Rowland LM, Shadmehr R, Kravitz D, and Holcomb HH (2007)
Sequential neural changes during motor learning in schizophrenia. Psychiatry Research Neuroimaging.
Abstract Positron emission tomography (PET) was
used to investigate differences in neural plasticity associated with learning a
unique motor task in schizophrenics and healthy volunteers. Working with a
robotic manipulandum, subjects learned reaching movements in a force field.
Visual cues were provided to guide the reaching movements. PET rCBF measures
were acquired while participants learned the motor skill over successive runs.
The groups did not differ in behavioral performance but did differ in their
rCBF activity patterns. Healthy volunteers displayed blood flow increases in
primary motor cortex and supplementary motor area with motor learning. The
schizophrenics displayed an increase in the primary visual cortex with motor
learning. Changes in these regions were positively correlated with changes in
each group’s motor accuracy, respectively. Schizophrenics may have an
inability to rapidly tune motor cortical neural populations to a preferred
direction. The visual system, however, appears to be highly compensated in
schizophrenia and the inability to rapidly modulate the motor cortex may be
substantially corrected by the schizophrenic group’s visuomotor
adaptations. This is the first study to employ a unique arm reaching motor
learning test to assess neural plasticity during multiple phases of motor
learning in subjects with schizophrenia.
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