Further evidence for "hyper-priming" in thought-disordered schizophrenic patients using repeated masked category priming.

BACKGROUND Previous research has yielded evidence for enhanced semantic priming in formal thought-disordered schizophrenia patients, a result that fits well with the hypothesis of disinhibited processes of spreading activation in this population. METHODS The present study tested this hypothesis by using masked repetition priming, which yields reversed semantic priming effects in healthy participants. Assuming that performance in this paradigm relies on a balance between activation and inhibition processes in healthy participants, we compared formal thought-disordered schizophrenia patients, non-thought disordered schizophrenia patients, and healthy controls. RESULTS For thought-disordered schizophrenia patients, we found a large positive semantic priming effect for dominant category exemplars (primed by the category name), whereas healthy controls had a small negative effect. For non-thought disordered patients, we found a non-significant, numerically positive effect. CONCLUSIONS This result yields further evidence for the lack of inhibitory processes in thought-disordered patients.