Vinckier, F;
Gaillard, R;
Palminteri, S;
Rigoux, L;
Salvador, A;
Fornito, A;
Adapa, R;
... Fletcher, PC; + view all
(2016)
Confidence and psychosis: a neuro-computational account of contingency learning disruption by NMDA blockade.
Molecular Psychiatry
, 21
(7)
pp. 946-955.
10.1038/mp.2015.73.
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Abstract
A state of pathological uncertainty about environmental regularities might represent a key step in the pathway to psychotic illness. Early psychosis can be investigated in healthy volunteers under ketamine, an NMDA receptor antagonist. Here, we explored the effects of ketamine on contingency learning using a placebo-controlled, double-blind, crossover design. During functional magnetic resonance imaging, participants performed an instrumental learning task, in which cue-outcome contingencies were probabilistic and reversed between blocks. Bayesian model comparison indicated that in such an unstable environment, reinforcement learning parameters are downregulated depending on confidence level, an adaptive mechanism that was specifically disrupted by ketamine administration. Drug effects were underpinned by altered neural activity in a fronto-parietal network, which reflected the confidence-based shift to exploitation of learned contingencies. Our findings suggest that an early characteristic of psychosis lies in a persistent doubt that undermines the stabilization of behavioral policy resulting in a failure to exploit regularities in the environment.
| Type: | Article |
|---|---|
| Title: | Confidence and psychosis: a neuro-computational account of contingency learning disruption by NMDA blockade |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1038/mp.2015.73 |
| Publisher version: | http://dx.doi.org/10.1038/mp.2015.73 |
| Language: | English |
| Additional information: | This article is published under a Creative Commons Attribution 4.0 International license (CC BY 4.0). This license allows you to share, copy, distribute and transmit the work for personal and non-commercial use providing author and publisher attribution is clearly stated. Further details about CC BY licenses are available at http://creativecommons.org/ licenses/by/4.0 |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1471127 |
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