for the first time. RESULTS: An ROC analysis revealed a cut-off score of greater than 9 for the subscale anxiety (sensitivity: 50%; specificity: 90%) for the use of HADS-D among breast cancer patients, whereas the recommended cut-off value was greater than 7 (sensitivity: 56%; specificity: 80%) for the subscale depression. Based on the anxiety and depression scores measured by HADS-D, 74% of the clinical cases could be classified correctly. Scores for physical and mental distress measured with PO-Bado were significantly lower in the investigated sample than in the control sample. CONCLUSIONS: HADS-D has only a moderate sensitivity for the group at hand. PO-Bado is a comprehensive basic documentation for specific psychooncological distress, though without cut-off values it is not useful as a screening instrument
Zapka, M., Heyers, D., Hein, C. M., Engels, S., Schneider, N. -L., Hans, J., Weiler, S., Dreyer, D., Kishkinev, D., Wild, J. M., and Mouritsen, H., Visual but not trigeminal mediation of magnetic compass information in a migratory bird, Nature, vol. 461, no. 7268. pp. 1274-1277, Oct.-2009.
Abstract DOI
Magnetic compass information has a key role in bird orientation, but the physiological mechanisms enabling birds to sense the Earth's magnetic field remain one of the unresolved mysteries in biology. Two biophysical mechanisms have become established as the most promising magnetodetection candidates. The iron-mineral-based hypothesis suggests that magnetic information is detected by magnetoreceptors in the upper beak and transmitted through the ophthalmic branch of the trigeminal nerve to the brain. The light-dependent hypothesis suggests that magnetic field direction is sensed by radical pair-forming photopigments in the eyes and that this visual signal is processed in cluster N, a specialized, night-time active, light-processing forebrain region. Here we report that European robins with bilateral lesions of cluster N are unable to show oriented magnetic-compass-guided behaviour but are able to perform sun compass and star compass orientation behaviour. In contrast, bilateral section of the ophthalmic branch of the trigeminal nerve in European robins did not influence the birds' ability to use their magnetic compass for orientation. These data show that cluster N is required for magnetic compass orientation in this species and indicate that it may be specifically involved in processing of magnetic compass information. Furthermore, the data strongly suggest that a vision-mediated mechanism underlies the magnetic compass in this migratory songbird, and that the putative iron-mineral-based receptors in the upper beak connected to the brain by the trigeminal nerve are neither necessary nor sufficient for magnetic compass orientation in European robins
Metz, M., Friedl, T., and Klump, G. M., Male nest-building behaviour and mating success in the red bishop (Euplectes orix), Behaviour, vol. 146, no. 6. Brill Academic Publishers, pp. 771-794, 1-Jun.-2009.
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Seeba, F. and Klump, G. M., Stimulus Familiarity Affects Perceptual Restoration in the European Starling (Sturnus vulgaris), PLoS ONE, vol. 4, no. 6. Public Library of Science (PLoS), p. e5974, 24-Jun.-2009.
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Maier, J. K., Mcalpine, D., Klump, G. M., and Pressnitzer, D., Context Effects in the Discriminability of Spatial Cues, Journal of the Association for Research in Otolaryngology, vol. 11, no. 2. Springer Science + Business Media, pp. 319-328, 22-Dec.-2009.
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Klinge, A. and Klump, G. M., Frequency difference limens of pure tones and harmonics within complex stimuli in Mongolian gerbils and humans, J. Acoust. Soc. Am., vol. 125, no. 1. Acoustical Society of America (ASA), p. 304, 2009.
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Sun, L., Rieger, J. W., and Hinrichs, H., Maximum noise fraction (MNF) transformation to remove ballistocardiographic artifacts in EEG signals recorded during fMRI scanning, NeuroImage, vol. 46, no. 1. Elsevier BV, pp. 144-153, 15-May-2009.
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Hanke, M., Halchenko, Y. O., Sederberg, P. B., Olivetti, E., Fründ, I., Rieger, J. W., Herrmann, C. S., Haxby, J. V., Hanson, S. J., and Pollmann, S., PyMVPA: A Unifying Approach to the Analysis of Neuroscientific Data, Frontiers in neuroinformatics, vol. 3. p. 3, 2009.
Abstract DOI
The Python programming language is steadily increasing in popularity as the language of choice for scientific computing. The ability of this scripting environment to access a huge code base in various languages, combined with its syntactical simplicity, make it the ideal tool for implementing and sharing ideas among scientists from numerous fields and with heterogeneous methodological backgrounds. The recent rise of reciprocal interest between the machine learning (ML) and neuroscience communities is an example of the desire for an inter-disciplinary transfer of computational methods that can benefit from a Python-based framework. For many years, a large fraction of both research communities have addressed, almost independently, very high-dimensional problems with almost completely non-overlapping methods. However, a number of recently published studies that applied ML methods to neuroscience research questions attracted a lot of attention from researchers from both fields, as well as the general public, and showed that this approach can provide novel and fruitful insights into the functioning of the brain. In this article we show how PyMVPA, a specialized Python framework for machine learning based data analysis, can help to facilitate this inter-disciplinary technology transfer by providing a single interface to a wide array of machine learning libraries and neural data-processing methods. We demonstrate the general applicability and power of PyMVPA via analyses of a number of neural data modalities, including fMRI, EEG, MEG, and extracellular recordings
Zaehle, T., Fründ, I., Schadow, J., Thärig, S., Schoenfeld, M. A., and Herrmann, C. S., Inter- and intra-individual covariations of hemodynamic and oscillatory gamma responses in the human cortex, Frontiers in human neuroscience, vol. 3. p. 8, 2009.
Abstract DOI
The time course of local field potentials (LFPs) displaying typical discharge frequencies in the gamma frequency range highly correlates with the blood oxygen level dependent (BOLD) signal in response to rotating checkerboard stimuli in animals. In humans, oscillatory gamma-band responses (GBRs) show strong inter-individual variations in frequency and amplitude but considerable intra-individual reliability indicating that individual gamma activity reflects a personal trait. While the functional role of these GBRs is still debated, investigations combining electroencephalography-functional magnetic resonance imaging (EEG-fMRI) measurements provide a tool to obtain further insights into the underlying functional architecture of the human brain and will shed light onto the understanding of the dynamic relation between the BOLD signal and the properties of the electrical activity recorded on the scalp. We investigated the relation between the hemodynamic response and evoked gamma-band response (eGBR) to visual stimulation. We tested the hypothesis that the amplitude of human eGBRs and BOLD responses covary intra-individually as a function of stimulation as well as inter-individually as a function of gamma-trait. Seventeen participants performed visual discrimination tasks during separate EEG and fMRI recordings. Results revealed that visual stimuli that evoked high GBRs also elicited strong BOLD responses in the human V1/V2 complex. Furthermore, inter-individual variations of BOLD responses to visual stimuli in the bilateral primary (Area 17) and secondary (Area V5/MT) visual cortex and the right hippocampal formation were correlated with the individual gamma-trait of the subjects. The present study further supports the notion that neural oscillations in the gamma frequency range are involved in the cascade of neural processes that underlie the hemodynamic responses measured with fMRI
Fründ, I., Ohl, F. W., and Herrmann, C. S., Spike-timing-dependent plasticity leads to gamma band responses in a neural network, Biological cybernetics, vol. 101, no. 3. pp. 227-240, Sep.-2009.
Abstract DOI
Early gamma band responses of the human electroencephalogram have been identified as an early interface linking top-down and bottom-up processing. This was based on findings that observed strong sensitivity of this signal to stimulus size and at the same time, to processes of attention and memory. Here, we simulate these findings in a simple random network of biologically plausible spiking neurons. During a learning phase, different stimuli were presented to the network and the synaptic connections were modified according to a spike-timing-dependent plasticity learning rule. In a subsequent test phase, we stimulated the network with (i) patterns of different sizes to simulate bottom-up effects and (ii) with patterns that were or were not presented during the learning phase. The network displayed qualitatively similar behavior as early gamma band responses measured from the scalp of human subjects: there was a general increase in response strength with increasing stimulus size and stronger responses for learned stimuli. We demonstrated that within one neural architecture early gamma band responses can be modulated both by bottom-up factors and by basal learning mechanisms mediated via spike-timing-dependent plasticity
Schadow, J., Lenz, D., Dettler, N., Fründ, I., and Herrmann, C. S., Early gamma-band responses reflect anticipatory top-down modulation in the auditory cortex, NeuroImage, vol. 47, no. 2. pp. 651-658, Aug.-2009.
Abstract DOI
For efficient and fast encoding of our complex acoustic environment, not only aspects of bottom-up processing are significant, but rather top-down influences such as attention, memory, and anticipation promote specific behavior and perception. Neural oscillatory activity in the gamma-range (30-80 Hz) is discussed as a conceivable candidate to represent very rapid modulations of top-down factors. We investigated effects of anticipation on early gamma-band responses (GBRs) of the EEG and event-related potentials (ERPs) in response to tone sequences. These sequences were composed of six sinusoidal tones, which could be either regularly ascending or descending in frequency. Thus, the sequences reflected a good continuation of pitch, which also resulted in the buildup of strong expectancies for the upcoming stimulus within the sequence. However, some of the tone sequences contained a violation of the good continuation of pitch at the third or fifth tone position. The early phase-locked portion of the gamma-band activity was significantly increased when tones were in line with the good continuation of sequences compared to deviant tones. Further, a pronounced early negative ERP response, starting at 150 ms, was elicited by deviant tones at the third and fifth position. Our results support the notion that gamma-band oscillations reflect perceptual grouping processes of concurrent sounds and anticipatory top-down modulation, which involves some of the first stages of auditory information processing
Schadow, J., Dettler, N., Paramei, G. V., Lenz, D., Fründ, I., Sabel, B. A., and Herrmann, C. S., Impairments of Gestalt perception in the intact hemifield of hemianopic patients are reflected in gamma-band EEG activity, Neuropsychologia, vol. 47, no. 2. pp. 556-568, Jan.-2009.
Abstract DOI
Gamma-band responses (GBRs) are associated with Gestalt perception processes. In the present EEG study, we investigated the effects of perceptual grouping on the visual GBR in the perimetrically intact visual field of patients with homonymous hemianopia and compared them to healthy participants. All observers were presented either random arrays of Gabor elements or arrays with an embedded circular arrangement. For the hemianopic patients, the circle was presented in their intact hemifield only. For controls, the hemifield for the circle presentation was counterbalanced across subjects. The participants were instructed to detect the circle by pressing a corresponding button. A wavelet transform based on Morlet wavelets was employed for the calculation of oscillatory GBRs. The early evoked GBR exhibited a larger amplitude and shorter latency for the healthy group compared to hemianopic patients and was associated with behavioral measures. The late total GBR between 200 and 400ms after stimulus onset was significantly increased for Gestalt-like patterns in healthy participants. This effect was not manifested in patients. The present findings indicate deficits in the early and late visual processing of Gestalt patterns even in the intact hemifield of hemianopic patients compared to healthy participants
Wenz, M., Hartmann, A. -M., Friauf, E., and Nothwang, H. G., CIP1 is an activator of the K+–Cl− cotransporter KCC2, Biochemical and Biophysical Research Communications, vol. 381, no. 3. Elsevier BV, pp. 388-392, Apr.-2009.
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Hartmann, A. -M., Blaesse, P., Kranz, T., Wenz, M., Schindler, J., Kaila, K., Friauf, E., and Nothwang, H. G., Opposite effect of membrane raft perturbation on transport activity of KCC2 and NKCC1, Journal of Neurochemistry, vol. 111, no. 2. Wiley-Blackwell, pp. 321-331, Oct.-2009.
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Soeroes, P., Inamoto, Y., and Martin, R. E., Functional Brain Imaging of Swallowing: An Activation Likelihood Estimation Meta-Analysis, HUMAN BRAIN MAPPING, vol. 30, no. 8. Aug.-2009.
Abstract
A quantitative, voxel-wise meta-analysis was performed to investigate the cortical control of water and saliva swallowing. Studies that were included in the meta-analysis (1) examined water swallowing, saliva swallowing, or both, and (2) reported brain activation as coordinates in standard space. Using these criteria, a systematic literature search identified seven Studies that examined water swallowing and five studies of saliva swallowing. An activation likelihood estimation (ALE) meta-analysis of these studies was performed with GingerALE. For water swallowing, clusters with high activation likelihood were found in the bilateral sensorimotor cortex, right inferior parietal lobule, and right anterior insula. For saliva swallowing, Clusters with high activation likelihood were found in the left sensorimotor cortex, right motor cortex, and bilateral cingulate gyrus. A between-condition meta-analysis revealed clusters with higher activation likelihood for water than for saliva swallowing in the right inferior parietal lobule, right postcentral gyrus, and right anterior insula. Clusters with higher activation likelihood for saliva than for water swallowing were found in the bilateral supplementary motor area, bilateral anterior cingulate gyrus, and bilateral precentral gyrus. This meta-analysis emphasizes the distributed and partly overlapping cortical networks involved in the control of water and saliva swallowing. Water swallowing is associated with right inferior parietal activation, likely reflecting the sensory processing of intraoral water stimulation. Saliva swallowing more strongly involves premotor areas, which are crucial for the initiation and control of movements. Hum Brain Mapp 30:2426-2439, 2009. (c) 2008 Wiley-Liss, Inc.
Soeroes, P., Teismann, I. K., Manemann, E., and Luetkenhoener, B., Auditory temporal processing in healthy aging: a magnetoencephalographic study, BMC NEUROSCIENCE, vol. 10. Apr.-2009.
Abstract
Background: Impaired speech perception is one of the major sequelae of aging. In addition to peripheral hearing loss, central deficits of auditory processing are supposed to contribute to the deterioration of speech perception in older individuals. To test the hypothesis that auditory temporal processing is compromised in aging, auditory evoked magnetic fields were recorded during stimulation with sequences of 4 rapidly recurring speech sounds in 28 healthy individuals aged 20-78 years. Results: The decrement of the N1m amplitude during rapid auditory stimulation was not significantly different between older and younger adults. The amplitudes of the middle-latency P1m wave and of the long-latency N1m, however, were significantly larger in older than in younger participants. Conclusion: The results of the present study do not provide evidence for the hypothesis that auditory temporal processing, as measured by the decrement (short-term habituation) of the major auditory evoked component, the N1m wave, is impaired in aging. The differences between these magnetoencephalographic findings and previously published behavioral data might be explained by differences in the experimental setting between the present study and previous behavioral studies, in terms of speech rate, attention, and masking noise. Significantly larger amplitudes of the P1m and N1m waves suggest that the cortical processing of individual sounds differs between younger and older individuals. This result adds to the growing evidence that brain functions, such as sensory processing, motor control and cognitive processing, can change during healthy aging, presumably due to experience-dependent neuroplastic mechanisms.
Smorodchenko, A., Rupprecht, A., Sarilova, I., Ninnemann, O., Braeuer, A. U., Franke, K., Schumacher, S., Techritz, S., Nitsch, R., Schuelke, M., and Pohl, E. E., Comparative analysis of uncoupling protein 4 distribution in various tissues under physiological conditions and during development, BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES, vol. 1788, no. 10. ELSEVIER SCIENCE BV, Oct.-2009.
Abstract
UCP4 is a member of the mitochondrial uncoupling protein subfamily and one of the three UCPs (UCP2, UCP4, UCP5), associated with the nervous system. Its putative functions include thermogenesis, attenuation of reactive oxidative species (ROS), regulation of mitochondrial calcium concentration and involvement in cell differentiation and apoptosis. Here we investigate UCP4's subcellular, cellular and tissue distribution, using an antibody designed specially for this study, and discuss the findings in terms of the protein's possible functions. Western blot and immunohistochemistry data confirmed that UCP4 is expressed predominantly in the central nervous system (CNS), as previously shown at mRNA level. No protein was found in heart, spleen, stomach, intestine, lung, thymus, muscles, adrenal gland, testis and liver. The reports revealing UCP4 mRNA in kidney and white adipose tissue were not confirmed at protein level. The amount of UCP4 varies in the mitochondria of different brain regions, with the highest protein content found in cortex. We show that UCP4 is present in fetal murine brain tissue as early as embryonic days 12-14 (E12-E14), which coincides with the beginning of neuronal differentiation. The UCP4 content in mitochondria decreases as the age of mice increases. UCP4 preferential expression in neurons and its developmental expression pattern under physiological conditions may indicate a specific protein function, e.g. in neuronal cell differentiation. (C) 2009 Elsevier B.V. All rights reserved.
Trimbuch, T., Beed, P., Vogt, J., Schuchmann, S., Maier, N., Kintscher, M., Breustedt, J., Schuelke, M., Streu, N., Kieselmann, O., Brunk, I., Laube, G., Strauss, U., Battefeld, A., Wende, H., Birchmeier, C., Wiese, S., Sendtner, M., Kawabe, H., Kishimoto-Suga, M., Brose, N., Baumgart, J., Geist, B., Aoki, J., Savaskan, N. E., Braeuer, A. U., Chun, J., Ninnemann, O., Schmitz, D., and Nitsch, R., Synaptic PRG-1 Modulates Excitatory Transmission via Lipid Phosphate-Mediated Signaling, CELL, vol. 138, no. 6. CELL PRESS, Sep.-2009.
Abstract
Plasticity related gene-1 (PRG-1) is a brain-specific membrane protein related to lipid phosphate phosphatases, which acts in the hippocampus specifically at the excitatory synapse terminating on glutamatergic neurons. Deletion of prg-1 in mice leads to epileptic seizures and augmentation of EPSCs, but not IPSCs. In utero electroporation of PRG-1 into deficient animals revealed that PRG-1 modulates excitation at the synaptic junction. Mutation of the extracellular domain of PRG-1 crucial for its interaction with lysophosphatidic acid (LPA) abolished the ability to prevent hyperexcitability. As LPA application in vitro induced hyperexcitability in wild-type but not in LPA(2) receptor-deficient animals, and uptake of phospholipids is reduced in PRG-1-deficient neurons, we assessed PRG-1/LPA(2) receptor deficient animals, and found that the pathophysiology observed in the PRG-1-deficient mice was fully reverted. Thus, we propose PRG-1 as an important player in the modulatory control of hippocampal excitability dependent on presynaptic LPA(2) receptor signaling.
Wirth, E. K., Roth, S., Blechschmidt, C., Hoelter, S. M., Becker, L., Racz, I., Zimmer, A., Klopstock, T., Gailus-Durner, V., Fuchs, H., Wurst, W., Naumann, T., Braeuer, A., de Angelis, M. H., Koehrle, J., Grueters, A., and Schweizer, U., Neuronal 3 `,3,5-Triiodothyronine (T-3) Uptake and Behavioral Phenotype of Mice Deficient in Mct8, the Neuronal T-3 Transporter Mutated in Allan-Herndon-Dudley Syndrome, JOURNAL OF NEUROSCIENCE, vol. 29, no. 30. SOC NEUROSCIENCE, Jul.-2009.
Abstract
Thyroid hormone transport into cells requires plasma membrane transport proteins. Mutations in one of these, monocarboxylate transporter 8 (MCT8), have been identified as underlying cause for the Allan-Herndon-Dudley syndrome, an X-linked mental retardation in which the patients also present with abnormally high 3 `,3,5-triiodothyronine (T-3) plasma levels. Mice deficient in Mct8 replicate the thyroid hormone abnormalities observed in the human condition. However, no neurological deficits have been described in mice lacking Mct8. Therefore, we subjected Mct8-deficient mice to a comprehensive immunohistochemical, neurological, and behavioral screen. Several behavioral abnormalities were found in the mutants. Interestingly, some of these behavioral changes are compatible with hypothyroidism, whereas others rather indicate hyperthyroidism. We thus hypothesized that neurons exclusively dependent on Mct8 are in a hypothyroid state, whereas neurons expressing other T-3 transporters become hyperthyroid, if they are exposed directly to the high plasma T-3. The majority of T-3 uptake in primary cortical neurons is mediated by Mct8, but pharmacological inhibition suggested functional expression of additional T-3 transporter classes. mRNAs encoding six T-3 transporters, including L-type amino acid transporters (LATs), were coexpressed with Mct8 in isolated neurons. We then demonstrated Lat2 expression in cultured neurons and throughout murine brain development. In contrast, LAT2 is expressed in microglia in the developing human brain during gestation, but not in neurons. We suggest that lack of functional complementation by alternative thyroid hormone transporters in developing human neurons precipitates the devastating neurodevelopmental phenotype in MCT8-deficient patients, whereas Mct8-deficient mouse neurons are functionally complemented by other transporters, for possibly Lat2.
Drews, D., Klar, M., Dame, C., and Braeuer, A. U., Developmental expression profile of the yy2 gene in mice, BMC DEVELOPMENTAL BIOLOGY, vol. 9. BIOMED CENTRAL LTD, Jul.-2009.
Abstract
Background: The transcription factor Yin Yang 2 (YY2) shares a structural and functional highly homologue DNA-binding domain with the ubiquitously expressed YY1 protein, which has been implicated in regulating fundamental biological processes. However, the biological relevance of YY2 has not been identified yet. Results: Towards the understanding of YY2 biology, we analyzed in detail the expression pattern of yy2 in various organs during embryonic and postnatal mouse development till adulthood. Thereby, a constant yy2 level was detected in heart and lung tissue, whereas in different brain regions yy2 expression was dynamically regulated. Interestingly, in any analyzed tissue neither the homologue yy1 nor the mbtps2 gene showed changes in mRNA expression levels like yy2, although the intronless yy2 gene is located within the mbtps2 locus. Furthermore, we detected yy1, yy2, and mbtps2 mRNA in primary mouse neurons, microglia cells, and astrocytes. In comparison to yy2 and mbtps2, yy1 revealed the highest expression level in all cell types. Again, only yy2 showed significantly altered gene expression levels among the cell types. Higher yy2 expression levels were detected in microglia cells and astrocytes than in primary neurons. Conclusion: Yy2 expression in the heart and lung is constitutively expressed during embryogenesis and in adult mice. For the first time, developmental changes of yy2 transcription became obvious in various areas of the brain. This suggests that yy2 is involved in developmental gene regulation.
Kuehbacher, M., Bartel, J., Hoppe, B., Alber, D., Bukalis, G., Braeuer, A. U., Behne, D., and Kyriakopoulos, A., The brain selenoproteome: priorities in the hierarchy and different levels of selenium homeostasis in the brain of selenium-deficient rats, JOURNAL OF NEUROCHEMISTRY, vol. 110, no. 1. WILEY-BLACKWELL PUBLISHING, INC, Jul.-2009.
Abstract
The application of radionuclides for the localization of essential trace elements in vivo and the characterization of their binding proteins is a story of intermittently made improvements of the techniques used for their detection. In this study we present the use of neutron activation analysis and different autoradiographic imaging methods including real-time digital autoradiography to reveal new insights in the hierarchy of selenium homeostasis. Selenoproteins containing the essential trace element selenium play important roles in the CNS. Although the CNS does not show the highest selenium concentration in the case of selenium-sufficient supply in comparison with other organs, it shows a high priority for selenium uptake and retention in the case of dietary selenium deficiency. To characterize the hierarchy of selenium supply in the brain, in vivo radiotracer labeling with (75)Se in rats with different selenium status was combined with autoradiographic detection of (75)Se in brain tissue sections and (75)Se-labeled selenoproteins after protein separation by two-dimensional gel electrophoresis. This study demonstrates significant differences in the uptake of (75)Se into the brain of rats with different selenium status. A brain region-specific uptake pattern of the radiotracer (75)Se in selenium-deficient rats could be revealed and the CSF was identified as a key part of the brain selenium homeostasis.
Herzog, J., Moeller, B., Witt, K., Pinsker, M. O., Deuschl, G., and Volkmann, J., Influence of Subthalamic Deep Brain Stimulation Versus Levodopa on Motor Perseverations in Parkinson's Disease, MOVEMENT DISORDERS, vol. 24, no. 8. WILEY, Jun.-2009.
Abstract
Patients with Parkinson's disease (PD) show impairment in generating random motor sequences reflecting a higher order motor deficit in set-shifting and suppression of perseverative behavior. The impact of deep brain stimulation (DBS) of the subthalamic nucleus (STN) on motor perseverations has not yet been elucidated. In 35 patients with PD, we evaluated the effect of STN-DBS and levodopa on motor perseverations using the Vienna perseveration task. The task was performed 6 months after implantation of stimulation electrodes in the following three conditions: Stimulation off/medication off (Stim OFF/Med OFF), Stim ON/Med OFF, and Stim OFF/Med ON. Perseverations were measured by redundancy of second order (R-2) with higher values indicating more severe perseverations. ANCOVA analysis revealed that influence of STN-DBS on R2 significantly depended on R-2 severity during Stim OFF/Med OFF (F = 4.69, P = 0.035). Accordingly, we classified patients with PD into two groups based on the R-2 value during off treatment. In patients with mild perseveration (R-2 < 35) neither STN-DBS nor levodopa changed perseverations. By contrast, in patients with severe perseveration (R-2 > 35), STN-DBS significantly reduced R-2 by 9.7 +/- 2.6 (P < 0.001) whereas levodopa had no impact (R reduction 3.7 +/- 1.6, P = 0.081). This demonstrates that STN-DBS, by reducing motor perseveration, influences higher order aspects of motor behavior of patients with PD. (C) 2009 Movement Disorder Society
Weiss, M. M., Wolbers, T., Peller, M., Witt, K., Marshall, L., Buchel, C., and Siebner, H. R., Rotated alphanumeric characters do not automatically activate frontoparietal areas subserving mental rotation, NEUROIMAGE, vol. 44, no. 3. ACADEMIC PRESS INC ELSEVIER SCIENCE, Feb.-2009.
Abstract
Functional neuroimaging studies have identified a set of areas in the intraparietal sulcus and dorsal precentral cortex which show a linear increase in activity with the angle of rotation across a variety of mental rotation tasks. This linear increase in activity with angular disparity suggests that these frontoparietal regions compute rotational transformations. An open question is whether rotated target stimuli automatically activate these frontoparietal regions, even if the task does not require rotational transformations. To address this question, we performed functional MRI while healthy male volunteers made two-choice reaction-time judgements on canonical or mirror images of two-dimensional alphanumeric characters presented at various angles of rotation. Participants had either to decide whether characters were normal or mirror-reversed (i.e., mental rotation) or judge whether the stimulus was a letter or a number (i.e., stimulus categorization). Reaction times and error rates linearly increased with the angle of rotation for mirror-reversed judgements but not for number-letter judgements, showing that only the mental rotation task required rotational transformations of the characters. The mental rotation task was associated with a linear increase in neuronal activity with angular disparity in a bilateral set of frontoparietal areas, comprising the rostral dorsal premotor cortex, frontal eye field, ventral and medial intraparietal sulcus. Neuronal activity in these regions was neither increased nor modulated by angular disparity during the stimulus categorization task. These results suggest that at least for alphanumerical characters, areas implicated in mental rotation will only be called into action if the task requires a rotational transformation. (C) 2008 Elsevier Inc. All rights reserved.
Balzer, F., Schiek, M., Lützen, A., and Rubahn, H. -G., Organic Nanofibers from PPTPP, Interface Controlled Organic Thin Films. Springer Science + Business Media, pp. 11-17, 2009.
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Debener, S., Kranczioch, C., and Gutberlet, I., EEG Quality: Origin and Reduction of the EEG Cardiac-Related Artefact, EEG - fMRI. Springer Science + Business Media, pp. 135-151, 2009.
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D'Amelio, R., Retz, W., Philipsen, A., and Rösler, M., Vorwort, Psychoedukation und Coaching ADHS im Erwachsenenalter. Elsevier BV, p. V, 2009.
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Philipsen, A., Richter, H., Matthies, S., and Hesslinger, B., Psychotherapy in Adult Attention-Deficit Hyperactivity Disorder, Key Issues in Mental Health. S. Karger AG, pp. 159-173, 2009.
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Richter-Landsberg, C. and Goldbaum, O., Small Heat Shock Proteins and the Cytoskeleton, Heat Shock Proteins in Neural Cells. Springer Science + Business Media, pp. 13-24, 2009.
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Leicht, G., Herrmann, C. S., and Mulert, C., BOLD Response and EEG Gamma Oscillations, EEG - fMRI. Springer Science + Business Media, pp. 465-483, 2009.
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Strüber, D. and Roth, G., Liebe, Sexualität und Gehirn. Schattauer, pp. 31-41, 2009.
Abstract
Dedek, K., Pandarinath, C., Alam, N. M., Wellershaus, K., Schubert, T., Willecke, K., Prusky, G. T., Weiler, R., and Nirenberg, S., Ganglion Cell Adaptability: Does the Coupling of Horizontal Cells Play a Role?, PLoS ONE, vol. 3, no. 3. Public Library of Science (PLoS), p. e1714, 5-Mar.-2008.
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Zeitz, C., Gross, A. K., Leifert, D., Kloeckener-Gruissem, B., McAlear, S. D., Lemke, J., Neidhardt, J., and Berger, W., Identification and Functional Characterization of a Novel Rhodopsin Mutation Associated with Autosomal Dominant CSNB, Invest. Ophthalmol. Vis. Sci., vol. 49, no. 9. Association for Research in Vision and Ophthalmology (ARVO), p. 4105, 1-Sep.-2008.
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Kloeckener-Gruissem, B., Vandekerckhove, K., Nürnberg, G., Neidhardt, J., Zeitz, C., Nürnberg, P., Schipper, I., and Berger, W., Mutation of Solute Carrier SLC16A12 Associates with a Syndrome Combining Juvenile Cataract with Microcornea and Renal Glucosuria, The American Journal of Human Genetics, vol. 82, no. 3. Elsevier BV, pp. 772-779, Mar.-2008.
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Luhmann, U. F. O., Neidhardt, J., Kloeckener-Gruissem, B., Schäfer, N. F., Glaus, E., Feil, S., and Berger, W., Vascular changes in the cerebellum of Norrin / Ndph knockout mice correlate with high expression of Norrin and Frizzled-4 , European Journal of Neuroscience, vol. 27, no. 10. Wiley-Blackwell, pp. 2619-2628, May-2008.
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Lützen, A., Wallmann, I., Schiek, M., and Koch, R., Synthesis of Monofunctionalized p-Quaterphenyls, Synthesis, vol. 2008, no. 15. Thieme Publishing Group, pp. 2446-2450, 8-Jul.-2008.
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Schiek, M., Balzer, F., Al-Shamery, K., Brewer, J. R., Lützen, A., and Rubahn, H. -G., Organic Molecular Nanotechnology, Small, vol. 4, no. 2. Wiley-Blackwell, pp. 176-181, 1-Feb.-2008.
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Schiek, M., Balzer, F., Al-Shamery, K., Lützen, A., and Rubahn, H. -G., Light-emitting organic nanoaggregates from functionalized p-quaterphenylenes, Soft Matter, vol. 4, no. 2. Royal Society of Chemistry (RSC), pp. 277-285, 2008.
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Balzer, F., Schiek, M., Rubahn, H. -G., Al-Shamery, K., and Lützen, A., Surface bound organic nanowires, Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, vol. 26, no. 4. American Vacuum Society, p. 1619, 2008.
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Koch, R., Schiek, M., Al-Shamery, K., Lützen, A., Balzer, F., and Rubahn, H. -G., Light emitting nanofibers from functionalised para-quaterphenylenes: theory, synthesis and application, Chemistry Central Journal, vol. 2, no. Suppl 1. Springer Science + Business Media, p. P38, 2008.
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Sienknecht, U. J. and Fekete, D. M., Comprehensive Wnt-related gene expression during cochlear duct development in chicken, J. Comp. Neurol., vol. 510, no. 4. Wiley-Blackwell, pp. 378-395, 1-Oct.-2008.
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Hauff, E. von, Meteleva-Fischer, Y., Parisi, J., and Weiler, R., Binding and Release of Glutamate from Overoxidized Polypyrrole via an Applied Potential for Application as a Molecular Switch, Zeitschrift für Naturforschung A, vol. 63, no. 5-6. Walter de Gruyter GmbH, 1-Jan.-2008.
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Wellershaus, K., Degen, J., Deuchars, J., Theis, M., Charollais, A., Caille, D., Gauthier, B., Janssen-Bienhold, U., Sonntag, S., Herrera, P., Meda, P., and Willecke, K., A new conditional mouse mutant reveals specific expression and functions of connexin36 in neurons and pancreatic beta-cells, Experimental Cell Research, vol. 314, no. 5. Elsevier BV, pp. 997-1012, Mar.-2008.
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Bendixen, A. and Schröger, E., Memory trace formation for abstract auditory features and its consequences in different attentional contexts, Biological psychology, vol. 78, no. 3. pp. 231-241, Jul.-2008.
Abstract DOI
The capacity for abstraction is vital for adaptive behavior. Based on behavioral data and event-related potentials (ERPs), the present study investigates the brain's ability to encode abstract auditory rules with a dynamic approach in which rules constantly emerge and vanish. In successive conditions, abstract rules are task-irrelevant and task-relevant. Results show that as few as two consecutive exemplars of an abstract feature (frequency relation between successive tones) are sufficient for rule extraction. The extraction of just emerging rules is independent of the amount of attention devoted to the rules, and it is not modulated by further rule-conforming exemplars. The extracted rules are immediately applied, as evidenced by the interference of task-irrelevant rule violations with concurrent mental processes (distraction condition) and by the conscious detection of task-relevant violations (detection condition). The ability to rapidly encode abstract rules and to detect presumably important rule-violating events underlines the brain's adaptability to the environmental demands
Burkhardt, P., Avrutin, S., Piñango, M. M., and Ruigendijk, E., Slower-than-normal syntactic processing in agrammatic Broca's aphasia: Evidence from Dutch, Journal of Neurolinguistics, vol. 21, no. 2. Elsevier BV, pp. 120-137, Mar.-2008.
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Thorne, J. D. and Debener, S., Irrelevant visual stimuli improve auditory task performance, NeuroReport, vol. 19, no. 5. Ovid Technologies (Wolters Kluwer Health), pp. 553-557, Mar.-2008.
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Debener, S. and Herrmann, C. S., Editorial, International Journal of Psychophysiology, vol. 67, no. 3. Elsevier BV, pp. 159-160, Mar.-2008.
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Zokoll, M. A., Naue, N., Herrmann, C. S., and Langemann, U., Auditory memory: A comparison between humans and starlings, Brain Research, vol. 1220. Elsevier BV, pp. 33-46, Jul.-2008.
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Zokoll, M. A., Klump, G. M., and Langemann, U., Auditory memory for temporal characteristics of sound, Journal of Comparative Physiology A, vol. 194, no. 5. Springer Science + Business Media, pp. 457-467, 26-Feb.-2008.
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Schwartzman, D., Maravic, K., Kranczioch, C., and Barnes, J., Altered early visual processing components in hallucination-prone individuals, NeuroReport, vol. 19, no. 9. Ovid Technologies (Wolters Kluwer Health), pp. 933-937, Jun.-2008.
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Strobel, A., Debener, S., Sorger, B., Peters, J. C., Kranczioch, C., Hoechstetter, K., Engel, A. K., Brocke, B., and Goebel, R., Novelty and target processing during an auditory novelty oddball: A simultaneous event-related potential and functional magnetic resonance imaging study, NeuroImage, vol. 40, no. 2. Elsevier BV, pp. 869-883, Apr.-2008.
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Spitzer, M. S., Ziemssen, F., Yoeruek, E., Petermeier, K., Aisenbrey, S., and Szurman, P., Efficacy of intravitreal bevacizumab in treating postoperative pseudophakic cystoid macular edema, Journal of Cataract & Refractive Surgery, vol. 34, no. 1. Elsevier BV, pp. 70-75, Jan.-2008.
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Spitzer, M. S., Yoeruek, E., Kaczmarek, R. T., Sierra, A., Aisenbrey, S., Grisanti, S., Bartz-Schmidt, K. U., and Szurman, P., Sodium hyaluronate gels as a drug-release system for corticosteroids: release kinetics and antiproliferative potential for glaucoma surgery, Acta Ophthalmologica, vol. 86, no. 8. Wiley-Blackwell, pp. 842-848, 28-Jun.-2008.
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Zhu, Q., Ziemssen, F., Henke-Fahle, S., Tatar, O., Szurman, P., Aisenbrey, S., Schneiderhan-Marra, N., Xu, X., and Grisanti, S., Vitreous Levels of Bevacizumab and Vascular Endothelial Growth Factor-A in Patients with Choroidal Neovascularization, Ophthalmology, vol. 115, no. 10. Elsevier BV, pp. 1750-1755.e1, Oct.-2008.
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Neubauer, H., Lask, S., Engelhardt, A., and Mügge, A., How to optimise clopidogrel therapy? Reducing the low-response incidence by aggregometry-guided therapy modification, Thrombosis and Haemostasis. Schattauer GmbH, 17-Jan.-2008.
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Seidel, J. A., Koenig, R., Antoniadis, G., Richter, H. -P., and Kretschmer, T., SURGICAL TREATMENT OF TRAUMATIC PERONEAL NERVE LESIONS, Neurosurgery, vol. 62, no. 3. Ovid Technologies (Wolters Kluwer Health), pp. 664-673, Mar.-2008.
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Gharabaghi, A., Löwenheim, H., Heckl, S., Koerbel, A., Kaminsky, J., and Tatagiba, M., AUDITORY REHABILITATION AFTER LONG-TERM DEAFNESS, Neurosurgery, vol. 62, no. 4. Ovid Technologies (Wolters Kluwer Health), pp. 983-986, Apr.-2008.
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Sobanski, E., Brüggemann, D., Alm, B., Kern, S., Philipsen, A., Schmalzried, H., Heßlinger, B., Waschkowski, H., and Rietschel, M., Subtype differences in adults with attention-deficit/hyperactivity disorder (ADHD) with regard to ADHD-symptoms, psychiatric comorbidity and psychosocial adjustment, European Psychiatry, vol. 23, no. 2. Elsevier BV, pp. 142-149, Mar.-2008.
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Goldbaum, O., Jensen, P. H., and Richter-Landsberg, C., The expression of tubulin polymerization promoting protein TPPP/p25α is developmentally regulated in cultured rat brain oligodendrocytes and affected by proteolytic stress, Glia, vol. 56, no. 16. Wiley-Blackwell, pp. 1736-1746, Dec.-2008.
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Richter-Landsberg, C., Oligodendrocytes Take Center Stage, J Mol Neurosci, vol. 35, no. 1. Springer Science + Business Media, pp. 1-2, 2-Apr.-2008.
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Burgmaier, G., Schönrock, L. M., Kuhlmann, T., Richter-Landsberg, C., and Brück, W., Association of Increased Bcl-2 Expression with Rescue from Tumor Necrosis Factor-α-Induced Cell Death in the Oligodendrocyte Cell Line OLN-93, Journal of Neurochemistry, vol. 75, no. 6. Wiley-Blackwell, pp. 2270-2276, 29-Jul.-2008.
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Steiner, J., Bernstein, H. -G., Bogerts, B., Gos, T., Richter-Landsberg, C., Wunderlich, M. T., and Keilhoff, G., S100B is expressed in, and released from, OLN-93 oligodendrocytes: Influence of serum and glucose deprivation, Neuroscience, vol. 154, no. 2. Elsevier BV, pp. 496-503, Jun.-2008.
