Background. Current cognitive models of positive symptoms of psychosis suggest a mechanism of defective self-monitoring that may be relevant for (i) expression of psychosis at the clinical and subclinical level and (ii) transmission of risk for psychosis.

Method. The study included 41 patients with psychosis, 39 non-psychotic first-degree relatives, 39 subjects from the general population with a high level of positive psychotic experiences, and 52 healthy controls with an average level of positive psychotic experiences. All subjects performed a speech attribution task in which single adjectives with a complimentary or derogatory meaning were presented to them on a computer screen; subjects had to read aloud and determine the source (self/other/uncertain) of the words they heard. In some of the trials, participants’ speech was distorted, in others they heard someone else's voice (alien feedback condition) that could also be distorted.

Results. No large or significant differences in errors in the speech attribution task were found between the four groups in any of the conditions.

Conclusions. Contrary to previous work using this paradigm, this study found no evidence that either expression of psychosis or risk for psychosis was associated with impairment in self-monitoring.