The Prominent Deck B Phenomenon in Schizophrenia: An Empirical Study on Iowa Gambling Task

Mei Xu; We-Kang Lee; Chih-Hung Ko; Yao-Chu Chiu; Ching-Hung Lin

doi:10.3389/fpsyg.2021.619855

The Prominent Deck B Phenomenon in Schizophrenia: An Empirical Study on Iowa Gambling Task

Front Psychol. 2021 Sep 3:12:619855. doi: 10.3389/fpsyg.2021.619855. eCollection 2021.

Authors

Mei Xu^{1

2}, We-Kang Lee^{3

4}, Chih-Hung Ko^{5

6

7}, Yao-Chu Chiu⁴, Ching-Hung Lin^{1

8}

Affiliations

¹ Department of Psychology, Kaohsiung Medical University, Kaohsiung, Taiwan.
² School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
³ Sleep Center, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.
⁴ Department of Psychology, Soochow University, Taipei, Taiwan.
⁵ Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
⁶ Department of Psychiatry, Kaohsiung Municipal Siaogang Hospital, Kaohsiung, Taiwan.
⁷ College of Medicine, Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
⁸ Research Center for Non-linear Analysis and Optimization, Kaohsiung Medical University, Kaohsiung, Taiwan.

Abstract

Background: The Iowa Gambling Task (IGT) was established to evaluate emotion-based decision-making ability under uncertain circumstances in clinical populations, including schizophrenia (Sz). However, there remains a lack of stable behavioral measures regarding discrimination for decision-making performance in IGT between schizophrenic cases and healthy participants. None of the Sz-IGT studies has specifically verified the prominent deck B (PDB) phenomenon gradually revealed in other populations. Here, we provided a global review and empirical study to verify these Sz-IGT issues. Methods: Seeking reliable and valid behavioral measures, we reviewed 38 studies using IGT to investigate decision-making behavior in Sz groups. The IGT, the Wisconsin Card Sorting Test (WCST), and clinical symptoms evaluations were administered to 61 schizophrenia or schizoaffective cases diagnosed by psychiatrists and 62 demographically matched healthy participants. Results: There were no valid behavioral measures in IGT that could significantly identify the decision-making dysfunction of Sz. However, Sz cases, on average, made more choices from disadvantageous deck B relative to other decks, particularly in the later learning process (block 3-5). Compared to the control group, the Sz group was more impaired on the WCST. The high-gain frequency decks B and D showed significant correlations with WCST but no correlation between clinical symptoms and IGT/WCST. Conclusions: Gain-loss frequency (GLF) has a dominant and stable impact on the decision-making process in both Sz and control groups. PDB phenomenon is essentially challenging to be observed on the ground of the expected value (EV) viewpoint approach on the IGT in both populations. Consequently, caution should be exercised when launching the IGT to assess the decision-making ability of Sz under a clinical scenario.

Keywords: Iowa Gambling Task; decision making; expected value; gain-loss frequency; prominent deck B phenomenon; schizophrenia.