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

BACKGROUND

Cognitive models emphasise that source monitoring, top-down processes, and inhibitory control are mechanisms of perceptual anomalies, particularly auditory hallucinations (AHs) and hallucinatory-like experiences (HLEs). Nonetheless, limited research integrates clinical and non-clinical perceptual anomalies to examine these cognitive mechanisms and the connections between them. The present study aimed to investigate the role of three cognitive processes within the perceptual anomalies continuum. Moreover, the study examines the relationship between perceptual anomalies, cognitive processes, self-disturbances, and general functioning.

METHODS

Eighty-nine patients with schizophrenia spectrum disorders (SSD) were divided into two groups based on AHs presence - 46 with AHs and 43 - non-hallucinating, 43 matched healthy controls (HC), and a sample selected from the general population of 40 participants with high HLEs and 43 with low HLEs performed three experimental tasks assessing top-down processes (False Perception Task - FPT), source monitoring (Action Memory Task - AMT), and inhibitory control (Go/No-Go Task).

RESULTS

Both patient groups committed significantly more source monitoring errors and more false perceptions (after accounting for response bias) than HC, with no differences between SSD with AH vs SSD without current AH and high HLEs vs low HLEs. No significant group differences were found for false alarms in the Go/No-Go Task. However, there was a significant relationship between perceptual anomalies and all the cognitive processes as well as self-disturbances and functioning in the entire sample.

CONCLUSIONS

This study sheds further light on the mechanisms and correlates of perceptual anomalies in clinical and non-clinical populations.