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.