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Kollmeier, B., Huber, R., Rohdenburg, T., Beutelmann, R., and Hohmann, V., Model-based objective assessment of noise reduction systems for hearing aids, J. Acoust. Soc. Am., vol. 123, no. 5. Acoustical Society of America (ASA), p. 3166, 2008.
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Mauermann, M. and Kollmeier, B., Changes in distortion product otoacoustic emission (DPOAE) fine structure due to contralateral acoustic stimulation, J. Acoust. Soc. Am., vol. 123, no. 5. Acoustical Society of America (ASA), p. 3853, 2008.
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Heise, S. J., Verhey, J. L., and Mauermann, M., Automatic screening and detection of threshold fine structure, International Journal of Audiology, vol. 47, no. 8. Informa UK Limited, pp. 520-532, Jan.-2008.
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von Hauff, E., Spethmann, N., and Parisi, J., A Gated Four Probe Technique for Field Effect Measurements on Disordered Organic Semiconductors, Zeitschrift für Naturforschung A, vol. 63, no. 9. Walter de Gruyter GmbH, 1-Jan.-2008.
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Pomraenke, R., Vasa, P., and Lienau, C., Optical spectroscopy of single-walledcarbon nanotubes: From excitonic effects towards control of the radiative lifetime, phys. stat. sol. (b), vol. 245, no. 6. Wiley-Blackwell, pp. 1033-1040, Jun.-2008.
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Diederich, A., Colonius, H., and Schomburg, A., Assessing age-related multisensory enhancement with the time-window-of-integration model, Neuropsychologia, vol. 46, no. 10. Elsevier BV, pp. 2556-2562, Aug.-2008.
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Diederich, A. and Colonius, H., Crossmodal interaction in saccadic reaction time: separating multisensory from warning effects in the time window of integration model, Experimental brain research, vol. 186, no. 1. pp. 1-22, Mar.-2008.
Abstract DOI
In a focused attention task saccadic reaction time (SRT) to a visual target stimulus (LED) was measured with an auditory (white noise burst) or tactile (vibration applied to palm) non-target presented in ipsi- or contralateral position to the target. Crossmodal facilitation of SRT was observed under all configurations and stimulus onset asynchrony (SOA) values ranging from -500 (non-target prior to target) to 0 ms, but the effect was larger for ipsi- than for contralateral presentation within an SOA range from -200 ms to 0. The time-window-of-integration (TWIN) model (Colonius and Diederich in J Cogn Neurosci 16:1000, 2004) is extended here to separate the effect of a spatially unspecific warning effect of the non-target from a spatially specific and genuine multisensory integration effect
Diederich, A., A further test of sequential-sampling models that account for payoff effects on response bias in perceptual decision tasks, Perception & psychophysics, vol. 70, no. 2. pp. 229-256, Feb.-2008.
Abstract DOI
Recently, Diederich and Busemeyer (2006) evaluated three hypotheses formulated as particular versions of a sequential-sampling model to account for the effects of payoffs in a perceptual decision task with time constraints. The bound-change hypothesis states that payoffs affect the distance of the starting position of the decision process to each decision bound. The drift-rate-change hypothesis states that payoffs affect the drift rate of the decision process. The two-stage-processing hypothesis assumes two processes, one for processing payoffs and another for processing stimulus information, and that on a given trial, attention switches from one process to the other. The latter hypothesis gave the best account of their data. The present study investigated two questions: (1) Does the experimental setting influence decisions, and consequently affect the fits of the hypotheses? A task was conducted in two experimental settings--either the time limit or the payoff matrix was held constant within a given block of trials, using three different payoff matrices and four different time limits--in order to answer this question. (2) Could it be that participants neglect payoffs on some trials and stimulus information on others? To investigate this idea, a further hypothesis was considered, the mixture-of-processes hypothesis. Like the two-stage-processing hypothesis, it postulates two processes, one for payoffs and another for stimulus information. However, it differs from the previous hypothesis in assuming that on a given trial exactly one of the processes operates, never both. The present design had no effect on choice probability but may have affected choice response times (RTs). Overall, the two-stage-processing hypothesis gave the best account, with respect both to choice probabilities and to observed mean RTs and mean RT patterns within a choice pair
Steenken, R., Colonius, H., Diederich, A., and Rach, S., Visual-auditory interaction in saccadic reaction time: effects of auditory masker level, Brain research, vol. 1220. pp. 150-156, Jul.-2008.
Abstract DOI
Saccadic reaction time (SRT) to a visual target tends to be shorter when auditory stimuli are presented in close temporal and spatial proximity, even when subjects are instructed to ignore the auditory non-target (focused attention paradigm). Observed SRT reductions typically range between 10 and 50 ms and decrease as spatial disparity between the stimuli increases. Previous studies using pairs of visual and auditory stimuli differing in both azimuth and vertical position suggest that the amount of SRT facilitation decreases not with the physical but with the perceivable distance between visual target and auditory accessory. Here we probe this hypothesis by presenting an additional white-noise masker background of 3 s duration. Increasing the masker level had a diametrical effect on SRTs in spatially coincident vs. disparate stimulus configurations: saccadic responses to coincident visual-auditory stimuli are slowed down, whereas saccadic responses to disparate stimuli are speeded up. As verified in a separate auditory localization task, localizability of the auditory accessory decreases with masker level. The SRT results are accounted for by a conceptual model positing that increasing masker level enlarges the area of possible auditory stimulus locations: it implies that perceivable distances decrease for disparate stimulus configurations and increase for coincident stimulus pairs
Diederich, A. and Colonius, H., When a high-intensity "distractor" is better then a low-intensity one: modeling the effect of an auditory or tactile nontarget stimulus on visual saccadic reaction time, Brain research, vol. 1242. pp. 219-230, Nov.-2008.
Abstract DOI
In a focused attention task saccadic reaction time (SRT) to a visual target stimulus (LED) was measured with an auditory (white noise burst) or tactile (vibration applied to palm) nontarget presented in ipsi- or contralateral position to the target. Crossmodal facilitation of SRT was observed under all configurations and stimulus onset asynchrony (SOA) values ranging from -250 ms (nontarget prior to target) to 50 ms. This study specifically addressed the effect of varying nontarget intensity. While facilitation effects for auditory nontargets are somewhat more pronounced than for tactile ones, decreasing intensity slightly reduced facilitation for both types of nontargets. The time course of crossmodal mean SRT over SOA and the pattern of facilitation observed here suggest the existence of two distinct underlying mechanisms: (a) a spatially unspecific crossmodal warning triggered by the nontarget being detected early enough before the arrival of the target plus (b) a spatially specific multisensory integration mechanism triggered by the target processing time terminating within the time window of integration. It is shown that the time window of integration (TWIN) model introduced by the authors gives a reasonable quantitative account of the data relating observed SRT to the unobservable probability of integration and crossmodal warning for each SOA value under a high and low intensity level of the nontarget
Steenken, R., Diederich, A., and Colonius, H., Time course of auditory masker effects: tapping the locus of audiovisual integration?, Neuroscience letters, vol. 435, no. 1. pp. 78-83, Apr.-2008.
Abstract DOI
In a focused attention paradigm, saccadic reaction time (SRT) to a visual target tends to be shorter when an auditory accessory stimulus is presented in close temporal and spatial proximity. Observed SRT reductions typically diminish as spatial disparity between the stimuli increases. Here a visual target LED (500 ms duration) was presented above or below the fixation point and a simultaneously presented auditory accessory (2 ms duration) could appear at the same or the opposite vertical position. SRT enhancement was about 35 ms in the coincident and 10 ms in the disparate condition. In order to further probe the audiovisual integration mechanism, in addition to the auditory non-target an auditory masker (200 ms duration) was presented before, simultaneous to, or after the accessory stimulus. In all interstimulus interval (ISI) conditions, SRT enhancement went down both in the coincident and disparate configuration, but this decrement was fairly stable across the ISI values. If multisensory integration solely relied on a feed-forward process, one would expect a monotonic decrease of the masker effect with increasing ISI in the backward masking condition. It is therefore conceivable that the relatively high-energetic masker causes a broad excitatory response of SC neurons. During this state, the spatial audio-visual information from multisensory association areas is fed back and merged with the spatially unspecific excitation pattern induced by the masker. Assuming that a certain threshold of activation has to be achieved in order to generate a saccade in the correct direction, the blurred joint output of noise and spatial audio-visual information needs more time to reach this threshold prolonging SRT to an audio-visual object
Cerquera, A., Greschner, M., and Freund, J. A., Classifying the motion of visual stimuli from the spike response of a population of retinal ganglion cells, Conference proceedings : .. Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, vol. 2008. pp. 4082-4085, 2008.
Abstract DOI
We present an analysis of the spike response of a retinal ganglion cell ensemble. The retina of a turtle was stimulated in vitro by moving light patterns. Its non-steady motion was specified by two features: changes of direction and changes of speed. The spike response of a ganglion cell population was recorded extracellularly with a multielectrode array and responding neurons were identified through spike sorting. Restricting further analysis to a time window of greatest firing activity, we selected a subset of cells with reliable firing patterns, excluding cells that were not selective to the stimulus. The reliability of a firing pattern was assessed on the single cell level in terms of two measures: temporal precision (jitter) of the first spike and the fraction of trials in which a spike was generated. We then condensed the spike response of the extracted group by merging the multivariate spike trains into a single spike train. Finally, we compared different coding hypotheses that are based on the timing of the first and the second spike of the population or the spike count in the preselected time window. We found that the second spike of the population significantly increases the classification efficiency beyond that of the first spike. Moreover, the combination of first plus second spike is comparably efficient as the combination of the first spike plus the spike count but allows for a classification that is much faster
Elstrott, J., Anishchenko, A., Greschner, M., Sher, A., Litke, A. M., Chichilnisky, E. J., and Feller, M. B., Direction selectivity in the retina is established independent of visual experience and cholinergic retinal waves, Neuron, vol. 58, no. 4. pp. 499-506, May-2008.
Abstract DOI
Direction selectivity in the retina requires the asymmetric wiring of inhibitory inputs onto four subtypes of On-Off direction-selective ganglion cells (DSGCs), each preferring motion in one of four cardinal directions. The primary model for the development of direction selectivity is that patterned activity plays an instructive role. Here, we use a unique, large-scale multielectrode array to demonstrate that DSGCs are present at eye opening, in mice that have been reared in darkness and in mice that lack cholinergic retinal waves. These data suggest that direction selectivity in the retina is established largely independent of patterned activity and is therefore likely to emerge as a result of complex molecular interactions
Strüber, D., Lück, M., and Roth, G., Sex, aggression and impulse control: An integrative account, Neurocase, vol. 14, no. 1. Informa UK Limited, pp. 93-121, 30-May-2008.
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Buschermöhle, M., Feudel, U., and Freund, J. A., Enhanced signal detectability in comodulated noise introduced by compression, Biol Cybern, vol. 99, no. 6. Springer Science + Business Media, pp. 491-502, 23-Sep.-2008.
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Gross, T. and Feudel, U., Local dynamical equivalence of certain food webs, Ocean Dynamics, vol. 59, no. 2. Springer Science + Business Media, pp. 417-427, 9-Dec.-2008.
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FEUDEL, U. L. R. I. K. E., COMPLEX DYNAMICS IN MULTISTABLE SYSTEMS, Int. J. Bifurcation Chaos, vol. 18, no. 06. World Scientific Pub Co Pte Lt, pp. 1607-1626, Jun.-2008.
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Zahnow, J. C., Vilela, R. D., Feudel, U., and Tél, T., Aggregation and fragmentation dynamics of inertial particles in chaotic flows, Phys. Rev. E, vol. 77, no. 5. American Physical Society (APS), 6-May-2008.
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Zahnow, J. C. and Feudel, U., Moving finite-size particles in a flow: A physical example of pitchfork bifurcations of tori, Phys. Rev. E, vol. 77, no. 2. American Physical Society (APS), 21-Feb.-2008.
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Bertsch, T., Alber, B., and Bauer, J. M., [Laboratory tests in the elderly and their relationship with frailty], Therapeutische Umschau. Revue therapeutique, vol. 65, no. 8. pp. 431-435, Aug.-2008.
Abstract DOI
Frailty is a geriatric syndrome that has been characterized by an increased vulnerability against external stressors. The aim of laboratory investigations in the context of frailty is to screen for conditions that are pathophysiologically related to the development of this syndrome. Successful therapy of these conditions may help to stabilize the elderly individual who is at risk for functional decline and increasing frailty. In this review laboratory parameters for the detection of anemia, impaired vitamin D intake, thyroid and gonadal function are described in their relationship with developing frailty
Kooijman, S. A. L. M., Feudel, U., Kooi, B. W., Gross, T., Stiefs, D., and Voorn, G. A. K. van, Stabilization due to predator interference: comparison of different analysis approaches, Mathematical Biosciences and Engineering, vol. 5, no. 3. American Institute of Mathematical Sciences (AIMS), pp. 567-583, Jun.-2008.
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Bauer, J. M., Kaiser, M. J., Anthony, P., Guigoz, Y., and Sieber, C. C., The Mini Nutritional Assessment--its history, today's practice, and future perspectives, Nutrition in clinical practice : official publication of the American Society for Parenteral and Enteral Nutrition, vol. 23, no. 4. pp. 388-396, 2008.
Abstract DOI
In the early 1990s, the Mini Nutritional Assessment (MNA; Nestle Nutrition, Vevey, Switzerland) was developed for nutrition screening in the elderly. Since then, it became the most established and widespread screening tool for older persons and has been translated into many different languages. The MNA shows prognostic relevance with regard to functionality, morbidity, and mortality of the elderly in different settings. This article recalls the development of the MNA with its short form (MNA-SF) and reviews the literature, focusing on the most recent publications. Specific features of the application of the MNA in different settings (community, nursing home, hospital) are considered. Minor shortcomings of the tool, such as the resources and the cooperation necessary for completion of the MNA, are discussed. Future options for the adaptation of this valuable tool are briefly characterized
Bauer, J. M., Kaiser, M. J., and Sieber, C. C., Sarcopenia in nursing home residents, Journal of the American Medical Directors Association, vol. 9, no. 8. pp. 545-551, Oct.-2008.
Abstract DOI
The age-associated loss of muscle mass and muscle strength described by the term sarcopenia is highly relevant for functionality among nursing home residents. Nevertheless, the scientific literature concentrating on sarcopenia in this population is scarce. For practical reasons, common definitions of this entity, which rely on dual energy x-ray absorptiometry (DEXA) and bioimpedance analysis (BIA), cannot be applied in this setting. Anthropometric measurements like arm muscle circumference and calf circumference seem to be most suitable. Handgrip may be used as an alternative. Prevalence data show a wide range but are mostly high. There is a close association of the degree of sarcopenia with dependence among residents. The pathophysiology of sarcopenia in this population is strongly influenced by comorbidity and often there is significant overlap with the cachexia syndrome. At present, physical exercise is regarded to be the most promising therapeutic option, with resistance training being superior to endurance programs. Physical exercise has been successful even among Alzheimer patients and physically restrained residents. It has to be accompanied by the provision of adequate and diverse meals based on individual energy and nutrient requirements. Special attention should be paid to the treatment of vitamin D deficiency if present. New therapeutic options include Whole Body Vibration, oral supplements with essential amino acids and leucine, ACE-inhibitors, and cytokine-modifying drugs
Behrmann-Godel, J. and Gerlach, G., First evidence for postzygotic reproductive isolation between two populations of Eurasian perch (Perca fluviatilis L.) within Lake Constance, Frontiers in zoology, vol. 5. p. 3, 2008.
Abstract DOI
BACKGROUND: The evolution of reproductive traits, such as hybrid incompatibility (postzygotic isolation) and species recognition (prezygotic isolation), have shown their key role in speciation. Theoretical modeling has recently predicted that close linkage between genes controlling pre- and postzygotic reproductive isolation could accelerate the conditions for speciation. Postzygotic isolation could develop during the sympatric speciation process contributing to the divergence of populations. Using hybrid fitness as a measure of postzygotic reproductive isolation, we empirically studied population divergence in perch (Perca fluviatilis L.) from two genetically divergent populations within a lake. RESULTS: During spawning time of perch we artificially created parental offspring and F1 hybrids of the two populations and studied fertilization rate and hatching success under laboratory conditions. The combined fitness measure (product of fertilization rate and hatching success) of F1 hybrids was significantly reduced compared to offspring from within population crosses. CONCLUSION: Our results suggest intrinsic genetic incompatibility between the two populations and indicate that population divergence between two populations of perch inhabiting the same lake may indeed be promoted by postzygotic isolation
Gerlach, G., Hodgins-Davis, A., Avolio, C., and Schunter, C., Kin recognition in zebrafish: a 24-hour window for olfactory imprinting, Proceedings. Biological sciences / The Royal Society, vol. 275, no. 1647. pp. 2165-2170, Sep.-2008.
Abstract DOI
Distinguishing kin from non-kin profoundly impacts the evolution of social behaviour. Individuals able to assess the genetic relatedness of conspecifics can preferentially allocate resources towards related individuals and avoid inbreeding. We have addressed the question of how animals acquire the ability to recognize kin by studying the development of olfactory kin preference in zebrafish (Danio rerio). Previously, we showed that zebrafish use an olfactory template to recognize even unfamiliar kin through phenotype matching. Here, we show for the first time that this phenotype matching is based on a learned olfactory imprinting process in which exposure to kin individuals on day 6 post fertilization (pf) is necessary and sufficient for imprinting. Larvae that were exposed to kin before or after but not on day 6 pf did not recognize kin. Larvae isolated from all contact with conspecifics did not imprint on their own chemical cues; therefore, we see no evidence for kin recognition through self-matching in this species. Surprisingly, exposure to non-kin odour during the sensitive phase of development did not result in imprinting on the odour cues of unrelated individuals, suggesting a genetic predisposition to kin odour. Urine-born peptides expressed by genes of the immune system (MHC) are important messengers carrying information about 'self' and 'other'. We suggest that phenotype matching is acquired through a time-sensitive learning process that, in zebrafish, includes a genetic predisposition potentially involving MHC genes expressed in the olfactory receptor neurons
Chernetsov, N., Kishkinev, D., and Mouritsen, H., A long-distance avian migrant compensates for longitudinal displacement during spring migration, Current biology : CB, vol. 18, no. 3. pp. 188-190, Feb.-2008.
Abstract DOI
In order to perform true bicoordinate navigation, migratory birds need to be able to determine geographic latitude and longitude. The determination of latitude is relatively easy from either stellar or magnetic cues [1-3], but the determination of longitude seems challenging [4, 5]. It has therefore been suggested that migrating birds are unable to perform bicoordinate navigation and that they probably only determine latitude during their return migration [5]. However, proper testing of this hypothesis requires displacement experiments with night-migratory songbirds in spring that have not been performed. We therefore displaced migrating Eurasian reed warblers (Acrocephalus scirpaceus) during spring migration about 1000 km toward the east and found that they were correcting for displacements by shifting their orientation from the northeast at the capture site to the northwest after the displacement. This new direction would lead them to their expected breeding areas. Our results suggest that Eurasian reed warblers are able to determine longitude and perform bicoordinate navigation. This finding is surprising and presents a new intellectual challenge to bird migration researchers, namely, which cues enable birds to determine their east-west position
Heyers, D., Manns, M., Luksch, H., Güntürkün, O., and Mouritsen, H., Calcium-binding proteins label functional streams of the visual system in a songbird, Brain research bulletin, vol. 75, no. 2-4. pp. 348-355, Mar.-2008.
Abstract DOI
The vertebrate nervous system has been shown to contain high concentrations of intracellular calcium-binding proteins, each of them with a restricted expression pattern in specific brain regions and specific neuronal subpopulations. Using immunohistochemical staining techniques, we analyzed the expression pattern of calbindin, calretinin and parvalbumin in visual brain areas of a songbird species, the zebra finch (Taeniopyga guttata). Here we show that the analyzed proteins are expressed in a complementary fashion within different brain substructures generally corresponding to functional subpathways of the avian visual system. In detail, calbindin is expressed in the brain structures that belong to the thalamofugal pathway, whereas parvalbumin-positive neurons are found in the brain structures that are part of the tectofugal visual pathway. Originally, the expression of calcium-binding proteins has been associated with specific morphological or neurochemical criteria of neurons. Our results suggest that their expression pattern also indicates a functional segregation of brain substructures linked to vision in the zebra finch brain. As the selective labeling of functional streams has also been shown for the visual system in mammalian species, function-selective expression of calcium-binding proteins might be a general feature of vertebrates
Chapman, J. W., Reynolds, D. R., Mouritsen, H., Hill, J. K., Riley, J. R., Sivell, D., Smith, A. D., and Woiwod, I. P., Wind selection and drift compensation optimize migratory pathways in a high-flying moth, Current biology : CB, vol. 18, no. 7. pp. 514-518, Apr.-2008.
Abstract DOI
Numerous insect species undertake regular seasonal migrations in order to exploit temporary breeding habitats [1]. These migrations are often achieved by high-altitude windborne movement at night [2-6], facilitating rapid long-distance transport, but seemingly at the cost of frequent displacement in highly disadvantageous directions (the so-called "pied piper" phenomenon [7]). This has lead to uncertainty about the mechanisms migrant insects use to control their migratory directions [8, 9]. Here we show that, far from being at the mercy of the wind, nocturnal moths have unexpectedly complex behavioral mechanisms that guide their migratory flight paths in seasonally-favorable directions. Using entomological radar, we demonstrate that free-flying individuals of the migratory noctuid moth Autographa gamma actively select fast, high-altitude airstreams moving in a direction that is highly beneficial for their autumn migration. They also exhibit common orientation close to the downwind direction, thus maximizing the rectilinear distance traveled. Most unexpectedly, we find that when winds are not closely aligned with the moth's preferred heading (toward the SSW), they compensate for cross-wind drift, thus increasing the probability of reaching their overwintering range. We conclude that nocturnally migrating moths use a compass and an inherited preferred direction to optimize their migratory track
Feenders, G., Liedvogel, M., Rivas, M., Zapka, M., Horita, H., Hara, E., Wada, K., Mouritsen, H., and Jarvis, E. D., Molecular mapping of movement-associated areas in the avian brain: a motor theory for vocal learning origin, PloS one, vol. 3, no. 3. p. e1768, 2008.
Abstract DOI
Vocal learning is a critical behavioral substrate for spoken human language. It is a rare trait found in three distantly related groups of birds-songbirds, hummingbirds, and parrots. These avian groups have remarkably similar systems of cerebral vocal nuclei for the control of learned vocalizations that are not found in their more closely related vocal non-learning relatives. These findings led to the hypothesis that brain pathways for vocal learning in different groups evolved independently from a common ancestor but under pre-existing constraints. Here, we suggest one constraint, a pre-existing system for movement control. Using behavioral molecular mapping, we discovered that in songbirds, parrots, and hummingbirds, all cerebral vocal learning nuclei are adjacent to discrete brain areas active during limb and body movements. Similar to the relationships between vocal nuclei activation and singing, activation in the adjacent areas correlated with the amount of movement performed and was independent of auditory and visual input. These same movement-associated brain areas were also present in female songbirds that do not learn vocalizations and have atrophied cerebral vocal nuclei, and in ring doves that are vocal non-learners and do not have cerebral vocal nuclei. A compilation of previous neural tracing experiments in songbirds suggests that the movement-associated areas are connected in a network that is in parallel with the adjacent vocal learning system. This study is the first global mapping that we are aware for movement-associated areas of the avian cerebrum and it indicates that brain systems that control vocal learning in distantly related birds are directly adjacent to brain systems involved in movement control. Based upon these findings, we propose a motor theory for the origin of vocal learning, this being that the brain areas specialized for vocal learning in vocal learners evolved as a specialization of a pre-existing motor pathway that controls movement
Djouguela, A., Griessbach, I., Harder, D., Kollhoff, R., Chofor, N., Rühmann, A., Willborn, K., and Poppe, B., Dosimetric characteristics of an unshielded p-type Si diode: linearity, photon energy dependence and spatial resolution, Zeitschrift fur medizinische Physik, vol. 18, no. 4. pp. 301-306, 2008.
Abstract DOI
The unshielded Si diode PTW 60012, used for accurate measurements of the transversal dose profiles of narrow photon beams, has been investigated with regard to its linearity, photon energy dependence and spatial resolution. The diode shows a slight supralinearity, i.e., increase of the response with pulse dose, by 3% over the pulse dose range 0.1 to 0.8 mGy. In p-type silicon, supralinearity results from the increased chance for radiation-induced electrons to escape recombination when the pulse dose increases. Over the energy range from 6 to 15 MV, the response decreases by about 4%. This small variation of the response results from partial compensation between the influences of the secondary electron energy on the mass stopping power ratio silicon/water and on electron backscattering from the silicon chip. The lateral response function of the examined diode has a full half width of 1.3 mm. Dose profiles of 5 mm half-width can still be recorded with negligible error
Wagner, D., Anton, M., Vorwerk, H., Gsänger, T., Christiansen, H., Poppe, B., Hess, C. F., and Hermann, R. M., In vivo alanine/electron spin resonance (ESR) dosimetry in radiotherapy of prostate cancer: a feasibility study, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, vol. 88, no. 1. pp. 140-147, Jul.-2008.
Abstract DOI
PURPOSE: We have developed a device to evaluate the potential of alanine/electron spin resonance (ESR) dosimetry for quality assurance in 3D conformal radiotherapy for prostate cancer. It consists of a rectal balloon carrying eight alanine dosimeter probes and two metal markers to document the exact position of the balloon. We measured the effects of an air-filled rectal balloon on the dose at the rectal wall and compared these results with the applied dose distribution of the treatment planning system. MATERIALS AND METHODS: During 10 fractions with 2.0 Gy per fraction, the accumulated doses were measured in 3 patients. The results of the ESR measurements were compared to the applied doses. RESULTS: It was possible to insert the device without clinical complications and without additional rectal discomfort for the patients. The measurements of the dose accumulated at the anterior and the posterior rectal wall agreed with the applied dose within a mean deviation of 1.5% (overestimation of the dose) and 3.5% (underestimation of the dose), respectively. However, clinically significant differences between applied and measured rectal doses were seen in a patient with a hip prosthesis. In this case, the dose at the anterior rectal wall was overestimated by the TPS by about 11% and the dose at the posterior rectal wall was underestimated by approximately 7%. CONCLUSION: The method presented in this study is useful for quality control of irradiations in vivo
Münte, T. F. and Klump, G. M., Special Issue: Active Listening, Brain Research, vol. 1220. Elsevier BV, p. 1, Jul.-2008.
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Klump, G. M., The European starling as a model for understanding mechanisms underlying auditory scene analysis, J. Acoust. Soc. Am., vol. 123, no. 5. Acoustical Society of America (ASA), p. 3052, 2008.
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Rieger, J. W., Schoenfeld, M. A., Heinze, H. -J., and Bodis-Wollner, I., Different spatial organizations of saccade related BOLD-activation in parietal and striate cortex, Brain Research, vol. 1233. Elsevier BV, pp. 89-97, Oct.-2008.
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Rieger, J. W., Reichert, C., Gegenfurtner, K. R., Noesselt, T., Braun, C., Heinze, H. -J., Kruse, R., and Hinrichs, H., Predicting the recognition of natural scenes from single trial MEG recordings of brain activity, NeuroImage, vol. 42, no. 3. Elsevier BV, pp. 1056-1068, Sep.-2008.
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Rieger, J. W., Köchy, N., Schalk, F., Grüschow, M., and Heinze, H. -J., Speed limits: Orientation and semantic context interactions constrain natural scene discrimination dynamics., Journal of Experimental Psychology: Human Perception and Performance, vol. 34, no. 1. American Psychological Association (APA), pp. 56-76, 2008.
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Rieger, J. W., Kim, A., Argyelan, M., Farber, M., Glazman, S., Liebeskind, M., Meyer, T., and Bodis-wollner, I., Cortical functional anatomy of voluntary saccades in Parkinson disease, Clinical EEG and neuroscience, vol. 39, no. 4. pp. 169-174, Oct.-2008.
Abstract
In Parkinson Disease (PD) several aspects of saccades are affected. The saccade-generating brainstem neurons are spared, however, the signals they receive may be flawed. In particular voluntary saccades suffer, but the functional anatomy of the impairment of saccade-related cortical control is unknown. We measured blood-oxygenation-level-dependent (BOLD) activation with functional Magnetic Resonance Imaging (fMRI) while healthy participants and patients with PD performed horizontal voluntary saccades between peripheral visual targets or fixated centrally. We compared saccade-related BOLD-activity vs. fixation in patients with PD and in healthy controls and correlated perisaccadic BOLD-activity in PD patients with saccade kinetics (multistep saccades). Saccade related BOLD-activation was found in both PD and healthy participants in the superior parietal cortex (PEF) and the occipital cortex. Our results suggest remarkable hypoactivity of the frontal and supplementary eye fields (FEF and SEF) in PD patients. On the other hand, PD patients showed a statistically more reliable BOLD modulation than healthy participants in the posterior cingulate gyrus, the parahippocampal gyrus, inferior parietal lobule, precuneus and in the middle temporal gyrus. Given abnormal frontal and normal PEF responses, our results suggest that in PD a frontal cortical circuitry, known to be associated with saccade planning, selection, and predicting a metric error of the saccade, is deficient
Herrmann, C. S., Pauen, M., Min, B. -K., Busch, N. A., and Rieger, J. W., Analysis of a choice-reaction task yields a new interpretation of Libet's experiments, International journal of psychophysiology : official journal of the International Organization of Psychophysiology, vol. 67, no. 2. pp. 151-157, Feb.-2008.
Abstract DOI
Benjamin Libet has demonstrated that the readiness potential precedes the time at which participants consciously decide to perform an intentional motor act, and suggested that free will is an illusion. We performed an experiment where participants observed a stimulus on a computer monitor and were instructed to press one of two buttons, depending on the presented stimulus. We found neural activity preceding the motor response, similar to Libet's experiments. However, this activity was already present prior to stimulus presentation, and thus before participants could decide which button to press. Therefore, we argue that this activity does not specifically determine behaviour. Instead, it may reflect a general expectation. This interpretation would not interfere with the notion of free will
Fründ, I., Busch, N. A., Schadow, J., Gruber, T., Körner, U., and Herrmann, C. S., Time pressure modulates electrophysiological correlates of early visual processing, PloS one, vol. 3, no. 2. p. e1675, 2008.
Abstract DOI
BACKGROUND: Reactions to sensory events sometimes require quick responses whereas at other times they require a high degree of accuracy-usually resulting in slower responses. It is important to understand whether visual processing under different response speed requirements employs different neural mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: We asked participants to classify visual patterns with different levels of detail as real-world or non-sense objects. In one condition, participants were to respond immediately, whereas in the other they responded after a delay of 1 second. As expected, participants performed more accurately in delayed response trials. This effect was pronounced for stimuli with a high level of detail. These behavioral effects were accompanied by modulations of stimulus related EEG gamma oscillations which are an electrophysiological correlate of early visual processing. In trials requiring speeded responses, early stimulus-locked oscillations discriminated real-world and non-sense objects irrespective of the level of detail. For stimuli with a higher level of detail, oscillatory power in a later time window discriminated real-world and non-sense objects irrespective of response speed requirements. CONCLUSIONS/SIGNIFICANCE: Thus, it seems plausible to assume that different response speed requirements trigger different dynamics of processing
Fründ, I., Schadow, J., Busch, N. A., Naue, N., Körner, U., and Herrmann, C. S., Anticipation of natural stimuli modulates EEG dynamics: physiology and simulation, Cognitive neurodynamics, vol. 2, no. 2. pp. 89-100, Jun.-2008.
Abstract DOI
In everyday life we often encounter situations in which we can expect a visual stimulus before we actually see it. Here, we study the impact of such stimulus anticipation on the actual response to a visual stimulus. Participants were to indicate the sex of deer and cattle on photographs of the respective animals. On some trials, participants were cued on the species of the upcoming animal whereas on other trials this was not the case. Time frequency analysis of the simultaneously recorded EEG revealed modulations by this cue stimulus in two time windows. Early [Formula: see text] spectral responses [Formula: see text] displayed strongest stimulus-locking for stimuli that were preceded by a cue if they were sufficiently large. Late [Formula: see text] responses displayed enhanced amplitudes in response to large stimuli and to stimuli that were preceded by a cue. For late responses, however, no interaction between cue and stimulus size was observed. We were able to explain these results in a simulation by prestimulus gain modulations (early response) and by decreased response thresholds (late response). Thus, it seems plausible, that stimulus anticipation results in a pretuning of local neural populations
Lenz, D., Krauel, K., Schadow, J., Baving, L., Duzel, E., and Herrmann, C. S., Enhanced gamma-band activity in ADHD patients lacks correlation with memory performance found in healthy children, Brain research, vol. 1235. pp. 117-132, Oct.-2008.
Abstract DOI
Previous electrophysiological as well as imaging research has contributed to the understanding of impairments in attention, executive functions, and memory in patients with attention-deficit/hyperactivity disorder (ADHD). However, there is a lack of studies investigating ADHD related differences in the gamma range of human electroencephalogram (EEG), although gamma activity is strongly associated with cognitive processes impaired in ADHD patients and is also modulated by dopamine polymorphisms linked with ADHD. To close this gap, the present study compared gamma activity in ADHD children with that of healthy controls and correlated it with memory performance. EEG was recorded from 13 ADHD patients as well as 13 healthy control subjects during the encoding phase of a visual memory paradigm. In a subsequent recognition test, participants had to judge pictures as being old or new. Analysis of evoked gamma-band responses (GBRs) during stimulus encoding revealed a strong task-related enhancement for ADHD patients in parieto-occipital areas. Interestingly, this augmentation was not associated with recognition performance, whereas healthy subjects exhibited a strong positive correlation between evoked gamma activity during stimulus encoding and subsequent recognition performance. We interpret this finding as evidence of enhanced excitation levels and unspecific activation of processing resources in ADHD patients. Furthermore, enhanced GBRs in ADHD could also indicate a decrease of neuronal signal-to-noise ratio, partially caused by the genetic variations within the dopaminergic pathway of ADHD patients. The involved genetic polymorphisms have been shown to modulate evoked GBRs, which therefore could be a possible marker of impaired neurotransmission in ADHD
Lenz, D., Jeschke, M., Schadow, J., Naue, N., Ohl, F. W., and Herrmann, C. S., Human EEG very high frequency oscillations reflect the number of matches with a template in auditory short-term memory, Brain research, vol. 1220. pp. 81-92, Jul.-2008.
Abstract DOI
Auditory perception comprises bottom-up as well as top-down processes. While research in the past has revealed many neural correlates of bottom-up processes, less is known about top-down modulation. Memory processes have recently been associated with oscillations in the gamma-band of human EEG (30 Hz and above) which are enhanced when incoming information matches a stored memory template. Therefore, we investigated event-related potentials (ERPs) and gamma-band activity in 17 healthy participants in a Go/NoGo-task. They listened to four frequency-modulated (FM) sounds which varied regarding the frequency range traversed and the direction of frequency modulation. One sound was defined as target and required a button press. The results of ERPs (N1, P2, N2, and P3) were consistent with previous studies. Analysis of evoked gamma-band responses yielded no significant task-dependent modulation, but we observed a stimulus dependency, which was also present in a control experiment: The amplitude of evoked gamma responses showed an inverted U-shape as a function of stimulus frequency. Investigation of total gamma activity revealed functionally relevant responses at high frequencies (90 Hz to 250 Hz), which showed significant modulations by matches with STM: Complete matches led to the strongest enhancements (starting around 100 ms after stimulus onset) and partial matches resulted in intermediate ones. The results support the conclusion that very high frequency oscillations (VHFOs) are markers of active stimulus discrimination in STM matching processes and are attributable to higher cognitive functions
Busch, N. A., Groh-Bordin, C., Zimmer, H. D., and Herrmann, C. S., Modes of memory: early electrophysiological markers of repetition suppression and recognition enhancement predict behavioral performance, Psychophysiology, vol. 45, no. 1. pp. 25-35, Jan.-2008.
Abstract DOI
Different forms of perceptual memory have opposite physiological effects. Whereas repetition priming often leads to suppression of brain responses, explicit recognition has been found to enhance brain activity. We investigated effects of repetition priming and recognition memory on early gamma-band responses. In a study phase, participants performed a visual discrimination task with task-irrelevant item repetitions. Stimulus repetition suppressed early evoked gamma responses in participants with strong behavioral repetition effects. In a test phase, participants discriminated old from new items. Evoked and induced gamma activity was enhanced for old items. Effects were stronger in participants with better recognition performance. The results demonstrate a modulation of earliest stages of visual information processing by different memory systems, which is dependent on retrieval intention and predicts individual behavioral performance
Beste, C., Saft, C., Konrad, C., Andrich, J., Habbel, A., Schepers, I. M., Jansen, A., Pfleiderer, B., and Falkenstein, M., Levels of error processing in Huntington's disease: A combined study using event-related potentials and voxel-based morphometry, Human Brain Mapping, vol. 29, no. 2. Wiley-Blackwell, pp. 121-130, 2008.
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Soeroes, P., Lalone, E., Smith, R., Stevens, T., Theurer, J., Menon, R. S., and Martin, R. E., Functional MRI of oropharyngeal air-pulse stimulation, NEUROSCIENCE, vol. 153, no. 4. Jun.-2008.
Abstract
Although the posterior oral cavity and oropharynx play a major role in swallowing, their central representation is poorly understood. High-field functional magnetic resonance imaging of the brain was used to study the central processing of brief air-pulses, delivered to the peritonsillar region of the lateral oropharynx, in six healthy adults. Bilateral air-pulse stimulation was associated with the activation of a bilateral network including the primary somatosensory cortex and the thalamus, classic motor areas (primary motor cortex, supplementary motor area, cingulate motor areas), and polymodal areas (including the insula and frontal cortex). These results suggest that oropharyngeal stimulation can activate a bilaterally distributed cortical network that overlaps cortical regions previously implicated in oral and pharyngeal sensorimotor functions such as tongue movement, mastication, and swallowing. The present study also demonstrates the utility of air-pulse stimulation in investigating oropharyngeal sensorimotor processing in functional brain imaging experiments. Crown Copyright (C) 2008 Published by Elsevier Ltd on behalf of IBRO. All rights reserved.
Nuernberg, A., Braeuer, A. U., Wettschureck, N., and Offermanns, S., Antagonistic Regulation of Neurite Morphology through G(q)/G(11) and G(12)/G(13), JOURNAL OF BIOLOGICAL CHEMISTRY, vol. 283, no. 51. AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC, Dec.-2008.
Abstract
The induction of neurite retraction and growth cone collapse via G-protein-coupled receptors is involved in developmental as well as regenerative processes. The role of individual G-protein-mediated signaling processes in the regulation of neurite morphology is still incompletely understood. Using primary neurons from brains lacking G alpha(q)/G alpha(11) or G alpha(12)/G alpha(13), we show here that G(12)/G(13)-mediated signaling is absolutely required for neurite retraction and growth cone collapse induced by the blood-borne factors lysophosphatidic acid and thrombin. Interestingly, the effects of lysophosphatidic acid were mediated mainly by G(13), whereas thrombin effects required G(12). Surprisingly, lack of G alpha(q)/G alpha(11) resulted in overshooting responses to both stimuli, indicating that G(q)/G(11)-mediated signaling most likely via activation of Rac antagonizes the effects of G(12)/G(13).
