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.