Impairment of perceptual metacognitive accuracy and reduced prefrontal grey matter volume in first-episode psychosis

Davies, Geoff, Rae, Charlotte L, Garfinkel, Sarah N, Seth, Anil K, Medford, Nick, Critchley, Hugo D and Greenwood, Kathryn (2018) Impairment of perceptual metacognitive accuracy and reduced prefrontal grey matter volume in first-episode psychosis. Cognitive Neuropsychiatry, 23 (3). pp. 165-179. ISSN 1354-6805

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Introduction: Metacognition, or “thinking about thinking”, is a higher-order thought process that allows for the evaluation of perceptual processes for accuracy. Metacognitive accuracy is associated with the grey matter volume (GMV) in the prefrontal cortex (PFC), an area also impacted in schizophrenia. The present study set out to investigate whether deficits in metacognitive accuracy are present in the early stages of psychosis.

Methods: Metacognitive accuracy in first-episode psychosis (FEP) was assessed on a perceptual decision making task and their performance compared to matched healthy control participants (N = 18). A novel signal detection theory approach was used to model metacognitive sensitivity independently from objective perceptual performance. A voxel-based morphometry investigation was also conducted on GMV.

Results: We found that the FEP group demonstrated significantly worse metacognitive accuracy compared to controls (p = .039). Importantly, GMV deficits were also observed in the superior frontal gyrus. The findings suggest a specific deficit in this processing domain to exist at first episode; however, no relationship was found between GMV and metacognitive accuracy.

Conclusions: Our findings support the notion that an inability to accurately scrutinise perception may underpin functional deficits observed in later schizophrenia; however, the exact neural basis of metacognitive deficits in FEP remains elusive.

Item Type: Article
Keywords: Schizophrenia, psychosis, metacognition, consciousness, voxel-based morphometry
Schools and Departments: Brighton and Sussex Medical School > Neuroscience
School of Engineering and Informatics > Informatics
School of Psychology > Psychology
Research Centres and Groups: Sackler Centre for Consciousness Science
Depositing User: Alexei Fisk
Date Deposited: 16 Mar 2018 16:34
Last Modified: 15 Oct 2018 13:18

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