The cognitive electrophysiological assessment will employ a parametrically designed A-X Continuous Performance Test (AX-CPT) task with increasing levels of difficulty proven to elicit traditional behavioral measures of WM function such as reaction time (RT) and accuracy (Bates et al, 2000). This paradigm provides a means to evaluate the efficacy of ziprasidone treatment in remitting cognitive dysfunction in patients with schizophrenia. However, accuracy and RT only index the final motor response and do not capture information about antecedent stages of information processing. Visual evoked response potentials (ERP's) will be collected while subjects perform the AX-CPT tasks allowing for assessment of early sensory registration of stimuli (N1), and the time course of subsequent cognitive analysis (P3) (Bates et al, 2000). This methodology will facilitate assessment of the stage of information processing where schizophrenia deficits in WM become manifest. Topographical analysis will assess whether schizophrenia patients display amplitude attenuation over scalp sites correlating to prefrontal cortex while performing the WM tasks, and if functioning improves over the course of ziprasidone intervention.