Can an experimental white noise task assess psychosis vulnerability in adult healthy controls?

Background This is an extension of a paper published earlier. We investigated the association between the tendency to detect speech illusion in random noise and levels of positive schizotypy in a sample of 185 adult healthy controls. Materials and methods Subclinical positive, negative and depressive symptoms were assessed with the Community Assessment of Psychic Experiences (CAPE); positive and negative schizotypy was assessed with the Structured Interview for Schizotypy-Revised (SIS-R). Results Speech illusions were associated with positive schizotypy (OR: 4.139, 95% CI: 1.074-15.938; p = 0.039) but not with negative schizotypy (OR: 1.151, 95% CI: 0.183-7.244; p = 0.881). However, the association of positive schizotypy with speech illusions was no longer significant after adjusting for age, sex and WAIS-III (OR: 2.577, 95% CI: 0.620-10.700; p = 0.192). Speech illusions were not associated with self-reported CAPE measures. Conclusions The association between schizotypy and the tendency to assign meaning in random noise in healthy controls may be mediated by cognitive ability and not constitute an independent trait.