Journal article

Spontaneous brain network activity: Analysis of its temporal complexity

Mangor Pedersen, Amir Omidvarnia, Jennifer M Walz, Andrew Zalesky, Graeme D Jackson



The brain operates in a complex way. The temporal complexity underlying macroscopic and spontaneous brain network activity is still to be understood. In this study, we explored the brain's complexity by combining functional connectivity, graph theory, and entropy analyses in 25 healthy people using task-free functional magnetic resonance imaging. We calculated the pairwise instantaneous phase synchrony between 8,192 brain nodes for a total of 200 time points. This resulted in graphs for which time series of clustering coefficients (the "cliquiness" of a node) and participation coefficients (the between-module connectivity of a node) were estimated. For these two network metrics, sample entro..

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Awarded by 16 National Institutes of Health (NIH)

Awarded by National Health and Medical Research Council (NHMRC) of Australia

Awarded by NHMRC

Funding Acknowledgements

Data were provided by the Human Connectome Project, WU-Minn Consortium (1U54MH091657; principal investigators David Van Essen and Kamil Ugurbil), funded by the 16 National Institutes of Health (NIH) institutes and centers that support the NIH Blueprint for Neuroscience Research; and by the McDonnell Center for Systems Neuroscience at Washington University. We thank Mira Semmelroch, Donna Parker, and Magdalena Kowalczyk for assistance with the fMRI data acquisition. This study was supported by the National Health and Medical Research Council (NHMRC) of Australia (#628952). The Florey Institute of Neuroscience and Mental Health acknowledges strong support from the Victorian Government, and in particular, funding from the Operational Infrastructure Support Grant. We also acknowledge the facilities and the scientific and technical assistance of the National Imaging Facility at the Florey node. G.J. is supported by an NHMRC practitioner's fellowship (#1060312) and has received honoraria from UCB and royalties from Elsevier for Magnetic Resonance in Epilepsy, 2nd edition.