title: The modular and integrative functional architecture of the human brain.
abstract: Network-based analyses of brain imaging data consistently reveal distinct modules and connector nodes with diverse global connectivity across the modules. How discrete the functions of modules are, how dependent the computational load of each module is to the other modules' processing, and what the precise role of connector nodes is for between-module communication remains underspecified. Here, we use a network model of the brain derived from resting-state functional MRI (rs-fMRI) data and investigate the modular functional architecture of the human brain by analyzing activity at different types of nodes in the network across 9,208 experiments of 77 cognitive tasks in the BrainMap database. Using an author-topic model of cognitive functions, we find a strong spatial correspondence between the cognitive functions and the network's modules, suggesting that each module performs a discrete cognitive function. Crucially, activity at local nodes within the modules does not increase in tasks that require more cognitive functions, demonstrating the autonomy of modules' functions. However, connector nodes do exhibit increased activity when more cognitive functions are engaged in a task. Moreover, connector nodes are located where brain activity is associated with many different cognitive functions. Connector nodes potentially play a role in between-module communication that maintains the modular function of the brain. Together, these findings provide a network account of the brain's modular yet integrated implementation of cognitive functions.
authors.affiliation: Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720; Department of Psychology, University of California, Berkeley, CA 94720; bertolero@berkeley.edu.
authors.forename: Maxwell A
authors.initials: MA
authors.lastname: Bertolero
authors.affiliation: Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119077; Clinical Imaging Research Centre, National University of Singapore, Singapore 117599; Singapore Institute for Neurotechnology, National University of Singapore, Singapore 117456; Memory Networks Programme, National University of Singapore, Singapore 119077.
authors.forename: B T Thomas
authors.initials: BT
authors.lastname: Yeo
authors.affiliation: Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720; Department of Psychology, University of California, Berkeley, CA 94720;
authors.forename: Mark
authors.initials: M
authors.lastname: D'Esposito
mesh_terms: D001921:Brain / Q000502:physiology*; D003071:Cognition; D006801:Humans; D008279:Magnetic Resonance Imaging
keywords: cognition; graph theory; hubs; modularity; network