The psychopathology, neuropsychology, and neurobiology of associative and working memory in schizophrenia.

A large number of psycholinguistic findings on how human beings store lexical information suggest the existence of associative memory, which may be characterized by a large capacity and a long duration. Its anatomical basis supposedly is, at least in part, the frontal lobes, and some of its functional characteristics have been tentatively linked to dopamine release. Working memory has a limited capacity, lasts only for seconds and is relevant for goal-directed behavior. Its anatomical basis in the frontal cortex is established and strong evidence suggests the involvement of dopaminergic pathways. Experimental evidence using several lexical decision tasks and a delayed response task is provided to demonstrate that some characteristic features of schizophrenic thinking--in particular the rapid shift of associations, the indirect relationship of associations, the overly abstract or overly concrete use of concepts, the lack of context-sensitivity and of general integrative function and intellectual capacity--can be explained in terms of an activation or disinhibition of associative memory, and of a dysfunctional working memory. The findings serve as an example of schizophrenia research in a cognitive neuroscience framework.