<qa>  What is the SDS?Subjects Ten male schizophrenic subjects ages 18-60 will be recruited. Diagnosis will be confirmed by structured diagnostic interview SCID-I. Primary deficit syndrome will be confirmed by rating with the Schedule for the Deficit Syndrome SDS, a scale that defines schizophrenic subjects according to whether they have chronic negative symptoms even across periods when positive symptoms are in remission Kirkpatrick et al. 1989. This scale thus allows for the differentiation of those patients who have negative symptoms consistently across clinical states from those whose negative symptoms emerge when they are acutely psychotic and remit when positive symptoms remit. Additionally, subjects must have a minimum score of 30 on the SANS. Subjects will be excluded for clinically significant unstable medical illness, history of neurological disease including head trauma with loss of consciousness 5 minutes, active substance abuse or dependence within the prior three months, any contraindication to fMRI, left handedness, mental retardation, color blindness, antipsychotic treatment resistance, or known allergy to or nonresponse to aripiprazole. Subjects with schizophrenia will be excluded if they do not have a working telephone. 