Over the past year, our work has been concentrated on better understand- ing various facets of schizophrenic cognition. In particular, we have examined: 1) Working memory. We have used a Brown Peterson paradigm with differ- ent cognitive loads to reexamine the capacity of this system in patients with schizophrenia. In addition, we have developed a number of novel tasks including a simple spatial delayed response, delayed alternation task and a letter-number span task. 2) Memory function. We have examined conditions under which schizo- phrenic patients may learn. These have included long list learning paradigms in which material is well encoded and also ecologically based paradigms with reward. 3) Atypical neuroleptics. We are comparing patients performance on neuropsychological tests while they are receiving clozapine or haloperi- dol. 4) Specificity. In order to better delineate the cognitive profile of schizophrenia, we are examining other groups of patients with neuropsy- chiatric diseases (affective disorder, temporal lobe epilepsy, and traumatic brain injury). 5) Cognitive enhancing strategies. We are comparing cognitive rehabili- tation techniques and glucose administration directly, continuing work with amphetamine as a cognitive enhancer, as well. 6) Cognitive accounts of symptomatology. Recent theoretical views of schizophrenia have suggested that delusions and hallucinations may be the result of a defective self monitoring system. We are assessing the validity of these theories using delayed auditory feedback. 7) We have developed a number of cognitive activation techniques to be used in PET studies and ligand studies in order to better understand the biological underpinnings of various types of mentation.
