Our work has focused on characterizing various facets of cognitive failure in schizophrenia. We have attempted in particular: 1. To examine memory function. Studies are underway which are examining remote or autobiographical memory and implicit memory in a priming paradigm. Other studies involve assessing working memory using the Parson Petersen paradigm with different interference conditions. 2. To examine specificity. We are assessing cognitive functions in twins discordant for affective disorder, twins discordant for schizophrenia, temporal lobe epilepsy, traumatic brain injury (at NRH), and affective disorder. 3. To examine executive function. A number of tasks that involve delayed response and senile learning have been developed both to ascertain performance profiles and to be used as cognitive activators in PET and SPECT. 4. To examine the effects of neuroleptics. We are comparing patients' performance on neuropsychological tests while they am receiving clozapine, haloperidol, and placebo. 5. To examine course. We are assessing schizophrenic and bipolar patients in cross-sectional designs and schizophrenic patients in a longitudinal design. 6. To examine cognitive enhancing strategies. We are examining the effects of amphetamine on attentional and executive tasks. 7. To examine the relation between movement disorder, cognitive impairment, and psychopathology. We are intensively assessing MZ twins with Tourette's syndrome on neuropsychology, psychopathology, and MRI and patients with Tardive dyskinesia and dystonia. 8. To examine the relation to cognition to psychopathology. The Chapman Scales of anhedonia, perceptual aberration, and magical ideation offer the possibility of ascertaining meaningful relations between brain abnormalities and psychological abnormalities.
