title: Goal-directed visuomotor skill learning: off-line enhancement and the importance of the primary motor cortex.
abstract: OBJECTIVE
  The time course and neural substrates of motor skill learning are not well-understood in healthy or neurologic patient populations. Certain motor skills undergo off-line skill enhancement following training and the primary motor cortex (M1) may be involved. It is unknown if goal-directed visuomotor skill undergoes off-line enhancement or if M1 is associated with that enhancement.
  
  
  METHODS
  32 right-handed, healthy subjects were randomly assigned to two groups: real repetitive transcranial magnetic stimulation (rTMS) or sham rTMS applied to the contralateral M1 immediately following one 20-minute finger tracking training session. Tracking performance and cortical excitability were assessed before and after training, following rTMS and 24 hours post-training.
  
  
  RESULTS
  Results demonstrate that skill performance continues to develop for at least 30 minutes after training completion, is maintained for 24 hours post-training, and is not affected by inhibitory rTMS applied to M1. Level of skill improvement was associated with the degree of intracortical inhibition increase.
  
  
  CONCLUSIONS
  These results suggest dispersed information processing for goal-directed visuomotor skill learning following training and a relationship between cortical excitability and skill development in healthy individuals. These findings invite further investigation of the neural mechanisms underlying motor skill learning and may have rehabilitation implications for patients with neurologic injury.
authors.affiliation: Department of Physical Medicine and Rehabilitation Program in Physical Therapy/Rehabilitation Science, University of Minnesota, MN, USA. mborich@umn.edu
authors.forename: Michael
authors.initials: M
authors.lastname: Borich
authors.forename: Mary
authors.initials: M
authors.lastname: Furlong
authors.forename: Dennis
authors.initials: D
authors.lastname: Holsman
authors.forename: Teresa Jacobson
authors.initials: TJ
authors.lastname: Kimberley
mesh_terms: D000328:Adult; D005260:Female; D006040:Goals; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D016037:Single-Blind Method; D055815:Young Adult