A Dynamic Core Network and Global Efficiency in the Resting Human Brain.
Spontaneous brain activity is spatially and temporally organized in the absence of any stimulation or task in networks of cortical and subcortical regions that appear largely segregated when imaged at slow temporal resolution with functional magnetic resonance imaging (fMRI). When imaged at high temporal resolution with magneto-encephalography (MEG), these resting-state networks (RSNs) show correlated fluctuations of band-limited power in the beta frequency band (14-25 Hz) that alternate between epochs of strong and weak internal coupling. This study presents 2 novel findings on the fundamental issue of how different brain regions or networks interact in the resting state. First, we demonstrate the existence of multiple dynamic hubs that allow for across-network coupling. Second, dynamic network coupling and related variations in hub centrality correspond to increased global efficiency. These findings suggest that the dynamic organization of across-network interactions represents a property of the brain aimed at optimizing the efficiency of communication between distinct functional domains (memory, sensory-attention, motor). They also support the hypothesis of a dynamic core network model in which a set of network hubs alternating over time ensure efficient global communication in the whole brain.
Institute for Advanced Biomedical Technologies, Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University, Chieti, Italy.
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de Pasquale
Institute for Advanced Biomedical Technologies, Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University, Chieti, Italy.
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Della Penna
Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA.
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Sporns
Institute for Advanced Biomedical Technologies, Department of Neuroscience, Imaging and Clinical Sciences, "G. D'Annunzio" University, Chieti, Italy.
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Romani
Departments of Neurology, Radiology, Anatomy and Neurobiology, Washington University School of Medicine, Saint Louis, MO, USA ITAB, University of Chieti, Chieti, Italy.
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Corbetta
D000328:Adult; D000071437:Axon Guidance / Q000502:physiology; D001921:Brain / Q000502:physiology*; D063132:Connectome; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D012372:ROC Curve; D012146:Rest; D012815:Signal Processing, Computer-Assisted
MEG; betweenness centrality; brain dynamics; core network model; resting-state networks