The excitatory-inhibitory branching process: a parsimonious view of cortical asynchronous states, excitability, and criticality

TL;DR

This paper introduces an extended branching process model with inhibitory nodes to better understand cortical asynchronous states, excitability, and criticality, capturing complex brain activity features in a unified, minimal framework.

Contribution

It presents a novel inhibitory-augmented branching process model that explains diverse cortical phenomena and spontaneous brain activity features.

Findings

Identifies an intermediate phase between quiescence and saturation.

Captures key features of asynchronous cortical states.

Explains empirical brain activity phenomena within a simple model.

Abstract

The branching process is the minimal model for propagation dynamics, avalanches and criticality, broadly used in neuroscience. A simple extension of it, adding inhibitory nodes, induces a much-richer phenomenology, including, an intermediate phase, between quiescence and saturation, that exhibits the key features of "asynchronous states" in cortical networks. Remarkably, in the inhibition-dominated case, it exhibits an extremely-rich phase diagram, that captures a wealth of non-trivial features of spontaneous brain activity, such as collective excitability, hysteresis, tilted avalanche shapes, and partial synchronization, allowing us to rationalize striking empirical findings within a common and parsimonious framework.