Hoppe, B., Braeuer, A. U., Kuehbacher, M., Savaskan, N. E., Behne, D., and Kyriakopoulos, A., Biochemical analysis of selenoprotein expression in brain cell lines and in distinct brain regions, CELL AND TISSUE RESEARCH, vol. 332, no. 3. SPRINGER, Jun.-2008.
Abstract
Selenium is present in various biologically important selenoproteins. The preferential incorporation of selenium into the brain indicates its significance for this organ, but so far knowledge concerning the cerebral selenoproteome is scarce. We therefore investigated the expression of selenoproteins in various regions of the rat brain, various subcellular fractions and several brain cell lines by Se-75-labelling, gel electrophoretic separation and autoradiography, with the Se-75 tracer as the selenoprotein marker. Quantitative evaluation of the labelled proteins in selenium-deficient rats revealed information regarding preferentially supplied selenoproteins and their distribution; 21 selenoproteins could be distinguished, among them a novel or modified 15-kDa selenoprotein enriched in the cerebellum cytosol. The selenoproteins differed in the degree of their expression among the brain regions and within a region among the Subcellular fractions. Some cell-type-specific selenium-containing proteins were found in the cell lines. Differences in the distribution patterns between mono-cultured and co-cultured endothelial cells and astrocytes showed that mediators produced by other cells could affect the selenoprotein expression of a specific cell-type. This effect might play a role in the uptake and distribution of selenium in the brain but could also be of significance in the selenium metabolism of other tissues.
Witt, K., Daniels, C., Reiff, J., Krack, P., Volkmann, J., Pinsker, M. O., Krause, M., Tronnier, V., Kloss, M., Schnitzler, A., Wojtecki, L., Boetzel, K., Danek, A., Hilker, R., Sturm, V., Kupsch, A., Karner, E., and Deuschl, G., Neuropsychological and psychiatric changes after deep brain stimulation for Parkinson's disease: a randomised, multicentre study, LANCET NEUROLOGY, vol. 7, no. 7. ELSEVIER SCIENCE INC, Jul.-2008.
Abstract
Background Deep brain stimulation (DBS) of the subthalamic nucleus (STN) reduces motor symptoms in patients with Parkinson's disease (PD) and improves their quality of life; however, the effect of DBS on cognitive functions and its psychiatric side-effects are still controversial. To assess the neuropsychiatric consequences of DBS in patients with PD we did an ancillary protocol as part of a randomised study that compared DBS with the best medical treatment. Methods 156 patients with advanced Parkinson's disease and motor fluctuations were randomly assigned to have DBS of the STN or the best medical treatment for PD according to the German Society of Neurology guidelines. 123 patients had neuropsychological and psychiatric examinations to assess the changes between baseline and after 6 months. The primary outcome was the comparison of the effect of DBS with the best medical treatment on overall cognitive functioning (Mattis dementia rating scale). Secondary outcomes were the effects on executive function, depression, anxiety, psychiatric status, manic symptoms, and quality of life. Analysis was per protocol. The study is registered at ClinicalTrials.gov, number NCT00196911. Findings 60 patients were randomly assigned to receive STN-DBS and 63 patients to have best medical treatment. After 6 months, impairments were seen in executive function (difference of changes {[}DBS-best medical treatment] in verbal fluency {[}semantic] -4.50 points, 95\% CI -8.07 to -0.93, Cohen's d=-0.4; verbal fluency {[}phonemic] -3.06 points, -5.50 to -0.62, -0.5; Stroop 2 naming colour error rate -0.37 points, -0.73 to 0.00, -0.4; Stroop 3 word reading time -5.17 s, -8.82 to -1.52, -0.5; Stroop 4 colour naming time -13.00 s, -25.12 to -0.89, -0.4), irrespective of the improvement in quality of life (difference of changes in PDQ-39 10.16 points, 5.45 to 14.87, 0.6; SF-36 physical 16.55 points, 10.89 to 22.21, 0.9; SF-36 psychological 9.74 points, 2.18 to 17.29, 0.5). Anxiety was reduced in the DBS group compared with the medication group (difference of changes in Beck anxiety inventory 10.43 points, 6.08 to 14.78, 0.8). Ten patients in the DBS group and eight patients in the best medical treatment group had severe psychiatric adverse events. Interpretation DBS of the STN does not reduce overall cognition or affectivity, although there is a selective decrease in frontal cognitive functions and an improvement in anxiety in patients after the treatment. These changes do not affect improvements in quality of life. DBS of the STN is safe with respect to neuropsychological. and psychiatric effects in carefully selected patients during a 6-month follow-up period.
Raethjen, J., Austermann, K., Witt, K., Zeuner, K. E., Papengut, F., and Deuschl, G., Provocation of Parkinsonian tremor, MOVEMENT DISORDERS, vol. 23, no. 7. WILEY-LISS, May-2008.
Abstract
Classical Parkinsonian rest tremor typically fluctuates over time and can be provoked by stressful situations. We quantified and compared the influence of different provocation methods on classical rest tremor severity. The effect of counting backwards from 100, tapping of the contralateral foot and a Stroop test on the Unified Parkinson's Disease Rating Scale (UPDRS) III rest tremor scores and the accelcrometrically measured tremor amplitudes (total power) were analyzed in 18 patients with Parkinson's disease and a Type I tremor. Each of the three provocation methods increased the UPDRS III rest tremor score by 1-2 and the total power by 1-2 orders of magnitude compared with baseline (P < 0.001). The maximal effect was reached on average after 2-3 minutes of provocation. The effects were not significantly different. Provocations clearly influence the result of clinical rest tremor ratings, with the kind of provocation being of minor importance. We therefore suggest that each assessment of Parkinsonian rest tremor should include a systematic provocation and this should be formally included in future versions of the UPDRS. (c) 2008 Movement Disorder Society.
Schiek, M., Light-Emitting Organic Nanoaggregates from Functionalizedpara-Quaterphenylenes, Tomorrow's Chemistry Today. Wiley-Blackwell, pp. 185-213, 21-Feb.-2008.
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Al-Shamery, K., Schiek, M., Koch, R., and Lützen, A., Tailored Organic Nanoaggregates Generated by Self-Assembly of Designed Functionalised p-Quaterphenylenes on Muscovite Mica Substrates, Springer Series in Materials Science. Springer Science + Business Media, pp. 67-88, 2008.
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Kollmeier, B., Riedel, H., Mauermann, M., and Uppenkamp, S., Physiological Measures of Auditory Function, Handbook of Signal Processing in Acoustics. Springer Science + Business Media, pp. 159-173, 2008.
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Roth, G., Lück, M., and Strüber, D., Willensfreiheit und strafrechtliche Schuld aus Sicht der Hirnforschung, Willensfreiheit und rechtliche Ordnung. Suhrkamp, pp. 126-139, 2008.
Abstract
Strüber, D., Geschlechtsunterschiede im Verhalten und ihre hirnbiologischen Grundlagen, Handbuch Jungen-Pädagogik. Beltz, pp. 34-48, 2008.
Abstract
Helten, A. and Koch, K. -W., Calcium-dependent conformational changes in guanylate cyclase-activating protein 2 monitored by cysteine accessibility, Biochemical and biophysical research communications, vol. 356, no. 3. May-2007.
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Helten, A., Säftel, W., and Koch, K. -W., Expression level and activity profile of membrane bound guanylate cyclase type 2 in rod outer segments, Journal of neurochemistry, vol. 103, no. 4. Nov.-2007.
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Gensch, T., Komolov, K. E., Senin, I. I., Philippov, P. P., and Koch, K. -W., Ca2+-dependent conformational changes in the neuronal Ca2+-sensor recoverin probed by the fluorescent dye Alexa647, Proteins, vol. 66, no. 2. Feb.-2007.
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Senin, I. I., Churumova, V. A., Philippov, P. P., and Koch, K. -W., Membrane binding of the neuronal calcium sensor recoverin - modulatory role of the charged carboxy-terminus, BMC biochemistry, vol. 8. 2007.
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Hensley, C. J., Ouzounov, D. G., Gaeta, A. L., Venkataraman, N., Gallagher, M. T., and Koch, K. W., Silica-glass contribution to the effective nonlinearity of hollow-core photonic band-gap fibers, Optics express, vol. 15, no. 6. Mar.-2007.
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Neidhardt, J., Glaus, E., Barthelmes, D., Zeitz, C., Fleischhauer, J., and Berger, W., Identification and characterization of a novel RPGR isoform in human retina, Hum. Mutat., vol. 28, no. 8. Wiley-Blackwell, pp. 797-807, Aug.-2007.
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Zeitz, C., Forster, U., Neidhardt, J., Feil, S., Kälin, S., Leifert, D., Flor, P. J., and Berger, W., Night blindness-associated mutations in the ligand-binding, cysteine-rich, and intracellular domains of the metabotropic glutamate receptor 6 abolish protein trafficking, Hum. Mutat., vol. 28, no. 8. Wiley-Blackwell, pp. 771-780, Aug.-2007.
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Schiek, M., Al-Shamery, K., and Luetzen, A., Synthesis of Symmetrically and Unsymmetrically para-Functionalized p-Quaterphenylenes., ChemInform, vol. 38, no. 25. Wiley-Blackwell, 19-Jun.-2007.
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Reichenbacher, B., Sienknecht, U., Küchenhoff, H., and Fenske, N., Combined otolith morphology and morphometry for assessing taxonomy and diversity in fossil and extant killifish (Aphanius, †Prolebias), J. Morphol., vol. 268, no. 10. Wiley-Blackwell, pp. 898-915, 2007.
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Pérez De Sevilla Müller, L., Shelley, J., and Weiler, R., Displaced amacrine cells of the mouse retina, J. Comp. Neurol., vol. 505, no. 2. Wiley-Blackwell, pp. 177-189, 2007.
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Bendixen, A., Roeber, U., and Schröger, E., Regularity extraction and application in dynamic auditory stimulus sequences, Journal of cognitive neuroscience, vol. 19, no. 10. pp. 1664-1677, Oct.-2007.
Abstract DOI
Traditional auditory oddball paradigms imply the brain's ability to encode regularities, but are not optimal for investigating the process of regularity establishment. In the present study, a dynamic experimental protocol was developed that simulates a more realistic auditory environment with changing regularities. The dynamic sequences were included in a distraction paradigm in order to study regularity extraction and application. Subjects discriminated the duration of sequentially presented tones. Without relevance to the task, tones repeated or changed in frequency according to a pattern unknown to the subject. When frequency repetitions were broken by a deviating tone, behavioral distraction (prolonged reaction time in the duration discrimination task) was elicited. Moreover, event-related brain potential components indicated deviance detection (mismatch negativity), involuntary attention switches (P3a), and attentional reorientation. These results suggest that regularities were extracted from the dynamic stimulation and were used to predict forthcoming stimuli. The effects were already observed with deviants occurring after as few as two presentations of a standard frequency, that is, violating a just emerging rule. Effects of regularity violation strengthened with the number of standard repetitions. Control stimuli comprising no regularity revealed that the observed effects were due to both improvements in standard processing (benefits of regularity establishment) and deteriorations in deviant processing (costs of regularity violation). Thus, regularities are exploited in two different ways: for an efficient processing of regularity-conforming events as well as for the detection of nonconforming, presumably important events. The present results underline the brain's flexibility in its adaptation to environmental demands
Ruigendijk, E. and Baauw, S., Syntactic and pragmatic aspects of determiner and pronoun production in Dutch agrammatic Broca's aphasia, Aphasiology, vol. 21, no. 6-8. Informa UK Limited, pp. 535-547, Jun.-2007.
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Kranczioch, C., Debener, S., Maye, A., and Engel, A. K., Temporal dynamics of access to consciousness in the attentional blink, NeuroImage, vol. 37, no. 3. Elsevier BV, pp. 947-955, Sep.-2007.
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Hine, J. and Debener, S., Late auditory evoked potentials asymmetry revisited, Clinical Neurophysiology, vol. 118, no. 6. Elsevier BV, pp. 1274-1285, Jun.-2007.
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Debener, S., Hine, J., Bleeck, S., and Eyles, J., Source localization of auditory evoked potentials after cochlear implantation, Psychophysiology. Wiley-Blackwell, p. 071003012229003-???, 2-Oct.-2007.
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, Hearing – From Sensory Processing to Perception. Springer Science + Business Media, 2007.
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Zokoll, M. A., Klump, G. M., and Langemann, U., Auditory short-term memory persistence for tonal signals in a songbird, J. Acoust. Soc. Am., vol. 121, no. 5. Acoustical Society of America (ASA), p. 2842, 2007.
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Min, B. -K., Busch, N. A., Debener, S., Kranczioch, C., Hanslmayr, S., Engel, A. K., and Herrmann, C. S., The best of both worlds: Phase-reset of human EEG alpha activity and additive power contribute to ERP generation, International Journal of Psychophysiology, vol. 65, no. 1. Elsevier BV, pp. 58-68, Jul.-2007.
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Debener, S., Strobel, A., Sorger, B., Peters, J., Kranczioch, C., Engel, A. K., and Goebel, R., Improved quality of auditory event-related potentials recorded simultaneously with 3-T fMRI: Removal of the ballistocardiogram artefact, NeuroImage, vol. 34, no. 2. Elsevier BV, pp. 587-597, Jan.-2007.
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Aisenbrey, S., Long-term Follow-up of Macular Translocation With 360° Retinotomy for Exudative Age-Related Macular Degeneration, Arch Ophthalmol, vol. 125, no. 10. American Medical Association (AMA), p. 1367, 1-Oct.-2007.
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Yoeruek, E., Spitzer, M. S., Tatar, O., Aisenbrey, S., Bartz-Schmidt, K. U., and Szurman, P., Safety Profile of Bevacizumab on Cultured Human Corneal Cells, Cornea, vol. 26, no. 8. Ovid Technologies (Wolters Kluwer Health), pp. 977-982, Sep.-2007.
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SZURMAN, P. E. T. E. R., ROTERS, S. I. G. R. I. D., GRISANTI, S. A. L. V. A. T. O. R. E., AISENBREY, S. A. B. I. N. E., ROHRBACH, J. E. N. S. M., WARGA, M. A. X., GELISKEN, F. A. I. K., SPITZER, M. A. R. T. I. N. S., and BARTZ-SCHMIDT, K. A. R. L. U., PRIMARY SILICONE OIL TAMPONADE IN THE MANAGEMENT OF SEVERE INTRAOCULAR FOREIGN BODY INJURIES, Retina, vol. 27, no. 3. Ovid Technologies (Wolters Kluwer Health), pp. 304-311, Mar.-2007.
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Gelisken, F., Voelker, M., Schwabe, R., Besch, D., Aisenbrey, S., Szurman, P., Grisanti, S., Herzau, V., and Bartz-Schmidt, K. U., Full macular translocation versus photodynamic therapy with verteporfin in the treatment of neovascular age-related macular degeneration: 1-year results of a prospective, controlled, randomised pilot trial (FMT-PDT), Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 245, no. 8. Springer Science + Business Media, pp. 1085-1095, 12-Jan.-2007.
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Brell, M. and Hein, A., Positioning Tasks in Multimodal Computer Navigated Surgery, IEEE Multimedia, vol. 14, no. 99. Institute of Electrical & Electronics Engineers (IEEE), p. x3, 2007.
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Brell, M. and Hein, A., Positioning Tasks in Multimodal Computer-Navigated Surgery, IEEE Multimedia, vol. 14, no. 4. Institute of Electrical & Electronics Engineers (IEEE), pp. 42-51, Oct.-2007.
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Löwenheim, H. and Gummer, A. W., Terminal differentiation – A challenge in regeneration, Hearing Research, vol. 227, no. 1-2. Elsevier BV, pp. 1-2, May-2007.
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Gharabaghi, A., Andre Acioly, M., Henrique Carvalho, C., Koerbel, A., Löwenheim, H., and Tatagiba, M., Intraoperative Changes of Brainstem Auditory Evoked Potentials during the Trigeminocardiac Reflex in Cerebellopontine Angle Surgery, Skull Base, vol. 17, no. S 1. Thieme Publishing Group, 2007.
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Philipsen, A. and Hesslinger, B., Psychotherapie der ADHS - Warum im Erwachsenenalter?, psychoneuro, vol. 33, no. 10. Thieme Publishing Group, pp. 396-402, Oct.-2007.
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Matthies, S., Hesslinger, B., and Philipsen, A., Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) im Erwachsenenalter, Psychiatrie und Psychotherapie up2date, vol. 1, no. 6. Thieme Publishing Group, pp. 433-448, Nov.-2007.
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Philipsen, A. and van Elst, L. T., Corpus Callosum Dysplasia in Adult Attention-Deficit/Hyperactivity Disorder, The Journal of Clinical Psychiatry, vol. 68, no. 12. Physicians Postgraduate Press, Inc, pp. 1985-1988, 15-Dec.-2007.
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Ludäscher, P., Bohus, M., Lieb, K., Philipsen, A., Jochims, A., and Schmahl, C., Elevated pain thresholds correlate with dissociation and aversive arousal in patients with borderline personality disorder, Psychiatry Research, vol. 149, no. 1-3. Elsevier BV, pp. 291-296, Jan.-2007.
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Sobanski, E., Brüggemann, D., Alm, B., Kern, S., Deschner, M., Schubert, T., Philipsen, A., and Rietschel, M., Psychiatric comorbidity and functional impairment in a clinically referred sample of adults with attention-deficit/hyperactivity disorder (ADHD), European Archives of Psychiatry and Clinical Neuroscience, vol. 257, no. 7. Springer Science + Business Media, pp. 371-377, 27-Sep.-2007.
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Philipsen, A., Richter, H., Peters, J., Alm, B., Sobanski, E., Colla, M., Münzebrock, M., Scheel, C., Jacob, C., Perlov, E., Tebartz van Elst, L., and Hesslinger, B., Structured Group Psychotherapy in Adults With Attention Deficit Hyperactivity Disorder, The Journal of Nervous and Mental Disease, vol. 195, no. 12. Ovid Technologies (Wolters Kluwer Health), pp. 1013-1019, Dec.-2007.
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Molnar, Z., Umgelter, A., Toth, I., Livingstone, D., Weyland, A., Sakka, S. G., and Meier-Hellmann, A., Continuous monitoring of ScvO2 by a new fibre-optic technology compared with blood gas oximetry in critically ill patients: a multicentre study, Intensive Care Medicine, vol. 33, no. 10. Springer Science + Business Media, pp. 1767-1770, 19-Jun.-2007.
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Richter-Landsberg, C., The Cytoskeleton in Oligodendrocytes, J Mol Neurosci, vol. 35, no. 1. Springer Science + Business Media, pp. 55-63, 4-Dec.-2007.
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Riedel, M., Thiessen, A., Siepmann, M., Dringen, R., and Richter-Landsberg, C., HSP27: A protective means against oxidative stress in oligodendroglial cells?, GBM Fall meeting Hamburg 2007, vol. 2007, no. Fall. Elsevier BV, Sep.-2007.
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Bolhuis, S., Riedel, M., Siepmann, M., and Richter-Landsberg, C., Protein aggregate formation in oligodendroglial cells after proteasomal inhibition is modulated by the small heat shock protein Hsp27, GBM Fall meeting Hamburg 2007, vol. 2007, no. Fall. Elsevier BV, Sep.-2007.
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Stahnke, T., Stadelmann, C., Netzler, A., Brück, W., and Richter-Landsberg, C., Differential upregulation of heme oxygenase-1 (HSP32) in glial cells after oxidative stress and in demyelinating disorders, Journal of molecular neuroscience : MN, vol. 32, no. 1. pp. 25-37, 2007.
Abstract DOI
Oxidative stress is implicated in the pathogenesis of demyelinating disorders and inflammatory responses. Heme oxygenase-1 (HO-1; HSP32) is a small heat shock protein (HSP) with enzymatic activity, which is inducible by oxidative stress. In this study we analyzed autopsy and biopsy brain samples of patients with multiple sclerosis (MS) and ADEM (acute disseminated leucoencephalomyelits) and spinal cord lesions of mouse EAE (experimental autoimmune encephalomyelitis), which was actively induced by immunization with myelin oligodendrocyte glycoprotein (MOG35-55) peptide, for the presence of HO-1. HO-1 was observed in glial cells during different stages: (1) during acute phases of mainly inflammatory diseases (EAE and ADEM) expression of HO-1 was prominent in microglia/macrophages and astrocytes, and upregulation correlated with inflammation, and (2) in early MS lesions HO-1 was expressed in oligodendrocytes. Furthermore, in glial cell cultures, we can show that upregulation of HO-1 in oligodendrocytes was paralleled by severe morphological damage. Oligodendrocytes underwent apoptotic cell death at a concentration of hydrogen peroxide (50-200 microM) which did not affect astrocytes or microglia. Using oligodendroglial OLN-93 cells, we demonstrate that oxidative stress led to mitochondrial impairment and the disorganization of the microtubule network. Zinc protoporphyrin, an inhibitor of HO-1, augmented the cytotoxic consequences of hydrogen peroxide in OLN-93 cells. Hence, the presence of HO-1 in EAE, ADEM, and MS points to the involvement of oxidative stress and a role of HO-1 in the pathogenesis of the diseases. The data suggest that stress-induced HO-1 initially plays a protective role, while its chronic upregulation, might contribute to oligodendroglial cell death rather than providing protection
Meyer-Helms, B., Stahnke, T., Goldbaum, O., and Richter-Landsberg, C., Effect of proteasomal inhibition by MG-132 on inclusion body formation in astrocytes, BMC Neurosci, vol. 8, no. Suppl 1. Springer Nature, p. P12, 2007.
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Riedel, M., Goldbaum, O., Uryu, K., Bruce, J., Trojanowski, J. Q., Lee, V. M. Y., and Richter-Landsberg, C., Alpha-Synuclein aggregate formation in oligodendroglia OLN-t40 cells stably transfected with alpha-Synuclein, BMC Neurosci, vol. 8, no. Suppl 1. Springer Nature, p. P13, 2007.
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Scholz, P., Bauer, N. G., Thiel, G., and Richter-Landsberg, C., Transient overexpression of alpha-Synuclein in OLN-93 oligodendroglial cells is not cytotoxic and not affected by HSP70, BMC Neurosci, vol. 8, no. Suppl 1. Springer Nature, p. P11, 2007.
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Rätscho, N., Scholten, A., Behnen, P., Rinkwitz, S., and Koch, K. -W., Spatial-temporal differences of the expression profiles of the GCAP isoforms in the zebrafish retina, GBM Fall meeting Hamburg 2007, vol. 2007, no. Fall. Elsevier BV, Sep.-2007.
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Mauermann, M. and Hohmann, V., Differences in loudness of positive and negative Schroeder-phase tone complexes as a function of the fundamental frequency, J. Acoust. Soc. Am., vol. 121, no. 2. Acoustical Society of America (ASA), p. 1028, 2007.
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Knipper, M., Parisi, J., Coakley, K., Waldauf, C., Brabec, C. J., and Dyakonov, V., Impedance Spectroscopy on Polymer-Fullerene Solar Cells, Zeitschrift für Naturforschung A, vol. 62, no. 9. Walter de Gruyter GmbH, 1-Jan.-2007.
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Govor, L. V., Reiter, G., Bauer, G. H., and Parisi, J., Formation of low-dimensional close-packed arrays of nanoparticles in a dewetting water layer, Phys. Rev. E, vol. 76, no. 4. American Physical Society (APS), 29-Oct.-2007.
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Borchert, H., Fenske, D., Kolny-Olesiak, J., Parisi, J., Al-Shamery, K., and Bäumer, M., Ligand-capped Pt nanocrystals as oxide-supported catalysts: FTIR spectroscopic investigations of the adsorption and oxidation of CO, Angewandte Chemie (International ed. in English), vol. 46, no. 16. pp. 2923-2926, 2007.
Abstract DOI
Pomraenke, R., Ropers, C., Renard, J., Lienau, C., Lüer, L., Polli, D., and Cerullo, G., Structural phase contrast in polycrystalline organic semiconductor films observed by broadband near-field optical spectroscopy, Nano letters, vol. 7, no. 4. pp. 998-1002, Apr.-2007.
Abstract DOI
We demonstrate a novel near-field absorption spectrometer with 100 nm spatial resolution based on an ultrabroadband Ti:sapphire oscillator coupled to an aperture NSOM, enabling the measurement of nanoscale absorption spectra. The instrument is particularly suited for structural phase-selective imaging of organic materials at the nanoscale. We demonstrate that variations in the local absorption spectrum allow us to distinguish between the crystalline and the amorphous phases in polycrystalline phtalocyanine films, thus providing previously unavailable information on their mesoscopic texture
Diederich, A. and Colonius, H., Modeling spatial effects in visual-tactile saccadic reaction time, Perception & psychophysics, vol. 69, no. 1. pp. 56-67, Jan.-2007.
Abstract DOI
Saccadic reaction time (SRT) to visual targets tends to be shorter when nonvisual stimuli are presented in close temporal or spatial proximity, even when subjects are instructed to ignore the accessory input. Here, we investigate visual-tactile interaction effects on SRT under varying spatial configurations. SRT to bimodal stimuli was reduced by up to 30 msec, in comparison with responses to unimodal visual targets. In contrast to previous findings, the amount of multisensory facilitation did not decrease with increases in the physical distance between the target and the nontarget but depended on (1) whether the target and the nontarget were presented in the same hemifield (ipsilateral) or in different hemifields (contralateral), (2) the eccentricity of the stimuli, and (3) the frequency of the vibrotactile nontarget. The time-window-of-integration (TWIN) model for SRT (Colonius & Diederich, 2004) is shown to yield an explicit characterization of the observed multisensory spatial interaction effects through the removal of the peripheral-processing effects of stimulus location and tactile frequency
Diederich, A. and Colonius, H., Why two "Distractors" are better than one: modeling the effect of non-target auditory and tactile stimuli on visual saccadic reaction time, Experimental brain research, vol. 179, no. 1. pp. 43-54, May-2007.
Abstract DOI
Saccadic reaction time (SRT) was measured in a focused attention task with a visual target stimulus (LED) and auditory (white noise burst) and tactile (vibration applied to palm) stimuli presented as non-targets at five different onset times (SOAs) with respect to the target. Mean SRT was reduced (i) when the number of non-targets was increased and (ii) when target and non-targets were all presented in the same hemifield; (iii) this facilitation first increases and then decreases as the time point of presenting the non-targets is shifted from early to late relative to the target presentation. These results are consistent with the time-window-of-integration (TWIN) model (Colonius and Diederich in J Cogn Neurosci 16:1000-1009, 2004) which distinguishes a peripheral stage of independent sensory channels racing against each other from a second stage of neural integration of the input and preparation of an oculomotor response. Cross-modal interaction manifests itself in an increase or decrease of second stage processing time. For the first time, without making specific distributional assumptions on the processing times, TWIN is shown to yield numerical estimates for the facilitative effects of the number of non-targets and of the spatial configuration of target and non-targets. More generally, the TWIN model framework suggests that multisensory integration is a function of unimodal stimulus properties, like intensity, in the first stage and of cross-modal stimulus properties, like spatial disparity, in the second stage
Assmus, A., Gießing, C., Weiss, P. H., and Fink, G. R., Functional Interactions during the Retrieval of Conceptual Action Knowledge: An fMRI Study, Journal of Cognitive Neuroscience, vol. 19, no. 6. MIT Press - Journals, pp. 1004-1012, Jun.-2007.
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Field, G. D., Sher, A., Gauthier, J. L., Greschner, M., Shlens, J., Litke, A. M., and Chichilnisky, E. J., Spatial properties and functional organization of small bistratified ganglion cells in primate retina, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 27, no. 48. pp. 13261-13272, Nov.-2007.
Abstract DOI
The primate visual system consists of parallel pathways initiated by distinct cell types in the retina that encode different features of the visual scene. Small bistratified cells (SBCs), which form a major projection to the thalamus, exhibit blue-ON/yellow-OFF [S-ON/(L+M)-OFF] light responses thought to be important for high-acuity color vision. However, the spatial processing properties of individual SBCs and their spatial arrangement across the visual field are poorly understood. The present study of peripheral primate retina reveals that contrary to previous suggestions, SBCs exhibit center-surround spatial structure, with the (L+M)-OFF component of the receptive field approximately 50% larger in diameter than the S-ON component. Analysis of response kinetics shows that the (L+M)-OFF response in SBCs is slower than the S-ON response and significantly less transient than that of simultaneously recorded OFF-parasol cells. The (L+M)-OFF response in SBCs was eliminated by bath application of the metabotropic glutamate receptor agonist L-APB. These observations indicate that the (L+M)-OFF response of SBCs is not formed by OFF-bipolar cell input as has been suspected and suggest that it arises from horizontal cell feedback. Finally, the receptive fields of SBCs form orderly mosaics, with overlap and regularity similar to those of ON-parasol cells. Thus, despite their distinctive morphology and chromatic properties, SBCs exhibit two features of other retinal ganglion cell types: center-surround antagonism and regular mosaic sampling of visual space
Thiel, A., Greschner, M., Eurich, C. W., Ammermüller, J., and Kretzberg, J., Contribution of individual retinal ganglion cell responses to velocity and acceleration encoding, Journal of neurophysiology, vol. 98, no. 4. pp. 2285-2296, Oct.-2007.
Abstract DOI
We investigate the capability of turtle retinal ganglion cell (RGC) ensembles to simultaneously encode multiple aspects of visual motion: speed, direction, and acceleration of moving patterns. Bayesian stimulus reconstruction reveals that the instantaneous firing rates of RGCs contain information about all of these stimulus properties. Stimulus velocity is mainly encoded by steady-state firing rates, whereas acceleration can be reconstructed from transient components in RGC activity induced by abrupt velocity changes. Therefore neurons in higher brain areas may in principle extract information about changing velocity from the instantaneous firing activity of RGCs, without the need to compare responses to present velocities to previous ones. However, reconstruction requires the estimation of a combined acceleration and velocity signal, indicating that RGC ensembles signal both properties simultaneously. In accordance with this conclusion, combined velocity/acceleration sensitivity enhances the similarity of artificial spike trains to experimental data by 50% compared with the case of pure velocity tuning. Decoding of motion direction in addition to speed and acceleration requires direction-sensitive cells, which generate higher firing rates for one of the motion directions and therefore show asymmetric velocity tuning. By dividing the entire ensemble of simultaneously recorded cells into one group of direction-sensitive cells and one group with symmetric tuning, we demonstrate that the population of direction-sensitive cells encodes a combination of motion speed, acceleration, and direction. However, estimation of velocity and acceleration is improved by including the larger group of RGC responses that are sensitive to speed but not to motion direction
Petrusca, D., Grivich, M. I., Sher, A., Field, G. D., Gauthier, J. L., Greschner, M., Shlens, J., Chichilnisky, E. J., and Litke, A. M., Identification and characterization of a Y-like primate retinal ganglion cell type, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 27, no. 41. pp. 11019-11027, Oct.-2007.
Abstract DOI
The primate retina communicates visual information to the brain via a set of parallel pathways that originate from at least 22 anatomically distinct types of retinal ganglion cells. Knowledge of the physiological properties of these ganglion cell types is of critical importance for understanding the functioning of the primate visual system. Nonetheless, the physiological properties of only a handful of retinal ganglion cell types have been studied in detail. Here we show, using a newly developed multielectrode array system for the large-scale recording of neural activity, the existence of a physiologically distinct population of ganglion cells in the primate retina with distinctive visual response properties. These cells, which we will refer to as upsilon cells, are characterized by large receptive fields, rapid and transient responses to light, and significant nonlinearities in their spatial summation. Based on the measured properties of these cells, we speculate that they correspond to the smooth/large radiate cells recently identified morphologically in the primate retina and may therefore provide visual input to both the lateral geniculate nucleus and the superior colliculus. We further speculate that the upsilon cells may be the primate retina's counterparts of the Y-cells observed in the cat and other mammalian species
Cierpka, M., Lück, M., Strüber, D., and Roth, G., Zur Ontogenese aggressiven Verhaltens, Psychotherapeut, vol. 52, no. 2. Springer Science + Business Media, pp. 87-101, Mar.-2007.
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Baurmann, M., Gross, T., and Feudel, U., Instabilities in spatially extended predator-prey systems: spatio-temporal patterns in the neighborhood of Turing-Hopf bifurcations, Journal of theoretical biology, vol. 245, no. 2. pp. 220-229, Mar.-2007.
Abstract DOI
We investigate the emergence of spatio-temporal patterns in ecological systems. In particular, we study a generalized predator-prey system on a spatial domain. On this domain diffusion is considered as the principal process of motion. We derive the conditions for Hopf and Turing instabilities without specifying the predator-prey functional responses and discuss their biological implications. Furthermore, we identify the codimension-2 Turing-Hopf bifurcation and the codimension-3 Turing-Takens-Bogdanov bifurcation. These bifurcations give rise to complex pattern formation processes in their neighborhood. Our theoretical findings are illustrated with a specific model. In simulations a large variety of different types of long-term behavior, including homogenous distributions, stationary spatial patterns and complex spatio-temporal patterns, are observed
Buschermöhle, M., Verhey, J. L., Feudel, U., and Freund, J. A., The role of the auditory periphery in comodulation detection difference and comodulation masking release, Biological cybernetics, vol. 97, no. 5-6. pp. 397-411, Dec.-2007.
Abstract DOI
Natural sounds often exhibit correlated amplitude modulations at different frequency regions, so-called comodulation. Therefore, the ear might be especially adapted to these kinds of sounds. Two effects have been related to the sensitivity of the auditory system to common modulations across frequency: comodulation detection difference (CDD) and comodulation masking release (CMR). Research on these effects has been done on the psychophysical and on the neurophysiological level in humans and other animals. Until now, models have focused only on one of the effects. In the present study, a simple model based on data from neuronal recordings obtained during CDD experiments with starlings is discussed. This model demonstrates that simple peripheral processing in the ear can go a substantial way to explaining psychophysical signal detection thresholds in response to CDD and CMR stimuli. Moreover, it is largely analytically tractable. The model is based on peripheral processing and incorporates the basic steps frequency filtering, envelope extraction, and compression. Signal detection is performed based on changes in the mean compressed envelope of the filtered stimulus. Comparing the results of the model with data from the literature, the scope of this unifying approach to CDD and CMR is discussed
Spence, R., Gerlach, G., Lawrence, C., and Smith, C., The behaviour and ecology of the zebrafish, Danio rerio, Biological Reviews, vol. 83, no. 1. Wiley-Blackwell, pp. 13-34, 17-Dec.-2007.
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Weiss, E., Bennie, M., Hodgins-Davis, A., Roberts, S., and Gerlach, G., Characterization of new SSR-EST markers in cod, Gadus morhua, Mol Ecol Notes, vol. 7, no. 5. Wiley-Blackwell, pp. 866-867, Sep.-2007.
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Gerlach, G., Atema, J., Kingsford, M. J., Black, K. P., and Miller-Sims, V., Smelling home can prevent dispersal of reef fish larvae, PNAS, vol. 104, no. 3. Proceedings of the National Academy of Sciences, pp. 858-863, 9-Jan.-2007.
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Fabian, N. J., Albright, L. B., Gerlach, G., Fisher, H. S., and Rosenthal, G. G., Humic Acid Interferes with Species Recognition in Zebrafish (Danio rerio), Journal of Chemical Ecology, vol. 33, no. 11. Springer Science + Business Media, pp. 2090-2096, 19-Oct.-2007.
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Gerlach, G., Hodgins-Davis, A., MacDonald, B., and Hannah, R. C., Benefits of kin association: related and familiar zebrafish larvae (Danio rerio) show improved growth, Behav Ecol Sociobiol, vol. 61, no. 11. Springer Science + Business Media, pp. 1765-1770, 22-May-2007.
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Heyers, D., Manns, M., Luksch, H., Güntürkün, O., and Mouritsen, H., A visual pathway links brain structures active during magnetic compass orientation in migratory birds, PloS one, vol. 2, no. 9. p. e937, 2007.
Abstract DOI
The magnetic compass of migratory birds has been suggested to be light-dependent. Retinal cryptochrome-expressing neurons and a forebrain region, "Cluster N", show high neuronal activity when night-migratory songbirds perform magnetic compass orientation. By combining neuronal tracing with behavioral experiments leading to sensory-driven gene expression of the neuronal activity marker ZENK during magnetic compass orientation, we demonstrate a functional neuronal connection between the retinal neurons and Cluster N via the visual thalamus. Thus, the two areas of the central nervous system being most active during magnetic compass orientation are part of an ascending visual processing stream, the thalamofugal pathway. Furthermore, Cluster N seems to be a specialized part of the visual wulst. These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds "see" the reference compass direction provided by the geomagnetic field
Liedvogel, M., Feenders, G., Wada, K., Troje, N. F., Jarvis, E. D., and Mouritsen, H., Lateralized activation of Cluster N in the brains of migratory songbirds, The European journal of neuroscience, vol. 25, no. 4. pp. 1166-1173, Feb.-2007.
Abstract DOI
Cluster N is a cluster of forebrain regions found in night-migratory songbirds that shows high activation of activity-dependent gene expression during night-time vision. We have suggested that Cluster N may function as a specialized night-vision area in night-migratory birds and that it may be involved in processing light-mediated magnetic compass information. Here, we investigated these ideas. We found a significant lateralized dominance of Cluster N activation in the right hemisphere of European robins (Erithacus rubecula). Activation predominantly originated from the contralateral (left) eye. Garden warblers (Sylvia borin) tested under different magnetic field conditions and under monochromatic red light did not show significant differences in Cluster N activation. In the fairly sedentary Sardinian warbler (Sylvia melanocephala), which belongs to the same phyolgenetic clade, Cluster N showed prominent activation levels, similar to that observed in garden warblers and European robins. Thus, it seems that Cluster N activation occurs at night in all species within predominantly migratory groups of birds, probably because such birds have the capability of switching between migratory and sedentary life styles. The activation studies suggest that although Cluster N is lateralized, as is the dependence on magnetic compass orientation, either Cluster N is not involved in magnetic processing or the magnetic modulations of the primary visual signal, forming the basis for the currently supported light-dependent magnetic compass mechanism, are relatively small such that activity-dependent gene expression changes are not sensitive enough to pick them up
Liedvogel, M., Maeda, K., Henbest, K., Schleicher, E., Simon, T., Timmel, C. R., Hore, P. J., and Mouritsen, H., Chemical magnetoreception: bird cryptochrome 1a is excited by blue light and forms long-lived radical-pairs, PloS one, vol. 2, no. 10. p. e1106, 2007.
Abstract DOI
Cryptochromes (Cry) have been suggested to form the basis of light-dependent magnetic compass orientation in birds. However, to function as magnetic compass sensors, the cryptochromes of migratory birds must possess a number of key biophysical characteristics. Most importantly, absorption of blue light must produce radical pairs with lifetimes longer than about a microsecond. Cryptochrome 1a (gwCry1a) and the photolyase-homology-region of Cry1 (gwCry1-PHR) from the migratory garden warbler were recombinantly expressed and purified from a baculovirus/Sf9 cell expression system. Transient absorption measurements show that these flavoproteins are indeed excited by light in the blue spectral range leading to the formation of radicals with millisecond lifetimes. These biophysical characteristics suggest that gwCry1a is ideally suited as a primary light-mediated, radical-pair-based magnetic compass receptor
Gleich, O., Hamann, I., Kittel, M. C., Klump, G. M., and Strutz, J., Forward masking in gerbils: The effect of age, Hearing Research, vol. 223, no. 1-2. Elsevier BV, pp. 122-128, Jan.-2007.
