Biology subjects

Corlett, P. R.

Publications and source records attributed to Corlett, P. R..

3 recordsLinked to original sources

bioRxiv2020

Expecting the unexpected: the paranoid style of belief updating across species

Paranoia is the belief that harm is intended by others. It may arise from selective pressures to infer and avoid social threats, particularly in ambiguous or changing circumstances. We propose that uncertainty may be sufficient to elicit learning differences in paranoid individuals, without social threat. We used reversal learning behaviour and computational modelling to estimate belief updating across individuals with and without mental illness, online participants, and rats exposed to chronic methamphetamine, an elicitor of paranoia in humans. Paranoia is associated with a strong but immutable prior on volatility, accompanied by elevated sensitivity to perceived changes in the task environment. Methamphetamine exposure in rats recapitulates this impaired uncertainty-driven belief updating and rigid anticipation of a volatile environment. Our work provides evidence of fundamental, domain-general learning differences in paranoid individuals. This paradigm enables further assessment of the interplay between uncertainty and belief-updating across individuals and species.

neuroscience↗

bioRxiv2019

Induced illusory body ownership in Borderline Personality Disorder

BackgroundOne aspect of selfhood that may have relevance for Borderline Personality Disorder (BPD) is variation in sense of body ownership. We employed the rubber hand illusion (RHI) to manipulate sense of body ownership in BPD. We extended previous research on illusory body ownership in BPD by testing: 1) two illusion conditions: asynchronous & synchronous stimulation, 2) relationship between Illusion experience and BPD symptoms, and 3) relationship between illusion experience and maladaptive personality traits.\n\nMethodsWe measured illusion strength (questionnaire responses), proprioceptive drift (perceived shift in physical hand position), BPD symptoms (DIB-R score), and maladaptive personality traits (PID-5) in 24 BPD and 21 control participants.\n\nResultsFor subjective illusion strength, we found a main effect of group (BPD > HC, F = 11.94 p = 0.001), and condition (synchronous > asynchronous, F(1,43) = 22.80, p < 0.001). There was a group x condition interaction for proprioceptive drift (F(1,43) = 6.48, p = 0.015) such that people with BPD maintained illusion susceptibility in the asynchronous condition. Borderline symptom severity correlated with illusion strength within the BPD group, and this effect was specific to affective symptoms (r = 0.48, p < 0.01). Across all participants, trait psychoticism correlated with illusion strength (r = 0.44, p < 0.01).\n\nConclusionPeople with BPD are more susceptible to illusory body ownership than controls. This is consistent with the clinical literature describing aberrant physical and emotional experience of self in BPD. A predictive-coding framework holds promise to develop testable mechanistic hypotheses for disrupted bodily self in BPD.\n\nHighlightsO_LIThe rubber hand illusion (RHI) allows measurement of self-disturbance.\nC_LIO_LIPeople with BPD had greater illusion susceptibility and this correlated with affective symptoms.\nC_LIO_LIInteroception stabilizes representations of body ownership, and is impaired in BPD.\nC_LIO_LIIllusion strength correlates with psychotic traits across levels of psychopathology.\nC_LIO_LIPredictive coding frameworks can probe mechanisms of impaired body ownership in psychopathology.\nC_LI

neuroscience↗

bioRxiv2017

Trait-level paranoia shapes inter-subject synchrony in brain activity during an ambiguous social narrative

Individuals often interpret the same event in different ways. How do personality traits modulate brain activity evoked by a complex stimulus? Here we report results from a naturalistic paradigm designed to draw out both neural and behavioral variation along a specific dimension of interest, namely paranoia. Participants listen to a narrative during functional MRI describing an ambiguous social scenario, written such that some individuals would find it highly suspicious, while others less so. Using inter-subject correlation analysis, we identify several brain areas that are differentially synchronized during listening between participants with high- and low trait-level paranoia, including theory-of-mind regions. Follow-up analyses indicate that these regions are more active to mentalizing events in high-paranoia individuals. Analyzing participants speech as they freely recall the narrative reveals semantic and syntactic features that also scale with paranoia. Results indicate that a personality trait can act as an intrinsic prime, yielding different neural and behavioral responses to the same stimulus across individuals.

neuroscience↗