Does the brain behave like a (complex) network? I. Dynamics

TL;DR

This paper investigates whether the brain's activity genuinely exhibits network properties that influence its dynamics and function, beyond mere anatomical description, by analyzing the concept of 'networkness' in brain behavior.

Contribution

It introduces a formal definition of 'networkness' and explores how network structures may serve as fundamental organizational principles of brain activity.

Findings

Analysis of brain dynamics through network properties

Discussion on the role of network structure in brain function

Proposals for identifying genuine network-based organizational principles

Abstract

Graph theory is now becoming a standard tool in system-level neuroscience. However, endowing observed brain anatomy and dynamics with a complex network structure does not entail that the brain actually works as a network. Asking whether the brain behaves as a network means asking whether network properties count. From the viewpoint of neurophysiology and, possibly, of brain physics, the most substantial issues a network structure may be instrumental in addressing relate to the influence of network properties on brain dynamics and to whether these properties ultimately explain some aspects of brain function. Here, we address the dynamical implications of complex network, examining which aspects and scales of brain activity may be understood to genuinely behave as a network. To do so, we first define the meaning of networkness, and analyse some of its implications. We then examine ways in which brain anatomy and dynamics can be endowed with a network structure and discuss possible ways in which network structure may be shown to represent a genuine organisational principle of brain activity, rather than just a convenient description of its anatomy and dynamics.