The role of predisposition to hallucinations on non-clinical paranoid vs. socially anxious individuals after hearing negative affective-laden sounds: an experimental investigation.

Background: Research suggested that negative affective-laden sounds act as environmental stressors that elicit negative affect (Bradley and Lang, 2000a).

Aims: We tried to test for the role of an interaction between predisposition to hallucinatory experiences and exposure to negative affective laden sounds for the presence of paranoid ideation.

Method: We used an experimental design that followed the vulnerability × stress model. We defined three groups from a sample of students: paranoia group vs. social anxiety group vs. control group. Their psychological characteristics were measured through self-reports of paranoia, anxiety, predisposition to hallucinations and depressive symptoms at Time 1 (before the experiment). Participants had to listen to either negative affective laden sounds (e.g. screaming) or positive affective laden sounds (e.g. sound of ocean waves). Their paranoid ideation and positive vs. negative emotional reactions to sounds were measured through self-reports at Time 2 (after the experiment).

Results: Data showed that the paranoia group presented more serious psychological vulnerabilities than the social anxiety group. A MANCOVA also showed that the independent variables ("group" and "experimental sound conditions") had statistically significant main effects on general paranoia ideation at Time 2. Furthermore, there was a significant three-way interaction between group x predisposition to hallucinatory experiences × experimental condition of sounds for the presence of general paranoid ideation at Time 2. Limitations included the small sample size and the effects of parasite variables, e.g. noise.

Conclusions: Individuals' predisposition for hallucinatory experiences increases the probability of possessing paranoid ideation. This tendency is a characteristic of paranoid non-clinical individuals.