A cognitive model of perceptual anomalies: The role of source monitoring, top-down influence and inhibitory control processes for hallucinations in schizophrenia spectrum disorders and hallucinatory-like experiences in the general population

Background: Cognitive models emphasise that source monitoring, top-downprocesses, and inhibitory control are mechanisms of perceptual anomalies, particularlyauditory hallucinations (AHs) and hallucinatory-like experiences (HLEs). Nonetheless,limited research integrates clinical and non-clinical perceptual anomalies to examinethese cognitive mechanisms and the connections between them. The present studyaimed to investigate the role of three cognitive processes within the perceptualanomalies continuum. Moreover, the study examines the relationship betweenperceptual anomalies, cognitive processes, self-disturbances, and general functioning.Methods: Eighty-nine patients with schizophrenia spectrum disorders (SSD) weredivided into two groups based on AHs presence - 46 with AHs and 43 - nonhallucinating, 43 matched healthy controls (HC), and a sample selected from thegeneral population of 40 participants with high HLEs and 43 with low HLEs performedthree experimental tasks assessing top-down processes (False Perception Task -FPT), source monitoring (Action Memory Task - AMT), and inhibitory control (Go/NoGo Task). Results: Both patient groups committed significantly more source monitoring errors andmore false perceptions (after accounting for response bias) than HC, with nodifferences between SSD with AH vs SSD without current AH and high HLEs vs lowHLEs. No significant group differences were found for false alarms in the Go/No-GoTask. However, there was a significant relationship between perceptual anomalies andall the cognitive processes as well as self-disturbances and functioning in the entiresample. Conclusions: This study sheds further light on the mechanisms and correlates ofperceptual anomalies in clinical and non-clinical populations.