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Rieger, J. W., Grüschow, M., Heinze, H. -J., and Fendrich, R., The appearance of figures seen through a narrow aperture under free viewing conditions: Effects of spontaneous eye motions, Journal of Vision, vol. 7, no. 6. Association for Research in Vision and Ophthalmology (ARVO), p. 10, 25-Apr.-2007.
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Kanowski, M., Rieger, J. W., Noesselt, T., Tempelmann, C., and Hinrichs, H., Endoscopic eye tracking system for fMRI, Journal of Neuroscience Methods, vol. 160, no. 1. Elsevier BV, pp. 10-15, Feb.-2007.
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Schadow, J., Lenz, D., Thaerig, S., Busch, N. A., Fründ, I., Rieger, J. W., and Herrmann, C. S., Stimulus intensity affects early sensory processing: Visual contrast modulates evoked gamma-band activity in human EEG, International Journal of Psychophysiology, vol. 66, no. 1. Elsevier BV, pp. 28-36, Oct.-2007.
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Noesselt, T., Rieger, J. W., Schoenfeld, M. A., Kanowski, M., Hinrichs, H., Heinze, H. -jochen, and Driver, J., Audiovisual temporal correspondence modulates human multisensory superior temporal sulcus plus primary sensory cortices, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 27, no. 42. pp. 11431-11441, Oct.-2007.
Abstract DOI
The brain should integrate related but not unrelated information from different senses. Temporal patterning of inputs to different modalities may provide critical information about whether those inputs are related or not. We studied effects of temporal correspondence between auditory and visual streams on human brain activity with functional magnetic resonance imaging (fMRI). Streams of visual flashes with irregularly jittered, arrhythmic timing could appear on right or left, with or without a stream of auditory tones that coincided perfectly when present (highly unlikely by chance), were noncoincident with vision (different erratic, arrhythmic pattern with same temporal statistics), or an auditory stream appeared alone. fMRI revealed blood oxygenation level-dependent (BOLD) increases in multisensory superior temporal sulcus (mSTS), contralateral to a visual stream when coincident with an auditory stream, and BOLD decreases for noncoincidence relative to unisensory baselines. Contralateral primary visual cortex and auditory cortex were also affected by audiovisual temporal correspondence or noncorrespondence, as confirmed in individuals. Connectivity analyses indicated enhanced influence from mSTS on primary sensory areas, rather than vice versa, during audiovisual correspondence. Temporal correspondence between auditory and visual streams affects a network of both multisensory (mSTS) and sensory-specific areas in humans, including even primary visual and auditory cortex, with stronger responses for corresponding and thus related audiovisual inputs
Fründ, I., Busch, N. A., Schadow, J., Körner, U., and Herrmann, C. S., From perception to action: phase-locked gamma oscillations correlate with reaction times in a speeded response task, BMC neuroscience, vol. 8. p. 27, 2007.
Abstract DOI
BACKGROUND: Phase-locked gamma oscillations have so far mainly been described in relation to perceptual processes such as sensation, attention or memory matching. Due to its very short latency ( approximately 90 ms) such oscillations are a plausible candidate for very rapid integration of sensory and motor processes. RESULTS: We measured EEG in 13 healthy participants in a speeded reaction task. Participants had to press a button as fast as possible whenever a visual stimulus was presented. The stimulus was always identical and did not have to be discriminated from other possible stimuli. In trials in which the participants showed a fast response, a slow negative potential over central electrodes starting approximately 800 ms before the response and highly phase-locked gamma oscillations over central and posterior electrodes between 90 and 140 ms after the stimulus were observed. In trials in which the participants showed a slow response, no slow negative potential was observed and phase-locked gamma oscillations were significantly reduced. Furthermore, for slow response trials the phase-locked gamma oscillations were significantly delayed with respect to fast response trials. CONCLUSION: These results indicate the relevance of phase-locked gamma oscillations for very fast (not necessarily detailed) integration processes
Ohla, K., Busch, N. A., and Herrmann, C. S., Early electrophysiological markers of visual awareness in the human brain, NeuroImage, vol. 37, no. 4. pp. 1329-1337, Oct.-2007.
Abstract DOI
The present study investigated neuronal correlates of stimulus processing leading to conscious perception of a task irrelevant global structure in a visual display. To study the underlying neuronal processes, participants were presented different types of dot patterns (Glass patterns) either forming a global structure or forming no global structure while EEG was recorded. Participants were naive about the pattern types and performed a demanding colour discrimination task. Following the experiment, the degree to which participants acquired awareness of the global visual structure was assessed. Early gamma-frequency band responses (gamma, 25-100 Hz) over occipital, parietal, and central areas were enhanced to circular Glass patterns as compared to random dot patterns at 90 ms post-stimulus. This effect was observed exclusively in participants who were subjectively aware of the global pattern structure. In this group of observers, the pattern effect built up gradually during the course of the experiment. The significance of enhanced early gamma responses to global patterns for the production of awareness of the pattern might lie in the increased impact of information conveyed by well synchronised neuronal assemblies to upstream cortical areas
Fründ, I., Schadow, J., Busch, N. A., Körner, U., and Herrmann, C. S., Evoked gamma oscillations in human scalp EEG are test-retest reliable, Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, vol. 118, no. 1. pp. 221-227, Jan.-2007.
Abstract DOI
OBJECTIVE: Evoked, phase-locked gamma oscillations of the electroencephalogram (EEG) have been demonstrated to be modulated by both bottom-up as well as top-down factors. However, to date the test-retest reliability of these oscillations has not been studied systematically. METHODS: We recorded EEG activity of 12 healthy volunteers in response to stimuli of different sizes. Each participant took part in two sessions separated by two weeks in time. To obtain an estimate of the reliability of evoked gamma band responses (GBRs), we compared frequency and magnitude of phase-locked EEG oscillations between sessions. RESULTS: In response to large stimuli magnitude and frequency of the evoked GBR yielded significant reliability. However, this was not the case for stimuli which were too small to evoke detectable GBRs. CONCLUSIONS: The results are in accordance with studies demonstrating a dependence of gamma oscillations on stimulus parameters. SIGNIFICANCE: The current findings suggest that using appropriate stimulation, the evoked gamma response has sufficient test-retest reliability for use in assessing clinical changes in neurophysiological status
Fründ, I., Busch, N. A., Körner, U., Schadow, J., and Herrmann, C. S., EEG oscillations in the gamma and alpha range respond differently to spatial frequency, Vision research, vol. 47, no. 15. pp. 2086-2098, Jul.-2007.
Abstract DOI
Physical properties of visual stimuli affect electrophysiological markers of perception. One important stimulus property is spatial frequency (SF). Therefore, we studied the influence of SF on human alpha (8-13 Hz) and gamma (>30 Hz) electroencephalographic (EEG) responses in a choice reaction task. Since real world images contain multiple SFs, an SF mixture was also examined. Event related potentials were modulated by SF around 80 and 300 ms. Evoked gamma responses were strongest for the low SF and the mixture stimulus; alpha responses were strongest for high SFs. The results link evoked and induced alpha and evoked gamma responses in human EEG to different modes of stimulus processing
Roeder, S., Hartmann, A. -M., Effmert, U., and Piechulla, B., Regulation of simultaneous synthesis of floral scent terpenoids by the 1,8-cineole synthase of Nicotiana suaveolens, Plant Molecular Biology, vol. 65, no. 1-2. Springer Nature, pp. 107-124, 5-Jul.-2007.
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Pattij, T., Janssen, M. C. W., Schepers, I. M., González-cuevas, G., De Vries, T. J., and Schoffelmeer, A. N. M., Effects of the cannabinoid CB1 receptor antagonist rimonabant on distinct measures of impulsive behavior in rats, Psychopharmacology, vol. 193, no. 1. Springer Science + Business Media, pp. 85-96, 27-Mar.-2007.
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Soros, P., Marmurek, J., Tam, F., Baker, N., Staines, W. R., and Graham, S. J., Functional MRI of working memory and selective attention in vibrotactile frequency discrimination, BMC NEUROSCIENCE, vol. 8. BIOMED CENTRAL LTD, Jul.-2007.
Abstract
Background: Focal lesions of the frontal, parietal and temporal lobe may interfere with tactile working memory and attention. To characterise the neural correlates of intact vibrotactile working memory and attention, functional MRI was conducted in 12 healthy young adults. Participants performed a forced-choice vibrotactile frequency discrimination task, comparing a cue stimulus of fixed frequency to their right thumb with a probe stimulus of identical or higher frequency. To investigate working memory, the time interval between the 2 stimuli was pseudo-randomized (either 2 or 8 s). To investigate selective attention, a distractor stimulus was occasionally presented contralaterally, simultaneous to the probe. Results: Delayed vibrotactile frequency discrimination, following a probe presented 8 s after the cue in contrast to a probe presented 2 s after the cue, was associated with activation in the bilateral anterior insula and the right inferior parietal cortex. Frequency discrimination under distraction was correlated with activation in the right anterior insula, in the bilateral posterior parietal cortex, and in the right middle temporal gyrus. Conclusion: These results support the notion that working memory and attention are organised in partly overlapping neural circuits. In contrast to previous reports in the visual or auditory domain, this study emphasises the involvement of the anterior insula in vibrotactile working memory and selective attention.
Savaskan, N. E., Borchert, A., Braeuer, A. U., and Kuhn, H., Role for glutathione peroxidase-4 in brain development and neuronal apoptosis: Specific induction of enzyme expression in reactive astrocytes following brain injury, FREE RADICAL BIOLOGY AND MEDICINE, vol. 43, no. 2. ELSEVIER SCIENCE INC, Jul.-2007.
Abstract
Glutathione peroxidase-4 (GPx4) is a multifunctional selenoprotein expressed as mitochondrial, cytosolic, or nuclear isoforms. As a catalytically active enzyme it has been implicated in antioxidative defense, but during sperm development it functions as a structural protein. GPx4 null mice die in utero at midgestation and knockdown of GPx4 during embryogenesis disturbs brain development. To explore the cerebral function of GPx4 we profiled cell-specific enzyme expression at various stages of perinatal brain maturation and investigated its regulation following brain injury by immunohistochemistry, in situ hybridization, and quantitative RT-PCR. Large amounts of GPx4 mRNA were detected in all neuronal layers during perinatal brain development but expression became restricted during postnatal maturation. In adult brain mitochondrial and cytosolic GPx4 isoforms were detected in neurons of cerebral cortex, hippocampus, and cerebellum whereas glial cells were devoid of GPx4. Following selective brain injury expression of the enzyme was upregulated in reactive astrocytes of lesioned areas and deafferented regions but not in neurons. Selective knockdown of GPx4 by small interfering RNA induced depletion of phosphatidylinositol-(4,5)-bisphosphate in the neuronal plasma membrane and subsequently apoptosis as indicated by caspase-3 activation. We hypothesize that astrocytic upregulation of GPx4 in response to injury is part of a protective cascade counteracting further cell damage. (C) 2007 Elsevier Inc. All rights reserved.
Kole, M. H. P., Braeuer, A. U., and Stuart, G. J., Inherited cortical HCN1 channel loss amplifies dendritic calcium electrogenesis and burst firing in a rat absence epilepsy model, JOURNAL OF PHYSIOLOGY-LONDON, vol. 578, no. 2. WILEY-BLACKWELL PUBLISHING, INC, Jan.-2007.
Abstract
While idiopathic generalized epilepsies are thought to evolve from temporal highly synchronized oscillations between thalamic and cortical networks, their cellular basis remains poorly understood. Here we show in a genetic rat model of absence epilepsy (WAG/Rij) that a rapid decline in expression of hyperpolarization-activated cyclic-nucleotide gated (HCN1) channels (I(h)) precedes the onset of seizures, suggesting that the loss of HCN1 channel expression is inherited rather than acquired. Loss of HCN1 occurs primarily in the apical dendrites of layer 5 pyramidal neurons in the cortex, leading to a spatially uniform 2-fold reduction in dendritic HCN current throughout the entire somato-dendritic axis. Dual whole-cell recordings from the soma and apical dendrites demonstrate that loss of HCN1 increases somato-dendritic coupling and significantly reduces the frequency threshold for generation of dendritic Ca(2+) spikes by backpropagating action potentials. As a result of increased dendritic Ca(2+) electrogenesis a large population of WAG/Rij layer 5 neurons showed intrinsic high-frequency burst firing. Using morphologically realistic models of layer 5 pyramidal neurons from control Wistar and WAG/Rij animals we show that the experimentally observed loss of dendritic I(h) recruits dendritic Ca(2+) channels to amplify action potential-triggered dendritic Ca(2+) spikes and increase burst firing. Thus, loss of function of dendritic HCN1 channels in layer 5 pyramidal neurons provides a somato-dendritic mechanism for increasing the synchronization of cortical output, and is therefore likely to play an important role in the generation of absence seizures.
Witt, K., Boersch, K., Daniels, C., Walluscheck, K., Alfke, K., Jansen, O., Czech, N., Deuschl, G., and Stingele, R., Neuropsychological consequences of endarterectomy and endovascular angioplasty with stent placement for treatment of symptomatic carotid stenosis - A prospective randomised study, JOURNAL OF NEUROLOGY, vol. 254, no. 11. SPRINGER HEIDELBERG, Nov.-2007.
Abstract
Background and purpose Previous studies compared carotid endarterectomy (CEA) and carotid artery stent placement (CAS) for treatment of symptomatic carotid artery stenosis. Whereas most previous studies showed both treatment modalities to be associated with a comparable risk of periprocedural cerebrovascular complications, these previous studies have shown significantly more microemboli and significantly more lesions in diffusion-weighted MR imaging after CAS compared to CEA. The clinical relevance of these differences remains unknown. We therefore compared the neuropsychological consequences of CAS and CEA and additionally measured the S100 beta protein, a marker of cerebral damage. Methods A total of 48 patients with symptomatic carotid artery stenosis greater than 70\% (according to ECST criteria) were enrolled and 45 patients participated in the follow-up. The patients were randomly assigned for CEA (24 patients) or CAS (21 patients). S100 beta protein values were evaluated 2 hours before the procedure, as well as one and two hours thereafter. Patients were assessed before treatment, and again 6 and 30 days after treatment using a comprehensive neuropsychological test battery. Methods Patients of the CAS and the CEA groups did not significantly differ in terms of age, gender, education, degree of carotid artery stenosis, cerebrovascular symptoms and vascular risk factors. Following previously used criteria, a cognitive change in patients was assumed to have occurred when there was a decline of more than one standard deviation in two or more tests assessing various cognitive domains. Six days and 30 days after the treatment both groups showed a comparable number of patients with cognitive changes compared to baseline. There were no significant differences in S100 beta protein values. Conclusion These results provide some reassurance that CAS is not associated with greater cognitive deterioration than CEA is.
Schmitt-Eliassen, J., Ferstl, R., Wiesner, C., Deuschl, G., and Witt, K., Feedback-based versus observational classification learning in healthy aging and Parkinson's disease, BRAIN RESEARCH, vol. 1142. ELSEVIER SCIENCE BV, Apr.-2007.
Abstract
Previous studies underline the role of dopamine in cognitive reinforcement learning. This has been demonstrated by a striatal involvement in feedback-based probabilistic classification learning. in order to determine to which extent the dopaminergic loss of Parkinson's disease and aging affects the feedback aspect in classification learning, we applied two versions of the same visual classification task. One version had to be learnt by trial-by-trial feedback, the other by observing the correct assignment of stimulus and category. Performance was evaluated in test blocks that were identical under the feedback and the observational conditions. There were 31 patients with Parkinson's disease (PD), 30 older controls and 20 younger controls tested. The results show that younger healthy participants perform better than older participants in the classification task and this difference significantly interacts with the learning condition: both groups show nearly the same level of performance under the observational condition but younger participants show a better performance than older ones under the feedback condition. In contrast, PD patients and older controls did not differ in their performance in the classification task; both groups performed better under the observational than under the feedback condition. These results demonstrate that healthy aging affects feedback-based learning but does not affect learning by observation. The fact that PD patients showed no additional deficit in feedback-based learning is an indication that the loss of dopamine does not play the key role under the feedback condition of our classification task. This finding questions the general role of the striatum in feedback-based learning and demonstrates that healthy aging particularly affects feedback-based learning. (c) 2007 Elsevier B.V. All rights reserved.
Klump, G. M., Langemann, U., Gleich, O., Wagner, H., Neuweiler, G., and Schmidt, S., Comparative Animal Behaviour and Psychoacoustics, Auditory Worlds: Sensory Analysis and Perception in Animals and Man. Wiley-Blackwell, pp. 193-245, 14-Feb.-2007.
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Roth, G., Lück, M., and Strüber, D., Gehirn, Willensfreiheit und Strafrecht, Gehirnforschung und rechtliche Verantwortung, Archiv für Rechts- und Sozialphilosophie, Beiheft 111. Franz Steiner Verlag, pp. 105-115, 2007.
Abstract
Strüber, D. and Roth, G., Die neurowissenschaftliche Dimension bei der Erklärung gewalttätigen Verhaltens, Protokollband 1. Hubertusburger Friedensgespräche. Turnshare Ltd, pp. 252-269, 2007.
Abstract
Fehr, T., Strüber, D., Lück, M., Herrmann, M., and Roth, G., Neuronal correlates of perceiving aggressive behavior, Topics in Advanced Neuroimaging, Hanse-Studien, Bd. 6. BIS, pp. 27-30, 2007.
Abstract
Puppa, L. D., Savaskan, N. E., Braeuer, A. U., Behne, D., and Kyriakopoulos, A., The role of selenite on microglial migration, SIGNAL TRANSDUCTION PATHWAYS, PT D: INFLAMMATORY SIGNALING PATHWAYS AND NEUROPATHOLOGY, vol. 1096. BLACKWELL PUBLISHING, 2007.
Abstract
Oxidative brain damage, such as excitotoxicity and stroke, leads to primary neuronal destruction. The primary damage is further potentiated by macrophages and microglial cells, which are attracted and invade into the zone of damage resulting in secondary neuronal death. Since the essential trace element selenium has anti-inflammatory properties, we analyzed the effects of selenium on these inflammatory cells. Here, we show that the essential trace element selenium abrogates the stress-induced migration of microglial cells. Thus, the aintimigratory effects of selenium may attenuate the secondary cell death cascade by preventing microglial invasion.
Komolov, K. E., Senin, I. I., Philippov, P. P., and Koch, K. -W., Surface plasmon resonance study of g protein/receptor coupling in a lipid bilayer-free system, Analytical chemistry, vol. 78, no. 4. Feb.-2006.
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Weiergräber, O. H., Senin, I. I., Zernii, E. Y., Churumova, V. A., Kovaleva, N. A., Nazipova, A. A., Permyakov, S. E., Permyakov, E. A., Philippov, P. P., Granzin, J., and Koch, K. -W., Tuning of a neuronal calcium sensor, The Journal of biological chemistry, vol. 281, no. 49. Dec.-2006.
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Shelley, J., Dedek, K., Schubert, T., Feigenspan, A., Schultz, K., Hombach, S., Willecke, K., and Weiler, R., Horizontal cell receptive fields are reduced in connexin57-deficient mice, European Journal of Neuroscience, vol. 23, no. 12. Wiley-Blackwell, pp. 3176-3186, Jun.-2006.
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Dedek, K., Schultz, K., Pieper, M., Dirks, P., Maxeiner, S., Willecke, K., Weiler, R., and Janssen-Bienhold, U., Localization of heterotypic gap junctions composed of connexin45 and connexin36 in the rod pathway of the mouse retina, European Journal of Neuroscience, vol. 24, no. 6. Wiley-Blackwell, pp. 1675-1686, Sep.-2006.
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Kharkovets, T., Dedek, K., Maier, H., Schweizer, M., Khimich, D., Nouvian, R., Vardanyan, V., Leuwer, R., Moser, T., and Jentsch, T. J., Mice with altered KCNQ4 K+ channels implicate sensory outer hair cells in human progressive deafness, The EMBO Journal, vol. 25, no. 3. Wiley-Blackwell, pp. 642-652, 26-Jan.-2006.
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Neidhardt, J., Barthelmes, D., Farahmand, F., Fleischhauer, J. C., and Berger, W., Different Amino Acid Substitutions at the Same Position in Rhodopsin Lead to Distinct Phenotypes, Invest. Ophthalmol. Vis. Sci., vol. 47, no. 4. Association for Research in Vision and Ophthalmology (ARVO), p. 1630, 1-Apr.-2006.
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Wycisk, K. A., Budde, B., Feil, S., Skosyrski, S., Buzzi, F., Neidhardt, J., Glaus, E., Nu¨rnberg, P., Ruether, K., and Berger, W., Structural and Functional Abnormalities of Retinal Ribbon Synapses due to Cacna2d4 Mutation , Invest. Ophthalmol. Vis. Sci., vol. 47, no. 8. Association for Research in Vision and Ophthalmology (ARVO), p. 3523, 1-Aug.-2006.
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Wycisk, K. A., Zeitz, C., Feil, S., Wittmer, M., Forster, U., Neidhardt, J., Wissinger, B., Zrenner, E., Wilke, R., Kohl, S., and Berger, W., Mutation in the Auxiliary Calcium-Channel Subunit CACNA2D4 Causes Autosomal Recessive Cone Dystrophy, The American Journal of Human Genetics, vol. 79, no. 5. Elsevier BV, pp. 973-977, Nov.-2006.
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Brewer,, Schiek,, Lützen,, Al-Shamery,, and Rubahn, Nanofiber frequency doublers, Nano letters, vol. 6, no. 12. pp. 2656-2659, Dec.-2006.
Abstract DOI
Nanoscaled, needle-shaped frequency doublers have been generated via self-assembled surface growth from functionalized quaterphenylene molecules with a designed large hyperpolarizability. The nanofiber frequency doublers exhibit very weak fluorescence centered around 430 nm but emit a strong, resonance-enhanced second-harmonic signal when excited with infrared 80 fs laser pulses. The frequency doublers are employed to correlate second-harmonic response and morphology via two-dimensional true second-harmonic images of individual nanoaggregates obtained with the help of a femtosecond laser scanning microscope
Sienknecht, U. J. and Fekete, D. M., Wnt expression during inner ear development, Developmental Biology, vol. 295, no. 1. Elsevier BV, p. 396, Jul.-2006.
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Sienknecht, U. J., Genetic stabilization of vertebrate bilateral limb symmetry as an example of cryptic polarity, Developmental Biology, vol. 295, no. 1. Elsevier BV, pp. 414-415, Jul.-2006.
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Kreuzberg, M. M., Schrickel, J. W., Ghanem, A., Kim, J. -S., Degen, J., Janssen-Bienhold, U., Lewalter, T., Tiemann, K., and Willecke, K., Connexin30.2 containing gap junction channels decelerate impulse propagation through the atrioventricular node, Proceedings of the National Academy of Sciences, vol. 103, no. 15. Proceedings of the National Academy of Sciences, pp. 5959-5964, 29-Mar.-2006.
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Döring, B., Shynlova, O., Tsui, P., Eckardt, D., Janssen-Bienhold, U., Hofmann, F., Feil, S., Feil, R., Lye, S. J., and Willecke, K., Ablation of connexin43 in uterine smooth muscle cells of the mouse causes delayed parturition, Journal of cell science, vol. 119, no. Pt 9. pp. 1715-1722, May-2006.
Abstract DOI
Gap junctions are characteristically increased in the myometrium during term and preterm delivery and are thought to be essential for the development of uterine contractions during labour. Expression of connexin43 (Cx43), the major myometrial gap junction protein, is increased during delivery. We have generated a mouse mutant (Cx43fl/fl:SM-CreERT2), in which the coding region of Cx43 can be specifically deleted in smooth muscle cells at any given time point by application of tamoxifen. By this approach, we were able to study long-term effects on myometrial functions that are necessary for parturition as well as gap junction intercellular communication in primary myometrial cell cultures. We found a prolongation of the pregnancy in 82% of tamoxifen-treated Cx43fl/fl:SM-CreERT2 mice as well as decreased dye coupling in cultured primary myocytes of these animals. Other parturition-specific parameters such as the regulation of oxytocin receptor, prostaglandin F receptor or progesterone remained unchanged. Our results indicate the important function of Cx43 during parturition in the living animal and suggest further strategies to investigate the role of connexins in uterine contractility in transgenic mice
Vasić, N., Avrutin, S., and Ruigendijk, E., Interpretation of pronouns in VP-ellipsis constructions in Dutch Broca’s and Wernicke’s aphasia, Brain and Language, vol. 96, no. 2. Elsevier BV, pp. 191-206, Feb.-2006.
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Ruigendijk, E., Vasić, N., and Avrutin, S., Reference assignment: Using language breakdown to choose between theoretical approaches, Brain and Language, vol. 96, no. 3. Elsevier BV, pp. 302-317, Mar.-2006.
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Engel, A. K., Debener, S., and Kranczioch, C., Coming to Attention, Sci Am Mind, vol. 17, no. 4. Nature Publishing Group, pp. 46-53, Aug.-2006.
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Langemann, U. and Klump, G. M., Asymmetry of masking in the European starling: Behavioural auditory thresholds, Hearing Research, vol. 221, no. 1-2. Elsevier BV, pp. 26-35, Nov.-2006.
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Szurman, P., Kaczmarek, R., Spitzer, M. S., Jaissle, G. B., Decker, P., Grisanti, S., Henke-Fahle, S., Aisenbrey, S., and Bartz-Schmidt, K. U., Differential toxic effect of dissolved triamcinolone and its crystalline deposits on cultured human retinal pigment epithelium (ARPE19) cells, Experimental Eye Research, vol. 83, no. 3. Elsevier BV, pp. 584-592, Sep.-2006.
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Szurman, P., Warga, M., Grisanti, S., Roters, S., Rohrbach, J. M., Aisenbrey, S., Kaczmarek, R. T., and Bartz-Schmidt, K. U., Sutureless Amniotic Membrane Fixation Using Fibrin Glue for Ocular Surface Reconstruction in a Rabbit Model, Cornea, vol. 25, no. 4. Ovid Technologies (Wolters Kluwer Health), pp. 460-466, May-2006.
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Szurman, P., Roters, S., Grisanti, S., Aisenbrey, S., Schraermeyer, U., Lu¨ke, M., Bartz-Schmidt, K. U., and Thumann, G., Ultrastructural Changes after Artificial Retinal Detachment with Modified Retinal Adhesion, Invest. Ophthalmol. Vis. Sci., vol. 47, no. 11. Association for Research in Vision and Ophthalmology (ARVO), p. 4983, 1-Nov.-2006.
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Wölfer, J., Bantel, C., Köhling, R., Speckmann, E. -J., Wassmann, H., and Greiner, C., Electrophysiology in ischemic neocortical brain slices: species differences vs. influences of anaesthesia and preparation, European Journal of Neuroscience, vol. 23, no. 7. Wiley-Blackwell, pp. 1795-1800, Apr.-2006.
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Hein, A., Thorén, A. -B., and Herlitz, J., Characteristics and outcome of false cardiac arrests in hospital, Resuscitation, vol. 69, no. 2. Elsevier BV, pp. 191-197, May-2006.
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Philipsen, A., Hornyak, M., and Riemann, D., Sleep and sleep disorders in adults with attention deficit/hyperactivity disorder, Sleep Medicine Reviews, vol. 10, no. 6. Elsevier BV, pp. 399-405, Dec.-2006.
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Philipsen, A., Differential diagnosis and comorbidity of attention-deficit/hyperactivity disorder (ADHD) and borderline personality disorder (BPD) in adults, European Archives of Psychiatry and Clinical Neuroscience, vol. 256, no. S1. Springer Science + Business Media, pp. i42-i46, Sep.-2006.
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Goldbaum, O., Vollmer, G., and Richter-Landsberg, C., Proteasome inhibition by MG-132 induces apoptotic cell death and mitochondrial dysfunction in cultured rat brain oligodendrocytes but not in astrocytes, Glia, vol. 53, no. 8. Wiley-Blackwell, pp. 891-901, 2006.
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Bauer, N. G. and Richter-Landsberg, C., The Dynamic Instability of Microtubules Is Required for Aggresome Formation in Oligodendroglial Cells After Proteolytic Stress, JMN, vol. 29, no. 2. Springer Science + Business Media, pp. 153-168, 2006.
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Braumann, T., Jastorff, B., and Richter-Landsberg, C., Fate of Cyclic Nucleotides in PC12 Cell Cultures: Uptake, Metabolism, and Effects of Metabolites on Nerve Growth Factor-Induced Neurite Outgrowth, Journal of Neurochemistry, vol. 47, no. 3. Wiley-Blackwell, pp. 912-919, 5-Oct.-2006.
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Uryu, K., Richter-Landsberg, C., Welch, W., Sun, E., Goldbaum, O., Norris, E. H., Pham, C. -T., Yazawa, I., Hilburger, K., Micsenyi, M., Giasson, B. I., Bonini, N. M., Lee, V. M. -Y., and Trojanowski, J. Q., Convergence of heat shock protein 90 with ubiquitin in filamentous alpha-synuclein inclusions of alpha-synucleinopathies, The American journal of pathology, vol. 168, no. 3. pp. 947-961, Mar.-2006.
Abstract DOI
Heat shock proteins (Hsps) facilitate refolding of denatured polypeptides, but there is limited understanding about their roles in neurodegenerative diseases characterized by misfolded proteins. Because Parkinson's disease (PD), dementia with Lewy bodies, and multiple system atrophy are alpha-synucleinopathies characterized by filamentous alpha-synuclein (alpha-syn) inclusions, we assessed which Hsps might be implicated in these disorders by examining human brain samples, transgenic mouse models, and cell culture systems. Light and electron microscopic multiple-label immunohistochemistry showed Hsp90 was the predominant Hsp examined that co-localized with alpha-syn in Lewy bodies, Lewy neurites, and glial cell inclusions and that Hsp90 co-localized with alpha-syn filaments of Lewy bodies in PD. Hsp90 levels were most predominantly increased in PD brains, which correlated with increased levels of insoluble alpha-syn. These alterations in Hsp90 were recapitulated in a transgenic mouse model of PD-like alpha-syn pathologies. Cell culture studies also revealed that alpha-syn co-immunoprecipitated preferentially with Hsp90 and Hsc70 relative to other Hsps, and exposure of cells to proteasome inhibitors resulted in increased levels of Hsp90. These data implicate predominantly Hsp90 in the formation of alpha-syn inclusions in PD and related alpha-synucleinopathies
Beutelmann, R. and Brand, T., Prediction of speech intelligibility in spatial noise and reverberation for normal-hearing and hearing-impaired listeners, J. Acoust. Soc. Am., vol. 120, no. 1. Acoustical Society of America (ASA), p. 331, 2006.
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Govor, L. V., Reiter, G., Bauer, G. H., and Parisi, J., Self-assembled treelike patterns from an evaporating binary solution, Phys. Rev. E, vol. 74, no. 6. American Physical Society (APS), 8-Dec.-2006.
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Parisi, J., Govor, L. V., Bauer, G. H., and Reiter, G., Self-Assembly of Nanoparticle Ring Patterns, Zeitschrift für Naturforschung A, vol. 61, no. 1-2. Walter de Gruyter GmbH, 1-Jan.-2006.
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Rössler, O. E., Parisi, J., Fröhlich, D., and Toffano, Z., Direction-Correlated Correlated Photons Cannot Self-Interfere: A Prediction, Zeitschrift für Naturforschung A, vol. 61, no. 7-8. Walter de Gruyter GmbH, 1-Jan.-2006.
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Rach, S. and Diederich, A., Visual-tactile integration: does stimulus duration influence the relative amount of response enhancement?, Experimental brain research, vol. 173, no. 3. pp. 514-520, Aug.-2006.
Abstract DOI
Responses to multiple stimuli from different modalities tend to be faster compared to responses to each of these stimuli alone. Neurophysiological studies on higher mammals and behavioral studies on humans suggest that the relative amount of enhancement is inversely related to stimuli intensity. In two experiments the duration of visual and tactile stimuli was varied to investigate whether duration, as a further determinant of stimulus effectiveness, is also inversely related to the relative amount of response enhancement. Visual and tactile stimuli were presented left or right of fixation either in the same or different hemifields. Participants were required to gaze only at visual stimuli and to ignore tactile (focused attention paradigm). Saccadic reaction times were recorded. Results from both experiments show that the relative amount of response enhancement was largest for the shortest stimulus duration and decreases with increasing stimulus duration, i.e., inverse effectiveness of stimulus duration
Colonius, H. and Diederich, A., The race model inequality: interpreting a geometric measure of the amount of violation, Psychological review, vol. 113, no. 1. pp. 148-154, Jan.-2006.
Abstract DOI
An inequality by J. O. Miller (1982) has become the standard tool to test the race model for redundant signals reaction times (RTs), as an alternative to a neural summation mechanism. It stipulates that the RT distribution function to redundant stimuli is never larger than the sum of the distribution functions for 2 single stimuli. When many different experimental conditions are to be compared, a numerical index of violation is very desirable. Widespread practice is to take a certain area with contours defined by the distribution functions for single and redundant stimuli. Here this area is shown to equal the difference between 2 mean RT values. This result provides an intuitive interpretation of the index and makes it amenable to simple statistical testing. An extension of this approach to 3 redundant signals is presented
Diederich, A. and Busemeyer, J. R., Modeling the effects of payoff on response bias in a perceptual discrimination task: bound-change, drift-rate-change, or two-stage-processing hypothesis, Perception & psychophysics, vol. 68, no. 2. pp. 194-207, Feb.-2006.
Abstract DOI
Three hypotheses--the bound-change hypothesis, drift-rate-change hypothesis, and two-stage-processing hypothesis--are proposed to account for data from a perceptual discrimination task in which three different response deadlines were involved and three different payoffs were presented prior to each individual trial. The aim of the present research was to show (1) how the three different hypotheses incorporate response biases into a sequential sampling decision process, (2) how payoffs and deadlines affect choice probabilities, and (3) the hypotheses' predictions of response times and choice probabilities. The two-stage-processing hypothesis gave the best account, especially for the choice probabilities, whereas the drift-rate-change hypothesis had problems predicting choice probabilities as a function of deadlines
Greschner, M., Thiel, A., Kretzberg, J., and Ammermüller, J., Complex spike-event pattern of transient ON-OFF retinal ganglion cells, Journal of neurophysiology, vol. 96, no. 6. pp. 2845-2856, Dec.-2006.
Abstract DOI
ON-OFF transient ganglion cells of the turtle retina show distinct spike-event patterns in response to abrupt intensity changes, such as during saccadic eye movements. These patterns consist of two main spike events, with the latency of each event showing a systematic dependency on stimulus contrast. Whereas the latency of the first event decreases monotonically with increasing contrast, as expected, the second event shows the shortest latency for intermediate contrasts and a longer latency for high and low contrasts. These spike-event patterns improve the discrimination of different light-intensity transitions based on ensemble responses of the ON-OFF transient ganglion cell subpopulation. Although the discrimination results are far better than chance using either spike counts or latencies of the first spikes, they are further improved by using properties of the second spike event. The best classification results are obtained when spike rates and latencies of both events are considered in combination. Thus spike counts and temporal structure of retinal ganglion cells carry complementary information about the stimulus condition, and thus spike-event patterns could be an important aspect of retinal coding. To investigate the origin of the spike-event patterns in retinal ganglion cells, two computational models of retinal processing are compared. A linear-nonlinear model consisting of separate filters for on and off response components fails to reproduce the spike-event patterns. A more complex cascade filter model, however, accurately predicts the timing of the spike events by using a combination of gain control loop and spike rate adaptation
Thiel, A., Greschner, M., and Ammermüller, J., The temporal structure of transient ON/OFF ganglion cell responses and its relation to intra-retinal processing, Journal of computational neuroscience, vol. 21, no. 2. pp. 131-151, Oct.-2006.
Abstract DOI
A subpopulation of transient ON/OFF ganglion cells in the turtle retina transmits changes in stimulus intensity as series of distinct spike events. The temporal structure of these event sequences depends systematically on the stimulus and thus carries information about the preceding intensity change. To study the spike events' intra-retinal origins, we performed extracellular ganglion cell recordings and simultaneous intracellular recordings from horizontal and amacrine cells. Based on these data, we developed a computational retina model, reproducing spike event patterns with realistic intensity dependence under various experimental conditions. The model's main features are negative feedback from sustained amacrine onto bipolar cells, and a two-step cascade of ganglion cell suppression via a slow and a fast transient amacrine cell. Pharmacologically blocking glycinergic transmission results in disappearance of the spike event sequence, an effect predicted by the model if a single connection, namely suppression of the fast by the slow transient amacrine cell, is weakened. We suggest that the slow transient amacrine cell is glycinergic, whereas the other types release GABA. Thus, the interplay of amacrine cell mediated inhibition is likely to induce distinct temporal structure in ganglion cell responses, forming the basis for a temporal code
Roth, G., Lück, M., and Strüber, D., »Freier Wille« und Schuld von Gewaltstraftätern aus Sicht der Hirnforschung und Neuropsychologie, NK, vol. 18, no. 2. Nomos Verlag, pp. 55-59, 2006.
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İşoğlu-Alkaç, Ü. and Strüber, D., Necker cube reversals during long-term EEG recordings: Sub-bands of alpha activity, International Journal of Psychophysiology, vol. 59, no. 2. Elsevier BV, pp. 179-189, Feb.-2006.
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Mathes, B., Strüber, D., Stadler, M. A., and Basar-Eroglu, C., Voluntary control of Necker cube reversals modulates the EEG delta- and gamma-band response, Neuroscience Letters, vol. 402, no. 1-2. Elsevier BV, pp. 145-149, Jul.-2006.
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Gross, T. and Feudel, U., Generalized models as a universal approach to the analysis of nonlinear dynamical systems, Phys. Rev. E, vol. 73, no. 1. American Physical Society (APS), 6-Jan.-2006.
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Feudel, U., Kuznetsov, S., and Pikovsky, A., Strange Nonchaotic Attractors, World Scientific Series on Nonlinear Science Series A. WORLD SCIENTIFIC, Apr.-2006.
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Freund, J. A., Mieruch, S., Scholze, B., Wiltshire, K., and Feudel, U., Bloom dynamics in a seasonally forced phytoplankton–zooplankton model: Trigger mechanisms and timing effects, Ecological Complexity, vol. 3, no. 2. Elsevier BV, pp. 129-139, Jun.-2006.
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Gerlach, G., Pheromonal regulation of reproductive success in female zebrafish: female suppression and male enhancement, Animal Behaviour, vol. 72, no. 5. Elsevier BV, pp. 1119-1124, Nov.-2006.
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Gerlach, G. and Lysiak, N., Kin recognition and inbreeding avoidance in zebrafish, Danio rerio, is based on phenotype matching, Animal Behaviour, vol. 71, no. 6. Elsevier BV, pp. 1371-1377, Jun.-2006.
