Ocular motor delayed-response task performance among patients with schizophrenia and their biological relatives

Schizophrenia patients and their relatives have saccadic abnormalities char acterized by problems inhibiting a response. The dorsolateral prefrontal co rtex and its associated circuitry ostensibly mediate inhibition and support correct delayed response performance. In this context, two components of d elayed response task performance are of interest: memory saccade metrics an d error saccades made during the delay. To evaluate these variables, an ocu lar motor delayed response task was presented to 23 schizophrenia patients, 25 of their first-degree biological relatives, and 19 normal subjects. The measure that best differentiated groups was an increased frequency of erro r saccades generated during the delay by schizophrenia subjects and relativ es. Decreased memory saccade gain also characterized patients and relatives . The similar pattern of results demonstrated by the patients with schizoph renia and their relatives suggests that performance on ocular motor delayed response tasks, either alone or in combination with other saccadic variabl es, may provide useful information about neural substrates associated with a liability for developing schizophrenia.