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Abnormal cognitive effort allocation and its association with amotivation in first-episode psychosis

Published online by Cambridge University Press:  02 October 2019

W. C. Chang ,
A. Westbrook ,
G. P. Strauss ,
A. O. K. Chu ,
C. S. Y. Chong ,
C. M. W. Siu ,
S. K. W. Chan ,
E. H. M. Lee ,
C. L. M. Hui  and
Y. M. Suen
...Show all authors
W. C. Chang*
Affiliation:
Department of Psychiatry, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong
A. Westbrook
Affiliation:
Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen 6525 EN, The Netherlands Department of Cognitive, Linguistics, and Psychological Sciences, Brown University, Providence, RI02906, USA
G. P. Strauss
Affiliation:
Department of Psychology, University of Georgia, Athens, GA30602, USA
A. O. K. Chu
Affiliation:
Department of Psychiatry, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong
C. S. Y. Chong
Affiliation:
Department of Psychiatry, Kwai Chung Hospital, Hong Kong
C. M. W. Siu
Affiliation:
Department of Psychiatry, Kwai Chung Hospital, Hong Kong
S. K. W. Chan
Affiliation:
Department of Psychiatry, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong
E. H. M. Lee
Affiliation:
Department of Psychiatry, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong
C. L. M. Hui
Affiliation:
Department of Psychiatry, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong
Y. M. Suen
Affiliation:
Department of Psychiatry, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong
T. L. Lo
Affiliation:
Department of Psychiatry, Kwai Chung Hospital, Hong Kong
E. Y. H Chen
Affiliation:
Department of Psychiatry, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong
*
Author for correspondence: W. C. Chang, E-mail: changwc@hku.hk
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Abstract

Background

Abnormal effort-based decision-making represents a potential mechanism underlying motivational deficits (amotivation) in psychotic disorders. Previous research identified effort allocation impairment in chronic schizophrenia and focused mostly on physical effort modality. No study has investigated cognitive effort allocation in first-episode psychosis (FEP).

Method

Cognitive effort allocation was examined in 40 FEP patients and 44 demographically-matched healthy controls, using Cognitive Effort-Discounting (COGED) paradigm which quantified participants’ willingness to expend cognitive effort in terms of explicit, continuous discounting of monetary rewards based on parametrically-varied cognitive demands (levels N of N-back task). Relationship between reward-discounting and amotivation was investigated. Group differences in reward-magnitude and effort-cost sensitivity, and differential associations of these sensitivity indices with amotivation were explored.

Results

Patients displayed significantly greater reward-discounting than controls. In particular, such discounting was most pronounced in patients with high levels of amotivation even when N-back performance and reward base amount were taken into consideration. Moreover, patients exhibited reduced reward-benefit sensitivity and effort-cost sensitivity relative to controls, and that decreased sensitivity to reward-benefit but not effort-cost was correlated with diminished motivation. Reward-discounting and sensitivity indices were generally unrelated to other symptom dimensions, antipsychotic dose and cognitive deficits.

Conclusion

This study provides the first evidence of cognitive effort-based decision-making impairment in FEP, and indicates that decreased effort expenditure is associated with amotivation. Our findings further suggest that abnormal effort allocation and amotivation might primarily be related to blunted reward valuation. Prospective research is required to clarify the utility of effort-based measures in predicting amotivation and functional outcome in FEP.

Keywords

Effort discountingeffort-based decision-makingeffort-cost computationmotivational deficitsnegative symptomspsychotic disordersreward valuation
Type
Original Articles
Information
Psychological Medicine , Volume 50 , Issue 15 , November 2020 , pp. 2599 - 2609
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Copyright
Copyright © Cambridge University Press 2019

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Footnotes

*

These authors contributed equally to this article

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