Movement-Dependent Spatial Expansion of Visual Receptive Fields of Neurons of the Extrastriate Cortex

Abstract

The spatial structure of the receptive field (RF) of a visually sensitive neuron, as defined by presentation of stationary visual stimuli, predetermines in most cases central processing of visual information concerning moving visual images. In our study, properties of a group of neurons in the extrastriate cortical area 21a (≈18% of the examined sampling) with extremely small RF sizes (≈1.5 deg2) determined by stationary visual stimuli were investigated. It was found that spatial dimensions of each neuronal RFs may undergo manifold expansions; the neuronal response profiles depended strongly on the size, shape, and contrast of the applied moving stimuli. As a result, a high degree of diversification of neuronal response patterns depending of the shapes and contrasts of applied moving stimuli was observed. These data confirm the suggestion that the RFs of neurons in the extrastriate area 21a undergo temporary dynamic changes due to activation of surrounding neuronal groups/networks by moving visual stimuli. Thus, it is evident that processing of visual information in the course of visual image recognition is realized by integrated activity of a complex of the corresponding cortical networks of visually sensitive neurons.