title: Benefit of interleaved practice of motor skills is associated with changes in functional brain network topology that differ between younger and older adults.
abstract: Practicing tasks arranged in an interleaved manner generally leads to superior retention compared with practicing tasks repetitively, a phenomenon known as the contextual interference (CI) effect. We investigated the brain network of motor learning under CI, that is, the CI network, and how it was affected by aging. Sixteen younger and 16 older adults practiced motor sequences arranged in a repetitive or an interleaved order over 2 days, followed by a retention test on day 5 to evaluate learning. Network analysis was applied to functional MRI data on retention to define the CI network by identifying brain regions with greater between-region connectivity after interleaved compared with repetitive practice. CI effects were present in both groups but stronger in younger adults. Moreover, CI networks in younger adults exhibited efficient small-world topology, with a significant association between higher network centrality and better learning after interleaved practice. Older adults did not show such favorable network properties. Our findings suggest that aging affects the efficiency of brain networks underlying enhanced motor learning after CI practice.
authors.affiliation: Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan; Yeong-An Orthopedic and Physical Therapy Clinic, Taipei, Taiwan.
authors.forename: Chien-Ho Janice
authors.initials: CH
authors.lastname: Lin
authors.affiliation: Department of Psychology, University of California, Los Angeles, CA, USA.
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Knowlton
authors.affiliation: Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA; Ahmanson-Lovelace Brain Mapping Center, University of California, Los Angeles, CA, USA.
authors.forename: Allan D
authors.initials: AD
authors.lastname: Wu
authors.affiliation: Ahmanson-Lovelace Brain Mapping Center, University of California, Los Angeles, CA, USA; Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, CA, USA.
authors.forename: Marco
authors.initials: M
authors.lastname: Iacoboni
authors.affiliation: Department of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Ho-Ching
authors.initials: HC
authors.lastname: Yang
authors.affiliation: Department of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan; Department of Diagnostic Radiology, Chang Gung Memorial Hospital, Chiayi, Taiwan.
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Ye
authors.affiliation: Department of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Kuan-Hong
authors.initials: KH
authors.lastname: Liu
authors.affiliation: Department of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan. Electronic address: mcchiang@ym.edu.tw.
authors.forename: Ming-Chang
authors.initials: MC
authors.lastname: Chiang
mesh_terms: D000368:Aged; D000375:Aging / Q000473:pathology / Q000502:physiology* / Q000523:psychology*; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009048:Motor Skills / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D011930:Reaction Time; D012153:Retention, Psychology / Q000502:physiology; D055815:Young Adult
keywords: Contextual interference; Functional connectivity; Functional magnetic resonance imaging; Psychophysiological interaction; Serial reaction time task; Small-world networks