Wörgötter, Florentin Andreas

[["dc.bibliographiccitation.firstpage","127"],["dc.bibliographiccitation.issue","2-3"],["dc.bibliographiccitation.journal","Reviews in the Neurosciences"],["dc.bibliographiccitation.lastpage","146"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Suder, Katrin"],["dc.contributor.author","Woergoetter, Florentin"],["dc.date.accessioned","2017-09-07T11:45:38Z"],["dc.date.available","2017-09-07T11:45:38Z"],["dc.date.issued","2011"],["dc.identifier.doi","10.1515/revneuro.2000.11.2-3.127"],["dc.identifier.gro","3151821"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8652"],["dc.language.iso","en"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","2191-0200"],["dc.title","The Control of Low-Level Information Flow in the Visual System"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","430"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Experimental Brain Research"],["dc.bibliographiccitation.lastpage","444"],["dc.bibliographiccitation.volume","144"],["dc.contributor.author","Suder, Katrin"],["dc.contributor.author","Funke, Klaus"],["dc.contributor.author","Zhao, Yongqiang"],["dc.contributor.author","Kerscher, Nicolas"],["dc.contributor.author","Wennekers, Thomas"],["dc.contributor.author","Woergoetter, Florentin"],["dc.date.accessioned","2017-09-07T11:45:25Z"],["dc.date.available","2017-09-07T11:45:25Z"],["dc.date.issued","2002"],["dc.description.abstract","We investigated how changes in the temporal firing rate of thalamocortical activity affect the spatiotemporal structure of receptive field (RF) subunits in cat primary visual cortex. Spike activity of 67 neurons (48 simple, 19 complex cells) was extracellulary recorded from area 17/18 of anesthetized and paralyzed cats. A total of 107 subfields (on/off) were mapped by applying a reverse correlation technique to the activity elicited by bright and dark rectangles flashed for 300 ms in a 20×10 grid. We found that the width of the (suprathreshold) discharge fields shrank on average by 22% during this 300-ms-long stimulus presentation time. Fifty-eight subfields (54%) shrank by more than 20% of peak width and only ten (less than 10%) showed a slight increase over time. The main size reduction took place 40–60 ms after response onset, which corresponded to the transition from transient peak firing to tonic visual activity in thalamocortical relay cells (TC). The experimentally obtained RFs were then fitted with the aid of a neural field model of the primary visual pathway. Assuming a Gaussian-shaped spatial sensitivity profile across the RF subfield width, the model allowed us to estimate the subthreshold RF (depolarization field, D-field) from the minimal discharge field (MDF). The model allowed us to test to what degree the temporal dynamics of thalamocortical activity contributes to the spatiotemporal changes of cortical RFs. To this end, we performed the fitting procedure either with a pure feedforward model or with a field model that also included intracortical feedback. Spatial and temporal parameters obtained from fits of the experimental RFs matched closely to those achieved by simulating a pure feedforward system with the field model but were not compatible with additional intracortical feedback. Thus, our results show that dot stimulation, which optimally excites thalamocortical cells, leads to a shrinkage with respect to the size of the RF subfield at the first transient response of visual cortical RFs which seems mainly due to a change in the thalamic firing pattern. In these experiments little or no influence from intracortical sources was observed, which, however, may play a role when using more complex visual stimuli."],["dc.identifier.doi","10.1007/s00221-002-1061-5"],["dc.identifier.gro","3151757"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8581"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","0014-4819"],["dc.title","Spatial dynamics of receptive fields in cat primary visual cortex related to the temporal structure of thalamocortical feedforward activity"],["dc.type","journal_article"],["dc.type.internalPublication","no"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","545"],["dc.bibliographiccitation.journal","Neurocomputing"],["dc.bibliographiccitation.lastpage","551"],["dc.bibliographiccitation.volume","32-33"],["dc.contributor.author","Suder, Katrin"],["dc.contributor.author","Wörgötter, Florentin"],["dc.contributor.author","Wennekers, Thomas"],["dc.date.accessioned","2017-09-07T11:45:23Z"],["dc.date.available","2017-09-07T11:45:23Z"],["dc.date.issued","2000"],["dc.description.abstract","Receptive fields (RFs) in V1 were found to be wider during synchronized than during non-synchronized EEG states, where, in addition, they can sharpen over time. These changes were suggested to be mainly driven by state-dependent LGN-firing patterns. Here we employ a neural field