Working Memory Control in Patients With Schizophrenia: A PET Study During a Random Number Generation Task

OBJECTIVE: The authors’ goal was to investigate brain regions involved in the deficiency of working memory control processes in patients with schizophrenia. METHOD: Regional cerebral blood flow was measured with positron emission tomography in eight men with stabilized schizophrenia and eight healthy men while they were performing a graded random number generation task. Twelve scans were made for each subject. Covariations between randomness of responses and regional activation were analyzed. RESULTS: The pattern of covariation between randomness of responses and activation in the anterior cingulate and superior parietal regions differed between patients and healthy subjects. CONCLUSIONS: These results suggest a cinguloparietal dysfunction underlying the impairment of working memory control processes during a random number generation task in patients with schizophrenia.