Brain Science Institute, Tamagawa University, Tokyo, Japan; Department of Neurology, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan.
Parkinsonism Relat Disord. 2010 Aug;16(7):453-7. doi: 10.1016/j.parkreldis.2010.04.011. Epub 2010 May 20.
Studies using the Iowa gambling task (IGT) have shown that patients with Parkinson's disease (PD) make disadvantageous choices characterized by immediate large rewards and delayed larger punishments. These results can be interpreted in two ways: either PD patients are hypersensitive to immediate outcomes and/or insensitive to delayed consequences or PD patients are hypersensitive to rewards and/or insensitive to punishments. In this study, we used a modified IGT in which selection of cards from the disadvantageous decks leads to immediate, small punishments and delayed, smaller rewards and selection of cards from the advantageous decks leads to immediate, large punishments and delayed larger rewards. We then compared the results obtained using this modified IGT with those obtained using the original IGT. If the PD patients were hypersensitive to the immediate outcomes of decisions, they would make disadvantageous choices in both the original and the modified IGTs. Differences between the results of the original and modified tasks would indicate impairments in balancing reward and punishment. In our analysis, PD patients selected advantageous decks and gained as much as normal subjects during the modified IGT, but they selected disadvantageous decks during the original IGT. These results indicate that the decision-making difficulties of PD patients are caused by their inability to balance reward and punishment and their hypersensitivity to reward and/or insensitivity to punishment.
使用爱荷华赌博任务（IGT）的研究表明，帕金森病（PD）患者做出不利的选择，其特征是即时的大奖励和延迟的大惩罚。这些结果可以有两种解释：要么 PD 患者对即时结果过于敏感，和/或对延迟后果不敏感，要么 PD 患者对奖励过于敏感，和/或对惩罚不敏感。在这项研究中，我们使用了一种改良的 IGT，其中选择不利牌组的牌会导致即时的小惩罚和延迟的小奖励，而选择有利牌组的牌会导致即时的大惩罚和延迟的大奖励。然后，我们将使用这种改良的 IGT 获得的结果与使用原始 IGT 获得的结果进行比较。如果 PD 患者对决策的即时结果过于敏感，他们在原始和改良的 IGT 中都会做出不利的选择。原始和改良任务结果之间的差异将表明在平衡奖励和惩罚方面存在障碍。在我们的分析中，PD 患者在改良的 IGT 中选择了有利的牌组，获得了与正常受试者相同的收益，但在原始的 IGT 中选择了不利的牌组。这些结果表明，PD 患者的决策困难是由于他们无法平衡奖励和惩罚，以及对奖励过于敏感和/或对惩罚不敏感造成的。
