Perceptual grouping in striate cortical networks mediated by synchronization and desynchronization

Abstract

One advantage of cortical synchronization as a binding mechanism is its ability to account for phenomena such as perceptual grouping. Such a mechanism requires the ability to synchronize groups of cells and to desynchronize these groups from each other. We present a striate cortical model of perceptual grouping in which synchronization and desynchronization is carried out by a single, common mechanism. Cortical pyramidal cells and interneurons are simulated using multi-compartmental models. Cells in different orientation columns are inter-connected via two sets of long-distance connections that differ in axonal delays and spatial projections. The relative influence of these two connections determines whether synchronization or desynchronization occurs. Once one group of cells synchronizes, inputs from these cells facilitate synchronization in other orientation columns. We address the role of these synchronizing and desynchronizing connections in mediating perceptual grouping and metastable percepts.