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Summary: Orientation selectivity in visual cortex
by fluctuation-controlled criticality
Louis Tao*, David Cai
, David W. McLaughlin§
, Michael J. Shelley§
, and Robert Shapley§
Courant Institute of Mathematical Sciences and §Center for Neural Science, New York University, New York, NY 10012; and *Department
of Mathematical Sciences, New Jersey Institute of Technology, Newark, NJ 07102
Contributed by David W. McLaughlin, June 30, 2006
Within a large-scale neuronal network model of macaque primary
visual cortex, we examined how intrinsic dynamic fluctuations in
synaptic currents modify the effect of strong recurrent excitation
on orientation selectivity. Previously, we showed that, using a
strong network inhibition countered by feedforward and recurrent
excitation, the cortical model reproduced many observed proper-
ties of simple and complex cells. However, that network's complex
cells were poorly selective for orientation, and increasing cortical
self-excitation led to network instabilities and unrealistically high
firing rates. Here, we show that a sparsity of connections in the
network produces large, intrinsic fluctuations in the cortico-cortical
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