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Hodgins-Davis, A., Roberts, S., Cowan, D. F., Atema, J., Bennie, M., Avolio, C., Defaveri, J., and Gerlach, G., Characterization of SSRs from the American lobster, Homarus americanus , Molecular Ecology Notes, vol. 7, no. 2. Wiley-Blackwell, pp. 330-332, 9-Nov.-2006.
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Gerlach, G. and Reidl, J., NAD+ utilization in Pasteurellaceae: simplification of a complex pathway, Journal of bacteriology, vol. 188, no. 19. pp. 6719-6727, Oct.-2006.
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Frost, B. J. and Mouritsen, H., The neural mechanisms of long distance animal navigation, Current opinion in neurobiology, vol. 16, no. 4. pp. 481-488, Aug.-2006.
Abstract DOI
Animal navigation is a complex process involving the integration of many sources of specialized sensory information for navigation in near and far space. Our understanding of the neurobiological underpinnings of near-space navigation is well-developed, whereas the neural mechanisms of long-distance navigation are just beginning to be unraveled. One crucial question for future research is whether the near space concepts of place cells, head direction cells, and maps in the entorhinal cortex scale up to animals navigating over very long distances and whether they are related to the map and compass concepts of long-distance navigation
Stalleicken, J., Labhart, T., and Mouritsen, H., Physiological characterization of the compound eye in monarch butterflies with focus on the dorsal rim area, Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology, vol. 192, no. 3. pp. 321-331, Mar.-2006.
Abstract DOI
The spectral, angular and polarization sensitivities of photoreceptors in the compound eye of the monarch butterfly (Danaus plexippus) are examined using electrophysiological methods. Intracellular recordings reveal a spectrally homogenous population of UV receptors with optical axes directed upwards and >or=10 degrees to the contralateral side. Based on optical considerations and on the opsin expression pattern (Sauman et al. 2005), we conclude that these UV receptors belong to the anatomically specialized dorsal rim area (DRA) of the eye. Photoreceptors in the main retina with optical axes <10 degrees contralateral or ipsilateral have maximal sensitivities in the UV (lambda(max)
Poppe, B., Blechschmidt, A., Djouguela, A., Kollhoff, R., Rubach, A., Willborn, K. C., and Harder, D., Two-dimensional ionization chamber arrays for IMRT plan verification, Medical physics, vol. 33, no. 4. pp. 1005-1015, Apr.-2006.
Abstract DOI
In this paper we describe a concept for dosimetric treatment plan verification using two-dimensional ionization chamber arrays. Two different versions of the 2D-ARRAY (PTW-Freiburg, Germany) will be presented, a matrix of 16 x 16 chambers (chamber cross section 8 mm x 8 mm; the distance between chamber centers, 16 mm) and a matrix of 27 x 27 chambers (chamber cross section 5 mm x 5 mm; the distance between chamber centers is 10 mm). The two-dimensional response function of a single chamber is experimentally determined by scanning it with a slit beam. For dosimetric plan verification, the expected two-dimensional distribution of the array signals is calculated via convolution of the planned dose distribution, obtained from the treatment planning system, with the two-dimensional response function of a single chamber. By comparing the measured two-dimensional distribution of the array signals with the expected one, a distribution of deviations is obtained that can be subjected to verification criteria, such as the gamma index criterion. As an example, this verification method is discussed for one sequence of an IMRT plan. The error detection capability is demonstrated in a case study. Both versions of two-dimensional ionization chamber arrays, together with the developed treatment plan verification strategy, have been found to provide a suitable and easy-to-handle quality assurance instrument for IMRT
Klink, K. B., Bendig, G., and Klump, G. M., Operant methods for mouse psychoacoustics, Behavior Research Methods, vol. 38, no. 1. Springer Nature, pp. 1-7, Feb.-2006.
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Maier, J. K. and Klump, G. M., Resolution in azimuth sound localization in the Mongolian gerbil (Meriones unguiculatus), J. Acoust. Soc. Am., vol. 119, no. 2. Acoustical Society of America (ASA), p. 1029, 2006.
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Hopf, J. -M., Luck, S. J., Boelmans, K., Schoenfeld, M. A., Boehler, C. N., Rieger, J. W., and Heinze, H. -J., The neural site of attention matches the spatial scale of perception, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 26, no. 13. pp. 3532-3540, Mar.-2006.
Abstract DOI
What is the neural locus of visual attention? Here we show that the locus is not fixed but instead changes rapidly to match the spatial scale of task-relevant information in the current scene. To accomplish this, we obtained electrical, magnetic, and hemodynamic measures of attention from human subjects while they detected large-scale or small-scale targets within multiscale stimulus patterns. Subjects did not know the scale of the target before stimulus onset, and yet the neural locus of attention-related activity between 250 and 300 ms varied according to the scale of the target. Specifically, maximal attention-related activity spread from a high-level, relatively anterior visual area (the lateral occipital complex) for large-scale targets to include a lower-level, more posterior area (visual area V4) for small-scale targets. This rapid change indicates that the neural locus of attention in visual cortex is not static but is instead determined rapidly and dynamically by means of an interaction between top-down task information and local information about the current visual input
Schicktanz, S., Rieger, J. W., and Luttenberg, B., Gender disparity in living kidney transplantation: a comparison of global, mid-European and German data and their ethical relevance, Transplantationsmedizin, vol. 18. Pabst science publishers, 2006.
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Soros, P., Sokoloff, L. G., Bose, A., McIntosh, A. R., Graham, S. J., and Stuss, D. T., Clustered functional MRI of overt speech production, NEUROIMAGE, vol. 32, no. 1. ACADEMIC PRESS INC ELSEVIER SCIENCE, Aug.-2006.
Abstract
To investigate the neural network of overt speech production, event-related fMRI was performed in 9 young healthy adult volunteers. A clustered image acquisition technique was chosen to minimize speech-related movement artifacts. Functional images were acquired during the production of oral movements and of speech of increasing complexity (isolated vowel as well as monosyllabic and trisyllabic utterances). This imaging technique and behavioral task enabled depiction of the articulo-phonologic network of speech production from the supplementary motor area at the cranial end to the red nucleus at the caudal end. Speaking a single vowel and performing simple oral movements involved very similar activation of the cortical and subcortical motor systems. More complex, polysyllabic utterances were associated with additional activation in the bilateral cerebellum, reflecting increased demand on speech motor control, and additional activation in the bilateral temporal cortex, reflecting the stronger involvement of phonologic processing. (c) 2006 Elsevier Inc. All rights reserved.
Peeva, G. P., Angelova, S. K., Guntinas-Lichius, O., Streppel, M., Irintchev, A., Schuetz, U., Popratiloff, A., Savaskan, N. E., Braeuer, A. U., Alvanou, A., Nitsch, R., and Angelov, D. N., Improved outcome of facial nerve repair in rats is associated with enhanced regenerative response of motoneurons and augmented neocortical plasticity, EUROPEAN JOURNAL OF NEUROSCIENCE, vol. 24, no. 8. BLACKWELL PUBLISHING, Oct.-2006.
Abstract
Within a recent study on the vibrissae motor performance after facial nerve repair in strains of blind (SD/RCS) and sighted (SD) rats we found that, despite persisting myotopic disorganization in the facial nucleus, the blind animals fully restored vibrissal whisking. Here we searched for morphological substrates of better recovery in the regenerating motoneurons and in the cerebral motor cortex. Expression analyses of the neurite growth-related proteins f-actin, neuronal class III beta-tubulin and plasticity-related gene-1, and stereological estimates of growth cone densities revealed a more vigorous regenerative response in the proximal nerve stump of blind SD/RCS rats compared with SD animals at 5-7 days after buccal nerve transection. Using c-Fos immunoreactivity as a marker for neuronal activation, we found that the volume of the cortex acutely responding to nerve transection (facial muscles reactive volume, FMRV) in both hemispheres of intact sighted rats was twofold smaller than that measured in blind animals. One month after transection and suture of the right facial nerve (FFA) we found a twofold increase in the FMRV in both rat strains compared with intact animals. The FMRV in SD/RCS animals, but not in SD rats, returned to the values in intact rats 2 months after FFA. Our findings suggest that enhanced plasticity in the CNS and an augmented regenerative response of the injured motoneurons contribute to better functional recovery in blind rats.
Schridde, U., Strauss, U., Braeuer, A. U., and van Luijtelaar, G., Environmental manipulations early in development alter seizure activity, I-h and HCN1 protein expression later in life, EUROPEAN JOURNAL OF NEUROSCIENCE, vol. 23, no. 12. BLACKWELL PUBLISHING, Jun.-2006.
Abstract
Although absence epilepsy has a genetic origin, evidence from an animal model (Wistar Albino Glaxo/Rijswijk; WAG/Rij) suggests that seizures are sensitive to environmental manipulations. Here, we show that manipulations of the early rearing environment (neonatal handling, maternal deprivation) of WAG/Rij rats leads to a pronounced decrease in seizure activity later in life. Recent observations link seizure activity in WAG/Rij rats to the hyperpolarization-activated cation current (I-h) in the somatosensory cortex, the site of seizure generation. Therefore, we investigated whether the alterations in seizure activity between rats reared differently might be correlated with changes in I-h and its channel subunits hyperpolarization-activated cation channel HCN1, 2 and 4. Whole-cell recordings from layer 5 pyramidal neurons, in situ hybridization and Western blot of the somatosensory cortex revealed an increase in I-h and HCN1 in neonatal handled and maternal deprived, compared to control rats. The increase was specific to HCN1 protein expression and did not involve HCN2/4 protein expression, or mRNA expression of any of the subunits (HCN1, 2, 4). Our findings provide the first evidence that relatively mild changes in the neonatal environment have a long-term impact of absence seizures, I-h and HCN1, and suggest that an increase of I-h and HCN1 is associated with absence seizure reduction. Our findings shed new light on the role of I-h and HCN in brain functioning and development and demonstrate that genetically determined absence seizures are quite sensitive for early interventions.
Witt, K., Daniels, C., Schmitt-Eliassen, J., Kernbichler, J., Rehm, S., Volkmann, J., and Dueschl, G., The impact of normal aging and Parkinson's disease on response preparation in task-switching behavior, BRAIN RESEARCH, vol. 1114. ELSEVIER SCIENCE BV, Oct.-2006.
Abstract
This study investigates the ability to use foreknowledge in preparation of cognitive processes in young and older participants and in PD patients. Additionally, we test the hypothesis that age-associated cognitive deficits in task switching reflect a dopaminergic dysfunction that accompanies healthy aging. To this end, we use a task-switching paradigm that (i) is known to be highly sensitive for dopaminergic dysfunction in the frontostriatal loops and (ii) can be applied with predictable and unpredictable switch and non-switch trials to assess the effect of task foreknowledge. Our results show that young participants benefit from foreknowledge and are thus able to prepare for predictable cognitive processes. Older participants have lost their ability to benefit from foreknowledge, which seems to be an effect of healthy aging. In predictable trials, the performance of PD patients did not differ from that of controls. Thus, PD patients do not show an additional deficit in the preparation of predictable cognitive switches. However, PD patients are specifically impaired in unpredictable trials compared to controls. We suggest that this result can be explained by the uncertainty about the next task in the unpredictable condition which prevents an automatic process and demands more attention. Furthermore, our results of older participants do not resemble the deficits seen in PD patients in task-switching behavior. This argues for different mechanisms that underlie the changes in task-switching behavior in healthy aging and PD. (c) 2006 Elsevier B.V. All rights reserved.
Witt, K., Daniels, C., Herzog, J., Lorenz, D., Volkmann, J., Reiff, J., Mehdorn, M., Deuschl, G., and Krack, P., Differential effects of L-dopa and subthalamic stimulation on depressive symptoms and hedonic tone in Parkinson's disease, JOURNAL OF NEUROPSYCHIATRY AND CLINICAL NEUROSCIENCES, vol. 18, no. 3. AMER PSYCHIATRIC PUBLISHING, INC, Jan.-2006.
Abstract
Patients with Parkinson's disease frequently have mild to moderate depression and exhibit low hedonic tone. The authors investigate the impact of a single L-dopa challenge and the acute effects of electric stimulation of the subthalamic nucleus (STN) on symptoms of depression and hedonic tone. Depressive symptoms improved with L-dopa and STN stimulation to the same extent. However, hedonic tone improved only with L-dopa. Most of the emotional changes did not correlate with changes in motor performance, indicating they were not just reactive but specific to the treatment. These results demonstrate a single dissociation of depressive symptoms and anhedonia in response to an acute L-dopa and STN-stimulation challenge.
Witt, K., Daniels, C., Daniel, V., Schmitt-Eliassen, J., Volkmann, J., and Deuschl, G., Patients with Parkinson's disease learn to control complex systems - an indication for intact implicit cognitive skill learning, NEUROPSYCHOLOGIA, vol. 44, no. 12. PERGAMON-ELSEVIER SCIENCE LTD, 2006.
Abstract
Implicit memory and learning mechanisms are composed of multiple processes and systems. Previous studies demonstrated a basal ganglia involvement in purely cognitive tasks that form stimulus response habits by reinforcement learning such as implicit classification learning. We will test the basal ganglia influence on two cognitive implicit tasks previously described by Berry and Broadbent, the sugar production task and the personal interaction task. Furthermore, we will investigate the relationship between certain aspects of an executive dysfunction and implicit learning. To this end, we have tested 22 Parkinsonian patients and 22 age-matched controls on two implicit cognitive tasks, in which participants learned to control a complex system. They interacted with the system by choosing an input value and obtaining an output that was related in a complex manner to the input. The objective was to reach and maintain a specific target value across trials (dynamic system learning). The two tasks followed the same underlying complex rule but had different surface appearances. Subsequently, participants performed an executive test battery including the Stroop test, verbal fluency and the Wisconsin card sorting test (WCST). The results demonstrate intact implicit learning in patients, despite an executive dysfunction in the Parkinsonian group. They lead to the conclusion that the basal ganglia system affected in Parkinson's disease does not contribute to the implicit acquisition of a new cognitive skill. Furthermore, the Parkinsonian patients were able to reach a specific goal in an implicit learning context despite impaired goal directed behaviour in the WCST, a classic test of executive functions. These results demonstrate a functional independence of implicit cognitive skill learning and certain aspects of executive functions. (c) 2006 Elsevier Ltd. All rights reserved.
Baauw, S., Kuipers, M., Ruigendijk, E., and Cuetos, F., The production of SE and SELF anaphors in Spanish and Dutch children, Language Acquisition and Language Disorders. John Benjamins Publishing Company, pp. 3-21, 2006.
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Lück, M., Strüber, D., and Roth, G., Neurobiologische und entwicklungspsychologische Grundlagen gewalttätigen Verhaltens, Bindung, Trauma und soziale Gewalt. Vandenhoeck & Ruprecht GmbH & Co, KG, pp. 78-99, 11-Apr.-2006.
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Klump, G. M., How Does the Hearing System Perform Auditory Scene Analysis?, 23 Problems in Systems Neuroscience. Oxford University Press (OUP), pp. 303-321, 5-Jan.-2006.
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Duda, T., Fik-Rymarkiewicz, E., Venkataraman, V., Krishnan, R., Koch, K. -W., and Sharma, R. K., The calcium-sensor guanylate cyclase activating protein type 2 specific site in rod outer segment membrane guanylate cyclase type 1, Biochemistry, vol. 44, no. 19. May-2005.
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Komolov, K. E., Zinchenko, D. V., Churumova, V. A., Vaganova, S. A., Weiergräber, O. H., Senin, I. I., Philippov, P. P., and Koch, K. -W., One of the Ca2+ binding sites of recoverin exclusively controls interaction with rhodopsin kinase, Biological chemistry, vol. 386, no. 3. Mar.-2005.
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Schubert, T., Maxeiner, S., Krüger, O., Willecke, K., and Weiler, R., Connexin45 mediates gap junctional coupling of bistratified ganglion cells in the mouse retina, J. Comp. Neurol., vol. 490, no. 1. Wiley-Blackwell, pp. 29-39, 2005.
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Schubert, T., Degen, J., Willecke, K., Hormuzdi, S. G., Monyer, H., and Weiler, R., Connexin36 mediates gap junctional coupling of alpha-ganglion cells in mouse retina, J. Comp. Neurol., vol. 485, no. 3. Wiley-Blackwell, pp. 191-201, 2005.
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Maxeiner, S., Dedek, K., Janssen-Bienhold, U., Ammermüller, J., Brune, H., Kirsch, T., Pieper, M., Degen, J., Krüger, O., Willecke, K., and Weiler, R., Deletion of connexin45 in mouse retinal neurons disrupts the rod/cone signaling pathway between AII amacrine and ON cone bipolar cells and leads to impaired visual transmission, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 25, no. 3. pp. 566-576, Jan.-2005.
Abstract DOI
Connexin45 (Cx45) is known to be expressed in the retina, but its functional analysis was problematic because general deletion of Cx45 coding DNA resulted in cardiovascular defects and embryonic lethality at embryonic day 10.5. We generated mice with neuron-directed deletion of Cx45 and concomitant activation of the enhanced green fluorescent protein (EGFP). EGFP labeling was observed in bipolar, amacrine, and ganglion cell populations. Intracellular microinjection of fluorescent dyes in EGFP-labeled somata combined with immunohistological markers revealed Cx45 expression in both ON and OFF cone bipolar cells. The scotopic electroretinogram of mutant mice revealed a normal a-wave but a 40% reduction in the b-wave amplitude, similar to that found in Cx36-deficient animals, suggesting a possible defect in the rod pathway of visual transmission. Indeed, neurotransmitter coupling between AII amacrine cells and Cx45-expressing cone bipolar cells was disrupted in Cx45-deficient mice. These data suggest that both Cx45 and Cx36 participate in the formation of functional heterotypic electrical synapses between these two types of retinal neurons that make up the major rod pathway
Bendixen, A., Grimm, S., and Schröger, E., Human auditory event-related potentials predict duration judgments, Neuroscience letters, vol. 383, no. 3. pp. 284-288, Aug.-2005.
Abstract DOI
Internal clock models postulate a pulse accumulation process underlying timing activities, with more accumulated pulses resulting in longer perceived durations. We investigated whether this accumulation is reflected in the amplitude of event-related brain potentials (ERPs) elicited by auditory stimuli with durations of 400-600 ms. In a duration discrimination paradigm, we found more negative amplitudes to physically identical stimuli when they were judged as longer than the memorized standard duration (500 ms) as compared to being classified as shorter. This sustained negativity was already developing during the first 100 ms after stimulus onset. It could not be explained as a bias to respond with a particular hand (lateralized readiness potential), but rather reflects a processing difference between the tones to be judged as shorter or longer. Our results are in line with models of time processing which assume that higher numbers of accumulated pulses of a temporal processor result in an increase in perceived duration
Ruigendijk, E., Burkhardt, P., and Avrutin, S., Slow sentence processing in agrammatic Broca’s aphasia: Evidence from Dutch reflexive-antecedent dependencies, Brain and Language, vol. 95, no. 1. Elsevier BV, pp. 84-85, Oct.-2005.
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Vasic, N. and Ruigendijk, E., Pronoun interpretation in Dutch Broca’s and Wernicke’s aphasia: A study of VP-ellipsis, Brain and Language, vol. 95, no. 1. Elsevier BV, pp. 125-126, Oct.-2005.
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Debener, S. and Engel, A. K., Kommentare zu C.S. Herrmann, Zeitschrift für Neuropsychologie, vol. 16, no. 3. Hogrefe & Huber, pp. 165-167, Jan.-2005.
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Kranczioch, C., Debener, S., Schwarzbach, J., Goebel, R., and Engel, A. K., Neural correlates of conscious perception in the attentional blink, NeuroImage, vol. 24, no. 3. Elsevier BV, pp. 704-714, Feb.-2005.
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Kranczioch, C., Debener, S., Herrmann, C. S., and Engel, A. K., EEG gamma-band activity in rapid serial visual presentation, Experimental Brain Research, vol. 169, no. 2. Springer Science + Business Media, pp. 246-254, 18-Nov.-2005.
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Szurman, P., Warga, M., Roters, S., Grisanti, S., Heimann, U., Aisenbrey, S., Rohrbach, J. M., Sellhaus, B., Ziemssen, F., and Bartz-Schmidt, K. U., Experimental implantation and long-term testing of an intraocular vision aid in rabbits, Archives of ophthalmology (Chicago, Ill. : 1960), vol. 123, no. 7. pp. 964-969, Jul.-2005.
Abstract DOI
OBJECTIVE: To develop an intraocular vision aid to provide artificial vision in severely traumatized eyes, where neuroretinal function could be preserved but irreversible anterior segment opacification resulted in blindness. METHODS: The basis of an intraocular vision aid is in principle a telemetric circuit to bridge the opaque cornea and to allow for artificial light stimulation of the retina. The visual prosthesis comprises an external high-dynamic range complementary metal oxide semiconductor camera and digital signal processing unit and an intraocular miniaturized light-emitting diode array to project the image onto the retina. For in vivo testing of long-term function and biocompatibility, silicone-encapsulated active photodiodes were implanted in 13 pigmented rabbits and were followed up for up to 21 months. RESULTS: Lens extraction and stable fixation of the device in the ciliary sulcus were successful in all cases. For up to 21 months inductive energy transmission and wireless stimulation of the implants could be maintained. Electrophysiologic data and histology demonstrated a good tissue biocompatibility in the long-term follow-up. CONCLUSION: The results demonstrate the general feasibility and biocompatibility to implant and fixate an intraocular light-emitting diode prosthesis. Inductive energy transmission to the intraocular device and wireless light stimulation are assured in the long term but depend on meticulous water-impermeable encapsulation of the delicate microelectronic components. Clinical Relevance An intraocular vision aid compound system with a high-resolution light-emitting diode matrix might be a future treatment option to restore vision in blind eyes with severe anterior segment disorders
Ma, W., Zhang, Y., Bantel, C., and Eisenach, J. C., Medium and large injured dorsal root ganglion cells increase TRPV-1, accompanied by increased α2C-adrenoceptor co-expression and functional inhibition by clonidine, Pain, vol. 113, no. 3. Ovid Technologies (Wolters Kluwer Health), pp. 386-394, Feb.-2005.
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Bantel, C., Eisenach, J. C., Duflo, F., Tobin, J. R., and Childers, S. R., Spinal nerve ligation increases α2-adrenergic receptor G-protein coupling in the spinal cord, Brain Research, vol. 1038, no. 1. Elsevier BV, pp. 76-82, Mar.-2005.
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Lenze, C. and Hein, A., Preliminary evaluation of an interactive milling system, International Congress Series, vol. 1281. Elsevier BV, pp. 559-564, May-2005.
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Plontke, >S., Plontke, >S., Löwenheim, H., Plontke, >S., Löwenheim, H., Preyer, S., Leins, P., Dietz, K., Koitschev, A., Zimmermann, R., and Zenner, H. -P., Outcomes research analysis of continuous intratympanic glucocorticoid delivery in patients with acute severe to profound hearing loss: Basis for planning randomized controlled trials, Acta Oto-Laryngologica, vol. 125, no. 8. Informa UK Limited, pp. 830-839, Jan.-2005.
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Nguyen-Duong, M., Koch, K. -W., and Merkel, R., The Effect of Tethering on the Chemical Kinetics of Single Bonds, MRS Proceedings, vol. 899. Cambridge University Press (CUP), Jan.-2005.
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Müller-Wehlau, M., Mauermann, M., Dau, T., and Kollmeier, B., The effects of neural synchronization and peripheral compression on the acoustic-reflex threshold, J. Acoust. Soc. Am., vol. 117, no. 5. Acoustical Society of America (ASA), p. 3016, 2005.
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Mauermann, M. and Hohmann, V., Differences in loudness of tone complexes with positive and negative Schroeder phase, J. Acoust. Soc. Am., vol. 117, no. 4. Acoustical Society of America (ASA), p. 2597, 2005.
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Govor, L. V., Parisi, J., Bauer, G. H., and Reiter, G., Instability and droplet formation in evaporating thin films of a binary solution, Phys. Rev. E, vol. 71, no. 5. American Physical Society (APS), 9-May-2005.
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Kittel, A., Müller-Hirsch, W., Parisi, J., Biehs, S. -A., Reddig, D., and Holthaus, M., Near-field heat transfer in a scanning thermal microscope, Physical review letters, vol. 95, no. 22. p. 224301, Nov.-2005.
Abstract DOI
We present measurements of the near-field heat transfer between the tip of a thermal profiler and planar material surfaces under ultrahigh vacuum conditions. For tip-sample distances below 10(-8) m, our results differ markedly from the prediction of fluctuating electrodynamics. We argue that these differences are due to the existence of a material-dependent small length scale below which the macroscopic description of the dielectric properties fails, and discuss a heuristic model which yields fair agreement with the available data. These results are of importance for the quantitative interpretation of signals obtained by scanning thermal microscopes capable of detecting local temperature variations on surfaces
Runge, E. and Lienau, C., Near-field wave-function spectroscopy of excitons and biexcitons, Physical Review B, vol. 71, no. 3. American Physical Society (APS), 31-Jan.-2005.
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Ropers, C., Steinmeyer, G., and Lienau, C., Lichtmanipulation in plasmonischen Kristallen, Physik in unserer Zeit, vol. 36, no. 3. Wiley-Blackwell, pp. 111-112, May-2005.
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Unold, T., Mueller, K., Lienau, C., Elsaesser, T., and Wieck, A. D., Optical Control of Excitons in a Pair of Quantum Dots Coupled by the Dipole-Dipole Interaction, Physical Review Letters, vol. 94, no. 13. American Physical Society (APS), 8-Apr.-2005.
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Hagen, A., Steiner, M., Raschke, M. B., Lienau, C., Hertel, T., Qian, H., Meixner, A. J., and Hartschuh, A., Exponential Decay Lifetimes of Excitons in Individual Single-Walled Carbon Nanotubes, Physical Review Letters, vol. 95, no. 19. American Physical Society (APS), 31-Oct.-2005.
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Åkerfelt, A., Colonius, H., and Diederich, A., Visual-tactile saccadic inhibition, Experimental Brain Research, vol. 169, no. 4. Springer Science + Business Media, pp. 554-563, 18-Nov.-2005.
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Busemeyer, J. R., Townsend, J. T., Diederich, A., and Barkan, R., Contrast effects or loss aversion? Comment on Usher and McClelland (2004), Psychological review, vol. 112, no. 1. pp. 253-255, Jan.-2005.
Abstract DOI
M. Usher and J. L. McClelland (2004) recently proposed a new connectionist type of model to explain context effects on preferential choice including the similarity, attraction, and compromise effects. They compared their model with an earlier connectionist type model for these same effects proposed by R. Roe, J. R. Busemeyer, and J. T. Townsend (2001) and raised several new issues. The authors address these issues and point out the main theoretical differences between the 2 explanations for context effects
Lück, M., Strüber, D., and Roth, G., Ontogenese aggressiven und gewalttätigen Verhaltens, Psychotherapeut, vol. 50, no. 6. Springer Science + Business Media, pp. 437-440, Nov.-2005.
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Gross, T., Ebenhöh, W., and Feudel, U., Long food chains are in general chaotic, Oikos, vol. 109, no. 1. Wiley-Blackwell, pp. 135-144, Apr.-2005.
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Shrimali, M. D., Prasad, A., Ramaswamy, R., and Feudel, U., Basin bifurcations in quasiperiodically forced coupled systems, Phys. Rev. E, vol. 72, no. 3. American Physical Society (APS), 22-Sep.-2005.
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Miller-Sims, V., Delaney, M., Atema, J., Kingsford, M., and Gerlach, G., DNA microsatellites in Acanthochromis polyacanthus, Mol Ecol Notes, vol. 5, no. 4. Wiley-Blackwell, pp. 841-843, Dec.-2005.
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Miller-Sims, V., Delaney, M., Atema, J., Kingsford, M. J., and Gerlach, G., DNA microsatellites in the neon damselfish (Pomacentrus coelestis), Molecular Ecology Notes, vol. 5, no. 2. Wiley-Blackwell, pp. 424-426, 31-Mar.-2005.
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Behrmann-Godel, J., Gerlach, G., and Eckmann, R., Kin and population recognition in sympatric Lake Constance perch (Perca fluviatilis L.): can assortative shoaling drive population divergence?, Behav Ecol Sociobiol, vol. 59, no. 4. Springer Science + Business Media, pp. 461-468, 27-Sep.-2005.
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Roberts, S., Romano, C., and Gerlach, G., Characterization of EST derived SSRs from the bay scallop, Argopecten irradians, Mol Ecol Notes, vol. 5, no. 3. Wiley-Blackwell, pp. 567-568, Sep.-2005.
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Mouritsen, H., Feenders, G., Liedvogel, M., Wada, K., and Jarvis, E. D., Night-vision brain area in migratory songbirds, Proceedings of the National Academy of Sciences of the United States of America, vol. 102, no. 23. pp. 8339-8344, Jun.-2005.
Abstract DOI
Twice each year, millions of night-migratory songbirds migrate thousands of kilometers. To find their way, they must process and integrate spatiotemporal information from a variety of cues including the Earth's magnetic field and the night-time starry sky. By using sensory-driven gene expression, we discovered that night-migratory songbirds possess a tight cluster of brain regions highly active only during night vision. This cluster, here named "cluster N," is located at the dorsal surface of the brain and is adjacent to a known visual pathway. In contrast, neuronal activation of cluster N was not increased in nonmigratory birds during the night, and it disappeared in migrants when both eyes were covered. We suggest that in night-migratory songbirds cluster N is involved in enhanced night vision, and that it could be integrating vision-mediated magnetic and/or star compass information for night-time navigation. Our findings thus represent an anatomical and functional demonstration of a specific night-vision brain area
Piersma, T., Pérez-Tris, J., Mouritsen, H., Bauchinger, U., and Bairlein, F., Is there a "migratory syndrome" common to all migrant birds?, Annals of the New York Academy of Sciences, vol. 1046. pp. 282-293, Jun.-2005.
Abstract DOI
Bird migration has been assumed, mostly implicitly, to represent a distinct class of animal behavior, with deep and strong homologies in the various phenotypic expressions of migratory behavior between different taxa. Here the evidence for the existence of what could be called a "migratory syndrome," a tightly integrated, old group of adaptive traits that enables birds to commit themselves to highly organized seasonal migrations, is assessed. A list of problems faced by migratory birds is listed first and the traits that migratory birds have evolved to deal with these problems are discussed. The usefulness of comparative approaches to investigate which traits are unique to migrants is then discussed. A provisional conclusion that, perhaps apart from a capacity for night-time compass orientation, there is little evidence for deeply rooted coadapted trait complexes that could make up such a migratory syndrome, is suggested. Detailed analyses of the genetic and physiological architecture of potential adaptations to migration, combined with a comparative approach to further identify the phylogenetic levels at which different adaptive traits for migration have evolved, are recommended
Mouritsen, H. and Ritz, T., Magnetoreception and its use in bird navigation, Current opinion in neurobiology, vol. 15, no. 4. pp. 406-414, Aug.-2005.
Abstract DOI
Recent advances have brought new insight into the physiological mechanisms that enable birds and other animals to use magnetic fields for orientation. Many birds seem to have two magnetodetection senses, one based on magnetite near the beak and one based on light-dependent radical-pair processes in the bird's eye(s). Among the most exciting recent results are: first, behavioural responses of birds experiencing oscillating magnetic fields. Second, the occurrence of putative magnetosensory molecules, the cryptochromes, in the eyes of migratory birds. Third, detection of a brain area that integrates specialised visual input at night in night-migratory songbirds. Fourth, a putative magnetosensory cluster of magnetite in the upper beak. These and other recent findings have important implications for magnetoreception; however, many crucial open questions remain
Stalleicken, J., Mukhida, M., Labhart, T., Wehner, R., Frost, B., and Mouritsen, H., Do monarch butterflies use polarized skylight for migratory orientation?, The Journal of experimental biology, vol. 208, no. Pt 12. pp. 2399-2408, Jun.-2005.
Abstract DOI
To test if migratory monarch butterflies use polarized light patterns as part of their time-compensated sun compass, we recorded their virtual flight paths in a flight simulator while the butterflies were exposed to patches of naturally polarized blue sky, artificial polarizers or a sunny sky. In addition, we tested butterflies with and without the polarized light detectors of their compound eye being occluded. The monarchs' orientation responses suggested that the butterflies did not use the polarized light patterns as a compass cue, nor did they exhibit a specific alignment response towards the axis of polarized light. When given direct view of the sun, migratory monarchs with their polarized light detectors painted out were still able to use their time-compensated compass: non-clockshifted butterflies, with their dorsal rim area occluded, oriented in their typical south-southwesterly migratory direction. Furthermore, they shifted their flight course clockwise by the predicted approximately 90 degrees after being advance clockshifted 6 h. We conclude that in migratory monarch butterflies, polarized light cues are not necessary for a time-compensated celestial compass to work and that the azimuthal position of the sun disc and/or the associated light-intensity and spectral gradients seem to be the migrants' major compass cue
Friedl, T. W. P. and Klump, G. M., EXTRAPAIR FERTILIZATIONS IN RED BISHOPS (EUPLECTES ORIX): DO FEMALES FOLLOW CONDITIONAL EXTRAPAIR STRATEGIES?, The Auk, vol. 122, no. 1. American Ornithologists' Union, p. 57, 2005.
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Friedl, T. Wp. and Klump, G. M., Sexual selection in the lek-breeding European treefrog: body size, chorus attendance, random mating and good genes, Animal Behaviour, vol. 70, no. 5. Elsevier BV, pp. 1141-1154, Nov.-2005.
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Fendrich, R., Rieger, J. W., and Heinze, H. -jochen, The effect of retinal stabilization on anorthoscopic percepts under free-viewing conditions, Vision research, vol. 45, no. 5. pp. 567-582, Mar.-2005.
Abstract DOI
Outline shapes were moved back and forth at .5 Hz behind a simulated narrow (10' or 15') slit without visible borders. Under free-viewing conditions observers reported spontaneous transitions between periods in which they saw a horizontally moving shape and periods in which they saw only vertically moving contour segments. Eye movements were monitored with a dual-Purkinje image eye-tracker. On half the trials we used retinal stabilization to eliminate any pursuit dependent retinal painting. With no stabilization, we observed low amplitude spontaneous pursuit of the horizontal figure motion when a shape was seen, and occasionally lower amplitude pursuit even when no shape was seen. Pursuit amplitudes increased when the display was stabilized. However, stabilization did not alter either the duration or frequency of the episodes of shape perception. Our findings indicate that under the free-viewing conditions we employed, spontaneous smooth pursuit and pursuit dependent painting did not contribute to the formation or maintenance of anorthoscopic percepts
Rieger, J. W., Braun, C., Bülthoff, H. H., and Gegenfurtner, K. R., The dynamics of visual pattern masking in natural scene processing: a magnetoencephalography study, Journal of vision, vol. 5, no. 3. pp. 275-286, 2005.
Abstract
We investigated the dynamics of natural scene processing and mechanisms of pattern masking in a scene-recognition task. Psychophysical recognition performance and the magnetoencephalogram (MEG) were recorded simultaneously. Photographs of natural scenes were briefly displayed and in the masked condition immediately followed by a pattern mask. Viewing the scenes without masking elicited a transient occipital activation that started approximately 70 ms after the pattern onset, peaked at 110 ms, and ended after 170 ms. When a mask followed the target an additional transient could be reliably identified in the MEG traces. We assessed psychophysical performance levels at different latencies of this transient. Recognition rates were reduced only when the additional activation produced by the pattern mask overlapped with the initial 170 ms of occipital activation from the target. Our results are commensurate with an early cortical locus of pattern masking and indicate that 90 ms of undistorted cortical processing is necessary to reliably recognize a scene. Our data also indicate that as little as 20 ms of undistorted processing is sufficient for above-chance discrimination of a scene from a distracter
Roth, G., Lück, M., and Strüber, D., Schuld und Verantwortung von Gewaltstraftätern aus Sicht der Hirnforschung und Neuropsychologie, Deutsche Richterzeitung, vol. 83. 2005.
Engelhardt, A., Mangelkrankheiten, Neurologie. Elsevier BV, pp. 963-973, 2005.
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Lienau, C. and Baumberg, J. J., Ultrafast Coherent Spectroscopy of Single Semiconductor Quantum Dots, Semiconductor Macroatoms. World Scientific Pub Co Pte Lt, pp. 101-149, Nov.-2005.
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Ropers, C., Müller, R., Lienau, C., Stibenz, G., Steinmeyer, G., Park, D. -J., Yoon, Y. -C., and Kim, D. -S., Ultrafast Dynamics of Light Transmission Through Plasmonic Crystals, Ultrafast Phenomena XIV. Springer Science + Business Media, pp. 650-654, 2005.
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Klump, G. M., Evolutionary Adaptations for Auditory Communication, Communication Acoustics. Springer Science + Business Media, pp. 27-45, 2005.
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Klump, G. M. and Hofer, S. B., The relevance of rate and time cues for CMR in starling auditory forebrain neurons, Auditory Signal Processing. Springer Science + Business Media, pp. 327-333, 2005.
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Censarek, P., Beyermann, M., and Koch, K. -W., Thermodynamics of apocalmodulin and nitric oxide synthase II peptide interaction, FEBS letters, vol. 577, no. 3. Nov.-2004.
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Hwang, J. -Y., Schlesinger, R., and Koch, K. -W., Irregular dimerization of guanylate cyclase-activating protein 1 mutants causes loss of target activation, European journal of biochemistry / FEBS, vol. 271, no. 18. Sep.-2004.
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Senin, I. I., Höppner-Heitmann, D., Polkovnikova, O. O., Churumova, V. A., Tikhomirova, N. K., Philippov, P. P., and Koch, K. -W., Recoverin and rhodopsin kinase activity in detergent-resistant membrane rafts from rod outer segments, The Journal of biological chemistry, vol. 279, no. 47. Nov.-2004.
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Dirks, P., Tieding, S., Schneider, I., Mey, J., and Weiler, R., Characterization of retinoic acid neuromodulation in the carp retina, Journal of Neuroscience Research, vol. 78, no. 2. Wiley-Blackwell, pp. 177-185, 2004.
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Schultz, K., Janssen-Bienhold, U., Gundelfinger, E. D., Kreutz, M. R., and Weiler, R., Calcium-binding protein Caldendrin and CaMKII are localized in spinules of the carp retina, J. Comp. Neurol., vol. 479, no. 1. Wiley-Blackwell, pp. 84-93, 2004.
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Hombach, S., Janssen-Bienhold, U., Sohl, G., Schubert, T., Bussow, H., Ott, T., Weiler, R., and Willecke, K., Functional expression of connexin57 in horizontal cells of the mouse retina, Eur J Neurosci, vol. 19, no. 10. Wiley-Blackwell, pp. 2633-2640, May-2004.
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Feigenspan, A., Janssen-Bienhold, U., Hormuzdi, S., Monyer, H., Degen, J., Söhl, G., Willecke, K., Ammermüller, J., and Weiler, R., Expression of connexin36 in cone pedicles and OFF-cone bipolar cells of the mouse retina, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 24, no. 13. pp. 3325-3334, Mar.-2004.
