Neurocognitive predictors of source monitoring in schizophrenia.

RATIONALE

Source monitoring (SM) is a metacognitive process involved in making judgments about the origin of information by recruiting cognitive processes. Deficits in SM have been linked to positive symptoms of schizophrenia. We investigated whether certain neurocognitive functions - specifically attention, working memory, and organizational sequencing - were associated with SM in a sample of schizophrenia patients.

METHODS

Attention (Auditory Continuous Performance Test), organizational sequencing (Trail-Making Test B-A), working memory (Digits Backward), and internal SM were assessed in 45 outpatients diagnosed with schizophrenia or schizoaffective disorder.

RESULTS

Standard multiple regression analysis showed attention, working memory and organizational sequencing together predicted SM. Organizational sequencing was the only significant individual predictor, with better organizational sequencing ability being associated with better SM. Hierarchical regression analysis showed that working memory by itself did not result in a significant predictive model of SM, but adding organizational sequencing led to a significant change from the working memory model and resulted in a significant overall model, accounting for 26% of the variance in SM.

CONCLUSIONS

Neurocognitive functions were associated with SM in schizophrenia. Organizational sequencing, which requires an awareness of self-generated actions, predicted SM performance even after controlling for working memory.