Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals

Teufel, Christoph, Subramaniam, Naresh, Dobler, Veronika, Perez, Jesus, Finnemann, Johanna, Mehta, Puja R., Goodyer, Ian M. and Fletcher, Paul C. 2015. Shift toward prior knowledge confers a perceptual advantage in early psychosis and psychosis-prone healthy individuals. Proceedings of the National Academy of Sciences of the United States of America 112 (43) , pp. 13401-13406. 10.1073/pnas.1503916112

[img]
Preview
PDF - Published Version
Download (966kB) | Preview

Abstract

Many neuropsychiatric illnesses are associated with psychosis, i.e., hallucinations (perceptions in the absence of causative stimuli) and delusions (irrational, often bizarre beliefs). Current models of brain function view perception as a combination of two distinct sources of information: bottom-up sensory input and top-down influences from prior knowledge. This framework may explain hallucinations and delusions. Here, we characterized the balance between visual bottom-up and top-down processing in people with early psychosis (study 1) and in psychosis-prone, healthy individuals (study 2) to elucidate the mechanisms that might contribute to the emergence of psychotic experiences. Through a specialized mental-health service, we identified unmedicated individuals who experience early psychotic symptoms but fall below the threshold for a categorical diagnosis. We observed that, in early psychosis, there was a shift in information processing favoring prior knowledge over incoming sensory evidence. In the complementary study, we capitalized on subtle variations in perception and belief in the general population that exhibit graded similarity with psychotic experiences (schizotypy). We observed that the degree of psychosis proneness in healthy individuals, and, specifically, the presence of subtle perceptual alterations, is also associated with stronger reliance on prior knowledge. Although, in the current experimental studies, this shift conferred a performance benefit, under most natural viewing situations, it may provoke anomalous perceptual experiences. Overall, we show that early psychosis and psychosis proneness both entail a basic shift in visual information processing, favoring prior knowledge over incoming sensory evidence. The studies provide complementary insights to a mechanism by which psychotic symptoms may emerge.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Cardiff University Brain Research Imaging Centre (CUBRIC)
Psychology
Subjects: B Philosophy. Psychology. Religion > BF Psychology
Publisher: National Academy of Sciences
ISSN: 0027-8424
Funders: Wellcome Trust and Bernard Wolfe Health Neuroscience Fund
Date of First Compliant Deposit: 30 March 2016
Date of Acceptance: 28 May 2015
Last Modified: 05 Mar 2019 10:14
URI: http://orca.cf.ac.uk/id/eprint/79064

Citation Data

Cited 54 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics