13 - Response Synchronization, Gamma Oscillations, and Perceptual Binding in Cat Primary Visual Cortex

Abstract

This chapter examines the extent to which current concepts about the nature of cortical codes and representations can be generalized to striate cortex functions. The functions of primary visual cortex are not confined to feature extraction, but are an integral part of the constructivistic processes that underlay visual perception. In addition to the elaboration of response selectivity for elementary features and some of their conjunctions, striate cortex seems to play an active role in state-, context-, and attention-dependent selection and grouping of distributed responses as any other cortical area. Striate cortex also appears to share with other cortical areas the mechanisms of synaptic plasticity required for the experience-dependent formation of durable associations among distributed responses. The analysis of precise temporal relations between simultaneously recorded responses of several neurons also reveals the existence of highly dynamic, context-sensitive synchronization phenomena. Their numerous and close relations to perceptual processes suggest that they are not epiphenomenal but play an essential role in cortical processing and coding. The structure and function of the primary visual cortex offer itself as a highly suitable model for the analysis of general cortical functions.