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Surround suppression sharpens orientation tuning in the cat primary visual cortex
Author(s) -
Okamoto Masahiro,
Naito Tomoyuki,
Sadakane Osamu,
Osaki Hironobu,
Sato Hiromichi
Publication year - 2009
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2009.06645.x
Subject(s) - receptive field , surround suppression , visual cortex , stimulus (psychology) , neuroscience , grating , sharpening , stimulation , orientation (vector space) , orientation column , physics , psychology , optics , visual perception , striate cortex , mathematics , computer science , artificial intelligence , geometry , perception , psychotherapist
Abstract In the primary visual cortex (V1), the response of a neuron to stimulation of its classical receptive field (CRF) is suppressed by concurrent stimulation of the extraclassical receptive field (ECRF), a phenomenon termed ‘surround suppression’. It is also known that the orientation tuning of V1 neurons becomes sharper as the size of the stimulus increases beyond the CRF. However, there have been few quantitative investigations of the relationship between sharpening of orientation tuning and surround suppression. We examined this relationship in 73 V1 neurons recorded from anesthetized and paralysed cats using sinusoidal grating patches as stimuli. We found that sharpening of orientation tuning was significantly correlated with the strength of surround suppression for large stimuli that cover both CRF and ECRF. Furthermore, simulation analysis using a variety of tuning widths and most suppressive orientation of orientation‐tuned surround suppression demonstrated that broadly orientation‐tuned surround suppression sharpens orientation tuning for large gratings without shift in optimal orientation. Our findings suggest that one of the functional roles of surround suppression in V1 is enhancement of orientation discrimination for large and uniformly patterned objects.