Source monitoring task in a sample of in-patients with verbal auditory hallucinations compared to control sample.

Patients with psychosis, especially those with specific positive symptoms such as auditory verbal hallucinations, show a source monitoring deficit, the cognitive process involved in the recognition of the information source. This defect can lead to the erroneous conclusion that self-generated thoughts are not "proper" but derive from an external source. We evaluated 37 patients diagnosed with psychotic disorder and 40 healthy controls using a modified version of the Reality Monitoring Task developed by Larøi et al. in 2004. The patients were also evaluated with PANSS, VGF, PSP. We have found that the performance of the Source Monitoring Task differs between patients with hallucinations and controls. According to the literature we can therefore state that patients with hallucinations are characterized by a difficulty in identifying the source of the information they perceive. Our study also adds a new finding to the literature: the source monitoring dysfunction is not due to the presence of current hallucinatory symptomatology but could be considered a stable trait in psychotic patients.