title: Motor learning in childhood reveals distinct mechanisms for memory retention and re-learning.
abstract: Adults can easily learn and access multiple versions of the same motor skill adapted for different conditions (e.g., walking in water, sand, snow). Following even a single session of adaptation, adults exhibit clear day-to-day retention and faster re-learning of the adapted pattern. Here, we studied the retention and re-learning of an adapted walking pattern in children aged 6-17 yr. We found that all children, regardless of age, showed adult-like patterns of retention of the adapted walking pattern. In contrast, children under 12 yr of age did not re-learn faster on the next day after washout had occurred-they behaved as if they had never adapted their walking before. Re-learning could be improved in younger children when the adaptation time on day 1 was increased to allow more practice at the plateau of the adapted pattern, but never to adult-like levels. These results show that the ability to store a separate, adapted version of the same general motor pattern does not fully develop until adolescence, and furthermore, that the mechanisms underlying the retention and rapid re-learning of adapted motor patterns are distinct.
authors.affiliation: The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore Maryland 21205, USA Motion Analysis Laboratory, The Kennedy Krieger Institute, Baltimore, Maryland 21205, USA.
authors.forename: Kristin E
authors.initials: KE
authors.lastname: Musselman
authors.affiliation: The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore Maryland 21205, USA Motion Analysis Laboratory, The Kennedy Krieger Institute, Baltimore, Maryland 21205, USA.
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Roemmich
authors.affiliation: The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore Maryland 21205, USA Motion Analysis Laboratory, The Kennedy Krieger Institute, Baltimore, Maryland 21205, USA.
authors.forename: Ben
authors.initials: B
authors.lastname: Garrett
authors.affiliation: The Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore Maryland 21205, USA Motion Analysis Laboratory, The Kennedy Krieger Institute, Baltimore, Maryland 21205, USA bastian@kennedykrieger.org.
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Bastian
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000367:Age Factors; D000704:Analysis of Variance; D002648:Child; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D012153:Retention, Psychology / Q000502:physiology*; D013663:Teaching; D013997:Time Factors; D016138:Walking / Q000502:physiology*