title: Bidirectional gray matter changes after complex motor skill learning.
abstract: Long-term motor skill learning has been consistently shown to result in functional as well as structural changes in the adult human brain. However, the effect of short learning periods on brain structure is not well understood. In the present study, subjects performed a sequential pinch force task (SPFT) for 20 min on 5 consecutive days. Changes in brain structure were evaluated with anatomical magnetic resonance imaging (MRI) scans acquired on the first and last day of motor skill learning. Behaviorally, the SPFT resulted in sequence-specific learning with the trained (right) hand. Structural gray matter (GM) alterations in left M1, right ventral premotor cortex (PMC) and right dorsolateral prefrontal cortex (DLPFC) correlated with performance improvements in the SPFT. More specifically we found that subjects with strong sequence-specific performance improvements in the SPFT also had larger increases in GM volume in the respective brain areas. On the other hand, subjects with small behavioral gains either showed no change or even a decrease in GM volume during the time course of learning. Furthermore, cerebellar GM volume before motor skill learning predicted (A) individual learning-related changes in the SPFT and (B) the amount of structural changes in left M1, right ventral PMC and DLPFC. In summary, we provide novel evidence that short-term motor skill learning is associated with learning-related structural brain alterations. Additionally, we showed that practicing a motor skill is not exclusively accompanied by increased GM volume. Instead, bidirectional structural alterations explained the variability of the individual learning success.
authors.affiliation: Department of Neurology and Clinic for Cognitive Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, University Hospital Leipzig Leipzig, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Gryga
authors.forename: Marco
authors.initials: M
authors.lastname: Taubert
authors.forename: Juergen
authors.initials: J
authors.lastname: Dukart
authors.forename: Henning
authors.initials: H
authors.lastname: Vollmann
authors.forename: Virginia
authors.initials: V
authors.lastname: Conde
authors.forename: Bernhard
authors.initials: B
authors.lastname: Sehm
authors.forename: Arno
authors.initials: A
authors.lastname: Villringer
authors.forename: Patrick
authors.initials: P
authors.lastname: Ragert