Reliance on Prior Expectations in Psychosis: A Systematic Review and Meta-Analysis of Perceptual Tasks
Chantal Miller-Silva, Benjamin Jg Illingworth, Kirsten Martey, Tamara Mujirishvili, Franciska De Beer, Dan Siskind, Graham K Murray
scientific journals March 31, 2026 preprint DOI: 10.64898/2026.03.31.26349835 via medRxiv
Summary
The predictive processing theory of psychosis suggests that symptoms result from an imbalance in how predictions (priors) and sensory evidence are weighted. However, studies testing this theory often yield conflicting results. This review highlights a key problem: findings from single tasks with small sample sizes are frequently used to support a generalized claim that people with psychosis have an altered reliance on priors. The authors caution against overinterpreting such limited evidence.
Study at a glance
| Characteristics | Review |
|---|---|
| Key finding | Studies on predictive processing in psychosis often present conflicting results, and single-task findings with modest sample sizes are frequently used to advance a theory of generalized altered prior reliance in psychosis. |
Abstract
Background The highly influential predictive processing theory of psychosis posits that symptoms arise from imbalances in the weighting of predictions (priors) and sensory evidence. Despite this theory’s increasing prominence, studies often present conflicting results. This is particularly problematic as findings from single tasks with modest sample sizes are frequently used to advance a theory for a generalised altered reliance on priors in psychosis.