 Cognitive Task Meaningful comparisons of schizophrenic and non-schizophrenic subjects by a cognitive task necessitates the use of a simple task to minimize confounds related to group differences in cognitive ability. A parametric manipulation of reward contingency will control for group differences in task performance. The proposed monetary incentive task, adapted from that of Elliott et al. 2003, is chosen because of its simplicity and parametric design. The subjects will be given a simple target detection task in which they will be instructed to squeeze a response bulb when they see a red or blue square. Different colored squares will be presented on a screen for 1.3 sec each. When they correctly signal the target stimuli they will see a reward stimulus informing them of how much money they have won on that trial. For trials with non-targets paying no reward if the subject squeezes the bulb the subjects will see a neutral text telling them to wait. The reward amounts will vary from 5 to 1 per trial 5, 25, 50, 75, or 1. The task will be divided into five blocks separated by 30 sec rest periods. Each block will contain 40 trials. Trial types will be presented in randomized order within each block: 30 of trials will contain one of the two target stimuli. Each block will pay correct responses at one of the five monetary reward levels. The task is designed specifically to allow for both an on-off assessment of activations in the presence or absence of reward, but also for a parametric analysis of brain areas that increase their activation with increased reward levels. The subjects will be told that their payment for participation in the fMRI scan will be the total money they accumulate by correct responses during the task. This latter point is important in that the money won during task performance has a real world salience more likely to enhance reward-related activations than if all subjects automatically were paid the same amount regardless of their accuracy. Thus the subjects receive actual rather than simulated reward. 