The Role of Feedback in Shaping Neural Representations in Cat Visual Cortex

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....

Full description

Saved in:

Bibliographic Details
Published in:	Proceedings of the National Academy of Sciences - PNAS 2002-12, Vol.99 (26), p.17083-17088
Main Authors:	Ralf A. W. Galuske, Schmidt, Kerstin E., Goebel, Rainer, Lomber, Stephen G., Payne, Bertram R.
Format:	Article
Language:	eng
Subjects:	Animals Auditory cortex Biological Sciences Cats Cerebral Cortex - physiology Cooling Electrophysiology Eyes & eyesight Feedback - physiology Imaging Movement Neurology Neurons Neurons - physiology Neuroscience Pixels Visual cortex Visual Cortex - physiology Visual stimulation
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	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.
ISSN:	0027-8424 1091-6490