A Model of Temporal Encoding of Stimulus Orientation by Neuronal Responses in the Primary Visual Cortex

Abstract

It has been shown experimentally that the stimulus orientation that elicits the optimal response in an orientation column in the primary visual cortex (area V1) undergoes rapid systemic changes that last 10–100 ms. These changes allow different orientation columns to encode information from multiple items in the visual space (the so-called temporal encoding). However, the mechanism of these changes is still unknown. In addition, most of the modern biophysical models are unable to reproduce these changes; the peak orientation of their responses is constant over time. In this paper, we suggest a method to improve the firing-rate ring model of the orientation hypercolumn by replacing the spatial symmetric distribution of local connections with a spatial anti-symmetric distribution. As a result, we obtained a more perfect model that is capable of reproducing such changes. Moreover, their amplitude is proportional to the extent of asymmetry in the spatial distribution of local connections.