The simplest maximum entropy model for collective behavior in a neural network

TL;DR

This paper introduces a simple maximum entropy model based on global network activity distributions, revealing a near-critical thermodynamic state in retinal neuron responses to natural stimuli.

Contribution

It proposes an analytically tractable maximum entropy model based on global activity, differing from pairwise models, and links neural network behavior to a critical thermodynamic point.

Findings

Model accurately captures global activity distributions.

Retinal responses exhibit thermodynamics close to a critical point.

Entropy equals energy at the critical point.

Abstract

Recent work emphasizes that the maximum entropy principle provides a bridge between statistical mechanics models for collective behavior in neural networks and experiments on networks of real neurons. Most of this work has focused on capturing the measured correlations among pairs of neurons. Here we suggest an alternative, constructing models that are consistent with the distribution of global network activity, i.e. the probability that K out of N cells in the network generate action potentials in the same small time bin. The inverse problem that we need to solve in constructing the model is analytically tractable, and provides a natural "thermodynamics" for the network in the limit of large N. We analyze the responses of neurons in a small patch of the retina to naturalistic stimuli, and find that the implied thermodynamics is very close to an unusual critical point, in which the entropy (in proper units) is exactly equal to the energy.