Inclusion Criteria:

1. Subjects will be males and females between the ages of 18 and 65
2. In good general medical health
3. For patient subjects, a DSM-IV diagnosis of schizophrenia, any subtype
4. Currently in remission or with stable, unchanging residual symptoms
5. Receiving treatment with olanzapine, aripiprazole, risperidone, or quetiapine as their antipsychotic medication at a stable dose for a minimum of eight weeks.
6. Able to complete neurocognitive tests
7. Able to give informed consent. All subjects will be required to have at least an 8th grade reading level and/or a full-scale IQ of at least 85 as assessed by the Wide Range Achievement Test (WRAT).

Exclusion Criteria:

1. Recent history (within previous year) of serious suicide, homicide, or physical violence, or current suicidal or homicidal thoughts
2. Any axis I DSM-IV diagnosis in addition to schizophrenia or schizoaffective disorder except substance abuse in remission
3. History of severe head trauma, neurological disorder, or medical illness which may contribute to the subjects’ psychiatric symptoms or cognitive impairment
4. Medical illness which requires taking any medication that has CNS activity which is known to impair cognition.
5. Untreated or unstable hypertension.
6. Coronary artery disease.
7. Receiving concomitant anticholinergic drugs, antidepressants or mood stabilizers. If patient subjects are receiving benzodiazepines, they must be short or intermediate acting (e.g. alprazolam, lorazepam) and must be held 48 hours prior to cognitive testing
8. Unable to give informed consent
9. History of developmental disorder or less than an eighth