Time-resolved resting-state brain networks

A. Zalesky, A. Fornito, L. Cocchi, L. L. Gollo, M. Breakspear
2014 Proceedings of the National Academy of Sciences of the United States of America  
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 highresolution resting-state fMRI data obtained from
more » ... 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 frontoparietal 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. network efficiency | dynamic connectivity | time-dependent network
doi:10.1073/pnas.1400181111 pmid:24982140 pmcid:PMC4104861 fatcat:dfrcyksvtfc4ddv6xrz5cl4jq4