Quasi-Critical Brain Dynamics on a Non-Equilibrium Widom Line

TL;DR

This paper investigates whether the brain operates at a critical point by studying a neural network model, revealing optimal quasi-critical dynamics on the Widom line with implications for understanding brain activity and epilepsy.

Contribution

It introduces a non-equilibrium neural network model with an analytical mean-field approximation, characterizes its phase transition, and identifies a quasiperiodic phase linked to synchronous activity.

Findings

Maximal correlation length on the Widom line.

Identification of a quasiperiodic phase related to synchronization.

The phase diagram includes ordered, disordered, and quasiperiodic phases.

Abstract

Is the brain really operating at a critical point? We study the non-equilibrium properties of a neural network which models the dynamics of the neocortex and argue for optimal quasi-critical dynamics on the Widom line where the correlation length is maximal. We simulate the network and introduce an analytical mean-field approximation, characterize the non-equilibrium phase transition, and present a non-equilibrium phase diagram, which shows that in addition to an ordered and disordered phase, the system exhibits a quasiperiodic phase corresponding to synchronous activity in simulations which may be related to the pathological synchronization associated with epilepsy.