Role of the visual environment in the formation of receptive fields according to the BCM theory

Abstract

The Bienenstock, Cooper, and Munro (BCM) theory of synaptic plasticity models the development of orientation selectivity and binocular interaction in primary visual cortex, and has successfully reproduced kitten visual deprivation experiments. To better compare the consequences of the BCM theory with experiment, the original abstraction of the visual environment is replaced in this chapter by real visual images. Circular regions from the left and right retinas covering the same visual space are used to generate input to a single BCM neuron. The lateral geniculate nucleus is assumed to simply relay signals generated in the retina to the visual cortex. Each ganglion selects an antagonistic center-surround receptive field generated by a difference of two Gaussians, and ganglion cell activity is restricted to be positive. This extension allows the BCM neuron to be trained and tested with static real two-dimensional images. The visual environment is represented by 24 gray scale natural images, which can be shifted across the artificial retinas. In this environment, the BCM neuron develops receptive similar to simple cells found in primary visual cortex. It displays adjacent excitatory and inhibitory bands, when tested with spot stimuli, and orientation selectivity when tested with bar stimuli.