Source flexibility in schizophrenia: specificity and role in auditory hallucinations.

INTRODUCTION: One important aspect of human cognition relies on the ability to bias attention towards stimulus-independent and stimulus-oriented thoughts and to switch between these states - or source flexibility. This mechanism has received very little attention in the literature, and in particular in schizophrenia. Moreover, there is good reason to believe that this mechanism could also be implicated in hallucinations, but this hypothesis has never been examined. Thus, the aim of the present study was, for the first time in the literature, to explore source flexibility abilities in schizophrenia and their potential relations with auditory hallucinations.

METHODS: Forty persons diagnosed with schizophrenia and 26 healthy controls were evaluated with tasks assessing source flexibility, cognitive flexibility and processing speed. Patients were also assessed with a measure of hallucinations and delusions.

RESULTS: Results revealed that persons diagnosed with schizophrenia presented a poorer performance than healthy controls for source flexibility. Moreover, results demonstrated that source flexibility performance could not be explained by a more general impairment of processing speed or buy difficulties in cognitive flexibility. Finally, source flexibility was found to be related to hallucinations.

CONCLUSIONS: Source flexibility plays an important role in schizophrenia and in particular is a cognitive mechanism involved in hallucinations.