Enhanced semantic priming in thought-disordered schizophrenic patients using a word pronunciation task.

Previous research on semantic priming in schizophrenia has produced contradictory findings. For the present study, it was intended to resolve some of the ambiguities in the literature. Using a semantic priming task with word pronunciation, evidence is provided that thought-disordered schizophrenic (TD) patients exhibit significantly increased semantic priming as compared to healthy and psychiatric controls. Results suggest that enhanced semantic priming is not confined to tasks that require lexical decision. Moreover, results indicate that TD schizophrenic patients suffer from a decay of hierarchical thinking, i.e. TD schizophrenics reveal a tendency to process the less meaningful rather than the dominant aspects of external information. Priming effects for the inferior meaning of homograph words (for example, 'dance' is an inferior, and 'game' is a superior associate of the word 'ball') were significantly greater compared to healthy controls and non-TD schizophrenics. Results were not moderated by sociodemographic background variables, psychomotor slowing and psychopathological symptoms other than thought disorder.