Differences in gamma frequencies across visual cortex restrict their possible use in computation

Neuronal oscillations in the gamma band (30-80 Hz) have been suggested to play a central role in feature binding or establishing channels for neural communication. For these functions, the gamma rhythm frequency must be consistent across neural assemblies encoding the features of a stimulus. Here we...

Full description

Saved in:
Bibliographic Details
Published in:Neuron (Cambridge, Mass.) Vol. 67; no. 5; p. 885
Main Authors: Ray, Supratim, Maunsell, John H R
Format: Journal Article
Language:English
Published: United States 09.09.2010
Subjects:
Action Potentials - physiology
Animals
Brain Mapping
Contrast Sensitivity - physiology
Electroencephalography
Entropy
Evoked Potentials, Visual - physiology
Eye Movements - physiology
Macaca mulatta
Male
Neurons - physiology
Numerical Analysis, Computer-Assisted
Pattern Recognition, Visual - physiology
Photic Stimulation - methods
Time Factors
Visual Cortex - cytology
Visual Cortex - physiology
Visual Pathways - physiology
Wakefulness
ISSN:1097-4199, 1097-4199
Online Access:Get more information
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Neuronal oscillations in the gamma band (30-80 Hz) have been suggested to play a central role in feature binding or establishing channels for neural communication. For these functions, the gamma rhythm frequency must be consistent across neural assemblies encoding the features of a stimulus. Here we test the dependence of gamma frequency on stimulus contrast in V1 cortex of awake behaving macaques and show that gamma frequency increases monotonically with contrast. Changes in stimulus contrast over time leads to a reliable gamma frequency modulation on a fast timescale. Further, large stimuli whose contrast varies across space generate gamma rhythms at significantly different frequencies in simultaneously recorded neuronal assemblies separated by as little as 400 microm, making the gamma rhythm a poor candidate for binding or communication, at least in V1. Instead, our results suggest that the gamma rhythm arises from local interactions between excitation and inhibition.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:1097-4199
1097-4199
DOI:10.1016/j.neuron.2010.08.004