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The role of feedback in shaping neural representations in cat visual cortex.

Galuske, Ralf A. W. and Schmidt, Kerstin E. and Goebel, Rainer and Lomber, Stephen G. and Payne, Bertram R. :
The role of feedback in shaping neural representations in cat visual cortex.
In: Proceedings of the National Academy of Sciences of the United States of America, 99 (26) pp. 17083-8. ISSN 0027-8424
[Article] , (2002)

Abstract

In the primary visual cortex, neurons with similar response preferences are grouped into domains forming continuous maps of stimulus orientation and direction of movement. These properties are widely believed to result from the combination of ascending and lateral interactions in the visual system. We have tested this view by examining the influence of deactivating feedback signals descending from the visuoparietal cortex on the emergence of these response properties and representations in cat area 18. We thermally deactivated the dominant motion-processing region of the visuoparietal cortex and used optical and electrophysiological methods to assay neural activity evoked in area 18 by stimulation with moving gratings and fields of coherently moving randomly distributed dots. Feedback deactivation decreased signal strength in both orientation and direction maps and virtually abolished the global layout of direction maps, whereas the basic structure of the orientation maps was preserved. These findings could be accounted for by a selective silencing of highly direction-selective neurons and by the redirection of preferences of less selective neurons. Our data suggest that signals fed back from the visuoparietal cortex strongly contribute to the emergence of direction selectivity in early visual areas. Thus we propose that higher cortical areas have significant influence over fundamental neuronal properties as they emerge in lower areas.

Item Type: Article
Erschienen: 2002
Creators: Galuske, Ralf A. W. and Schmidt, Kerstin E. and Goebel, Rainer and Lomber, Stephen G. and Payne, Bertram R.
Title: The role of feedback in shaping neural representations in cat visual cortex.
Language: English
Abstract:

In the primary visual cortex, neurons with similar response preferences are grouped into domains forming continuous maps of stimulus orientation and direction of movement. These properties are widely believed to result from the combination of ascending and lateral interactions in the visual system. We have tested this view by examining the influence of deactivating feedback signals descending from the visuoparietal cortex on the emergence of these response properties and representations in cat area 18. We thermally deactivated the dominant motion-processing region of the visuoparietal cortex and used optical and electrophysiological methods to assay neural activity evoked in area 18 by stimulation with moving gratings and fields of coherently moving randomly distributed dots. Feedback deactivation decreased signal strength in both orientation and direction maps and virtually abolished the global layout of direction maps, whereas the basic structure of the orientation maps was preserved. These findings could be accounted for by a selective silencing of highly direction-selective neurons and by the redirection of preferences of less selective neurons. Our data suggest that signals fed back from the visuoparietal cortex strongly contribute to the emergence of direction selectivity in early visual areas. Thus we propose that higher cortical areas have significant influence over fundamental neuronal properties as they emerge in lower areas.

Journal or Publication Title: Proceedings of the National Academy of Sciences of the United States of America
Volume: 99
Number: 26
Divisions: 10 Department of Biology > Systems Neurophysiology
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10 Department of Biology
Date Deposited: 21 Feb 2012 13:23
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