Gain control from beyond the classical receptive field in primate primary visual cortex

Webb, Ben S. and Tinsley, Chris J. and Barraclough, Nick E. and Parker, Amanda and Derrington, Andrew M. (2003) Gain control from beyond the classical receptive field in primate primary visual cortex. Visual Neuroscience, 20 (3). pp. 221-230. ISSN 0952-5238 . (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1017/S0952523803203011

Abstract

Gain control is a salient feature of information processing throughout the visual system. Heeger (1991, 1992) described a mechanism that could underpin gain control in primary visual cortex (VI). According to this model, a neuron's response is normalized by dividing its output by the sum of a population of neurons, which are selective for orientations covering a broad range. Gain control in this scheme is manifested as a change in the semisaturation constant (contrast gain) of a VI neuron. Here we examine how flanking and annular gratings of the same or orthogonal orientation to that preferred by a neuron presented beyond the receptive field modulate gain in V1 neurons in anesthetized marmosets (Callithrix jacchus). To characterize how gain was modulated by surround stimuli, the Michaelis-Menten equation was fitted to response versus contrast functions obtained under each stimulus condition. The modulation of gain by surround stimuli was modelled best as a divisive reduction in response gain. Response gain varied with the orientation of surround stimuli, but was reduced most when the orientation of a large annular grating beyond the classical receptive field matched the preferred orientation of neurons. The strength of surround suppression did not vary significantly with retinal eccentricity or laminar distribution. In the mannoset, as in macaques (Angelucci et al., 2002a,b), gain control over the sort of distances reported here (up to 10 deg) may be mediated by feedback from extrastriate areas.

Item Type: Article
Subjects: B Philosophy. Psychology. Religion > BF Psychology
Divisions: Faculties > Social Sciences > School of Psychology
Depositing User: C.A. Simms
Date Deposited: 16 Jun 2008 16:47
Last Modified: 16 Jun 2014 11:28
Resource URI: http://kar.kent.ac.uk/id/eprint/4562 (The current URI for this page, for reference purposes)
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