Practice, learning, and the likelihood of making an error: how task experience shapes physiological response in patients with schizophrenia.

Behavioral and functional neuroimaging research has extensively documented the ways in which people with schizophrenia perform poorly on cognitive tasks and exhibit abnormal brain activity patterns when engaged in those tasks, even when their performance is adjusted to become similar to that of healthy controls. There is, however, substantial diversity in the way this syndrome limits a person's ability to learn and acquire skills. This review considers how functional imaging has helped improve our understanding of learning, practice, and error detection in persons with schizophrenia. Positron Emission Tomography and functional magnetic resonance studies are reviewed with particular attention to the roles of these methods and interventions in understanding the biological substrates of cognitive dysfunction in schizophrenic patients. This is done with particular attention to the question of how brain regions change in response to motor, perceptual, and cognitive training interventions. Investigators agree that the prefrontal cortex, anterior cingulate cortex, and hippocampus are impaired in most persons with schizophrenia. Imaging studies with healthy controls support multiple models of biological change elicited by learning and practice. Application of these methods to patients with schizophrenia is in an early stage. A person's response to perceptual, motor, and cognitive training may help pharmacologists and clinicians better interpret medication treatment studies in this diverse population.