Fujimoto A, Tsurumi K, Kawada R, Murao T, Takeuchi H, Murai T, Takahashi H
Department of Psychiatry, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Department of Functional Brain Imaging, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan.
Transl Psychiatry. 2017 Apr 4;7(4):e1085. doi: 10.1038/tp.2017.55.
Gambling disorder (GD) is often considered as a problem of trait-like risk preference. However, the symptoms of GD cannot be fully understood by this trait view. In the present study, we hypothesized that GD patients also had problem with a flexible control of risk attitude (state-dependent strategy optimization), and aimed to investigate the mechanisms underlying abnormal risk-taking of GD. To address this issue, we tested GD patients without comorbidity (GD group: n=21) and age-matched healthy control participants (HC group: n=29) in a multi-step gambling task, in which participants needed to clear 'block quota' (required units to clear a block, 1000-7000 units) in 20 choices, and conducted a task-functional magnetic resonance imaging (fMRI) experiment. Behavioral analysis indeed revealed a less flexible risk-attitude change in the GD group; the GD group failed to avoid risky choice in a specific quota range (low-quota condition), in which risky strategy was not optimal to solve the quota. Accordingly, fMRI analysis highlighted diminished functioning of the dorsolateral prefrontal cortex (dlPFC), which has been heavily implicated in cognitive flexibility. To our knowledge, the present study provided the first empirical evidence of a deficit of state-dependent strategy optimization in GD. Focusing on flexible control of risk attitude under quota may contribute to a better understanding of the psychopathology of GDs.
赌博障碍(GD)通常被视为一种类似特质的风险偏好问题。然而,仅从这种特质观点无法完全理解GD的症状。在本研究中,我们假设GD患者在灵活控制风险态度(状态依赖策略优化)方面也存在问题,并旨在探究GD患者异常冒险行为背后的机制。为解决这一问题,我们在一项多步赌博任务中对无共病的GD患者(GD组:n = 21)和年龄匹配的健康对照参与者(HC组:n = 29)进行了测试,在该任务中参与者需要在20次选择中清除“方块配额”(清除一个方块所需的单位,1000 - 7000单位),并进行了任务功能磁共振成像(fMRI)实验。行为分析确实显示GD组的风险态度变化缺乏灵活性;GD组在特定配额范围内(低配额条件)未能避免冒险选择,在该范围内冒险策略并非解决配额的最佳选择。相应地,fMRI分析突出了背外侧前额叶皮层(dlPFC)功能的减弱,该区域与认知灵活性密切相关。据我们所知,本研究首次提供了GD患者存在状态依赖策略优化缺陷的实证证据。关注配额下风险态度的灵活控制可能有助于更好地理解GD的精神病理学。