Understanding MindBrain

 
 
Random Article


 
Latest Posts
 

Gamma oscillations mediate stimulus competition and attentional selection in a cortical network model

 

 
Overview
 

 
Summary
 
 
 
 
 


 


Bottom Line

Christoph Börgers, Steven Epstein, and Nancy J. Kopell Article in Proceedings of the National Academy of Science, USA Abstract Simultaneous presentation of multiple stimuli can reduce the firing rates of neurons in extrastriate visual cortex below the rate elicited by a single preferred stimulus. We describe computational results suggesting how this remarkable effect may arise from […]

0
Posted November 24, 2008 by Bernard J. Baars

 
Full Article
 
 

Christoph Börgers, Steven Epstein, and Nancy J. Kopell
Article in Proceedings of the National Academy of Science, USA

Abstract
Simultaneous presentation of multiple stimuli can reduce the firing rates of neurons in extrastriate visual cortex below the rate elicited by a single preferred stimulus. We describe computational results suggesting how this remarkable effect may arise from strong excitatory drive to a substantial local population of fast-spiking inhibitory interneurons, which can lead to a loss of coherence in that population and thereby raise the effectiveness of inhibition. We propose that in attentional states fast-spiking interneurons may be subject to a bath of inhibition resulting from cholinergic activation of a second class of inhibitory interneurons, restoring conditions needed for gamma rhythmicity. Oscillations and coherence are emergent features, not assumptions, in our model. The gamma oscillations in turn support stimulus competition. The mechanism is a form of “oscillatory selection,” in which neural interactions change phase relationships that regulate firing rates, and attention shapes those neural interactions.


Bernard J. Baars

 


0 Comments



Be the first to comment!


Leave a Response