approach to analytically describe the changing cortical RFs. For pure feedforward networks expressions for spatio-temporal RFs are given, as well as expected time courses of RF-sizes. It turns out that, although the RF-size depends on time, the width of the underlying spatial potential profile is constant. The analytically derived point-spread functions are fitted to experimental data. Fit results provide estimates for model parameters consistent with literature data and support the hypothesis that the observed RF-sharpening is mainly LGN-driven."],["dc.identifier.doi","10.1016/s0925-2312(00)00211-3"],["dc.identifier.gro","3151762"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8587"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","0925-2312"],["dc.subject","Receptive fields; Neural field model; EEG; Cortex; LGN"],["dc.title","Neural field description of state-dependent visual receptive field changes"],["dc.type","journal_article"],["dc.type.internalPublication","no"],["dc.type.peerReviewed","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Neurocomputing"],["dc.bibliographiccitation.volume","34–35"],["dc.contributor.author","Suder, Katrin"],["dc.contributor.author","Wörgötter, Florentin"],["dc.date.accessioned","2017-11-22T13:43:16Z"],["dc.date.available","2017-11-22T13:43:16Z"],["dc.date.issued","2001"],["dc.format.extent","612–618"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/10201"],["dc.language.iso","en"],["dc.notes.status","new -primates"],["dc.title","Modeling motion induction to analyze connectivity in the early visual system"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","165"],["dc.bibliographiccitation.lastpage","188"],["dc.contributor.author","Wörgötter, Florentin"],["dc.contributor.author","Suder, Katrin"],["dc.contributor.author","Pugeault, Nicolas"],["dc.contributor.author","Funke, Klaus"],["dc.contributor.editor","Buracas, G. T."],["dc.contributor.editor","Ruksenas, O."],["dc.contributor.editor","Boyton, G. M."],["dc.contributor.editor","Albright, T. D."],["dc.date.accessioned","2017-11-22T13:04:43Z"],["dc.date.available","2017-11-22T13:04:43Z"],["dc.date.issued","2003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/10195"],["dc.language.iso","en"],["dc.notes.status","new -primates"],["dc.publisher","Springer"],["dc.publisher.place","Heidelberg"],["dc.relation.ispartof","Life and Behavioral Sciences"],["dc.title","Response characteristics in the lateral geniculate nucleus and their primary afferent influences on the visual cortex of cat. Modulation of Neuronal Responses: Implications for Active Vision"],["dc.type","book_chapter"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","331"],["dc.bibliographiccitation.journal","Proceedings of the ... British Neural Network Society Meeting"],["dc.bibliographiccitation.lastpage","336"],["dc.contributor.author","Suder, Katrin"],["dc.contributor.author","Funke, Klaus"],["dc.contributor.author","Woergoetter, Florentin"],["dc.contributor.editor","Niklasson, Lars"],["dc.contributor.editor","Bodén, Mikael"],["dc.contributor.editor","Ziemke, Tom"],["dc.date.accessioned","2017-09-07T11:45:26Z"],["dc.date.available","2017-09-07T11:45:26Z"],["dc.date.issued","1998"],["dc.description.abstract","Changing patterns in the EEG reflect changing states of attentiveness and are correlated to changes in the firing behavior of single cells. Prom experiments it is known that LGN cells of the Thalamus exhibit a tonic firing pattern during desynchronized EEG reflecting faithfully properties of a stimulus; whereas they are in a burst mode during synchronized EEG, which leads to a stereotype stimulus response. We introduce a model in which these changes in the neural temporal behavior lead to changes in the spatial characteristics of cortical receptive fields through variations in the effective connectivity between thalamic and cortical cells. This spatio-temporal receptive field restructuring reflects different modes of information processing and might be controlled by selective attention."],["dc.identifier.doi","10.1007/978-1-4471-1599-1_48"],["dc.identifier.gro","3151768"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8593"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.publisher","Springer"],["dc.publisher.place","London"],["dc.relation.conference","98 International Conference on Artificial Neural Networks"],["dc.relation.doi","10.1007/978-1-4471-1599-1"],["dc.relation.eventend","1998-09-04"],["dc.relation.eventlocation","Schweden"],["dc.relation.eventstart","1998-09-02"],["dc.relation.isbn","978-3-540-76263-8"],["dc.relation.ispartof","ICANN 98"],["dc.relation.issn","1431-6854"],["dc.title","State-dependent Spatio-temporal Restructuring of Receptive Fields in the Primary Visual