Grant: Operating Grant

Schizophrenia usually involves both symptoms (delusions, hallucinations, apathy) and cognitive impairments (poor learning and memory, defective attention). However, some cognitive abilities, especially those involving verbal skills including word knowledge and vocabulary, may be less compromised by the illness. We recently reported that exceptionally high or "superior" verbal ability, defined as a score in the top 10% of the general population, occurs in a very small proportion of schizophrenia patients. These cognitively exceptional patients may exist because their brains have the abnormalities that cause psychotic symptoms, but not the abnormalities that cause impaired cognition. Hence they may be a great resource in the search for isolating the causes of psychosis. Before this potential can be realized, answers to three key questions must be provided. First, to what degree are cognitively exceptional schizophrenia patients truly free of cognitive impairments? Second, do exceptional patients have a milder form of schizophrenia? Finally, do brain differences exist between exceptional and more typical schizophrenia patients and healthy people? To answer these questions we will study 35 cognitively exceptional and 35 cognitively impaired patients from Hamilton and Guelph-based clinical sites as well as 35 cognitively exceptional and 35 cognitively average healthy participants. The study will use cognitive, symptom and brain scanning instruments to answer the research questions. The results will provide the foundation for further cognitive and neurobiological studies aimed at illuminating the causes of both cognitive impairment and psychosis in schizophrenia.