PASCAL - Pattern Analysis, Statistical Modelling and Computational Learning

Centre-surround interactions in response to natural scene stimulation in the primary visual cortex
Kun Guo, Robert Robertson, Sasan Mahmoodi and Malcolm Young
European Journal of Neuroscience Volume 21, pp. 536-548, 2004.

Abstract

Centre–surround interaction in the primary visual cortex (area V1) has been studied extensively using artificial, abstract stimulus patterns, such as bars, gratings and simple texture patterns. In this experiment, we extend the study of centre–surround interaction by using natural scene images. We systematically varied the contrast of natural image surrounds presented outside the classical receptive field (CRF), and recorded neuronal response to a natural image patch presented within the CRF in area V1 of awake, fixating macaques. For the majority of neurons (67 out of 111), the natural image surrounds profoundly modulated, mainly by suppressing, neuronal responses to CRF images. These modulatory effects started at the earliest stage of neuronal responses, and often depended on the contrast and higher-order structures of the surrounds. For 47 out of 67 neurons, randomising the phases of the Fourier spectrum of the natural image surround diminished the centre–surround interaction. Our results suggest that the centre– surround interaction in area V1 can be extended to natural vision, and is sensitive to the higher-order structures of natural scene images, such as image contours

EPrint Type:Article
Project Keyword:Project Keyword UNSPECIFIED
Subjects:Brain Computer Interfaces
ID Code:4247
Deposited By:Sasan Mahmoodi
Deposited On:20 December 2008