title: Dynamic recruitment of resting state sub-networks.
abstract: Resting state networks (RSNs) are of fundamental importance in human systems neuroscience with evidence suggesting that they are integral to healthy brain function and perturbed in pathology. Despite rapid progress in this area, the temporal dynamics governing the functional connectivities that underlie RSN structure remain poorly understood. Here, we present a framework to help further our understanding of RSN dynamics. We describe a methodology which exploits the direct nature and high temporal resolution of magnetoencephalography (MEG). This technique, which builds on previous work, extends from solving fundamental confounds in MEG (source leakage) to multivariate modelling of transient connectivity. The resulting processing pipeline facilitates direct (electrophysiological) measurement of dynamic functional networks. Our results show that, when functional connectivity is assessed in small time windows, the canonical sensorimotor network can be decomposed into a number of transiently synchronising sub-networks, recruitment of which depends on current mental state. These rapidly changing sub-networks are spatially focal with, for example, bilateral primary sensory and motor areas resolved into two separate sub-networks. The likely interpretation is that the larger canonical sensorimotor network most often seen in neuroimaging studies reflects only a temporal aggregate of these transient sub-networks. Our approach opens new frontiers to study RSN dynamics, showing that MEG is capable of revealing the spatial, temporal and spectral signature of the human connectome in health and disease.
authors.affiliation: Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
authors.forename: George C
authors.initials: GC
authors.lastname: O'Neill
authors.affiliation: School of Psychology, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
authors.forename: Markus
authors.initials: M
authors.lastname: Bauer
authors.affiliation: Oxford Centre for Human Brain Activity, University of Oxford, Warneford Hospital, Oxford OX3 7JX, United Kingdom; fMRIB Centre, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Woolrich
authors.affiliation: Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Morris
authors.affiliation: Wellcome Trust Centre for Neuroimaging, University College London, 12 Queen Square, London WC1N 3BG, United Kingdom.
authors.forename: Gareth R
authors.initials: GR
authors.lastname: Barnes
authors.affiliation: Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom. Electronic address: matthew.brookes@nottingham.ac.uk.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Brookes
mesh_terms: D000328:Adult; D063132:Connectome; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D009044:Motor Cortex / Q000502:physiology; D009415:Nerve Net / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011999:Recruitment, Neurophysiological / Q000502:physiology*; D015203:Reproducibility of Results; D012146:Rest / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology; D055815:Young Adult