Abstract DOI
Transgenic technology, immunocytochemistry, electrophysiology, intracellular injection techniques, and reverse transcription PCR were combined to study the expression of neuronal connexin36 (Cx36) in the outer plexiform layer of the mouse retina. Transgenic animals expressed either a fusion protein of full-length Cx36 with enhanced green fluorescent protein (EGFP) attached at the C terminus or exon 2 of Cx36 was replaced bybeta-galactosidase (beta-gal). In the outer nuclear layer,beta-gal-positive cell bodies, which were confined to the most distal region close to the outer limiting membrane, displayed immunoreactivity against S-cone opsin. Cx36-EGFP puncta colocalized with cone pedicles, which were visualized by intracellular injection. In reverse transcriptase PCR experiments, Cx36 mRNA was never detected in samples of rods harvested from the outer nuclear layer. These results strongly suggest expression of Cx36 in cones but not in rods. In vertical sections, Cx36 expression in the vitreal part of the outer plexiform layer was characterized by a patchy distribution. Immunocytochemistry with antibodies against the neurokinin-3 receptor and the potassium channel HCN4 (hyperpolarization-activated cyclic nucleotide-gated potassium channel) displayed clusters of the Cx36 label on the dendrites of OFF-cone bipolar cells. In horizontal sections, these clusters of Cx36 appeared as round or oval-shaped groups of individual puncta, and they were always aligned with the base of cone pedicles. Double-labeling experiments and single-cell reverse transcriptase PCR ruled out expression of Cx36 in horizontal cells and rod bipolar cells. At light microscopic resolution, we found close association of Cx36-EGFP with the AMPA-type glutamate receptor subunit GluR1 but not with GluR2-GluR4, the kainate receptor subunit GluR5, or the metabotropic glutamate receptor mGluR6
Ruigendijk, E., Question production in Dutch agrammatism, Brain and Language, vol. 91, no. 1. Elsevier BV, pp. 116-117, Oct.-2004.
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Makeig, S., Debener, S., Onton, J., and Delorme, A., Mining event-related brain dynamics, Trends in Cognitive Sciences, vol. 8, no. 5. Elsevier BV, pp. 204-210, May-2004.
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Busch, N. A., Debener, S., Kranczioch, C., Engel, A. K., and Herrmann, C. S., Size matters: effects of stimulus size, duration and eccentricity on the visual gamma-band response, Clinical Neurophysiology, vol. 115, no. 8. Elsevier BV, pp. 1810-1820, Aug.-2004.
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Li, X., Bantel, C., Conklin, D., Childers, S. R., and Eisenach, J. C., Repeated Dosing with Oral Allosteric Modulator of Adenosine A1 Receptor Produces Tolerance in Rats with Neuropathic Pain, Anesthesiology, vol. 100, no. 4. Ovid Technologies (Wolters Kluwer Health), pp. 956-961, Apr.-2004.
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Lieb, K., Rexhausen, J. E., Kahl, K. G., Schweiger, U., Philipsen, A., Hellhammer, D. H., and Bohus, M., Increased diurnal salivary cortisol in women with borderline personality disorder, Journal of Psychiatric Research, vol. 38, no. 6. Elsevier BV, pp. 559-565, Nov.-2004.
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Schmahl, C., Greffrath, W., Baumgärtner, U., Schlereth, T., Magerl, W., Philipsen, A., Lieb, K., Bohus, M., and Treede, R. -D., Differential nociceptive deficits in patients with borderline personality disorder and self-injurious behavior: laser-evoked potentials, spatial discrimination of noxious stimuli, and pain ratings, Pain, vol. 110, no. 1. Ovid Technologies (Wolters Kluwer Health), pp. 470-479, Jul.-2004.
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Stahnke, T. and Richter-Landsberg, C., Triethyltin-induced stress responses and apoptotic cell death in cultured oligodendrocytes, Glia, vol. 46, no. 3. Wiley-Blackwell, pp. 334-344, 2004.
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Mronga, T., Stahnke, T., Goldbaum, O., and Richter-Landsberg, C., Mitochondrial pathway is involved in hydrogen-peroxide-induced apoptotic cell death of oligodendrocytes, Glia, vol. 46, no. 4. Wiley-Blackwell, pp. 446-455, 2004.
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Richter-Landsberg, C. and Bauer, N. G., Tau-inclusion body formation in oligodendroglia: the role of stress proteins and proteasome inhibition, International Journal of Developmental Neuroscience, vol. 22, no. 7. Elsevier BV, pp. 443-451, Nov.-2004.
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Wang, Y., Richter-Landsberg, C., and Reiser, G., Expression of protease-activated receptors (PARs) in OLN-93 oligodendroglial cells and mechanism of PAR-1-induced calcium signaling, Neuroscience, vol. 126, no. 1. Elsevier BV, pp. 69-82, Jan.-2004.
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Dabir, D. V., Trojanowski, J. Q., Richter-Landsberg, C., Lee, V. M. -Y., and Forman, M. S., Expression of the Small Heat-Shock Protein αB-Crystallin in Tauopathies with Glial Pathology, The American Journal of Pathology, vol. 164, no. 1. Elsevier BV, pp. 155-166, Jan.-2004.
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Goldbaum, O. and Richter-Landsberg, C., Proteolytic stress causes heat shock protein induction, tau ubiquitination, and the recruitment of ubiquitin to tau-positive aggregates in oligodendrocytes in culture, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 24, no. 25. pp. 5748-5757, Jun.-2004.
Abstract DOI
Molecular chaperones and the ubiquitin-proteasome system are participants in the defense against unfolded proteins and provide an effective protein quality control system that is essential for cellular functions and survival. Ubiquitinated tau-positive inclusion bodies containing the small heat shock protein alphaB-crystallin in oligodendrocytes are consistent features of a variety of neurodegenerative diseases, and defects in the proteasome system might contribute to the aggregation process. Oligodendrocytes, the myelin-forming cells of the CNS, are specifically sensitive to stress situations. Here we can show that in cultured rat brain oligodendrocytes proteasomal inhibition by MG-132 or lactacystin caused apoptotic cell death and the induction of heat shock proteins in a time- and concentration-dependent manner. Specifically, alphaB-crystallin was upregulated, and ubiquitinated proteins accumulated. After incubation with MG-132 the tau was dephosphorylated, which enhanced its microtubule-binding capacity. Proteasomal inhibition led to ubiquitination of tau and its association with alphaB-crystallin and to the occurrence of thioflavine S-positive aggregates in the oligodendroglial cytoplasm. These aggregates were positive for tau and also contained ubiquitin and alphaB-crystallin; hence they resembled the glial cytoplasmic inclusions observed in white matter disease and frontotemporal dementias with parkinsonism linked to chromosome 17 (FTDP-17). In summary, the data underscore the specific sensitivity of oligodendrocytes to stress situations and point to a causal relationship of proteasomal impairment and inclusion body formation
Mauermann, M., Long, G. R., and Kollmeier, B., Fine structure of hearing threshold and loudness perception, J. Acoust. Soc. Am., vol. 116, no. 2. Acoustical Society of America (ASA), p. 1066, 2004.
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Mauermann, M. and Kollmeier, B., Distortion product otoacoustic emission (DPOAE) input/output functions and the influence of the second DPOAE source, J. Acoust. Soc. Am., vol. 116, no. 4. Acoustical Society of America (ASA), p. 2199, 2004.
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Parisi, J. and Rössler, O. E., An Idea to Transport High Angular Momenta with Ultralow Frequency Photons, Physics Essays, vol. 17, no. 4. Physics Essays Publication, pp. 521-522, Dec.-2004.
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Govor, L. V., Reiter, G., Parisi, J., and Bauer, G. H., Self-assembled nanoparticle deposits formed at the contact line of evaporating micrometer-size droplets, Phys. Rev. E, vol. 69, no. 6. American Physical Society (APS), 14-Jun.-2004.
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Unold, T., Mueller, K., Lienau, C., and Elsaesser, T., Space and time resolved coherent optical spectroscopy of single quantum dots, Semicond. Sci. Technol., vol. 19, no. 4. IOP Publishing, pp. S260-S263, 8-Mar.-2004.
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Unold, T., Mueller, K., Lienau, C., Elsaesser, T., and Wieck, A. D., Optical Stark Effect in a Quantum Dot: Ultrafast Control of Single Exciton Polarizations, Physical Review Letters, vol. 92, no. 15. American Physical Society (APS), 16-Apr.-2004.
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Lienau, C., Intonti, F., Guenther, T., Elsaesser, T., Savona, V., Zimmermann, R., and Runge, E., Near-field autocorrelation spectroscopy of disordered semiconductor quantum wells, Physical Review B, vol. 69, no. 8. American Physical Society (APS), 10-Feb.-2004.
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Müller, R., Ropers, C., and Lienau, C., Femtosecond light pulse propagation through metallic nanohole arrays: The role of the dielectric substrate, Optics express, vol. 12, no. 21. pp. 5067-5081, Oct.-2004.
Abstract DOI
We study theoretically ultrafast light propagation through a periodic array of holes in a silver film deposited on a dielectric substrate using a three-dimensional finite-difference time-domain (FDTD) simulation. We focus on studying the effects of the coherent coupling between resonant surface plasmon polariton (SPP) excitations at the top and bottom interfaces of the metal film on the transmission dynamics. In a free standing film, the SPP excitations at both interfaces are fully in resonance and pronounced temporal oscillations in the energy flow between the bottom and top interfaces give evidence for coupling between the (+/-1,0) SPP modes via photon tunneling through the holes. Variation of the dielectric constant of the substrate lifts the energetic degeneracy between the two modes and thus decreases the coupling and suppresses the energy oscillations. New SPP-enhanced transmission peaks appear when higher order modes at the substrate/metal interface are brought into resonance with the (+/-1,0) air/metal resonance and efficient mode coupling is achieved. Both temporal transmission dynamics and near-field mode profiles are reported and their implications for tailoring the optical properties of these two-dimensional plasmonic crystals are discussed
Lienau, C., Ultrafast near-field spectroscopy of single semiconductor quantum dots, Philosophical transactions. Series A, Mathematical, physical, and engineering sciences, vol. 362, no. 1817. pp. 861-879, Apr.-2004.
Abstract DOI
Excitonic and spin excitations of single semiconductor quantum dots (QDs) currently attract attention as possible candidates for solid-state-based implementations of quantum logic devices. Due to their rather short decoherence times in the picosecond to nanosecond range, such implementations rely on using ultrafast optical pulses to probe and control coherent polarizations. We combine ultrafast spectroscopy and near-field microscopy to probe the nonlinear optical response of a single QD on a femtosecond time-scale. Transient reflectivity spectra show pronounced oscillations around the QD exciton line. These oscillations reflect phase-disturbing Coulomb interactions between the excitonic QD polarization and continuum excitations. The results show that although semiconductor QDs resemble in many respects atomic systems, Coulomb many-body interactions can contribute significantly to their optical nonlinearities on ultrashort time-scales
Diederich, A. and Colonius, H., Bimodal and trimodal multisensory enhancement: effects of stimulus onset and intensity on reaction time, Perception & psychophysics, vol. 66, no. 8. pp. 1388-1404, Nov.-2004.
Abstract DOI
Manual reaction times to visual, auditory, and tactile stimuli presented simultaneously, or with a delay, were measured to test for multisensory interaction effects in a simple detection task with redundant signals. Responses to trimodal stimulus combinations were faster than those to bimodal combinations, which in turn were faster than reactions to unimodal stimuli. Response enhancement increased with decreasing auditory and tactile stimulus intensity and was a U-shaped function of stimulus onset asynchrony. Distribution inequality tests indicated that the multisensory interaction effects were larger than predicted by separate activation models, including the difference between bimodal and trimodal response facilitation. The results are discussed with respect to previous findings in a focused attention task and are compared with multisensory integration rules observed in bimodal and trimodal superior colliculus neurons in the cat and monkey
Colonius, H. and Diederich, A., Why aren't all deep superior colliculus neurons multisensory? A Bayes' ratio analysis, Cognitive, affective & behavioral neuroscience, vol. 4, no. 3. pp. 344-353, Sep.-2004.
Abstract DOI
Multisensory neurons in the deep superior colliculus (SC) show response enhancement to cross-modal stimuli that coincide in time and space. However, multisensory SC neurons respond to unimodal input as well. It is thus legitimate to ask why not all deep SC neurons are multisensory or, at least, develop multisensory behavior during an organism's maturation. The novel answer given here derives from a signal detection theory perspective. A Bayes' ratio model of multisensory enhancement is suggested. It holds that deep SC neurons operate under the Bayes' ratio rule, which guarantees optimal performance-that is, it maximizes the probability of target detection while minimizing the false alarm rate. It is shown that optimal performance of multisensory neurons vis-à-vis cross-modal stimuli implies, at the same time, that modality-specific neurons will outperform multisensory neurons in processing unimodal targets. Thus, only the existence of both multisensory and modality-specific neurons allows optimal performance when targets of one or several modalities may occur
Colonius, H. and Diederich, A., Multisensory interaction in saccadic reaction time: a time-window-of-integration model, Journal of cognitive neuroscience, vol. 16, no. 6. pp. 1000-1009, 2004.
Abstract DOI
Saccadic reaction time to visual targets tends to be faster when stimuli from another modality (in particular, audition and touch) are presented in close temporal or spatial proximity even when subjects are instructed to ignore the accessory input (focused attention task). Multisensory interaction effects measured in neural structures involved in saccade generation (in particular, the superior colliculus) have demonstrated a similar spatio-temporal dependence. Neural network models of multisensory spatial integration have been shown to generate convergence of the visual, auditory, and tactile reference frames and the sensorimotor coordinate transformations necessary for coordinated head and eye movements. However, because these models do not capture the temporal coincidences critical for multisensory integration to occur, they cannot easily predict multisensory effects observed in behavioral data such as saccadic reaction times. This article proposes a quantitative stochastic framework, the time-window-of-integration model, to account for the temporal rules of multisensory integration. Saccadic responses collected from a visual-tactile focused attention task are shown to be consistent with the time-window-of-integration model predictions
Gießing, C., Thiel, C. M., Stephan, K. E., Rösler, F., and Fink, G. R., Visuospatial attention: how to measure effects of infrequent, unattended events in a blocked stimulus design, NeuroImage, vol. 23, no. 4. Elsevier BV, pp. 1370-1381, Dec.-2004.
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Gross, T. and Feudel, U., Analytical search for bifurcation surfaces in parameter space, Physica D: Nonlinear Phenomena, vol. 195, no. 3-4. Elsevier BV, pp. 292-302, Aug.-2004.
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Baurmann, M., Ebenhöh, W., and Feudel, U., Turing instabilities and pattern formation in a benthic nutrient-microorganism system, Mathematical Biosciences and Engineering, vol. 1, no. 1. American Institute of Mathematical Sciences (AIMS), pp. 111-130, Mar.-2004.
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Gross, T., Ebenhöh, W., and Feudel, U., Enrichment and foodchain stability: the impact of different forms of predator–prey interaction, Journal of Theoretical Biology, vol. 227, no. 3. Elsevier BV, pp. 349-358, Apr.-2004.
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Titz, S., Kuhlbrodt, T., and Feudel, U., Grid geometry effects on convection in ocean climate models: a conceptual study, Ocean Modelling, vol. 7, no. 1-2. Elsevier BV, pp. 165-181, Jan.-2004.
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Baurmann, M., Ebenhoh, W., and Feudel, U., Turing instabilities and pattern formation in a benthic nutrient-microoganism system, Mathematical biosciences and engineering : MBE, vol. 1, no. 1. pp. 111-130, Jun.-2004.
Abstract
In general, the distributions of nutrients and microorganisms in sediments show complex spatio-temporal patterns, which often cannot be explained asresulting exclusively from the temporal fluctuations of environmental conditions and the inhomogeneity of the studied sediment's material. We studied the dynamics of one population of microorganisms feeding on a nutrient in a simple model, taking into account that the considered bacteria can be in an active or in a dormant state. Using this model, we shoew that the formation of spatio-temporal patterns can be the consequence of the interaction between predation and transport processes. Employing the model on a two-dimensional vertical domain, we show by simulations which patterns can arise. Depending on the strength of bioirrigation, we observe stripes or "hot spots"(or "cold spots")with high (or low) microbiological activity. A detailed study regarding the effect of non-homogeneous (depth dependent) forcing by bioirrigation shows that different patterns can appear in different depths
Miller-Sims, V., Atema, J., Kingsford, M. J., and Gerlach, G., Characterization and isolation of DNA microsatellite primers in the cardinalfish (Apogon doederleini), Mol Ecol Notes, vol. 4, no. 3. Wiley-Blackwell, pp. 336-338, Sep.-2004.
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Gerlach, G., Janzen, S., Beier, D., and Gross, R., Functional characterization of the BvgAS two-component system of Bordetella holmesii, Microbiology (Reading, England), vol. 150, no. Pt 11. pp. 3715-3729, Nov.-2004.
Abstract DOI
The BvgAS two-component system is the master regulator of virulence gene expression in the mammalian pathogens Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica. This paper reports the partial cloning and characterization of the bvgAS loci of the 'new' Bordetella species Bordetella holmesii, Bordetella trematum and Bordetella hinzii, which are increasingly recognized as opportunistic pathogens in humans. It is demonstrated that the cytoplasmic signalling domains of the BvgS histidine kinases of B. pertussis and B. holmesii are functionally interchangeable, while signal perception by the two sensor proteins seems to be different. Furthermore, it is shown that, despite the high similarity of the BvgA proteins of B. pertussis and B. holmesii, promoter recognition by the response regulator proteins differs substantially in these organisms
Mouritsen, H., Feenders, G., Liedvogel, M., and Kropp, W., Migratory birds use head scans to detect the direction of the earth's magnetic field, Current biology : CB, vol. 14, no. 21. pp. 1946-1949, Nov.-2004.
Abstract DOI
Night-migratory songbirds are known to use a magnetic compass , but how do they detect the reference direction provided by the geomagnetic field, and where is the sensory organ located? The most prominent characteristic of geomagnetic sensory input, whether based on visual patterns or magnetite-mediated forces , is the predicted symmetry around the north-south or east-west magnetic axis. Here, we show that caged migratory garden warblers perform head-scanning behavior well suited to detect this magnetic symmetry plane. In the natural geomagnetic field, birds move toward their migratory direction after head scanning. In a zero-magnetic field , where no symmetry plane exists, the birds almost triple their head-scanning frequency, and the movement direction after a head scan becomes random. Thus, the magnetic sensory organ is located in the bird's head, and head scans are used to locate the reference direction provided by the geomagnetic field
Cochran, W. W., Mouritsen, H., and Wikelski, M., Migrating songbirds recalibrate their magnetic compass daily from twilight cues, Science (New York, N.Y.), vol. 304, no. 5669. pp. 405-408, Apr.-2004.
Abstract DOI
Night migratory songbirds can use stars, sun, geomagnetic field, and polarized light for orientation when tested in captivity. We studied the interaction of magnetic, stellar, and twilight orientation cues in free-flying songbirds. We exposed Catharus thrushes to eastward-turned magnetic fields during the twilight period before takeoff and then followed them for up to 1100 kilometers. Instead of heading north, experimental birds flew westward. On subsequent nights, the same individuals migrated northward again. We suggest that birds orient with a magnetic compass calibrated daily from twilight cues. This could explain how birds cross the magnetic equator and deal with declination
Aisenbrey, S., Thumann, G., and Bartz-Schmidt, K. U., Two-year results after macular translocation with 360° retinotomy, The Macula. Springer Science + Business Media, pp. 115-121, 2004.
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Hoppe, F., Jank, E., Hein, A., and Lüth, T., Ein System zum navigierten Schneiden unter Ultraschallkontrolle, Bildverarbeitung für die Medizin 2004. Springer Science + Business Media, pp. 219-223, 2004.
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Venkataraman, V., Duda, T., Vardi, N., Koch, K. -W., and Sharma, R. K., Calcium-modulated guanylate cyclase transduction machinery in the photoreceptor--bipolar synaptic region, Biochemistry, vol. 42, no. 19. May-2003.
Abstract DOIFull Text
Hwang, J. -Y., Lange, C., Helten, A., Höppner-Heitmann, D., Duda, T., Sharma, R. K., and Koch, K. -W., Regulatory modes of rod outer segment membrane guanylate cyclase differ in catalytic efficiency and Ca(2+)-sensitivity, European journal of biochemistry / FEBS, vol. 270, no. 18. Sep.-2003.
Abstract DOIFull Text
Weiergräber, O. H., Senin, I. I., Philippov, P. P., Granzin, J., and Koch, K. -W., Impact of N-terminal myristoylation on the Ca2+-dependent conformational transition in recoverin, The Journal of biological chemistry, vol. 278, no. 25. Jun.-2003.
Abstract DOIFull Text
Senin, I. I., Vaganova, S. A., Weiergräber, O. H., Ergorov, N. S., Philippov, P. P., and Koch, K. -W., Functional restoration of the Ca2+-myristoyl switch in a recoverin mutant, Journal of molecular biology, vol. 330, no. 2. Jul.-2003.
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Ouzounov, D. G., Ahmad, F. R., Müller, D., Venkataraman, N., Gallagher, M. T., Thomas, M. G., Silcox, J., Koch, K. -W., and Gaeta, A. L., Generation of megawatt optical solitons in hollow-core photonic band-gap fibers, Science (New York, N.Y.), vol. 301, no. 5640. Sep.-2003.
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Smith, C. M., Venkataraman, N., Gallagher, M. T., Müller, D., West, J. A., Borrelli, N. F., Allan, D. C., and Koch, K. -W., Low-loss hollow-core silica/air photonic bandgap fibre, Nature, vol. 424, no. 6949. Aug.-2003.
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Dedek, K., Fusco, L., Teloy, N., and Steinlein, O. K., Neonatal convulsions and epileptic encephalopathy in an Italian family with a missense mutation in the fifth transmembrane region of KCNQ2, Epilepsy Research, vol. 54, no. 1. Elsevier BV, pp. 21-27, Apr.-2003.
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Neidhardt, J., Fehr, S., Kutsche, M., Löhler, J., and Schachner, M., Tenascin-N: characterization of a novel member of the tenascin family that mediates neurite repulsion from hippocampal explants, Molecular and Cellular Neuroscience, vol. 23, no. 2. Elsevier BV, pp. 193-209, Jun.-2003.
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Pottek, M., Hoppenstedt, W., Janssen-Bienhold, U., Schultz, K., Perlman, I., and Weiler, R., Contribution of connexin26 to electrical feedback inhibition in the turtle retina, J. Comp. Neurol., vol. 466, no. 4. Wiley-Blackwell, pp. 468-477, 13-Oct.-2003.
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Dick, O., tom Dieck, S., Altrock, W. D., Ammermüller, J., Weiler, R., Garner, C. C., Gundelfinger, E. D., and Brandstätter, J. H., The Presynaptic Active Zone Protein Bassoon Is Essential for Photoreceptor Ribbon Synapse Formation in the Retina, Neuron, vol. 37, no. 5. Elsevier BV, pp. 775-786, Mar.-2003.
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Ruigendijk, E. and Avrutin, S., The comprehension of pronouns and reflexives in agrammatic and Wernicke’s aphasia, Brain and Language, vol. 87, no. 1. Elsevier BV, pp. 17-18, Oct.-2003.
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Bastiaanse, R., Jonkers, R., Ruigendijk, E., and Van Zonneveld, R., Gender and Case in Agrammatic Production, Cortex, vol. 39, no. 3. Elsevier BV, pp. 405-417, Jan.-2003.
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Kranczioch, C., Debener, S., and Engel, A. K., Event-related potential correlates of the attentional blink phenomenon, Cognitive Brain Research, vol. 17, no. 1. Elsevier BV, pp. 177-187, Jun.-2003.
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Debener, S., Herrmann, C. S., Kranczioch, C., Gembris, D., and Engel, A. K., Top-down attentional processing enhances auditory evoked gamma band activity, NeuroReport, vol. 14, no. 5. Ovid Technologies (Wolters Kluwer Health), pp. 683-686, Apr.-2003.
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Aisenbrey, S. and Bartz-Schmidt, U., Macular translocation with 360-degree retinotomy for management of age-related macular degeneration with subfoveal choroidal neovascularization, American Journal of Ophthalmology, vol. 135, no. 5. Elsevier BV, pp. 748-749, May-2003.
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Lüke, C., Alteheld, N., Aisenbrey, S., Lüke, M., Bartz-Schmidt, K. U., Walter, P., and Kirchhof, B., Electro-oculographic findings after 360° retinotomy and macular translocation for subfoveal choroidal neovascularisation in age-related macular degeneration, Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 241, no. 9. Springer Science + Business Media, pp. 710-715, 23-Aug.-2003.
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Aisenbrey, S., Lüke, C., Ayertey, H. D., Grisanti, S., Perniok, A., and Brunner, R., Vogt–Koyanagi–Harada syndrome associated with cutaneous malignant melanoma: an 11-year follow-up, Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 241, no. 12. Springer Science + Business Media, pp. 996-999, 14-Nov.-2003.
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Sandner-Kiesling, A. and Bantel, C., New models for visceral pain, Current Opinion in Anaesthesiology, vol. 16, no. 5. Ovid Technologies (Wolters Kluwer Health), pp. 535-540, Oct.-2003.
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Bantel, C., Li, X., and C. Eisenach, J., Intraspinal Adenosine Induces Spinal Cord Norepinephrine Release in Spinal Nerve-ligated Rats but not in Normal or Sham Controls, Anesthesiology, vol. 98, no. 6. Ovid Technologies (Wolters Kluwer Health), pp. 1461-1466, Jun.-2003.
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Goldbaum, O., Oppermann, M., Handschuh, M., Dabir, D., Zhang, B., Forman, M. S., Trojanowski, J. Q., Lee, V. M. -Y., and Richter-Landsberg, C., Proteasome inhibition stabilizes tau inclusions in oligodendroglial cells that occur after treatment with okadaic acid, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 23, no. 26. pp. 8872-8880, Oct.-2003.
Abstract
Tau-positive inclusions in oligodendrocytes are consistent neuropathological features of corticobasal degeneration, progressive supranuclear palsy, and frontotemporal dementias with Parkinsonism linked to chromosome 17. Here we show by immunohistochemistry that tau-positive oligodendroglial inclusion bodies also contain the small heat-shock protein (HSP) alphaB-crystallin but not HSP70. To study the molecular mechanisms underlying inclusion body formation, we engineered an oligodendroglia cell line (OLN-t40) to overexpress the longest human tau isoform. Treatment of OLN-t40 cells with okadaic acid (OA), an inhibitor of protein phosphatase 2A, caused tau hyperphosphorylation and a decrease in the binding of tau to microtubules. Simultaneously, tau-positive aggregates that also stained with the amyloid-binding dye thioflavin-S as well as with antibodies to tau and alphaB-crystallin were detected. However, they were only transiently expressed and were degraded within 24 hr. When the proteasomal apparatus was inhibited by carbobenzoxy-l-leucyl-l-leucyl-l-leucinal (MG-132) after OA treatment, the aggregates were stabilized and were still detectable after 18 hr in the absence of OA. Incubation with MG-132 alone inhibited tau proteolysis and led to the induction of HSPs, including alphaB-crystallin and to its translocation to the perinuclear region, but did not induce the formation of thioflavin-S-positive aggregates. Hence, although tau hyperphosphorylation induced by protein phosphatase inhibition contributes to pathological aggregate formation, only hyperphosporylation of tau followed by proteasome inhibition leads to stable fibrillary deposits of tau similar to those observed in neurodegenerative diseases
Horiguchi, T., Uryu, K., Giasson, B. I., Ischiropoulos, H., LightFoot, R., Bellmann, C., Richter-Landsberg, C., Lee, V. M. -Y., and Trojanowski, J. Q., Nitration of tau protein is linked to neurodegeneration in tauopathies, The American journal of pathology, vol. 163, no. 3. pp. 1021-1031, Sep.-2003.
Abstract DOI
Oxidative and nitrative injury is implicated in the pathogenesis of Alzheimer's disease (AD) and Down syndrome (DS), but no direct evidence links this type of injury to the formation of neurofibrillary tau lesions. To address this, we generated a monoclonal antibody (mAb), n847, which recognizes nitrated tau and alpha-synuclein. n847 detected nitrated tau in the insoluble fraction of AD, corticobasal degeneration (CBD), and Pick's disease (PiD) brains by Western blots. Immunohistochemistry (IHC) showed that n847 labeled neurons in the hippocampus and neocortex of AD and DS brains. Double-label immunofluorescence with n847 and an anti-tau antibody revealed partial co-localization of tau and n847 positive tangles, while n847 immunofluorescence and Thioflavin-S double-staining showed that a subset of n847-labeled neurons were Thioflavin-S-positive. In addition, immuno-electron microscopy revealed that tau-positive filaments in tangle-bearing neurons were also labeled by n847 and IHC of other tauopathies showed that some of glial and neuronal tau pathologies in CBD, progressive supranuclear palsy, PiD, and frontotemporal dementia with parkinsonism linked to chromosome 17 also were n847-positive. Finally, nitrated and Thioflavin-S-positive tau aggregates were generated in a oligodendrocytic cell line after treatment with peroxynitrite. Taken together, these findings imply that nitrative injury is directly linked to the formation of filamentous tau inclusions
Parisi, J. and Rössler, O. E., Superluminality Paradox in Special Relativity, Physics Essays, vol. 16, no. 2. Physics Essays Publication, pp. 254-258, Jun.-2003.
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Raschke, M. B. and Lienau, C., Apertureless near-field optical microscopy: Tip–sample coupling in elastic light scattering, Applied Physics Letters, vol. 83, no. 24. AIP Publishing, p. 5089, 2003.
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Müller, R., Malyarchuk, V., and Lienau, C., Three-dimensional theory on light-induced near-field dynamics in a metal film with a periodic array of nanoholes, Physical Review B, vol. 68, no. 20. American Physical Society (APS), 18-Nov.-2003.
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Diederich, A., Decision making under conflict: Decision time as a measure of conflict strength, Psychonomic Bulletin & Review, vol. 10, no. 1. Springer Science + Business Media, pp. 167-176, Mar.-2003.
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Diederich, A., Colonius, H., Bockhorst, D., and Tabeling, S., Visual-tactile spatial interaction in saccade generation, Experimental brain research, vol. 148, no. 3. pp. 328-337, Feb.-2003.
Abstract
Saccadic reaction times to visual targets tend to be faster when non-visual stimuli are presented in close temporal or spatial proximity even if subjects are instructed to ignore the accessory input. The effect tends to decrease with increasing spatial distance between the stimuli. Multisensory interaction effects measured in neural structures involved in saccade generation have demonstrated a similar spatial dependence. The present study investigated visual-tactile interaction effects on saccadic reaction time using a focused attention paradigm. Compared to unimodal visual targets saccadic reaction time to bimodal stimuli was reduced by up to 30 ms. The effect was larger for ipsi- than for contralateral presentations, and it increased with the eccentricity of the visual target. The results are consistent with attributing part of the facilitation to a multisensory effect of bimodal neurons with overlapping visual and tactile receptive field structures in the deep layers of the superior colliculus
Diederich, A., MDFT account of decision making under time pressure, Psychonomic bulletin & review, vol. 10, no. 1. pp. 157-166, Mar.-2003.
Abstract DOI
In this paper, decision making under time pressure for multiattribute choice alternatives in a risky environment is investigated. A model, multiattribute decision field theory (MDFT), is introduced that describes both the dynamic and the stochastic nature of decision making and accounts for the observed changes in choice probabilities, including preference reversals as a function of time limit. An experiment in which five different time limits were imposed on the decision maker is presented to test the predictions of the model. It is shown that MDFT is able to account for the complex decision behavior observed in the data. Furthermore, MDFT is compared with the predictions of decision field theory (Busemeyer & Townsend, 1993; Roe, Busemeyer, & Townsend, 2001)
Feudel, U. and Grebogi, C., Why Are Chaotic Attractors Rare in Multistable Systems?, Physical Review Letters, vol. 91, no. 13. American Physical Society (APS), 25-Sep.-2003.
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Kraut, S. and Feudel, U., Enhancement of noise-induced escape through the existence of a chaotic saddle, Phys. Rev. E, vol. 67, no. 1. American Physical Society (APS), 28-Jan.-2003.
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Neumann, E., Sushko, I., Maistrenko, Y., and Feudel, U., Synchronization and desynchronization under the influence of quasiperiodic forcing, Phys. Rev. E, vol. 67, no. 2. American Physical Society (APS), 5-Feb.-2003.
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Freund, J. A., Schimansky-Geier, L., and Hänggi, P., Frequency and phase synchronization in stochastic systems, Chaos: An Interdisciplinary Journal of Nonlinear Science, vol. 13, no. 1. AIP Publishing, p. 225, 2003.
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Pöschel, T. and Freund, J. A., How to decide whether small samples comply with an equidistribution, Biosystems, vol. 69, no. 1. Elsevier BV, pp. 63-72, Apr.-2003.
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Mouritsen, H., Huyvaert, K. P., Frost, B. J., and Anderson, D. J., Waved albatrosses can navigate with strong magnets attached to their head, The Journal of experimental biology, vol. 206, no. Pt 22. pp. 4155-4166, Nov.-2003.
Abstract DOI
The foraging excursions of waved albatrosses Phoebastria irrorata during incubation are ideally suited for navigational studies because they navigate between their Galápagos breeding site and one specific foraging site in the upwelling zone of Peru along highly predictable, straight-line routes. We used satellite telemetry to follow free-flying albatrosses after manipulating magnetic orientation cues by attaching magnets to strategic places on the birds' heads. All experimental, sham-manipulated and control birds, were able to navigate back and forth from Galápagos to their normal foraging sites at the Peruvian coast over 1000 km away. Birds subjected to the three treatments did not differ in the routes flown or in the duration and speed of the trips. The interpretations and implications of this result depend on which of the current suggested magnetic sensory mechanisms is actually being used by the birds
Anderson, D. J., Huyvaert, K. P., Wood, D. R., Gillikin, C. L., Frost, B. J., and Mouritsen, H., At-sea distribution of waved albatrosses and the Galápagos Marine Reserve, Biological Conservation, vol. 110, no. 3. Elsevier BV, pp. 367-373, Apr.-2003.
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Wagner, E., Klump, G. M., and Hamann, I., Gap detection in Mongolian gerbils (Meriones unguiculatus), Hearing Research, vol. 176, no. 1-2. Elsevier BV, pp. 11-16, Feb.-2003.
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Günther, T., Lienau, C., Elsaesser, T., Glanemann, M., Axt, V. M., Kuhn, T., Eshlagi, S., and Wieck, A. D., Ultrafast coherent spectroscopy of a single quantum dot, Springer Series in Chemical Physics. Springer Science + Business Media, pp. 345-349, 2003.
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Basar-Eroglu, C., Hoff, E., Strüber, D., and Stadler, M., Multistabile Phänomene in der Neurokognitionsforschung, Neurobiologie der Psychotherapie. Schattauer, pp. 349-364, 2003.
Abstract
Duda, T. and Koch, K. -W., Molecular and Cellular Biochemistry, vol. 230, no. 1/2. Springer Science + Business Media, pp. 107-116, 2002.
Abstract DOIFull Text
Rod outer segment guanylate cyclase 1 (ROS-GC1) is a pivotal enzyme for vertebrate phototransduction and the systematically growing evidence point to its connection with processes other than phototransduction within and outside the retina. ROS-GC1 activity is regulated by Ca2+ in two opposite modes. This regulation is indirect and occurs through Ca2+-binding proteins. At nanomolar Ca2+ concentrations, ROS-GC1 is activated by GCAPs and at micromolar Ca2+-concentrations, by S100β and neurocalcin. The former mode operates in phototransduction and the latter was proposed to play a role in synaptic activity. The last possibility was supported by findings of ROS-GC1 expression not only in various retinal layers other than photoreceptor outer segments but also outside the retina, in pineal gland and olfactory bulb. If ROS-GC1 indeed is to play a role in neurotransmission its expression must be colocalized with its Ca2+-dependent regulators and with possible targets of an increased cyclic GMP concentration, cyclic nucleotide-gated channels or cyclic GMP-dependent protein kinase, in synaptic regions. In this review these aspects of ROS-GC1 expression in retina, pineal gland and olfactory bulb are discussed.
Koch, K. -W., Target recognition of guanylate cyclase by guanylate cyclase-activating proteins, Advances in experimental medicine and biology, vol. 514. 2002.
AbstractFull Text
Duda, T. and Koch, K. -W., Calcium-modulated membrane guanylate cyclase in synaptic transmission?, Molecular and cellular biochemistry, vol. 230, no. 1-2. Jan.-2002.
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Duda, T. and Koch, K. -W., Retinal diseases linked with photoreceptor guanylate cyclase, Molecular and cellular biochemistry, vol. 230, no. 1-2. Jan.-2002.
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Hwang, J. -Y. and Koch, K. -W., Calcium- and myristoyl-dependent properties of guanylate cyclase-activating protein-1 and protein-2, Biochemistry, vol. 41, no. 43. Oct.-2002.
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Hwang, J. Y. and Koch, K. -W., The myristoylation of the neuronal Ca2+ -sensors guanylate cyclase-activating protein 1 and 2, Biochimica et biophysica acta, vol. 1600, no. 1-2. Nov.-2002.
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Koch, K. -W., Duda, T., and Sharma, R. K., Photoreceptor specific guanylate cyclases in vertebrate phototransduction, Molecular and cellular biochemistry, vol. 230, no. 1-2. Jan.-2002.
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Censarek, P., Beyermann, M., and Koch, K. -W., Target recognition of apocalmodulin by nitric oxide synthase I peptides, Biochemistry, vol. 41, no. 27. Jul.-2002.
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Senin, I. I., Koch, K. -W., Akhtar, M., and Philippov, P. P., Ca2+-dependent control of rhodopsin phosphorylation: recoverin and rhodopsin kinase, Advances in experimental medicine and biology, vol. 514. 2002.
AbstractFull Text
Duda, T., Koch, K. -W., Venkataraman, V., Lange, C., Beyermann, M., and Sharma, R. K., Ca(2+) sensor S100beta-modulated sites of membrane guanylate cyclase in the photoreceptor-bipolar synapse, The EMBO journal, vol. 21, no. 11. Jun.-2002.
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Senin, I. I., Fischer, T., Komolov, K. E., Zinchenko, D. V., Philippov, P. P., and Koch, K. -W., Ca2+-myristoyl switch in the neuronal calcium sensor recoverin requires different functions of Ca2+-binding sites, The Journal of biological chemistry, vol. 277, no. 52. Dec.-2002.
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Janssen-Bienhold, U., Buschmann-Gebhardt, B., and Weiler, R., Phorbol Ester Binding Sites in the Fish Retina: Correlation with Stimulation of Endogenous Phosphorylation and Protein Kinase C Activation, Journal of Neurochemistry, vol. 65, no. 2. Wiley-Blackwell, pp. 744-753, 23-Nov.-2002.
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Mouritsen, H. and Frost, B. J., Virtual migration in tethered flying monarch butterflies reveals their orientation mechanisms, Proceedings of the National Academy of Sciences of the United States of America, vol. 99, no. 15. pp. 10162-10166, Jul.-2002.
