Neuroimaging Studies of Neurophysiological Phenotypes in Schizophrenia

Background: \- Eye tracking, the ability to focus on and follow a moving target with the eyes, is often difficult for people who have schizophrenia. Research has shown that first-degree relatives of people with schizophrenia, such as parents and siblings, also tend to have difficulty with smooth eye movement and eye tracking. Researchers are interested in using functional magnetic resonance imaging (fMRI) to study brain activity during eye tracking tests in order to better understand the effect that schizophrenia has on brain function. Objectives: \- To study eye-tracking and eye-tracking impairments in people with and without schizophrenia. Eligibility: \- Individuals between 18 and 62 years of age in one of three groups: (1) patients who have been diagnosed with schizophrenia/schizoaffective disorder, (2) first-degree relatives of patients in group 1, and (3) healthy volunteers with no family history of psychosis. Design: * The study will involve two visits, one screening session and one testing session. Each session will take about 3 hours. * Participants will be asked to avoid consuming alcohol and restrict consumption of caffeine before the start of the study. Participants will provide urine and breath samples to be tested for chemicals that may interfere with the study. * Participants will visit the clinical center the morning of the day before the scanning session to provide blood and urine samples as required. Participants will return and be admitted for an overnight stay later that afternoon or evening. * During the screening session, participants will provide a medical and psychological history, provide blood samples, and learn the eye movement tasks they will do during the scanning session. * During the scanning session, participants will have an fMRI scan. During the scan, they will perform eye movement tasks that involve following moving light targets on a screen, and will also perform other tasks that test the ability to think and pay attention.