Many people who carry a diagnosis of schizotypal personality disorder have trouble with attention and memory. Increasing the presence of a brain chemical called dopamine has been found to help people with schizophrenia with their attention and memory problems. This study will investigate whether the same is true for people with schizotypal personality disorder by using DAR-0100A, a drug that has been shown to help with the cognitive deficits of people with Parkinson's disease by increasing dopamine effects. Information collected in this experiment may lead to a better understanding of the brain mechanisms involved in schizotypal personality disorder and improve treatments for the psychological problems associated with this condition.