Neural Patterns of Visual Learning in Schizophrenia

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DESCRIPTION (provided by applicant): Schizophrenia is an illness with multiple symptom manifestations that cluster into at 3 domains: (1) reality distortion (hallucinations and delusions), (2) negative symptoms (psychomotor retardation), and (3) disorganization (thought disorder). We have previously associated distinctive rCBF patterns with positive and negative symptom domains, supporting the idea of rCBF differences across symptom subtypes. In addition to symptoms, persons with schizophrenia show inadequate neuropsychological performance when evaluated on test of intelligence, memory, attention, and executive function. Blood oxygen level dependent contrast (BOLD) analysis using fMRI, focused on questions of integrative neurobiology in schizophrenia subtypes (particular symptom groups), brings a contemporary research technique to bear on a complex clinical brain/behavior disorder. We will assess performance improvement on a visual DMST with feedback in 15 schizophrenic patients with primary enduring negative symptoms (Deficit Schizophrenia or DS) and 15 schizophrenic patients with predominant hallucinations and delusions (Reality Distortion or RD). We predict that schizophrenic volunteers will show learning but that the deficit group will fail to improve as much as the RD group because the deficit volunteers will not be able to use feedback to enhance their learning. Using BOLD signal changes we will define the neural activity patterns in DS and RD volunteers during learning of the visual DMST. The RD will exhibit a significant increase in the anterior cingulate hemodynamic response after perceptual training. DS volunteers will exhibit a significantly reduced BOLD response in the inferior parietal lobe before and after training. Enduring primary negative symptoms are also expected to prevent feedback-dependent changes in the cingulate cortex.