Abstract DOI
A newly developed flight simulator allows monarch butterflies to fly actively for up to several hours in any horizontal direction while their fall migratory flight direction can be continuously recorded. From these data, long segments of virtual flight paths of tethered, flying, migratory monarch butterflies were reconstructed, and by advancing or retarding the butterflies' circadian clocks, we have shown that they possess a time-compensated sun compass. Control monarchs on local time fly approximately southwest, those 6-h time-advanced fly southeast, and 6-h time-delayed butterflies fly in northwesterly directions. Moreover, butterflies flown in the same apparatus under simulated overcast in natural magnetic fields were randomly oriented and did not change direction when magnetic fields were rotated. Therefore, these experiments do not provide any evidence that monarch butterflies use a magnetic compass during migration
Bastiaanse, R., Rispens, J., Ruigendijk, E., Rabadán, O. J., and Thompson, C. K., Verbs: some properties and their consequences for agrammatic Broca's aphasia, Journal of Neurolinguistics, vol. 15, no. 3-5. Elsevier BV, pp. 239-264, May-2002.
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Ruigendijk, E. and Bastiaanse, R., Two characteristics of agrammatic speech: Omission of verbs and omission of determiners, is there a relation?, Aphasiology, vol. 16, no. 4-6. Informa UK Limited, pp. 383-395, Apr.-2002.
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Debener, S., Strobel, A., Kürschner, K., Kranczioch, C., Hebenstreit, J., Maercker, A., Beauducel, A., and Brocke, B., Is auditory evoked potential augmenting/reducing affected by acute tryptophan depletion?, Biological Psychology, vol. 59, no. 2. Elsevier BV, pp. 121-133, Mar.-2002.
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Aisenbrey, S., Macular Translocation With 360° Retinotomy for Exudative Age-Related Macular Degeneration, Arch Ophthalmol, vol. 120, no. 4. American Medical Association (AMA), p. 451, 1-Apr.-2002.
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Cornely, O. A., Schmitz, K., and Aisenbrey, S., The first echinocandin: caspofungin, Mycoses, vol. 45, no. S3. Wiley-Blackwell, pp. 56-60, Apr.-2002.
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Bantel, C., Childers, S. R., and Eisenach, J. C., Role of Adenosine Receptors in Spinal G-Protein Activation after Peripheral Nerve Injury, Anesthesiology, vol. 96, no. 6. Ovid Technologies (Wolters Kluwer Health), pp. 1443-1449, Jun.-2002.
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Duflo, F., Li, X., Bantel, C., Pancaro, C., Vincler, M., and Eisenach, J. C., Peripheral Nerve Injury Alters the α2 Adrenoceptor Subtype Activated by Clonidine for Analgesia, Anesthesiology, vol. 97, no. 3. Ovid Technologies (Wolters Kluwer Health), pp. 636-641, Sep.-2002.
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Bantel, C., Tobin, J. R., Li, X., Childers, S. R., Chen, S. R., and Eisenach, J. C., Intrathecal Adenosine following Spinal Nerve Ligation in Rat, Anesthesiology, vol. 96, no. 1. Ovid Technologies (Wolters Kluwer Health), pp. 103-108, Jan.-2002.
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Thees, C., Scholz, M., Schaller, C., Gass, A., Pavlidis, C., Weyland, A., and Hoeft, A., Relationship between Intracranial Pressure and Critical Closing Pressure in Patients with Neurotrauma, Anesthesiology, vol. 96, no. 3. Ovid Technologies (Wolters Kluwer Health), pp. 595-599, Mar.-2002.
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Richter-Landsberg, C. and Besser, A., Effects of Organotins on Rat Brain Astrocytes in Culture, Journal of Neurochemistry, vol. 63, no. 6. Wiley-Blackwell, pp. 2202-2209, 23-Nov.-2002.
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Goldbaum, O. and Richter-Landsberg, C., Activation of PP2A-like phosphatase and modulation of tau phosphorylation accompany stress-induced apoptosis in cultured oligodendrocytes, Glia, vol. 40, no. 3. Wiley-Blackwell, pp. 271-282, 30-Oct.-2002.
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Sock, E., Leger, H., Kuhlbrodt, K., Schreiber, J., Enderich, J., Richter-Landsberg, C., and Wegner, M., Expression of Krox Proteins During Differentiation of the O-2A Progenitor Cell Line CG-4, Journal of Neurochemistry, vol. 68, no. 5. Wiley-Blackwell, pp. 1911-1919, 18-Nov.-2002.
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Plumb, J., Duprex, W. P., Cameron, C. H. S., Richter-Landsberg, C., Talbot, P., and McQuaid, S., Infection of human oligodendroglioma cells by a recombinant measles virus expressing enhanced green fluorescent protein, Journal of Neurovirology, vol. 8, no. 1. Springer Science + Business Media, pp. 24-34, Jan.-2002.
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Vollgraf, U., Wegner, M., and Richter-Landsberg, C., Activation of AP-1 and Nuclear Factor-κB Transcription Factors Is Involved in Hydrogen Peroxide-Induced Apoptotic Cell Death of Olligodendrocytes, Journal of Neurochemistry, vol. 73, no. 6. Wiley-Blackwell, pp. 2501-2509, 18-Jan.-2002.
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Fischer, T., Senin, I. I., Philippov, P. P., and Koch, K. -W., Application of Different Lipid Surfaces to Monitor Protein–Membrane Interactions by Surface Plasmon Resonance Spectroscopy, Spectroscopy, vol. 16, no. 3-4. Hindawi Publishing Corporation, pp. 271-279, 2002.
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Guenther, T., Lienau, C., Elsaesser, T., Glanemann, M., Axt, V. M., Kuhn, T., Eshlaghi, S., and Wieck, A. D., Coherent nonlinear optical response of single quantum dots studied by ultrafast near-field spectroscopy, Physical review letters, vol. 89, no. 5. p. 057401, Jul.-2002.
Abstract DOI
The nonlinear response of single GaAs quantum dots is studied in femtosecond near-field pump-probe experiments. At negative time delays, transient reflectivity spectra show pronounced oscillatory structure around the quantum dot exciton line, providing the first evidence for a perturbed free induction decay of the excitonic polarization. Phase-disturbing Coulomb interactions between the excitonic polarization and continuum excitations dominate the optical nonlinearity on ultrafast time scales. A theoretical analysis based on the semiconductor Bloch equations accounts for this behavior
Busemeyer, J. R. and Diederich, A., Survey of decision field theory, Mathematical Social Sciences, vol. 43, no. 3. Elsevier BV, pp. 345-370, Jul.-2002.
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Swait, J., Adamowicz, W., Hanemann, M., Diederich, A., Krosnick, J., Layton, D., Provencher, W., Schkade, D., and Tourangeau, R., Marketing Letters, vol. 13, no. 3. Springer Science + Business Media, pp. 195-205, 2002.
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Greschner, M., Bongard, M., Rujan, P., and Ammermüller, J., Retinal ganglion cell synchronization by fixational eye movements improves feature estimation, Nature neuroscience, vol. 5, no. 4. pp. 341-347, Apr.-2002.
Abstract DOI
Image movements relative to the retina are essential for the visual perception of stationary objects during fixation. Here we have measured fixational eye and head movements of the turtle, and determined their effects on the activity of retinal ganglion cells by simulating the movements on the isolated retina. We show that ganglion cells respond mainly to components of periodic eye movement that have amplitudes of roughly the diameter of a photoreceptor. Drift or small head movements have little effect. Driven cells that are located along contrast borders are synchronized, which reliably signals a preceding movement. In an artificial neural network, the estimation of spatial frequencies for various square wave gratings improves when timelocked to this synchronization. This could potentially improve stimulus feature estimation by the brain
Strüber, D. and Herrmann, C. S., MEG alpha activity decrease reflects destabilization of multistable percepts, Cognitive Brain Research, vol. 14, no. 3. Elsevier BV, pp. 370-382, Nov.-2002.
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Strüber, D. and Polich, J., P300 and slow wave from oddball and single-stimulus visual tasks: inter-stimulus interval effects, International Journal of Psychophysiology, vol. 45, no. 3. Elsevier BV, pp. 187-196, Sep.-2002.
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Kraut, S. and Feudel, U., Multistability, noise, and attractor hopping: The crucial role of chaotic saddles, Phys. Rev. E, vol. 66, no. 1. American Physical Society (APS), 26-Jul.-2002.
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Pohl, T., Feudel, U., and Ebeling, W., Bifurcations of a semiclassical atom in a periodic field, Phys. Rev. E, vol. 65, no. 4. American Physical Society (APS), 10-Apr.-2002.
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Titz, S., Kuhlbrodt, T., Rahmstorf, S., and Feudel, U., On freshwater-dependent bifurcations in box models of the interhemispheric thermohaline circulation, Tellus A. Co-Action Publishing, Jan.-2002.
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Pöschel, T. and Freund, J. A., Finite-sample frequency distributions originating from an equiprobability distribution, Phys. Rev. E, vol. 66, no. 2. American Physical Society (APS), 9-Aug.-2002.
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Naundorf, B. and Freund, J. A., Signal detection by means of phase coherence induced through phase resetting, Phys. Rev. E, vol. 66, no. 4. American Physical Society (APS), 9-Oct.-2002.
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Delaney, M., Follet, C., Ryan, N., Hanney, N., Lusk-Yablick, J., and Gerlach, G., Social Interaction and Distribution of Female Zebrafish (Danio rerio) in a Large Aquarium, Biological Bulletin, vol. 203, no. 2. JSTOR, p. 240, Oct.-2002.
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Dietz, P., Gerlach, G., and Beier, D., Identification of target genes regulated by the two-component system HP166-HP165 of Helicobacter pylori, Journal of bacteriology, vol. 184, no. 2. pp. 350-362, Jan.-2002.
Abstract DOI
Two-component systems are signal transduction systems which enable bacteria to regulate cellular functions in response to changing environmental conditions. In most cases regulation is accomplished on the transcriptional level by a response regulator protein, which, according to the phosphorylation state of its receiver domain, displays different affinities for its target promoters. Here we describe identification of genes regulated by the two-component system HP166-HP165 of Helicobacter pylori and characterization of the corresponding target promoters. We demonstrated that expression of the HP166-HP165 two-component system is negatively autoregulated under conditions favoring autophosphorylation of the histidine kinase. Furthermore, we found that response regulator HP166 activates transcription of genes encoding a protein family with an unknown function present in H. pylori 26695, as well as an operon composed of five H. pylori-specific genes. While open reading frame HP166 is an essential gene, the target genes of the response regulator are not required for growth under in vitro culture conditions
Friedl, T. and Klump, G. M., THE VOCAL BEHAVIOUR OF MALE EUROPEAN TREEFROGS (HYLA ARBOREA): IMPLICATIONS FOR INTER- AND INTRASEXUAL SELECTION, Behaviour, vol. 139, no. 1. Brill Academic Publishers, pp. 113-136, 1-Jan.-2002.
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Kittel, M., Wagner, E., and Klump, G. M., An estimate of the auditory-filter bandwidth in the Mongolian gerbil, Hearing Research, vol. 164, no. 1-2. Elsevier BV, pp. 69-76, Feb.-2002.
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Wade, A. R., Brewer, A. A., Rieger, J. W., and Wandell, B. A., Functional measurements of human ventral occipital cortex: retinotopy and colour, Philosophical transactions of the Royal Society of London. Series B, Biological sciences, vol. 357, no. 1424. pp. 963-973, Aug.-2002.
Abstract DOI
Human colour vision originates in the cone photoreceptors, whose spatial density peaks in the fovea and declines rapidly into the periphery. For this reason, one expects to find a large representation of the cone-rich fovea in those cortical locations that support colour perception. Human occipital cortex contains several distinct foveal representations including at least two that extend onto the ventral surface: a region thought to be critical for colour vision. To learn more about these ventral signals, we used functional magnetic resonance imaging to identify visual field maps and colour responsivity on the ventral surface. We found a visual map of the complete contralateral hemifield in a 4 cm(2) region adjacent to ventral V3; the foveal representation of this map is confluent with that of areas V1/2/3. Additionally, a distinct foveal representation is present on the ventral surface situated 3-5 cm anterior from the confluent V1/2/3 foveal representations. This organization is not consistent with the definition of area V8, which assumes the presence of a quarter field representation adjacent to V3v. Comparisons of responses to luminance-matched coloured and achromatic patterns show increased activity to the coloured stimuli beginning in area V1 and extending through the new hemifield representation and further anterior in the ventral occipital lobe
Ruigendijk, E., Case assignment as an explanation for determiner omission in German agrammatic speech, Theory and applications in speech pathology and therapy. John Benjamins Publishing Company, pp. 299-314, 2002.
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Thiel, S. and Hein, A., Systematic Integration of Variability into Product Line Architecture Design, Lecture Notes in Computer Science. Springer Science + Business Media, pp. 130-153, 2002.
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Strüber, D., Geschlecht und Kognition, Lebenswelt und Erleben. Beiträge zur Erfahrungspsychologie. Festschrift zum 65. Geburtstag von Gisla Gniech. Pabst Science Publishers, pp. 241-254, 2002.
Abstract
Fischer, T., Beyermann, M., and Koch, K. -W., Application of different surface plasmon resonance biosensor chips to monitor the interaction of the CaM-binding site of nitric oxide synthase I and calmodulin, Biochemical and biophysical research communications, vol. 285, no. 2. Jul.-2001.
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Hwang, Jy, Schlesinger, R., and Koch, K. -W., Calcium-dependent cysteine reactivities in the neuronal calcium sensor guanylate cyclase-activating protein 1, FEBS letters, vol. 508, no. 3. Nov.-2001.
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Müller, F., Vantler, M., Weitz, D., Eismann, E., Zoche, M., Koch, K. -W., and Kaupp, U., Ligand sensitivity of the 2 subunit from the bovine cone cGMP-gated channel is modulated by protein kinase C but not by calmodulin, The Journal of physiology, vol. 532, no. Pt 2. Apr.-2001.
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Schultz, K., Janssen-Bienhold, U., and Weiler, R., Selective synaptic distribution of AMPA and kainate receptor subunits in the outer plexiform layer of the carp retina, J. Comp. Neurol., vol. 435, no. 4. Wiley-Blackwell, pp. 433-449, 2001.
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Janssen-Bienhold, U., Schultz, K., Gellhaus, A., Schmidt, P., Ammermüller, J., and Weiler, R., Identification and localization of connexin26 within the photoreceptor-horizontal cell synaptic complex, Vis. Neurosci., vol. 18, no. 2. Cambridge University Press (CUP), pp. 169-178, Mar.-2001.
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Kamermans,, Fahrenfort,, Schultz,, Janssen-Bienhold, U., Sjoerdsma,, and Weiler, R., Hemichannel-mediated inhibition in the outer retina, Science (New York, N.Y.), vol. 292, no. 5519. pp. 1178-1180, May-2001.
Abstract DOI
An essential feature of the first synapse in the retina is a negative feedback pathway from horizontal cells to cones. Here we show that at this synapse, connexin26 forms hemichannels on horizontal cell dendrites near the glutamate release site of the cones. Blocking these hemichannels hyperpolarizes horizontal cells, modulates the Ca2+ channels of the cones, and abolishes all feedback-mediated responses. We propose a feedback mechanism in which the activity of the Ca2+ channels and the subsequent glutamate release of the cones are modulated by a current through these hemichannels. Because the current through the hemichannels depends on the polarization of the horizontal cells, their activity modulates the output of the cones
Langemann, U. and Klump, G. M., Signal detection in amplitude-modulated maskers. I. Behavioural auditory thresholds in a songbird, European Journal of Neuroscience, vol. 13, no. 5. Wiley-Blackwell, pp. 1025-1032, Mar.-2001.
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Roters, S., Aisenbrey, S., Severin, M., Konen, W., Seitz, H. M., and Krieglstein, G. K., Akanthamöbenkeratitis ohne Schmerzen12, Klin Monatsbl Augenheilkd, vol. 218, no. 8. Thieme Publishing Group, pp. 570-573, Aug.-2001.
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Lüke,, Aisenbrey, S., Lüke,, Marzella,, Bartz-Schmidt,, and Walter, Electrophysiological changes after 360 degrees retinotomy and macular translocation for subfoveal choroidal neovascularisation in age related macular degeneration, The British journal of ophthalmology, vol. 85, no. 8. pp. 928-932, Aug.-2001.
Abstract DOI
AIM: To evaluate electrophysiological changes after 360 degrees retinotomy and macular translocation for subfoveal choroidal neovascularisation in patients with age related macular degeneration (AMD). METHODS: A consecutive series of 32 patients suffering from subfoveal choroidal neovascularisation secondary to AMD underwent 360 degrees retinotomy and macular translocation. The ERG served as the main parameter of the study and was recorded 1 day before the translocation surgery and no earlier than 4 weeks after the silicone oil removal. RESULTS: The scotopic ERG amplitudes were significantly reduced after translocation surgery. Depending on the applied flash luminance the mean b-wave amplitude reduction of the scotopic ERG varied between 67% (0.2 cd.s/m2) and 74% (0.03 cd.s/m2). The a-waves and b-waves of the saturating light response decreased significantly by 46% and 59%, respectively. The photopic a-wave and b-wave amplitudes were significantly lower after the translocation surgery resulting in a mean reduction of 27% and 43%, respectively. CONCLUSIONS: Although macular translocation may provide the potential of preserving and even restoring vision in patients with subfoveal choroidal neovascular membranes secondary to AMD the present study indicates that a significant electrophysiological decrease is caused by surgical procedures associated with this technique. Further research is necessary to clarify if certain modifications of the surgical procedure are able to substantially reduce the neuroretinal trauma
Paqueron, X., Li, X., Bantel, C., Tobin, J. R., Voytko, M. L., and Eisenach, J. C., An Obligatory Role for Spinal Cholinergic Neurons in the Antiallodynic Effects of Clonidine after Peripheral Nerve Injury, Anesthesiology, vol. 94, no. 6. Ovid Technologies (Wolters Kluwer Health), pp. 1074-1081, Jun.-2001.
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Sörös, P., Knecht, S., Bantel, C., Imai, T., Wüsten, R., Pantev, C., Lütkenhöner, B., Bürkle, H., and Henningsen, H., Functional reorganization of the human primary somatosensory cortex after acute pain demonstrated by magnetoencephalography, Neuroscience Letters, vol. 298, no. 3. Elsevier BV, pp. 195-198, Feb.-2001.
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Hein, A., Bericht über die Robotik 2000 Konferenz, at - Automatisierungstechnik, vol. 49, no. 1/2001. Walter de Gruyter GmbH, Jan.-2001.
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Hein, A. and Lüth, T., Architektur und Anwendungen eines zugelassenen Medizinroboters (Architecture and Applications of an Approved Medical Robotic System), at - Automatisierungstechnik, vol. 49, no. 7/2001. Walter de Gruyter GmbH, Jan.-2001.
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Richter-Landsberg, C., Organization and functional roles of the cytoskeleton in oligodendrocytes, Microsc. Res. Tech., vol. 52, no. 6. Wiley-Blackwell, pp. 628-636, 2001.
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Goldbaum, O. and Richter-Landsberg, C., Stress proteins in oligodendrocytes: differential effects of heat shock and oxidative stress, Journal of Neurochemistry, vol. 78, no. 6. Wiley-Blackwell, pp. 1233-1242, 20-Dec.-2001.
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Zwingmann, C., Richter-Landsberg, C., and Leibfritz, D., 13C isotopomer analysis of glucose and alanine metabolism reveals cytosolic pyruvate compartmentation as part of energy metabolism in astrocytes, Glia, vol. 34, no. 3. Wiley-Blackwell, pp. 200-212, 2001.
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Gorath, M., Stahnke, T., Mronga, T., Goldbaum, O., and Richter-Landsberg, C., Developmental changes of tau protein and mRNA in cultured rat brain oligodendrocytes, Glia, vol. 36, no. 1. Wiley-Blackwell, pp. 89-101, 2001.
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Intonti, F., Emiliani, V., Lienau, C., Elsaesser, T., Nötzel, R., and Ploog, K. H., Near-field optical spectroscopy of localized and delocalized excitons in a single GaAs quantum wire, Physical Review B, vol. 63, no. 7. American Physical Society (APS), 30-Jan.-2001.
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Intonti, F., Emiliani, V., Lienau, C., Elsaesser, T., Savona, V., Runge, E., Zimmermann, R., Nötzel, R., and Ploog, K. H., Quantum Mechanical Repulsion of Exciton Levels in a Disordered Quantum Well, Physical Review Letters, vol. 87, no. 7. American Physical Society (APS), 25-Jul.-2001.
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Diederich, A., A Rational Reconstruction of Expert Judgments in Organ Allocation, Analyse & Kritik, vol. 23, no. 2. Walter de Gruyter GmbH, 1-Jan.-2001.
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Wallsten, T. S. and Diederich, A., Understanding pooled subjective probability estimates, Mathematical Social Sciences, vol. 41, no. 1. Elsevier BV, pp. 1-18, Jan.-2001.
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Strüber, D., Baar-Eroglu, C., Miener, M., and Stadler, M., EEG gamma-band response during the perception of Necker cube reversals, Visual Cognition, vol. 8, no. 3-5. Informa UK Limited, pp. 609-621, Jun.-2001.
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Rozenfeld, R., Freund, J. A., Neiman, A., and Schimansky-Geier, L., Noise-induced phase synchronization enhanced by dichotomic noise, Phys. Rev. E, vol. 64, no. 5. American Physical Society (APS), 18-Oct.-2001.
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Gerlach, G., von Wintzingerode, F., Middendorf, B., and Gross, R., Evolutionary trends in the genus Bordetella, Microbes and Infection, vol. 3, no. 1. Elsevier BV, pp. 61-72, Jan.-2001.
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Gerlach, G., Schardt, U., Eckmann, R., and Meyer, A., Kin-structured subpopulations in Eurasian perch (Perca fluviatilis L.), Heredity, vol. 86, no. 2. Nature Publishing Group, pp. 213-221, Feb.-2001.
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Bartmann, S. and Gerlach, G., Multiple Paternity and Similar Variance in Reproductive Success of Male and Female Wood Mice (Apodemus sylvaticus) Housed in an Enclosure, Ethology, vol. 107, no. 10. Wiley-Blackwell, pp. 889-899, 20-Oct.-2001.
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Klump, G. M. and Nieder, A., Release from masking in fluctuating background noise in a songbird's auditory forebrain, Neuroreport, vol. 12, no. 9. Ovid Technologies (Wolters Kluwer Health), pp. 1825-1829, Jul.-2001.
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Weiler, R., Pottek, M., Schultz, K., and Janssen-Bienhold, U., Chapter 21 Retinoic acid, a neuromodulator in the retina, Concepts and Challenges in Retinal Biology (Progress in Brain Research). Elsevier BV, pp. 309-318, 2001.
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Janssen-Bienhold, U., Schultz, K., Hoppenstedt, W., and Weiler, R., Chapter 6 Molecular diversity of gap junctions between horizontal cells, Concepts and Challenges in Retinal Biology (Progress in Brain Research). Elsevier BV, pp. 93-107, 2001.
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Freund, J. A., Neiman, A., and Schimansky-Geier, L., Stochastic resonance and noise-induced phase coherence, Stochastic Climate Models. Springer Science + Business Media, pp. 309-323, 2001.
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Strüber, D., Hoff, E., Mathes, B., and Basar-Eroglu, C., Multistabile Phänomene und ihre Bedeutung für die Untersuchung visueller Wahrnehmungsorganisation, Wahrnehmen und Erkennen. Festschrift zum 60. Geburtstag von Michael A. Stadler. Pabst Science Publishers, pp. 224-240, 2001.
Abstract
Koch, K. -W., Identification and characterization of calmodulin binding sites in cGMP-gated channel using surface plasmon resonance spectroscopy, Methods in enzymology, vol. 315. 2000.
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Duda, T., Venkataraman, V., Jankowska, A., Lange, C., Koch, K. -W., and Sharma, R., Impairment of the rod outer segment membrane guanylate cyclase dimerization in a cone-rod dystrophy results in defective calcium signaling, Biochemistry, vol. 39, no. 41. Oct.-2000.
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Kappler, J., Franken, S., Junghans, U., Hoffmann, R., Linke, T., Müller, H., and Koch, K. -W., Glycosaminoglycan-binding properties and secondary structure of the C-terminus of netrin-1, Biochemical and biophysical research communications, vol. 271, no. 2. May-2000.
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Okada, T. and Weiler, R., Multirecording of Ca2+ signals from inner retinal neurons evoked by light stimulation of photoreceptors, Vision Research, vol. 40, no. 15. Elsevier BV, pp. 1947-1954, Jul.-2000.
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Vaney, D. I. and Weiler, R., Gap junctions in the eye: evidence for heteromeric, heterotypic and mixed-homotypic interactions, Brain Research Reviews, vol. 32, no. 1. Elsevier BV, pp. 115-120, Mar.-2000.
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Weiler, R., Pottek, M., He, S., and Vaney, D. I., Modulation of coupling between retinal horizontal cells by retinoic acid and endogenous dopamine, Brain Research Reviews, vol. 32, no. 1. Elsevier BV, pp. 121-129, Mar.-2000.
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Göldenagel, M., Sühl, G., Plum, A., Traub, O., Teubner, B., Weiler, R., and Willecke, K., Expression patterns of connexin genes in mouse retina, J. Comp. Neurol., vol. 425, no. 2. Wiley-Blackwell, pp. 193-201, 2000.
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Pottek, M. and Weiler, R., Light-adaptive effects of retinoic acid on receptive field properties of retinal horizontal cells, European Journal of Neuroscience, vol. 12, no. 2. Wiley-Blackwell, pp. 437-445, Feb.-2000.
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He, S., Weiler, R., and Vaney, D. I., Endogenous dopaminergic regulation of horizontal cell coupling in the mammalian retina, J. Comp. Neurol., vol. 418, no. 1. Wiley-Blackwell, pp. 33-40, 28-Feb.-2000.
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Dermietzel,, Kremer,, Paputsoglu,, Stang,, Skerrett,, Gomes,, Srinivas,, Janssen-Bienhold, U., Weiler, R., Nicholson,, Bruzzone,, and Spray, Molecular and functional diversity of neural connexins in the retina, The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 20, no. 22. pp. 8331-8343, Nov.-2000.
Abstract
Electrical synapses (gap junctions) in neuronal circuits have become a major focus in the study of network properties such as synchronization and oscillation (Galarreta and Hestrin, 1999; Gibson et al., 1999). Despite the recent progress made in unraveling the contribution of gap junctions to network behavior, little is known about the molecular composition of the junctional constituents. By cloning gap junction proteins [connexins (Cxs)] from zebrafish retina and through functional expression, we demonstrate that the retina possesses a high degree of connexin diversity, which may account for differential functional properties of electrical synapses. Three new Cxs, designated as zebrafish Cx27.5 (zfCx27.5), zfCx44.1, and zfCx55.5, and the carp ortholog of mammalian Cx43 were cloned. By in situ hybridization and in situ RT-PCR, we demonstrate that the four fish connexin mRNAs show differential localization in the retina. Transient functional expression in paired Xenopus oocytes and in the neuroblastoma N2A cell line indicate an extreme range of electrophysiological properties of these connexins in terms of voltage dependence and unitary conductance. For instance, the new zfCx44.1 exhibited high sensitivity to voltage-induced closure with currents decaying rapidly for transjunctional potentials >10 mV, whereas zfCx55.5 channels showed an opposite voltage dependence in response to voltage steps of either polarity. Moreover, although zfCx44.1 channels showed unitary conductance as high as any previously reported for junctional channels (nearly 300 pS), zfCx55. 5 and zfCx27.5 exhibited much lower unitary conductances (<60 pS)
LAFAUT, B. A. R. T. A., AISENBREY, S. A. B. I. N. E., VAN DEN BROECKE, C. A. R. O. L. I. N. E., BARTZ-SCHMIDT, K. A. R. L. -U. L. R. I. C. H., and HEIMANN, K. L. A. U. S., POLYPOIDAL CHOROIDAL VASCULOPATHY PATTERN IN AGE-RELATED MACULAR DEGENERATION, Retina, vol. 20, no. 6. Ovid Technologies (Wolters Kluwer Health), p. 650, 2000.
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Lafaut, B. A., Aisenbrey, S., Den Broecke, C. V., Bartz-Schmidt, K. -U., and Heimann, K., POLYPOIDAL CHOROIDAL VASCULOPATHY PATTERN IN AGE-RELATED MACULAR DEGENERATION: A Clinicopathologic Correlation, Retina, vol. 20, no. 6. Ovid Technologies (Wolters Kluwer Health), pp. 650-654, Jun.-2000.
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Szurman, P., Di Tizio, F. M., Lafaut, B., Aisenbrey, S., Grisanti, S., Roters, S., and Bartz-Schmidt, K. U., Stellenwert der postoperativen Positionierung in der Chirurgie des idiopathischen Makulaforamens - Kontrollierte konsekutive Studie1, Klin Monatsbl Augenheilkd, vol. 217, no. 6. Thieme Publishing Group, pp. 351-355, Dec.-2000.
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Bantel, C., Li, X., and Eisenach, J. C., Room B, 10/16/2000 2: 00 PM - 4: 00 PM (PS) No Difference in Cerebrospinal Fluid Pharmacokinetics of Intrathecally Administered Adenosine in Normal Versus Spinal Nerve Ligated Rats, Anesthesiology, vol. 93, no. Supplement. Ovid Technologies (Wolters Kluwer Health), p. A-903, Sep.-2000.
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Lüth, T. and Hein, A., Medizinrobotik, it - Information Technology, vol. 42, no. 1. Walter de Gruyter GmbH, Jan.-2000.
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Weyland, A., Buhre, W., Grund, S., Ludwig, H., Kazmaier, S., Weyland, W., and Sonntag, H., Cerebrovascular Tone Rather Than Intracranial Pressure Determines the Effective Downstream Pressure of the Cerebral Circulation in the Absence of Intracranial Hypertension, Journal of Neurosurgical Anesthesiology, vol. 12, no. 3. Ovid Technologies (Wolters Kluwer Health), pp. 210-216, Jul.-2000.
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Richter-Landsberg, C., The oligodendroglia cytoskeleton in health and disease, Journal of Neuroscience Research, vol. 59, no. 1. Wiley-Blackwell, pp. 11-18, 1-Jan.-2000.
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Vogelsberg-Ragaglia,, Bruce,, Richter-Landsberg, C., Zhang,, Hong,, Trojanowski,, and Lee, Distinct FTDP-17 missense mutations in tau produce tau aggregates and other pathological phenotypes in transfected CHO cells, Molecular biology of the cell, vol. 11, no. 12. pp. 4093-4104, Dec.-2000.
Abstract DOI
Multiple tau gene mutations are pathogenic for hereditary frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), with filamentous tau aggregates as the major lesions in the CNS of these patients. Recent studies have shown that bacterially expressed recombinant tau proteins with FTDP-17 missense mutations cause functional impairments, i.e., a reduced ability of mutant tau to bind to or promote the assembly of microtubules. To investigate the biological consequences of FTDP-17 tau mutants and assess their ability to form filamentous aggregates, we engineered Chinese hamster ovary cell lines to stably express tau harboring one or several different FTDP-17 mutations and showed that different tau mutants produced distinct pathological phenotypes. For example, delta K, but not several other single tau mutants (e.g., V337 M, P301L, R406W), developed insoluble amorphous and fibrillar aggregates, whereas a triple tau mutant (VPR) containing V337M, P301L, and R406W substitutions also formed similar aggregates. Furthermore, the aggregates increased in size over time in culture. Significantly, the formation of aggregated delta K and VPR tau protein correlated with reduced affinity of these mutants to bind microtubules. Reduced phosphorylation and altered proteolysis was also observed in R406W and delta K tau mutants. Thus, distinct pathological phenotypes, including the formation of insoluble filamentous tau aggregates, result from the expression of different FTDP-17 tau mutants in transfected Chinese hamster ovary cells and implies that these missense mutations cause diverse neurodegenerative FTDP-17 syndromes by multiple mechanisms
Emiliani, V., Guenther, T., Lienau, C., Nötzel, R., and Ploog, K. H., Ultrafast near-field spectroscopy of quasi-one-dimensional transport in a single quantum wire, Physical Review B, vol. 61, no. 16. American Physical Society (APS), pp. R10583-R10586, 15-Apr.-2000.
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Müller, R. and Lienau, C., Propagation of femtosecond optical pulses through uncoated and metal-coated near-field fiber probes, Applied Physics Letters, vol. 76, no. 23. AIP Publishing, p. 3367, 2000.
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Strüber, D., Basar-Eroglu, C., Hoff, E., and Stadler, M., Reversal-rate dependent differences in the EEG gamma-band during multistable visual perception, International Journal of Psychophysiology, vol. 38, no. 3. Elsevier BV, pp. 243-252, Dec.-2000.
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Osinga, H. M. and Feudel, U., Boundary crisis in quasiperiodically forced systems, Physica D: Nonlinear Phenomena, vol. 141, no. 1-2. Elsevier BV, pp. 54-64, Jul.-2000.
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Feudel, U., Neiman, A., Pei, X., Wojtenek, W., Braun, H., Huber, M., and Moss, F., Homoclinic bifurcation in a Hodgkin-Huxley model of thermally sensitive neurons, Chaos (Woodbury, N.Y.), vol. 10, no. 1. pp. 231-239, Mar.-2000.
Abstract DOI
We study global bifurcations of the chaotic attractor in a modified Hodgkin-Huxley model of thermally sensitive neurons. The control parameter for this model is the temperature. The chaotic behavior is realized over a wide range of temperatures and is visualized using interspike intervals. We observe an abrupt increase of the interspike intervals in a certain temperature region. We identify this as a homoclinic bifurcation of a saddle-focus fixed point which is embedded in the chaotic attractors. The transition is accompanied by intermittency, which obeys a universal scaling law for the average length of trajectory segments exhibiting only short interspike intervals with the distance from the onset of intermittency. We also present experimental results of interspike interval measurements taken from the crayfish caudal photoreceptor, which qualitatively demonstrate the same bifurcation structure. (c) 2000 American Institute of Physics
Harr, B., Musolf, K., and Gerlach, G., Characterization and isolation of DNA microsatellite primers in wood mice (Apodemus sylvaticus, Rodentia), Molecular Ecology, vol. 9, no. 10. Wiley-Blackwell, pp. 1664-1665, Oct.-2000.
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Martin, Y., Gerlach, G., Schlötterer, C., and Meyer, A., Molecular Phylogeny of European Muroid Rodents Based on Complete Cytochrome b Sequences, Molecular Phylogenetics and Evolution, vol. 16, no. 1. Elsevier BV, pp. 37-47, Jul.-2000.
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Gerlach, G. and Musolf, K., Fragmentation of Landscape as a Cause for Genetic Subdivision in Bank Voles, Conservation Biology, vol. 14, no. 4. Wiley-Blackwell, pp. 1066-1074, 15-Aug.-2000.
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Gerlach, G., Derschum, H. S., Martin, Y., and Brinkmann, H., Characterization and isolation of DNA microsatellite primers in hyrax species (Procavia johnstoniandHeterohyrax brucei, hyracoidea), Molecular Ecology, vol. 9, no. 10. Wiley-Blackwell, pp. 1675-1677, Oct.-2000.
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Mouritsen, H. and Mouritsen, O., A Mathematical Expectation Model for Bird Navigation based on the Clock-and-Compass Strategy, Journal of Theoretical Biology, vol. 207, no. 2. Elsevier BV, pp. 283-291, Nov.-2000.
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Grothe, B. and Klump, G. M., Temporal processing in sensory systems, Current Opinion in Neurobiology, vol. 10, no. 4. Elsevier BV, pp. 467-473, Aug.-2000.
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Naguib, M., Klump, G. M., Hillmann, E., Grießmann, B., and Teige, T., Assessment of auditory distance in a territorial songbird: accurate feat or rule of thumb?, Animal Behaviour, vol. 59, no. 4. Elsevier BV, pp. 715-721, Apr.-2000.
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Gegenfurtner, K. R. and Rieger, J. W., Sensory and cognitive contributions of color to the recognition of natural scenes, Current Biology, vol. 10, no. 13. Elsevier BV, pp. 805-808, Jun.-2000.
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Ditzinger, T., Stadler, M., Strüber, D., and Kelso, J., Noise improves three-dimensional perception: Stochastic resonance and other impacts of noise to the perception of autostereograms, Physical Review E, vol. 62, no. 2. APS, 2000.
Hein, A., Schlick, M., and Vinga-Martins, R., Applying Feature Models in Industrial Settings, Software Product Lines. Springer Science + Business Media, pp. 47-70, 2000.
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Althaus, H. H. and Richter-Landsberg, C., Glial cells as targets and producers of neurotrophins, International Review of Cytology Volume 197. Elsevier BV, pp. 203-277, 2000.
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Klump, G. M., Sound Localization in Birds, Comparative Hearing: Birds and Reptiles. Springer Science + Business Media, pp. 249-307, 2000.
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Schrem, A., Lange, C., Beyermann, M., and Koch, K. -W., Identification of a domain in guanylyl cyclase-activating protein 1 that interacts with a complex of guanylyl cyclase and tubulin in photoreceptors, The Journal of biological chemistry, vol. 274, no. 10. Mar.-1999.
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Lange, C., Duda, T., Beyermann, M., Sharma, R., and Koch, K. -W., Regions in vertebrate photoreceptor guanylyl cyclase ROS-GC1 involved in Ca(2+)-dependent regulation by guanylyl cyclase-activating protein GCAP-1, FEBS letters, vol. 460, no. 1. Oct.-1999.
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Duda, T., Krishnan, A., Venkataraman, V., Lange, C., Koch, K. -W., and Sharma, R., Mutations in the rod outer segment membrane guanylate cyclase in a cone-rod dystrophy cause defects in calcium signaling, Biochemistry, vol. 38, no. 42. Oct.-1999.
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Duda, T., Venkataraman, V., Goraczniak, R., Lange, C., Koch, K. -W., and Sharma, R., Functional consequences of a rod outer segment membrane guanylate cyclase (ROS-GC1) gene mutation linked with Leber's congenital amaurosis, Biochemistry, vol. 38, no. 2. Jan.-1999.
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Körschen, H., Beyermann, M., Müller, F., Heck, M., Vantler, M., Koch, K. -W., Kellner, R., Wolfrum, U., Bode, C., Hofmann, K., and Kaupp, U., Interaction of glutamic-acid-rich proteins with the cGMP signalling pathway in rod photoreceptors, Nature, vol. 400, no. 6746. Aug.-1999.
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Ruigendijk, E., Zonneveld, R. van, and Bastiaanse, R., Case Assignment in Agrammatism, Journal of Speech Language and Hearing Research, vol. 42, no. 4. American Speech Language Hearing Association, p. 962, 1-Aug.-1999.
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Klump, G. M., Langemann, U., Hamann, I., and Nieder, A., Adaptations for hearing in background noise, J. Acoust. Soc. Am., vol. 105, no. 2. Acoustical Society of America (ASA), p. 1110, 1999.
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Buerkle, H., Bantel, C., Wuesten, R., Mae, M., and Van Aken, H., Continuing Inflammation Does Enhance Spinally Mediated Antinociception by Neostigmine in the Rat Model, Anesthesia & Analgesia, vol. 89, no. 1. Ovid Technologies (Wolters Kluwer Health), pp. 255-256, Jul.-1999.
