King's College London

Background: Hallucinations have been linked to failures in metacognitive reflection suggesting an association between hallucinations and overestimation of performance, although the cross-sectional findings are inconsistent. This inconsistency may relate to the fluctuating hallucinatory experiences that are not captured in cross-sectional studies. Ecological Momentary Assessment (EMA) captures in-the-moment experiences over time so can identify causal relationships between variables such as the associations between metacognition and hallucinatory experience in daily life and overcome problems in cross-sectional designs. Methods: Participants (N = 41) experiencing daily hallucinations completed baseline questionnaires and smartphone surveys 7 times per day for 14 days. They were prompted to identify a task they would complete in the next 4 h and to make metacognitive predictions around the likelihood of completing the task, the difficulty of the task, and how well they would complete it (standard of completion). Results: 76 % finished the 14-days of assessment with an average of 42.2 % survey completion. Less accurate metacognition was associated with more hallucinations, but less accurate likelihood and standard of completion was associated with fewer hallucinations. Using a cross-lagged analysis, metacognitive predictions around the likelihood of completion (p < .001) and standard of completion (p = .01) predicted hallucination intensity at the following timepoint, and metacognitive predictions regarding likelihood of completion (p = .02) predicted hallucination control at the following timepoint. Discussion: Interventions that aim to improve metacognitive ability in-the-moment may serve to reduce the intensity and increase the control of hallucinations.