title: Early consolidation in human primary motor cortex.
abstract: Behavioural studies indicate that a newly acquired motor skill is rapidly consolidated from an initially unstable state to a more stable state, whereas neuroimaging studies demonstrate that the brain engages new regions for performance of the task as a result of this consolidation. However, it is not known where a new skill is retained and processed before it is firmly consolidated. Some early aspects of motor skill acquisition involve the primary motor cortex (M1), but the nature of that involvement is unclear. We tested the possibility that the human M1 is essential to early motor consolidation. We monitored changes in elementary motor behaviour while subjects practised fast finger movements that rapidly improved in movement acceleration and muscle force generation. Here we show that low-frequency, repetitive transcranial magnetic stimulation of M1 but not other brain areas specifically disrupted the retention of the behavioural improvement, but did not affect basal motor behaviour, task performance, motor learning by subsequent practice, or recall of the newly acquired motor skill. These findings indicate that the human M1 is specifically engaged during the early stage of motor consolidation.
authors.affiliation: Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bldg 10, Rm 5N226, 10 Center Drive MSC 1428, Bethesda, Maryland 20892-1428, USA.
authors.forename: Wolf
authors.initials: W
authors.lastname: Muellbacher
authors.forename: Ulf
authors.initials: U
authors.lastname: Ziemann
authors.forename: Joerg
authors.initials: J
authors.lastname: Wissel
authors.forename: Nguyet
authors.initials: N
authors.lastname: Dang
authors.forename: Markus
authors.initials: M
authors.lastname: Kofler
authors.forename: Stefano
authors.initials: S
authors.lastname: Facchini
authors.forename: Babak
authors.initials: B
authors.lastname: Boroojerdi
authors.forename: Werner
authors.initials: W
authors.lastname: Poewe
authors.forename: Mark
authors.initials: M
authors.lastname: Hallett
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology