HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Suder, K. Articles by Wennekers, T. Search for Related Content PubMed PubMed Citation Articles by Suder, K. Articles by Wennekers, T.

Neural Field Model of Receptive Field Restructuring in Primary Visual Cortex

Institute of Physiology, Department of Neurophysiology, Ruhr-University, D-44780 Bochum, Germany

Florentin Wörgötter

Institute of Physiology, Department of Neurophysiology, Ruhr-University, D-44780 Bochum, Germany

Thomas Wennekers

Max-Planck-Institute for Mathematics in the Sciences, D-04103 Leipzig, Germany

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 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.

This article has been cited by other articles:

				T. Wennekers Dynamic Approximation of Spatiotemporal Receptive Fields in Nonlinear Neural Field Models Neural Comput., August 1, 2002; 14(8): 1801 - 1825. [Abstract] [Full Text] [PDF]

				T. Wennekers Orientation Tuning Properties of Simple Cells in Area V1 Derived from an Approximate Analysis of Nonlinear Neural Field Models Neural Comput., August 1, 2001; 13(8): 1721 - 1747. [Abstract] [Full Text]