Increased automatic spreading activation in healthy subjects with elevatedscores in a scale assessing schizophrenic language disturbances

Background. Previous studies on semantic priming have suggested that schizo phrenic patients with language disturbances demonstrate enhanced semantic a nd indirect semantic priming effects relative to controls. However, the int erpretation of semantic priming studies in schizophrenic patients is obscur ed by methological problems and several artefacts (such as length of illnes s). We, therefore, used a psychometric high-risk approach to test whether h ealthy subjects reporting language disturbances resembling those of schizop hrenics (as measured by the Frankfurt Complaint Questionnaire subscale 'lan guage') display increased priming effects. In addition, the Schizotypal Per sonality Questionnaire was used to cover symptoms of schizotypal personalit y. Enhanced priming was expected to occur under conditions favouring automa tic processes. Methods. One hundred and sixty healthy subjects performed a lexical decisio n semantic priming task containing two different stimulus onset asynchronic ities (200ms and 700 ms) with two experimental conditions (semantic priming and indirect semantic priming) each. Results. Analyses of variance revealed that the Frankfurt Complaint Questio nnaire- 'language' high scorers significantly differed from low scorers in three of the four priming conditions indicating increased automatic spreadi ng activation. No significant results were obtained for the Schizotypal Per sonality Questionnaire total and subscales scores. Conclusions. In line with Maher and Spitzer it is suggested that increased automatic spreading activation underlies schizophrenia-typical language dis turbances which in our study cannot be attributed to confounding variables such as different reaction time baselines, medication or length of illness. Finally, results confirm that the psychometric high-risk approach is an im portant tool for investigating issues relevant to schizophrenia.