The physics of brain network structure, function, and control

TL;DR

This paper reviews how physics-based models and theories help understand the brain's structural wiring, functional dynamics, and control mechanisms, with implications for treating mental health disorders.

Contribution

It synthesizes recent physics-inspired approaches to elucidate brain network architecture, dynamics, and control, highlighting open questions and future research directions.

Findings

Structural wiring follows principles of symmetry and energy minimization.

Neural activity propagates along structural connections, supporting complex dynamics.

Control models inform stimulation therapies for neurological and psychiatric disorders.

Abstract

The brain is a complex organ characterized by heterogeneous patterns of structural connections supporting unparalleled feats of cognition and a wide range of behaviors. New noninvasive imaging techniques now allow these patterns to be carefully and comprehensively mapped in individual humans and animals. Yet, it remains a fundamental challenge to understand how the brain's structural wiring supports cognitive processes, with major implications for the personalized treatment of mental health disorders. Here, we review recent efforts to meet this challenge that draw on intuitions, models, and theories from physics, spanning the domains of statistical mechanics, information theory, and dynamical systems and control. We begin by considering the organizing principles of brain network architecture instantiated in structural wiring under constraints of symmetry, spatial embedding, and energy minimization. We next consider models of brain network function that stipulate how neural activity propagates along these structural connections, producing the long-range interactions and collective dynamics that support a rich repertoire of system functions. Finally, we consider perturbative experiments and models for brain network control, which leverage the physics of signal transmission along structural wires to infer intrinsic control processes that support goal-directed behavior and to inform stimulation-based therapies for neurological disease and psychiatric disorders. Throughout, we highlight several open questions in the physics of brain network structure, function, and control that will require creative efforts from physicists willing to brave the complexities of living matter.