title: Aging reduces experience-induced sensorimotor plasticity. A magnetoencephalographic study.
abstract: Modulation of the mu-alpha and mu-beta spontaneous rhythms reflects plastic neural changes within the primary sensorimotor cortex (SM1). Using magnetoencephalography (MEG), we investigated how aging modifies experience-induced plasticity after learning a motor sequence, looking at post- vs. pre-learning changes in the modulation of mu rhythms during the execution of simple hand movements. Fifteen young (18-30 years) and fourteen older (65-75 years) right-handed healthy participants performed auditory-cued key presses using all four left fingers simultaneously (Simple Movement task - SMT) during two separate sessions. Following both SMT sessions, they repeatedly practiced a 5-elements sequential finger-tapping task (FTT). Mu power calculated during SMT was averaged across 18 gradiometers covering the right sensorimotor region and compared before vs. after sequence learning in the alpha (9/10/11Hz) and the beta (18/20/22Hz) bands separately. Source power maps in the mu-alpha and mu-beta bands were localized using Dynamic Statistical Parametric Mapping (dSPM). The FTT sequence was performed faster at retest than at the end of the learning session, indicating an offline boost in performance. Analyses conducted on SMT sessions revealed enhanced rebound after learning in the right SM1, 3000-3500ms after the initiation of movement, in young as compared to older participants. Source reconstruction indicated that mu-beta is located in the precentral gyrus (motor processes) and mu-alpha is located in the postcentral gyrus (somatosensory processes) in both groups. The enhanced post-movement rebound in young subjects potentially reflects post-training plastic changes in SM1. Age-related decreases in post-training modulatory effects suggest reduced experience-dependent plasticity in the aging brain.
authors.affiliation: UR2NF - Neuropsychology and Functional Neuroimaging Research Unit at CRCN, Center for Research in Cognition and Neurosciences, Université Libre de Bruxelles, Brussels, Belgium; UNI - ULB Neurosciences Institute, Université Libre de Bruxelles, Brussels, Belgium. Electronic address: alismary@ulb.ac.be.
authors.forename: Alison
authors.initials: A
authors.lastname: Mary
authors.affiliation: LCFC - Laboratoire de Cartographie Fonctionnelle du Cerveau, Université Libre de Bruxelles, Brussels, Belgium; UNI - ULB Neurosciences Institute, Université Libre de Bruxelles, Brussels, Belgium; Brain Research Unit and MEG Core, O.V. Lounasmaa Laboratory, Aalto University School of Science, Espoo, Finland.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Bourguignon
authors.affiliation: LCFC - Laboratoire de Cartographie Fonctionnelle du Cerveau, Université Libre de Bruxelles, Brussels, Belgium; UNI - ULB Neurosciences Institute, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Vincent
authors.initials: V
authors.lastname: Wens
authors.affiliation: LCFC - Laboratoire de Cartographie Fonctionnelle du Cerveau, Université Libre de Bruxelles, Brussels, Belgium; UNI - ULB Neurosciences Institute, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Op de Beeck
authors.affiliation: UR2NF - Neuropsychology and Functional Neuroimaging Research Unit at CRCN, Center for Research in Cognition and Neurosciences, Université Libre de Bruxelles, Brussels, Belgium; UNI - ULB Neurosciences Institute, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Rachel
authors.initials: R
authors.lastname: Leproult
authors.affiliation: LCFC - Laboratoire de Cartographie Fonctionnelle du Cerveau, Université Libre de Bruxelles, Brussels, Belgium; UNI - ULB Neurosciences Institute, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Xavier
authors.initials: X
authors.lastname: De Tiège
authors.affiliation: UR2NF - Neuropsychology and Functional Neuroimaging Research Unit at CRCN, Center for Research in Cognition and Neurosciences, Université Libre de Bruxelles, Brussels, Belgium; UNI - ULB Neurosciences Institute, Université Libre de Bruxelles, Brussels, Belgium. Electronic address: philippe.peigneux@ulb.ac.be.
authors.forename: Philippe
authors.initials: P
authors.lastname: Peigneux
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000513:Alpha Rhythm; D001611:Beta Rhythm; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015225:Magnetoencephalography; D008297:Male; D009048:Motor Skills; D009473:Neuronal Plasticity / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Aging; Magnetoencephalography; Motor learning; Mu rhythm; Power change; Rebound