Max Planck Institute for Dynamics and Self-Organization -- Department for Nonlinear Dynamics and Network Dynamics Group
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BCCN Sonderseminar

Monday, 14.12.2009 14 c.t.

Oscillations and irregular firing in a multi‐area cortical network model for selective attention

by Prof. Dr. Albert Compte
from Theoretical Cortical Neurobiology Group, IDIBAPS, Barcelona, Spain

Contact person: Demian Battaglia

Location

Seminarraum Haus 2, 4. Stock (Bunsenstr.)

Abstract

Synchronization across cortical circuits has been implicated in selective attention, but its mechanism and computational role remain unclear. In this study, we examined gamma-band synchronization in a reciprocally connected loop model of spiking neurons between a sensory-type (MT) and an executive-type (prefrontal/parietal) cortical circuit. The model reproduces and clarifies multiple observed features of synchronization by top-down attention, in a dynamic regime characterized by the coexistence of oscillatory local field potential and highly irregular single cell firing. Top-down attentional inputs have a profound effect on network oscillatory dynamics while only modestly affecting single-neuron spiking statistics. In addition, attentional synchrony modulations are highly selective: Inter-areal neuronal coherence occurs only when there is a close match between the preferred feature of neurons, the attended feature and the presented stimulus, a prediction that is experimentally testable. When inter-areal coherence was abolished attention-induced gain modulations of sensory neurons were only slightly reduced. Therefore, our model reconciles the rate and synchronization effects, and suggests that coherence contributes to large-scale neuronal computation in the brain through modest enhancement of rate modulations.

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