Pathway"],["dc.type","conference_paper"],["dc.type.internalPublication","no"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","165"],["dc.bibliographiccitation.issue","6707"],["dc.bibliographiccitation.journal","Nature"],["dc.bibliographiccitation.lastpage","168"],["dc.bibliographiccitation.volume","396"],["dc.contributor.author","Wörgötter, Florentin"],["dc.contributor.author","Suder, Katrin"],["dc.contributor.author","Zhao, Yongqiang"],["dc.contributor.author","Kerscher, Nicolas"],["dc.contributor.author","Eysel, Ulf T."],["dc.contributor.author","Funke, Klaus"],["dc.date.accessioned","2017-09-07T11:45:32Z"],["dc.date.available","2017-09-07T11:45:32Z"],["dc.date.issued","1998"],["dc.description.abstract","To extract important information from the environment on a useful timescale, the visual system must be able to adapt rapidly to constantly changing scenes. This requires dynamic control of visual resolution, possibly at the level of the responses of single neurons. Individual cells in the visual cortex respond to light stimuli on particular locations (receptive fields) on the retina, and the structure of these receptive fields can change in different contexts1,2,3,4. Here we show experimentally that the shape of receptive fields in the primary visual cortex of anaesthetized cats undergoes significant modifications, which are correlated with the general state of the brain as assessed by electroencephalography: receptive fields are wider during synchronized states and smaller during non-synchronized states. We also show that cortical receptive fields shrink over time when stimulated with flashing light spots. Finally, by using a network model we account for the changing size of the cortical receptive fields by dynamically rescaling the levels of excitation and inhibition in the visual thalamus and cortex. The observed dynamic changes in the sizes of the cortical receptive field could be a reflection of a process that adapts the spatial resolution within the primary visual pathway to different states of excitability."],["dc.identifier.doi","10.1038/24157"],["dc.identifier.gro","3151806"],["dc.identifier.pmid","9823895"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8635"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","0028-0836"],["dc.title","State-dependent receptive-field restructuring in the visual cortex"],["dc.type","journal_article"],["dc.type.internalPublication","no"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","139"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Neural Computation"],["dc.bibliographiccitation.lastpage","159"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Suder, Katrin"],["dc.contributor.author","Wennekers, Thomas"],["dc.contributor.author","Wörgötter, Florentin"],["dc.date.accessioned","2017-11-22T10:46:45Z"],["dc.date.available","2017-11-22T10:46:45Z"],["dc.date.issued","2001"],["dc.description.abstract","Receptive fields (RF) in the visual cortex can change their size depending on the state of the individual. This reflects a changing visual resolution according to different demands on information processing during drowsiness. So far, however, the possible mechanisms that underlie these size changes have not been tested rigorously. Only qualitatively has it been suggested that state-dependent lateral geniculate nucleus (LGN) firing patterns (burst versus tonic firing) are mainly responsible for the observed cortical receptive field restructuring. Here, we employ a neural field approach to describe the changes of cortical RF properties analytically. Expressions to describe the spatiotemporal receptive fields are given for pure feedforward networks. The model predicts that visual latencies increase nonlinearly with the distance of the stimulus location from the RF center. RF restructuring effects are faithfully reproduced. Despite the changing RF sizes, the model demonstrates that the width of the spatial membrane potential profile (as measured by the variance sigma of a gaussian) remains constant in cortex. In contrast, it is shown for recurrent networks that both the RF width and the width of the membrane potential profile generically depend on time and can even increase if lateral cortical excitatory connections extend further than fibers from LGN to cortex. In order to differentiate between a feedforward and a recurrent mechanism causing the experimental RF changes, we fitted the data to the analytically derived point-spread functions. Results of the fits provide estimates for model parameters consistent with the literature data and support the hypothesis that the observed RF sharpening is indeed mainly driven by input from LGN, not by recurrent intracortical connections."],["dc.identifier.pmid","11177431"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/10189"],["dc.language.iso","en"],["dc.notes.status","new -primates"],["dc.title","Neural field model of receptive field restructuring in primary visual cortex"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]