Schizophrenia is characterized by substantial cognitive impairments which, in addition to compromising the individual's ability to perform essential cognitive functions, contribute to the thought disorder and social maladaptations of schizophrenia. These deficits are less responsive to pharmacotherapy than the positive symptoms of schizophrenia, yet may be even more disabling over the long term. This study takes advantage of a partially overlapping disorder, schizotypal personality disorder (SPD), which shares many genetic, phenomenologic and neuropsychological features with schizophrenia, but is characterized by less severe cognitive impairments and the absence of overt psychotic symptoms, to learn more about the neurobiology of the cognitive impairment in schizophrenia and possible mechanisms that may protect SPD patients from the degree of cognitive dysfunction seen in schizophrenia. Identifying such protective factors could lead to new strategies to improve cognitive functioning in schizophrenia by suggesting new pharmacologic or cognitive remediation approaches. This study uses BOLD functional magnetic resonance imaging to compare regional brain activation between patients with schizophrenia, SPD and healthy control subjects as they carry out a cognitive task utilizing visuospatial working memory (VSWM). By comparing activation in specific regions of interest in the frontal cortex, this study will test the hypothesis that schizophrenic and SPD patients have decreased activation in a region traditionally associated with visuospatial working memory in healthy subjects and that SPD patients but not schizophrenic subjects are able to recruit another frontal region to compensate for the decreased functional activity in the region utilized for VSWM in healthy subjects.