Evidence for Reduced Sensory Precision and Increased Reliance on Priors in Hallucination-Prone Individuals in a General Population Sample
David A. Benrimoh, Victoria Fisher, Rashina D. Seabury, Ely Sibarium, Catalina Mourgues, Doris Chen, Albert R. Powers
Schizophrenia Bulletin September 19, 2023 DOI: 10.1093/schbul/sbad136 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study Peer reviewed |
|---|---|
| Sample size | 88 |
| Population | Online sample of 88 general population participants |
| Measures | conditioned hallucinations (CH) task, Hierarchical Gaussian Filter (HGF) model |
| Citations | 20 |
| Key findings | Higher conditioned hallucination rates were observed in participants with recent hallucinatory experiences and those with high hallucination-proneness, and these rates correlated with increased prior weighting, which was related to hallucination severity. Unlike past results, these participants also showed higher stimulus thresholds, lower sensitivity at the highest threshold, and lower response confidence, which the authors interpret as reduced sensory precision. |
Abstract
Background: There is increasing evidence that people with hallucinations overweight perceptual beliefs relative to incoming sensory evidence. Past work demonstrating prior overweighting has used simple, nonlinguistic stimuli. However, auditory hallucinations in psychosis are often complex and linguistic. There may be an interaction between the type of auditory information being processed and its perceived quality in engendering hallucinations. STUDY
Design: We administered a linguistic version of the conditioned hallucinations (CH) task to an online sample of 88 general population participants. Metrics related to hallucination-proneness, hallucination severity, stimulus thresholds, and stimulus detection rates were collected. Data were used to fit parameters of a Hierarchical Gaussian Filter (HGF) model of perceptual inference to determine how latent perceptual states influenced task behavior. STUDY
Results: Replicating past results, higher CH rates were observed both in those with recent hallucinatory experiences as well as participants with high hallucination-proneness; CH rates were positively correlated with increased prior weighting; and increased prior weighting was related to hallucination severity. Unlike past results, participants with recent hallucinatory experiences as well as those with higher hallucination-proneness had higher stimulus thresholds, lower sensitivity to stimuli presented at the highest threshold, and had lower response confidence, consistent with lower precision of sensory evidence.
Conclusions: We replicate the finding that increased CH rates and recent hallucinations correlate with increased prior weighting using a linguistic version of the CH task. Results support a role for reduced sensory precision in the interplay between prior weighting and hallucination-proneness.