Brevers Damien, Koritzky Gilly, Bechara Antoine, Noël Xavier
Department of Psychology, and Brain and Creativity Institute, University of Southern California, 3620A McClintock Avenue, 90089-2921, Los Angeles, CA, USA; Psychological Medicine Laboratory, Faculty of Medicine, Brugmann-Campus, Université Libre de Bruxelles (ULB), 4, Place van Gehuchten, 1002 Brussels, Belgium.
Department of Psychology, and Brain and Creativity Institute, University of Southern California, 3620A McClintock Avenue, 90089-2921, Los Angeles, CA, USA.
Addict Behav. 2014 Oct;39(10):1533-6. doi: 10.1016/j.addbeh.2014.06.004. Epub 2014 Jun 18.
Pathological gamblers display at the Iowa Gambling Task (IGT) a strong preference for choices featuring high immediate rewards, but higher unpredictable and more delayed losses. The present study aimed, by applying the Expectancy-Valence (EV) model to the IGT, at identifying impaired components of decision-making under uncertainty in pathological gamblers.
Twenty pathological gamblers and 20 non-gamblers performed the IGT. The EV model breaks down IGT performance into three cognitive processes: (i) the subjective weight that the individual assigns to gains versus losses (gain/loss parameter), (ii) the degree of prominence given to recently-obtained information, compared to past experience (recency parameter), and (iii) the consistency between learning and responding (consistency parameter).
Pathological gamblers obtained higher scores on the gain/loss parameter as compared to controls, indicating higher sensitivity to monetary gains. This measure was also correlated with the degree of gambling dependence severity. No between-group difference was observed in the recency and the consistency parameters.
These findings suggest that pathological gamblers' strong preference for choices featuring high rewards but higher losses during the IGT is due to hypersensitivity for large monetary gains, which might reflect a hypersensitivity in their reward systems. In contrast, we found in pathological gamblers no evidence of inability to integrate information across time, a function that has been shown previously to be linked to damage in the prefrontal cortex.
病态赌徒在爱荷华赌博任务（IGT）中表现出强烈偏好，即偏好具有高即时奖励但更高不可预测性和更多延迟损失的选择。本研究旨在通过将期望-效价（EV）模型应用于IGT，识别病态赌徒在不确定性下决策受损的成分。
20名病态赌徒和20名非赌徒进行了IGT。EV模型将IGT表现分解为三个认知过程：（i）个体赋予收益与损失的主观权重（收益/损失参数），（ii）与过去经验相比，给予最近获得信息的突出程度（近因参数），以及（iii）学习与反应之间的一致性（一致性参数）。
与对照组相比，病态赌徒在收益/损失参数上得分更高，表明对金钱收益更敏感。该指标也与赌博依赖严重程度相关。在近因和一致性参数上未观察到组间差异。
这些发现表明，病态赌徒在IGT期间对具有高奖励但更高损失的选择的强烈偏好是由于对大额金钱收益的超敏感性，这可能反映了他们奖励系统中的超敏感性。相比之下，我们在病态赌徒中未发现无法跨时间整合信息的证据，而之前已证明该功能与前额叶皮层损伤有关。
