In this study, we propose to administer cognitive tests to schizophrenic patients and to neurologic patients who will serve as contrast groups for neuropsychological studies of patients with schizophrenia. These include studies of Alzheimers disease to dissociate size and organization of lexicon and ADHD to understand error patterns on CPT-type tests of attention and vigilance. However, the majority of studies will examine schizophrenia in relation to normal controls.
In addition, we propose to obtain test results from a local sample of normal subjects of varying ages and educational backgrounds to further delineate degree of impairment in these clinical groups. As well as assessing adults we wish to assess normal children. In particular, we wish to identify in children the size of their lexicon and their degree of semantic organization within their lexicon.