title: Repeated Structural Imaging Reveals Nonlinear Progression of Experience-Dependent Volume Changes in Human Motor Cortex.
abstract: Evidence for experience-dependent structural brain change in adult humans is accumulating. However, its time course is not well understood, as intervention studies typically consist of only 2 imaging sessions (before vs. after training). We acquired up to 18 structural magnetic resonance images over a 7-week period while 15 right-handed participants practiced left-hand writing and drawing. After 4 weeks, we observed increases in gray matter of both left and right primary motor cortices relative to a control group; 3 weeks later, these differences were no longer reliable. Time-series analyses revealed that gray matter in the primary motor cortices expanded during the first 4 weeks and then partially renormalized, in particular in the right hemisphere, despite continued practice and increasing task proficiency. Similar patterns of expansion followed by partial renormalization are also found in synaptogenesis, cortical map plasticity, and maturation, and may qualify as a general principle of structural plasticity. Research on human brain plasticity needs to encompass more than 2 measurement occasions to capture expansion and potential renormalization processes over time.
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Wenger
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany.|Clinic and Policlinic for Psychiatry and Psychotherapy, University Clinic Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Kühn
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany.
authors.forename: Julius
authors.initials: J
authors.lastname: Verrel
authors.affiliation: Department of Psychology, Lund University, Lund, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Mårtensson
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany.
authors.forename: Nils Christian
authors.initials: NC
authors.lastname: Bodammer
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany.|European University Institute, San Domenico di Fiesole (FI), Italy.
authors.forename: Ulman
authors.initials: U
authors.lastname: Lindenberger
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany.|Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Lövdén
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D007839:Functional Laterality / Q000502:physiology; D066128:Gray Matter / Q000000981:diagnostic imaging; D006225:Hand / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007700:Kinetics; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000000981:diagnostic imaging* / Q000502:physiology; D017711:Nonlinear Dynamics; D011597:Psychomotor Performance / Q000502:physiology*; D012044:Regression Analysis; D013997:Time Factors; D014956:Writing
keywords: gray matter changes; motor learning; structural brain plasticity; time course; voxel-based morphometry