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Mertes, N., Goeters, C., Bantel, C., Gullotta, F., and Van Aken, H., Brain Death during Anesthesia Due to Undiagnosed Meningeal Carcinomatosis of Gastric Adenocarcinoma, Anesthesiology, vol. 90, no. 2. Ovid Technologies (Wolters Kluwer Health), pp. 630-631, Feb.-1999.
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Buerkle, H., Pogatzki, E., Pauser, M., Bantel, C., Brodner, G., Mollhoff, T., and Van Aken, H., Experimental Arthritis in the Rat Does Not Alter the Analgesic Potency of Intrathecal or Intraarticular Morphine, Anesthesia & Analgesia, vol. 89, no. 2. Ovid Technologies (Wolters Kluwer Health), pp. 403-408, Aug.-1999.
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Knoblauch,, Rüdiger,, Schönfeld,, Driessen,, Schneider-Mergener,, and Bukau, Substrate specificity of the SecB chaperone, The Journal of biological chemistry, vol. 274, no. 48. pp. 34219-34225, Nov.-1999.
Abstract DOI
The bacterial chaperone SecB assists translocation of proteins across the inner membrane. The mechanism by which it differentiates between secretory and cytosolic proteins is poorly understood. To identify its binding motif, we screened 2688 peptides covering sequences of 23 proteins for SecB binding. The motif is approximately 9 residues long and is enriched in aromatic and basic residues, whereas acidic residues are disfavored. Its identification allows the prediction of binding regions within protein sequences with up to 87% accuracy. SecB-binding regions occur statistically every 20-30 residues. The occurrence and affinity of binding regions are similar in SecB-dependent and -independent secretory proteins and in cytosolic proteins, and SecB lacks specificity toward signal sequences. SecB cannot thus differentiate between secretory and non-secretory proteins via its binding specificity. This conclusion is supported by the finding that SecB binds denatured luciferase, thereby allowing subsequent refolding by the DnaK system. SecB may rather be a general chaperone whose involvement in translocation is mediated by interactions of SecB and signal sequences of SecB-bound preproteins with the translocation apparatus
Mielck, F., Stephan, H., Weyland, A., and Sonntag, H., Effects of One Minimum Alveolar Anesthetic Concentration Sevoflurane on Cerebral Metabolism, Blood Flow, and CO2 Reactivity in Cardiac Patients, Anesthesia & Analgesia, vol. 89, no. 2. Ovid Technologies (Wolters Kluwer Health), pp. 364-369, Aug.-1999.
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Aleksic, I., Baryalei, M. M., Schorn, B., Busch, T., Strauch, J., Weyland, A., and Dalichau, H., Heart Transplantation After Successful Donor Postpartum Pulmonary Embolectomy, Chest, vol. 115, no. 4. Elsevier BV, pp. 1202-1203, Apr.-1999.
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Buhre, W., Weyland, A., Kazmaier, S., Hanekop, G. G., Baryalei, M. M., Sydow, M., and Sonntag, H., Comparison of cardiac output assessed by pulse-contour analysis and thermodilution in patients undergoing minimally invasive direct coronary artery bypass grafting, Journal of Cardiothoracic and Vascular Anesthesia, vol. 13, no. 4. Elsevier BV, pp. 437-440, Aug.-1999.
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Mauermann, M., Uppenkamp, S., van Hengel, P. W. J., and Kollmeier, B., Evidence for the distortion product frequency place as a source of distortion product otoacoustic emission (DPOAE) fine structure in humans. I. Fine structure and higher-order DPOAE as a function of the frequency ratio f2/f1, J. Acoust. Soc. Am., vol. 106, no. 6. Acoustical Society of America (ASA), p. 3473, 1999.
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Mauermann, M., Uppenkamp, S., van Hengel, P. W. J., and Kollmeier, B., Evidence for the distortion product frequency place as a source of distortion product otoacoustic emission (DPOAE) fine structure in humans. II. Fine structure for different shapes of cochlear hearing loss, J. Acoust. Soc. Am., vol. 106, no. 6. Acoustical Society of America (ASA), p. 3484, 1999.
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Heinemann, D., Parisi, J., Waldl, H. -P., and Beyer, H. G., Energiemeteorologie, Physik Journal, vol. 55, no. 4. Wiley-Blackwell, pp. 47-50, Apr.-1999.
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Strüber, D. and Stadler, M., Differences in top - down influences on the reversal rate of different categories of reversible figures, Perception, vol. 28, no. 10. SAGE Publications, pp. 1185-1196, 1999.
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Kraut, S., Feudel, U., and Grebogi, C., Preference of attractors in noisy multistable systems, Phys. Rev. E, vol. 59, no. 5. American Physical Society (APS), pp. 5253-5260, 1-May-1999.
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Freund, J. A. and Schimansky-Geier, L., Diffusion in discrete ratchets, Phys. Rev. E, vol. 60, no. 2. American Physical Society (APS), pp. 1304-1309, 1-Aug.-1999.
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Nieder, A. and Klump, G. M., Time course of simultaneous masking in the starling's auditory forebrain, Experimental Brain Research, vol. 124, no. 3. Springer Science + Business Media, pp. 311-320, 15-Jan.-1999.
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Nieder, A. and Klump, G. M., Adjustable frequency selectivity of auditory forebrain neurons recorded in a freely moving songbird via radiotelemetry, Hearing Research, vol. 127, no. 1-2. Elsevier BV, pp. 41-54, Jan.-1999.
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Rieger, J. W. and Gegenfurtner, K. R., Contrast sensitivity and appearance in briefly presented illusory figures, Spatial Vision, vol. 12, no. 3. Brill Academic Publishers, pp. 329-344, 1-Jan.-1999.
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Başar-Eroğlu, C., Başar, E., Schürmann, M., Schütt, A., Strüber, D., Stadler, M., and Karakaş, S., Gamma-Band Responses in the Brain: Functional Significance, Brain Function and Oscillations II: Integrative Brain Function. Neurophysiology and Cognitive Processes. Springer, pp. 367-380, 1999.
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Müller, F. and Koch, K. -W., Calcium-binding proteins and nitric oxide in retinal function and disease, Acta anatomica, vol. 162, no. 2-3. 1998.
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Weitz, D., Zoche, M., Müller, F., Beyermann, M., Körschen, H., Kaupp, U., and Koch, K. -W., Calmodulin controls the rod photoreceptor CNG channel through an unconventional binding site in the N-terminus of the beta-subunit, The EMBO journal, vol. 17, no. 8. Apr.-1998.
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Baldridge, W. H., Vaney, D. I., and Weiler, R., The modulation of intercellular coupling in the retina, Seminars in Cell & Developmental Biology, vol. 9, no. 3. Elsevier BV, pp. 311-318, Jun.-1998.
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Janssen-Bienhold, U., Dermietzel, R., and Weiler, R., Distribution of Connexin43 immunoreactivity in the retinas of different vertebrates, J. Comp. Neurol., vol. 396, no. 3. Wiley-Blackwell, pp. 310-321, 6-Jul.-1998.
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Weiler, R., Schultz, K., Pottek, M., Tieding, S., and Janssen-Bienhold, U., Retinoic acid has light-adaptive effects on horizontal cells in the retina, Proceedings of the National Academy of Sciences, vol. 95, no. 12. Proceedings of the National Academy of Sciences, pp. 7139-7144, 9-Jun.-1998.
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Pogatzi, E., Bantel, C., Pauser, M., Van Aken, H., and Buerkle, H., EFFECTS OF PERIPHERAL VERSUS SPINAL MORPHINE ON THERMAL HYPERALGESIA IN THE RAT INFLAMED KNEE JOINT MODEL, Anesthesiology, vol. 89, no. Supplement. Ovid Technologies (Wolters Kluwer Health), p. 1090A, Sep.-1998.
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Kazmaier, S., Weyland, A., Buhre, W., Stephan, H., Rieke, H., Filoda, K., and Sonntag, H., Effects of Respiratory Alkalosis and Acidosis on Myocardial Blood Flow and Metabolism in Patients with Coronary Artery Disease, Anesthesiology, vol. 89, no. 4. Ovid Technologies (Wolters Kluwer Health), pp. 831-837, Oct.-1998.
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Richter-Landsberg, C. and Vollgraf, U., Mode of Cell Injury and Death after Hydrogen Peroxide Exposure in Cultured Oligodendroglia Cells, Experimental Cell Research, vol. 244, no. 1. Elsevier BV, pp. 218-229, Oct.-1998.
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Feudel, U., Witt, A., Lai, Y. -C., and Grebogi, C., Basin bifurcation in quasiperiodically forced systems, Phys. Rev. E, vol. 58, no. 3. American Physical Society (APS), pp. 3060-3066, 1-Sep.-1998.
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Pikovsky, A. and Feudel, U., Comment on “Strange nonchaotic attractors in autonomous and periodically driven systems”, Phys. Rev. E, vol. 56, no. 6. American Physical Society (APS), pp. 7320-7321, 1-Dec.-1998.
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Kuznetsov, S., Feudel, U., and Pikovsky, A., Renormalization group for scaling at the torus-doubling terminal point, Phys. Rev. E, vol. 57, no. 2. American Physical Society (APS), pp. 1585-1590, Feb.-1998.
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Mouritsen, H., Redstarts,Phoenicurus phoenicurus, can orient in a true-zero magnetic field, Animal Behaviour, vol. 55, no. 5. Elsevier BV, pp. 1311-1324, May-1998.
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Mouritsen, H., Modelling migration: the clock-and-compass model can explain the distribution of ringing recoveries, Animal Behaviour, vol. 56, no. 4. Elsevier BV, pp. 899-907, Oct.-1998.
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Lange, C. and Koch, K. -W., Calcium-dependent binding of recoverin to membranes monitored by surface plasmon resonance spectroscopy in real time, Biochemistry, vol. 36, no. 40. Oct.-1997.
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Zoche, M., Beyermann, M., and Koch, K. -W., Introduction of a phosphate at serine741 of the calmodulin-binding domain of the neuronal nitric oxide synthase (NOS-I) prevents binding of calmodulin, Biological chemistry, vol. 378, no. 8. Aug.-1997.
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POTTEK, M. A. R. K., SCHULTZ, K. O. N. R. A. D., and WEILER, R. E. T. O., Effects of Nitric Oxide on the Horizontal Cell Network and Dopamine Release in the Carp Retina, Vision Research, vol. 37, no. 9. Elsevier BV, pp. 1091-1102, May-1997.
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Plinkert, P. and Löwenheim, H., Trends and Perspectives in Minimally Invasive Surgery in Otorhinolaryngology-Head and Neck Surgery, The Laryngoscope, vol. 107, no. 11. Wiley-Blackwell, pp. 1483-1489, Nov.-1997.
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Brand, A., Leibfritz, D., Wolburg, H., and Richter-Landsberg, C., Neurochemical Research, vol. 22, no. 2. Springer Science + Business Media, pp. 123-131, 1997.
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Müller, R., Heinrich, M., Heck, S., Blohm, D., and Richter-Landsberg, C., Expression of microtubule-associated proteins MAP2 and tau in cultured rat brain oligodendrocytes, Cell and Tissue Research, vol. 288, no. 2. Springer Science + Business Media, pp. 239-249, 9-Apr.-1997.
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Parisi, J., Self-organization in semiconductor physics, Biosystems, vol. 42, no. 2-3. Elsevier BV, pp. 145-152, Jan.-1997.
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Parisi, J. and Rössler, O. E., Some remarks on the experimental realization of a mind machine, Biosystems, vol. 42, no. 2-3. Elsevier BV, pp. 207-208, Jan.-1997.
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Diederich, A., Dynamic Stochastic Models for Decision Making under Time Constraints, Journal of Mathematical Psychology, vol. 41, no. 3. Elsevier BV, pp. 260-274, Sep.-1997.
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Başar-Eroglu, C., Strüber, D., and Stadler, M., Frontal gamma band enhancement during a dynamic reversal pattern, International Journal of Psychophysiology, vol. 25, no. 1. Elsevier BV, p. 42, Jan.-1997.
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Feudel, U., Grebogi, C., and Ott, E., Phase-locking in quasiperiodically forced systems, Physics Reports, vol. 290, no. 1-2. Elsevier BV, pp. 11-25, Nov.-1997.
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Feudel, U. and Grebogi, C., Multistability and the control of complexity, Chaos: An Interdisciplinary Journal of Nonlinear Science, vol. 7, no. 4. AIP Publishing, p. 597, 1997.
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Witt, A., Feudel, U., and Pikovsky, A., Birth of strange nonchaotic attractors due to interior crisis, Physica D: Nonlinear Phenomena, vol. 109, no. 1-2. Elsevier BV, pp. 180-190, Nov.-1997.
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Gegenfurtner, K. R., Brown, J. E., and Rieger, J. W., Interpolation processes in the perception of real and illusory contours, Perception, vol. 26, no. 11. SAGE Publications, pp. 1445-1458, 1997.
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Richter-Landsberg, C., OLN-Cells: a New Oligodendroglia Cell Line with Impact for Cell Transplantation, Molecular Signaling and Regulation in Glial Cells. Springer Science + Business Media, pp. 342-356, 1997.
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Stadler, M., Kruse, P., and Strüber, D., Struktur und Bedeutung in kognitiven Systemen, Selbstorganisation in Psychologie und Psychiatrie. Springer Science + Business Media, pp. 33-56, 1997.
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Zoche, M., Bienert, M., Beyermann, M., and Koch, K. -W., Distinct molecular recognition of calmodulin-binding sites in the neuronal and macrophage nitric oxide synthases: a surface plasmon resonance study, Biochemistry, vol. 35, no. 26. Jul.-1996.
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Frins, S., Bönigk, W., Müller, F., Kellner, R., and Koch, K. -W., Functional characterization of a guanylyl cyclase-activating protein from vertebrate rods. Cloning, heterologous expression, and localization, The Journal of biological chemistry, vol. 271, no. 14. Apr.-1996.
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Weiler, R., Schultz, K., and Janssen-Bienhold, U., Ca2+-dependency of spinule plasticity at dendrites of retinal horizontal cells and its possible implication for the functional role of spinules, Vision Research, vol. 36, no. 24. Elsevier BV, pp. 3891-3900, Dec.-1996.
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McCarty,, Rüdiger,, Schönfeld,, Schneider-Mergener,, Nakahigashi,, Yura,, and Bukau, Regulatory region C of the E. coli heat shock transcription factor, sigma32, constitutes a DnaK binding site and is conserved among eubacteria, Journal of molecular biology, vol. 256, no. 5. pp. 829-837, Mar.-1996.
Abstract DOI
The E. coli heat shock response is regulated at the transcriptional level through stress-dependent controls of the heat shock promoter-specific sigma32 subunit of RNA polymerase. A key aspect of this regulation, the sensing of stress and transmission of this information to sigma32, involves the chaperone system formed by the DnaK, DnaJ and GrpE heat shock proteins. This system mediates stress- dependent controls of levels and activity of sigma32 which rely, at least in part, on direct association of DnaK and DnaJ with sigma32. We identified DnaK binding sites within the sigma32 sequence by probing a cellulose-bound peptide library scanning sigma32. Two sites with high affinity for DnaK, containing the motifs RKLFFNLR and LRNWRIVK, were located centrally and peripherally, respectively, to the region C of sigma32, previously implicated genetically in chaperone-dependent control of sigma32 levels. Cloning and sequencing of rpoH homologs from five Gram-negative proteobacteria revealed that region C, including the DnaK binding motif central to it, is highly conserved among sigma32 homologs but missing in the other sigma factors. We propose that binding of DnaK to region C is central to a conserved regulatory mechanism allowing the sensing of stress by the heat shock gene transcription machinery
Uppenkamp, S., Mauermann, M., and Kollmeier, B., On the relation of distortion product and transient evoked emission spectral fine structure., J. Acoust. Soc. Am., vol. 99, no. 4. Acoustical Society of America (ASA), p. 2562, 1996.
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Lienau, C. and Zewail, A. H., Solvation Ultrafast Dynamics of Reactions. 11. Dissociation and Caging Dynamics in the Gas-to-Liquid Transition Region, J. Phys. Chem., vol. 100, no. 48. American Chemical Society (ACS), pp. 18629-18649, Jan.-1996.
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Materny, A., Lienau, C., and Zewail, A. H., Solvation Ultrafast Dynamics of Reactions. 12. Probing along the Reaction Coordinate and Dynamics in Supercritical Argon, J. Phys. Chem., vol. 100, no. 48. American Chemical Society (ACS), pp. 18650-18665, Jan.-1996.
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Başar-Eroglu, C., Strüber, D., Kruse, P., Başar, E., and Stadler, M., Frontal gamma-band enhancement during multistable visual perception, International Journal of Psychophysiology, vol. 24, no. 1-2. Elsevier BV, pp. 113-125, Nov.-1996.
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Başar-Eroglu, C., Strüber, D., Schürmann, M., Stadler, M., and Başar, E., Gamma-band responses in the brain: a short review of psychophysiological correlates and functional significance, International Journal of Psychophysiology, vol. 24, no. 1-2. Elsevier BV, pp. 101-112, Nov.-1996.
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Lai, Y. -C., Feudel, U., and Grebogi, C., Scaling behavior of transition to chaos in quasiperiodically driven dynamical systems, Phys. Rev. E, vol. 54, no. 6. American Physical Society (APS), pp. 6070-6073, 1-Dec.-1996.
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Gerlach, G., Emigration mechanisms in feral house mice - a laboratory investigation of the influence of social structure, population density, and aggression, Behavioral Ecology and Sociobiology, vol. 39, no. 3. Springer Science + Business Media, pp. 159-170, 16-Sep.-1996.
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Kruse, P., Carmesin, H. -O., Pahlke, L., Strüber, D., and Stadler, M., Continuous phase transitions in the perception of multistable visual patterns, Biological cybernetics, vol. 75, no. 4. Springer, 1996.
Weiler, R., The Modulation of Gap Junction Permeability in the Retina, Gap Junctions in the Nervous System. Springer Science + Business Media, pp. 103-121, 1996.
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Basar-Eroglu, C., Basar, E., Karakas, S., Strüber, D., and Stadler, M., Distributed gamma response of the brain, V congresso nazionale della societa` italiana di psicofisiologia e VI giornata pavese di neurofisiologia clinica. Tipolitografia Trabella, pp. 121-130, 1996.
Abstract
Koch, K. -W., Control of photoreceptor proteins by Ca2+, Cell calcium, vol. 18, no. 4. Oct.-1995.
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Zoche, M. and Koch, K. -W., Purified retinal nitric oxide synthase enhances ADP-ribosylation of rod outer segment proteins, FEBS letters, vol. 357, no. 2. Jan.-1995.
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Ammermüller, J., Weiler, R., and Perlman, I., Short-term effects of dopamine on photoreceptors, luminosity- and chromaticity-horizontal cells in the turtle retina, Vis. Neurosci., vol. 12, no. 03. Cambridge University Press (CUP), p. 403, May-1995.
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Baldridge, W. H., Weiler, R., and Dowling, J. E., Dark-suppression and light-sensitization of horizontal cell responses in the hybrid bass retina, Vis. Neurosci., vol. 12, no. 04. Cambridge University Press (CUP), p. 611, Jul.-1995.
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Brockerhoff, S. E., Hurley, J. B., Janssen-Bienhold, U., Neuhauss, S. C., Driever, W., and Dowling, J. E., A behavioral screen for isolating zebrafish mutants with visual system defects., Proceedings of the National Academy of Sciences, vol. 92, no. 23. Proceedings of the National Academy of Sciences, pp. 10545-10549, 7-Nov.-1995.
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Weiler, R., Schultz, K., and Janssen-Bienhold, U., Retraction of Spinule-type Neurites from Carp Retinal Horizontal Cell Dendrites during Dark Adaptation Involves the Activation of Ca2+/Calmodulin-dependent Protein Kinase II, European Journal of Neuroscience, vol. 7, no. 9. Wiley-Blackwell, pp. 1914-1919, Sep.-1995.
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Weyland, A., Stephan, H., Grune, F., Weyland, W., and Sonntag, H., Effect of Ketanserin on Global Cerebral Blood Flow and Middle Cerebral Artery Flow Velocity, Anesthesia & Analgesia, vol. 80, no. 1. Ovid Technologies (Wolters Kluwer Health), pp. 64-70, Jan.-1995.
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Weyland, A., Reply, Journal of Cardiothoracic and Vascular Anesthesia, vol. 9, no. 5. Elsevier BV, p. 619, Oct.-1995.
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Feudel, U., Pikovsky, A. S., and Zaks, M. A., Correlation properties of a quasiperiodically forced two-level system, Phys. Rev. E, vol. 51, no. 3. American Physical Society (APS), pp. 1762-1769, 1-Mar.-1995.
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Pikovsky, A. S. and Feudel, U., Characterizing strange nonchaotic attractors, Chaos: An Interdisciplinary Journal of Nonlinear Science, vol. 5, no. 1. AIP Publishing, p. 253, 1995.
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Kuznetsov, S. P., Pikovsky, A. S., and Feudel, U., Birth of a strange nonchaotic attractor: A renormalization group analysis, Phys. Rev. E, vol. 51, no. 3. American Physical Society (APS), pp. R1629-R1632, 1-Mar.-1995.
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Scharmann, M. G., Klump, G. M., and Ehret, G., Discrimination training in a GO/NOGO-procedure alters the 2-deoxyglucose pattern in the starling's forebrain, Brain Research, vol. 682, no. 1-2. Elsevier BV, pp. 83-92, Jun.-1995.
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Gleich, O., Klump, G. M., and Dooling, R. J., Peripheral basis for the auditory deficit in Belgian Waterslager canaries (Serinus canarius), Hearing Research, vol. 82, no. 1. Elsevier BV, pp. 100-108, Jan.-1995.
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Klump, G. M., Studying Sound Localization in Frogs with Behavioral Methods, Methods in Comparative Psychoacoustics. Springer Science + Business Media, pp. 221-233, 1995.
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Klump, G. M., Sound Localization Studies in Non-specialized Birds, Methods in Comparative Psychoacoustics. Springer Science + Business Media, pp. 171-182, 1995.
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Basar-Eroglu, C., Strüber, D., Stadler, M., Kruse, P., and Greitschus, F., Slow positive potentials in the EEG during multistable visual perception, Ambiguity in Mind and Nature. Springer, pp. 389-405, 1995.
Abstract
Kruse, P., Strüber, D., and Stadler, M., The significance of perceptual multistability for research on cognitive self-organization, Ambiguity in Mind and Nature. Springer, pp. 69-83, 1995.
Abstract
Stadler, M., Kruse, P., and Strüber, D., Die Entstehung von Bedeutungen in kognitiven Systemen, Gestalttheorie als Forschungsperspektive: Festschrift zur Emeritierung von Manfred Sader. Lit-Verlag, pp. 75-115, 1995.
Abstract
Koch, K. -W., Calcium as modulator of phototransduction in vertebrate photoreceptor cells, Reviews of physiology, biochemistry and pharmacology, vol. 125. 1994.
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Koch, K. -W., Stecher, P., and Kellner, R., Bovine retinal rod guanyl cyclase represents a new N-glycosylated subtype of membrane-bound guanyl cyclases, European journal of biochemistry / FEBS, vol. 222, no. 2. Jun.-1994.
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Koch, K. -W., Lambrecht, H., Haberecht, M., Redburn, D., and Schmidt, H., Functional coupling of a Ca2+/calmodulin-dependent nitric oxide synthase and a soluble guanylyl cyclase in vertebrate photoreceptor cells, The EMBO journal, vol. 13, no. 14. Jul.-1994.
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Weiler, R., Spinules: a case for synaptic plasticity, Trends in Neurosciences, vol. 17, no. 1. Elsevier BV, p. 6, Jan.-1994.
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Mangel, S. C., Baldridge, W. H., Weiler, R., and Dowling, J. E., Threshold and chromatic sensitivity changes in fish cone horizontal cells following prolonged darkness, Brain Research, vol. 659, no. 1-2. Elsevier BV, pp. 55-61, Oct.-1994.
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Ammermüller, J., Oltrogge, M., and Janssen-Bienhold, U., Neurotensin-like immunoreactivity in locust supraesophageal ganglion and optic lobes, Brain Research, vol. 636, no. 1. Elsevier BV, pp. 40-48, Feb.-1994.
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Janssen-Bienhold, U., Wenzel, A., Hannken, T., and Weiler, R., Involvement of Metabotropic and lonotropic Glutamate Receptors in Inositol Polyphosphate Formation in Carp Retinal Slices, European Journal of Neuroscience, vol. 6, no. 12. Wiley-Blackwell, pp. 1897-1902, Dec.-1994.
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WEYLAND, W. O. L. F. G. A. N. G., WEYLAND, A. N. D. R. E. A. S., GEFELLER, O. L. A. F., AL-SOUFI, S. U. H. E. L., SYDOW, M. I. C. H. A. E. L., and BRAUN, U. L. R. I. C. H., A ventilator with an integrated gas-exchange monitoring function, Critical Care Medicine, vol. 22, no. 5. Ovid Technologies (Wolters Kluwer Health), pp. 864-871, May-1994.
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Hoeft, A., Schorn, B., Weyland, A., Scholz, M., Buhre, W., Stepanek, E., Allen, S. J., and Sonntag, H., Bedside Assessment of Intravascular Volume Status in Patients Undergoing Coronary Bypass Surgery, Anesthesiology, vol. 81, no. 1. Ovid Technologies (Wolters Kluwer Health), pp. 76-86, Jul.-1994.
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Weyland, A., Stephan, H., Kazmaier, S., Weyland, W., Schorn, B., Grune, F., and Sonntag, H., Flow Velocity Measurements as an Index of Cerebral Blood Flow, Anesthesiology, vol. 81, no. 6. Ovid Technologies (Wolters Kluwer Health), pp. 1401-1410, Dec.-1994.
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Sydow, M., Weyland, C., Kettler, D., Weyland, A., and Weyland, W., Inverses Ficksches Prinzip im Vergleich zu Messungen der Sauerstoffaufnahme aus respiratorischen Gasen, Der Anaesthesist, vol. 43, no. 10. Springer Science + Business Media, pp. 658-666, 1-Oct.-1994.
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Diederich, A., A Diffusion Model For Intersensory Facilitation of Reaction Time, Contributions to Mathematical Psychology, Psychometrics, and Methodology. Springer Science + Business Media, pp. 207-220, 1994.
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Pongs, O., Lindemeier, J., Zhu, X., Theil, T., Engelkamp, D., Krah-Jentgens, I., Lambrecht, H., Koch, K. -W., Schwemer, J., and Rivosecchi, R., Frequenin--a novel calcium-binding protein that modulates synaptic efficacy in the Drosophila nervous system, Neuron, vol. 11, no. 1. Jul.-1993.
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Kolbinger, W. and Weiler, R., Modulation of endogenous dopamine release in the turtle retina: Effects of light, calcium, and neurotransmitters, Vis. Neurosci., vol. 10, no. 06. Cambridge University Press (CUP), p. 1035, Nov.-1993.
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Weiler, R. and Kewitz, B., The marker for nitric oxide synthase, NADPH-diaphorase, co-localizes with GABA in horizontal cells and cells of the inner retina in the carp retina, Neuroscience Letters, vol. 158, no. 2. Elsevier BV, pp. 151-154, Aug.-1993.
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Weiler, and Schultz, Ionotropic non-N-methyl-D-aspartate agonists induce retraction of dendritic spinules from retinal horizontal cells, Proceedings of the National Academy of Sciences of the United States of America, vol. 90, no. 14. pp. 6533-6537, Jul.-1993.
Abstract DOI
Horizontal cells invaginate the photoreceptors in the retina and form reciprocal synaptic connections in the cone pedicles. In fish retina the pattern of synaptic connections is plastic and modulated by the ambient light conditions. Numerous dendritic spinules protrude from the terminal horizontal-cell dendrites into the cone pedicle when the retina is light-adapted and are retracted during dark adaptation. The retraction of spinules can be induced during maintained illumination by an injection of the putative cone transmitter L-glutamate or its analogue kainic acid into the vitreous humor. The formation and the retraction of spinules have a time course of minutes. Activation of protein kinase C through phorbol esters initiates the formation of spinules, but the retraction has not yet been linked to a specific second messenger. Herein we report that physiological concentrations of the glutamate analogs quisqualic acid and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid induce retraction of spinules during maintained illumination. (+/-)-trans-1-Amino-1,3-cyclopentanedicarboxylic acid, an agonist for the metabotropic quisqualic acid receptor, was without effect on spinule retraction. N-Methyl-D-aspartate and L-2-amino-4-phosphonobutyric acid, agonists at other types of glutamate receptors, were also without any effect. The effects of the active agonists persisted when synaptic transmission was blocked. In the presence of the ionotropic quisqualate receptor antagonist 6-cyclo-7-nitro-quinoxaline-2,3-dione the effects of all active agonists were blocked. These results demonstrate that activation of ionotropic quisqualate receptors on the horizontal-cell membrane can induce dendritic spinule retraction, a process associated with dark adaptation
Weiler, R. and Janssen-Bienhold, U., Spinule-type neurite outgrowth from horizontal cells during light adaptation in the carp retina: an actin-dependentprocess, Journal of Neurocytology, vol. 22, no. 2. Springer Science + Business Media, pp. 129-139, Feb.-1993.
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Janssen-Bienhold, U., Nagel, H., and Weiler, R., In VitroPhosphorylation in Isolated Horizontal Cells of the Fish Retina: Effects of the State of Light Adaptation, European Journal of Neuroscience, vol. 5, no. 6. Wiley-Blackwell, pp. 584-593, Jun.-1993.
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Parisi, J., Nonlinearities, Dynamics, and Fractals, Zeitschrift für Naturforschung A, vol. 48, no. 5-6. Walter de Gruyter GmbH, 1-Jan.-1993.
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Peinke, J., Richter, R., and Parisi, J., Spatial coherence of nonlinear dynamics in a semiconductor experiment, Physical Review B, vol. 47, no. 1. American Physical Society (APS), pp. 115-124, 1-Jan.-1993.
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Lienau, C., Heikal, A. A., and Zewail, A. H., Picosecond dynamics of n-hexane solvated trans-stilbene, Chemical Physics, vol. 175, no. 1. Elsevier BV, pp. 171-191, Sep.-1993.
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FEUDEL, F. R. E. D., FEUDEL, U. L. R. I. K. E., and BRANDENBURG, A. X. E. L., ON THE BIFURCATION PHENOMENA OF THE KURAMOTO–SIVASHINSKY EQUATION, Int. J. Bifurcation Chaos, vol. 03, no. 05. World Scientific Pub Co Pte Lt, pp. 1299-1303, Oct.-1993.
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Basar-eroglu, C., Strüber, D., Stadler, M., Kruse, P., and Basar, E., Multistable visual perception induces a slow positive EEG wave, International Journal of Neuroscience, vol. 73, no. 1-2. Taylor \& Francis, 1993.
Koch, K. -W., Biochemical mechanism of light adaptation in vertebrate photoreceptors, Trends in biochemical sciences, vol. 17, no. 8. Aug.-1992.
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Lambrecht, H. and Koch, K. -W., Recoverin, a novel calcium-binding protein from vertebrate photoreceptors, Biochimica et biophysica acta, vol. 1160, no. 1. Nov.-1992.
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Kaupp, U. and Koch, K. -W., Role of cGMP and Ca2+ in vertebrate photoreceptor excitation and adaptation, Annual review of physiology, vol. 54. 1992.
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Janssen-Bienhold, U. and Weiler, R., Molecular mechanisms underlying synaptic plasticity of horizontal cells in the fish retina, Experimental Eye Research, vol. 55. Elsevier BV, p. 227, Sep.-1992.
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Weiler, R. and Akopian, A., Effects of background illuminations on the receptive field size of horizontal cells in the turtle retina are mediated by dopamine, Neuroscience Letters, vol. 140, no. 1. Elsevier BV, pp. 121-124, Jun.-1992.
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Akopian, A., McReynolds, J., and Weiler, R., Activation of Protein Kinase C Modulates Light Responses in Horizontal Cells of the Turtle Retina, European Journal of Neuroscience, vol. 4, no. 8. Wiley-Blackwell, pp. 745-749, Aug.-1992.
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Langemann, U. and Klump, G. M., Frequency discrimination in the European starling (Sturnus vulgaris): A comparison of different measures, Hearing Research, vol. 63, no. 1-2. Elsevier BV, pp. 43-51, Nov.-1992.
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Stoklosinski, A., Kruse, H., Richter-Landsberg, C., and Rensing, L., Effects of heat shock on neuroblastoma (N1E 115) cell proliferation and differentiation, Experimental Cell Research, vol. 200, no. 1. Elsevier BV, pp. 89-96, May-1992.
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Peinke, J., Parisi, J., Rössler, O. E., and Stoop, R., Encounter with Chaos. Springer Science + Business Media, 1992.
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Peinke, J., Parisi, J., Rössler, O. E., and Stoop, R., Mathematical Background, Encounter with Chaos. Springer Science + Business Media, pp. 171-276, 1992.
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Peinke, J., Parisi, J., Rössler, O. E., and Stoop, R., Introductory Remarks, Encounter with Chaos. Springer Science + Business Media, pp. 1-8, 1992.
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Peinke, J., Parisi, J., Rössler, O. E., and Stoop, R., Nonlinear Dynamics, Encounter with Chaos. Springer Science + Business Media, pp. 42-170, 1992.
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Peinke, J., Parisi, J., Rössler, O. E., and Stoop, R., Semiconductor Physics, Encounter with Chaos. Springer Science + Business Media, pp. 9-41, 1992.
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Klump, G. M. and Gerhardt, H. C., Mechanisms and Function of Call-Timing in Male-Male Interactions in Frogs, Playback and Studies of Animal Communication. Springer Science + Business Media, pp. 153-174, 1992.
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Koch, K. -W., Purification and identification of photoreceptor guanylate cyclase, The Journal of biological chemistry, vol. 266, no. 13. May-1991.
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Lambrecht, H. and Koch, K. -W., Phosphorylation of recoverin, the calcium-sensitive activator of photoreceptor guanylyl cyclase, FEBS letters, vol. 294, no. 3. Dec.-1991.
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Lambrecht, H. and Koch, K. -W., A 26 kd calcium binding protein from bovine rod outer segments as modulator of photoreceptor guanylate cyclase, The EMBO journal, vol. 10, no. 4. Apr.-1991.
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Akopian, A., McReynolds, J., and Weiler, R., Short-term potentiation of off-responses in turtle horizontal cells, Brain Research, vol. 546, no. 1. Elsevier BV, pp. 132-138, Apr.-1991.
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Weiler, R., Ball, A. K., and Ammermüller, J., Chapter 1 Neurotransmitter systems in the turtle retina, Progress in Retinal Research, vol. 10. Elsevier BV, pp. 1-26, Jan.-1991.
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Weiler, R., Kohler,, and Janssen-Bienhold, U., Protein kinase C mediates transient spinule-type neurite outgrowth in the retina during light adaptation, Proceedings of the National Academy of Sciences of the United States of America, vol. 88, no. 9. pp. 3603-3607, May-1991.
Abstract DOI
Light and dark adaptation of the teleost retina is accompanied by a remarkable morphological rearrangement of the synaptic connections between photoreceptors and second-order neurons: during light adaptation, numerous new neurites, the so-called spinules, arise from the terminal dendrites of horizontal cells invaginating the cone pedicle, and during dark adaptation, these spinules are retracted. The formation of these spinules is paralleled by the appearance of color opponency in horizontal and ganglion cells, which led to the suggestion that these spinules are the site of the inhibitory synapses in the negative feedback loop between cones and horizontal cells. The formation of the spinules in the light and their disappearance in darkness have a time course of minutes and are modulated by the neurotransmitters dopamine and glutamate, respectively. Neurotransmitters can modulate neuronal processing through a variety of second messengers that activate protein kinases, resulting most commonly in protein phosphorylation. Herein we report that activation of protein kinase C by phorbol esters promotes the formation of new horizontal-cell spinules in animals kept in the dark. Partial inhibition of protein kinase C activation with sphingosines prevents the formation of new spinules during light adaptation but does not affect established spinules. The spinule-forming effect of phorbol esters is not mediated by dopaminergic neurons, since the effect is also seen in retinas depleted of dopaminergic neurons. Phorbol esters also initiate the formation of spinules in synaptically isolated horizontal cells, demonstrating that they have a direct action on these cells. In addition, isolated horizontal cells have substrate proteins that are phosphorylated in a protein kinase C-dependent manner
Fischer, I., Richter-Landsberg, C., and Safaei, R., Regulation of microtubule associated protein 2 (MAP2) expression by nerve growth factor in PC12 cells, Experimental Cell Research, vol. 194, no. 2. Elsevier BV, pp. 195-201, Jun.-1991.
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Stoop, R., Peinke, J., and Parisi, J., Phase transitions in experimental systems, Physica D: Nonlinear Phenomena, vol. 50, no. 3. Elsevier BV, pp. 405-411, Jul.-1991.
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Parisi, J., Global symmetry aspects of a compartmentalized reaction-diffusion system, Computers & Mathematics with Applications, vol. 22, no. 12. Elsevier BV, pp. 23-31, 1991.
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Klump, G. M. and Okanoya, K., Temporal modulation transfer functions in the European Starling (Sturnus vulgaris): I. Psychophysical modulation detection thresholds, Hearing Research, vol. 52, no. 1. Elsevier BV, pp. 1-11, Mar.-1991.
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Kruse, P., Stadler, M., and Strüber, D., Psychological modification and synergetic modelling of perceptual oscillations, Rhythms in Physiological Systems. Springer, pp. 299-311, 1991.
Abstract
Koch, K. -W., Eckstein, F., and Stryer, L., Stereochemical course of the reaction catalyzed by guanylate cyclase from bovine retinal rod outer segments, The Journal of biological chemistry, vol. 265, no. 17. Jun.-1990.
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Ball, A., Ammermüller, J., and Weiler, R., Evaluation of horseradish peroxidase as an intracellular stain in electrophysiological recording, Journal of Neuroscience Methods, vol. 31, no. 1. Elsevier BV, pp. 35-41, Jan.-1990.
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Weyland, W., Hartung, T., Weyland, A., Kolenda, H., and Braun, U., Epidural pethidine for postoperative analgesia after lumbar spine surgery, Pain, vol. 41. Ovid Technologies (Wolters Kluwer Health), p. S146, Jan.-1990.
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Gerlach, G., Dispersal mechanisms in a captive wild house mouse population (Mus domesticus Rutty), Biological Journal of the Linnean Society, vol. 41, no. 1-3. Wiley-Blackwell, pp. 271-277, Sep.-1990.
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Hausfater, G., Gerhardt, H. C., and Klump, G. M., Parasites and Mate Choice in Gray Treefrogs, Hyla versicolor , Am Zool, vol. 30, no. 2. Oxford University Press (OUP), pp. 299-312, May-1990.
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Buck, W. and Parisi, J., Temporal Behavior of the Breakdown of Superconductivity, Zeitschrift für Naturforschung A, vol. 44, no. 3. Walter de Gruyter GmbH, 1-Jan.-1989.
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