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Nick Medford

2 papers in the library · 167 citations · publishing 2013-2018

Papers

Anomalous self-experience in depersonalization and schizophrenia: a comparative investigation.

Consciousness and cognition June 1, 2013 Louis Sass, Elizabeth Pienkos, Barnaby Nelson et al. 144 citations

Anomalous self-experiences are central to schizophrenia and other psychiatric disorders. This analysis compared such experiences in schizophrenia-spectrum disorders, as cataloged in the EASE, with those described in severe depersonalization. Numerous affinities were found, showing that pure forms of diminished self-affection (depersonalization) can involve experiences resembling those of schizophrenia. However, important discrepancies emerged, suggesting that more automatic or deficiency-like factors—probably involving self/world or self/other confusion and erosion of first-person perspective—are more distinctive of schizophrenia-spectrum disorders.

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

Cognitive Neuropsychiatry February 27, 2018 Geoff Davies, Charlotte L. Rae, Sarah N. Garfinkel et al. 23 citations

People in the early stages of psychosis show a reduced ability to accurately evaluate their own perceptions, a metacognitive deficit. In a perceptual decision-making task, individuals with first-episode psychosis performed worse on metacognitive accuracy than healthy controls, even when their basic perceptual performance was accounted for. Grey matter volume was also reduced in the superior frontal gyrus, a brain region linked to metacognition. However, no direct relationship was found between grey matter volume and metacognitive accuracy, leaving the neural basis of this deficit unclear. These findings suggest that a specific problem in scrutinizing one's own perceptions may underlie later functional difficulties in schizophrenia.