The flexible brain.

Abstract

This scientific commentary refers to ‘Neural, electrophysiological and anatomical basis of brain-network variability and its characteristic changes in mental disorders’ by Zhang et al. (doi:10.1093/aww143). The vastness of the brain’s dynamic repertoire is one of the remarkable features of brain function, making it possible to adapt rapidly and efficiently to external task demands, implement novel behaviours, and switch from one task to another. Variability in the neural dynamics is, nonetheless, constrained and displays heterogeneous topography—specific regions appear more or less variable over time, both in terms of their activity time courses (Garrett et al. , 2011) and also in terms of their interactions with other brain regions (their functional connectivity). In this issue of Brain , Zhang and co-workers present a novel method for characterizing the temporal variability of a region’s functional connectivity profile [estimated from blood oxygen level-dependent (BOLD) functional MRI], relating this variability to the region’s electrophysiology (measured with electroencephalography; EEG) and to its macroscale structural connectivity (white-matter pathways), and further demonstrating its potential utility as a neural marker for mental disorders (Zhang et al. , 2016). The past decade has witnessed a burgeoning interest in the functional network architecture of the human brain. Most of these earlier studies have adopted a ‘static’ point of view, wherein functional connections between regions are characterized over long time scales, obscuring faster dynamics. More recently, however, it has become apparent that over the course of seconds to minutes, the human brain displays network-wide reconfigurations both at rest (Zalesky et al. , 2014) and during task performance (Braun et al. , 2015). These findings …