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Recurrent Inhibition and Clustered Connectivity as a Basis for
Gabor-like Receptive Fields in the Visual Cortex
Silvio P. Sabatini
PSPC-Research Group
Department of Biophysical and Electronic Engineering-DIBE
University of Genova
Via Opera Pia 11a, 16145 Genova - ITALY
silvio@dibe.unige.it
Abstract
A continuous-space model of visual cortex interactions which, starting from
elongated Gaussian functions, leads to high-selective Gabor-like receptive
fields, is proposed. The model is based on intracortical inhibition
mechanisms occurring through medium-range clustered connections.
The analysis, carried out under the assumption of a linear superposition of
geniculate and intracortical contributions, shows how inhibition
enhances both spatial and spatial-frequency selectivity.
The effects of inhibition strength and of its spatial
organization on the properties of the resulting receptive
field are investigated. Specifically, the relationships between receptive
fields and
inhibition schemata are investigated by deriving analytical expressions
for their dependence and through a systematic numerical parametric
study.
The emergence of periodic receptive fields, as the ones observed in
neurophysiological measurements, is also evidenced in relation to the
clustered nature of the inhibitory schema.
Next: Introduction
Up: Lateral Interactions in the Cortex: Structure and Function
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