title: Time-resolved resting-state brain networks.
abstract: Neuronal dynamics display a complex spatiotemporal structure involving the precise, context-dependent coordination of activation patterns across a large number of spatially distributed regions. Functional magnetic resonance imaging (fMRI) has played a central role in demonstrating the nontrivial spatial and topological structure of these interactions, but thus far has been limited in its capacity to study their temporal evolution. Here, using high-resolution resting-state fMRI data obtained from the Human Connectome Project, we mapped time-resolved functional connectivity across the entire brain at a subsecond resolution with the aim of understanding how nonstationary fluctuations in pairwise interactions between regions relate to large-scale topological properties of the human brain. We report evidence for a consistent set of functional connections that show pronounced fluctuations in their strength over time. The most dynamic connections are intermodular, linking elements from topologically separable subsystems, and localize to known hubs of default mode and fronto-parietal systems. We found that spatially distributed regions spontaneously increased, for brief intervals, the efficiency with which they can transfer information, producing temporary, globally efficient network states. Our findings suggest that brain dynamics give rise to variations in complex network properties over time, possibly achieving a balance between efficient information-processing and metabolic expenditure.
authors: Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health, Melbourne, VIC 3010, Australia;Melbourne School of Engineering, The University of Melbourne, Melbourne, VIC 3010, Australia; azalesky@unimelb.edu.au.
authors: Andrew
authors: A
authors: Zalesky
authors: Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health, Melbourne, VIC 3010, Australia;Monash Clinical and Imaging Neuroscience, School of Psychological Sciences and Monash Biomedical Imaging, Monash University, Melbourne, VIC 3168, Australia;
authors: Alex
authors: A
authors: Fornito
authors: Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; and.
authors: Luca
authors: L
authors: Cocchi
authors: QIMR Berghofer Medical Research Institute.
authors: Leonardo L
authors: LL
authors: Gollo
authors: QIMR Berghofer Medical Research Institute,The Royal Brisbane and Women's Hospital, andMetro North Mental Health, Brisbane, QLD 4029, Australia.
authors: Michael
authors: M
authors: Breakspear
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000502:physiology; D011859:Radiography
keywords: dynamic connectivity; network efficiency; time-dependent network