THOUGHT-DISORDER, WORKING-MEMORY AND ATTENTION - INTERRELATIONSHIPS AND THE EFFECTS OF NEUROLEPTIC MEDICATIONS

Impairments in attention and vigilance, working memory and organizatio n of speech (thought disorder) have been reliably observed in patients with schizophrenia. The response in these cognitive parameters to neu roleptic medications can be used to sharpen their characterization in neuropsychological terms. In particular, a review of the literature su ggests that while working memory is relatively insensitive to neurolep tics attention and thought disorder may improve with neuroleptic admin istration. On the basis of the response to typical and atypical neurol eptics attention as deployed in the Continuous Performance Test may re flect response readiness rather than actual vigilance. Thought disorde r, which is often assumed to be the result of impaired discourse plann ing due to a reduced capacity for working memory, does not covary with working memory, and the two parameters show different responses to ne uroleptic medications. Rather, cognitive studies suggest that thought disorder may arise from abnormalities within the semantic system itsel f.