Abstract:
The functional anatomy of motor skill acquisition was investigated
in six normal human subjects who learned to perform a pursuit rotor task
with their dominant right hand during serial positron emission
tomography (PET) imaging of relative cerebral blood flow (relCBF). The
effect of motor execution, rather than learning, was identified by a
comparison of four motor performance scans with two control scans (eye
movements only). Motor execution was associated with activation of a
distributed network involving cortical, striatonigral, and cerebellar
sites. Second, the effect of early motor learning was examined.
Performance improved from 17% to 66% mean time on target across the four
PET scans obtained during pursuit rotor performance. Across the same
scans, significant longitudinal increases of relCBF were located in the
left primary motor cortex, the left supplementary motor area, and the
left pulvinar thalamus. The results demonstrate that changes of regional
cerebral activity associated with early learning of skilled movements
occur in sites that are a subset of a more widely distributed network
that is active during motor execution