title: Upregulation of cortico-cerebellar functional connectivity after motor learning.
abstract: Interactions between the cerebellum and primary motor cortex are crucial for the acquisition of new motor skills. Recent neuroimaging studies indicate that learning motor skills is associated with subsequent modulation of resting-state functional connectivity in the cerebellar and cerebral cortices. The neuronal processes underlying the motor-learning-induced plasticity are not well understood. Here, we investigate changes in functional connectivity in source-reconstructed electroencephalography (EEG) following the performance of a single session of a dynamic force task in twenty young adults. Source activity was reconstructed in 112 regions of interest (ROIs) and the functional connectivity between all ROIs was estimated using the imaginary part of coherence. Significant changes in resting-state connectivity were assessed using partial least squares (PLS). We found that subjects adapted their motor performance during the training session and showed improved accuracy but with slower movement times. A number of connections were significantly upregulated after motor training, principally involving connections within the cerebellum and between the cerebellum and motor cortex. Increased connectivity was confined to specific frequency ranges in the mu- and beta-bands. Post hoc analysis of the phase spectra of these cerebellar and cortico-cerebellar connections revealed an increased phase lag between motor cortical and cerebellar activity following motor practice. These findings show a reorganization of intrinsic cortico-cerebellar connectivity related to motor adaptation and demonstrate the potential of EEG connectivity analysis in source space to reveal the neuronal processes that underpin neural plasticity.
authors.affiliation: School of Medicine Human Motor Control Laboratory, University of Tasmania, Private Bag 51, Hobart TAS 7001, Australia. Electronic address: smehrkanoon@gmail.com.
authors.forename: Saeid
authors.initials: S
authors.lastname: Mehrkanoon
authors.affiliation: Black Dog Institute, University of New South Wales, Randwick, Sydney, NSW 2052, Australia; QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia. Electronic address: t.boonstra@unsw.edu.au.
authors.forename: Tjeerd W
authors.initials: TW
authors.lastname: Boonstra
authors.affiliation: QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia; Metro North Mental Health Service, Brisbane, QLD 4006, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Breakspear
authors.affiliation: School of Medicine Human Motor Control Laboratory, University of Tasmania, Private Bag 51, Hobart TAS 7001, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Hinder
authors.affiliation: School of Medicine Human Motor Control Laboratory, University of Tasmania, Private Bag 51, Hobart TAS 7001, Australia; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool L3 5UA, UK.
authors.forename: Jeffery J
authors.initials: JJ
authors.lastname: Summers
mesh_terms: D001931:Brain Mapping; D002531:Cerebellum / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007858:Learning / Q000502:physiology*; D008297:Male; D009048:Motor Skills / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
keywords: Cerebellum; EEG source analysis; Intrinsic connectivity; Motor learning; Neural plasticity