Competition through selective inhibitory synchrony

TL;DR

This paper introduces a modified winner-take-all (WTA) circuit that uses inhibitory synchrony to enable distributed competition across cortical areas, overcoming anatomical constraints and ensuring stability.

Contribution

It proposes a novel inhibitory synchrony mechanism allowing distributed WTAs to operate coherently across cortical space, supported by analytical and simulation validation.

Findings

Distributed WTAs can be coupled via synchronization.

Synchronization is faster than winner selection.

The proposed circuit is proven to be stable.

Abstract

Models of cortical neuronal circuits commonly depend on inhibitory feedback to control gain, provide signal normalization, and to selectively amplify signals using winner-take-all (WTA) dynamics. Such models generally assume that excitatory and inhibitory neurons are able to interact easily, because their axons and dendrites are co-localized in the same small volume. However, quantitative neuroanatomical studies of the dimensions of axonal and dendritic trees of neurons in the neocortex show that this co-localization assumption is not valid. In this paper we describe a simple modification to the WTA circuit design that permits the effects of distributed inhibitory neurons to be coupled through synchronization, and so allows a single WTA to be distributed widely in cortical space, well beyond the arborization of any single inhibitory neuron, and even across different cortical areas. We prove by non-linear contraction analysis, and demonstrate by simulation that distributed WTA sub-systems combined by such inhibitory synchrony are inherently stable. We show analytically that synchronization is substantially faster than winner selection. This circuit mechanism allows networks of independent WTAs to fully or partially compete with each other.