Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
Biol Psychiatry. 2012 Apr 15;71(8):741-8. doi: 10.1016/j.biopsych.2011.12.030. Epub 2012 Feb 18.
Pathologic gamblers are known to have abnormal neural responses associated with experiencing monetary wins and losses. However, neural responsiveness during reward and loss expectations in pathologic gamblers has not yet been investigated.
We used a functional magnetic resonance imaging paradigm that allowed us to investigate the dissociable reward- and loss-related expectancies with various probabilities of winning or losing different amounts of money in 15 patients with problem gambling (PRGs) and 16 healthy control subjects (HCs).
Compared with HCs, PRGs showed stronger activation in the bilateral ventral striatum to 5 euro than to 1 euro trials. PRGs also showed more activation of the bilateral ventral striatum and left orbitofrontal cortex associated with gain-related expected value than HCs. In addition, regression analyses indicated a highly significant negative correlation between gambling severity scores and right amygdala activation associated with gain-related expected value coding. There were no group differences in brain activation for loss-related expected value.
PRGs show higher activity in the reward system during reward expectation than HCs, whereas we observed no difference between PRGs and HC in the loss value system. Furthermore, the negative relation between gambling severity and amygdala activation in gain expected value coding suggests that more severe PRGs are less likely to be risk aversive during gambling. Our study provides evidence that PRGs are characterized by abnormally increased reward expectancy coding, which may render them overoptimistic with regard to gambling outcomes.
已知病态赌徒在经历金钱输赢时会出现异常的神经反应。然而，病态赌徒在奖励和损失预期期间的神经反应尚未得到研究。
我们使用了一种功能磁共振成像范式，使我们能够在 15 名有问题赌博（PRG）患者和 16 名健康对照组（HC）中，用不同的赢钱和输钱概率来研究可分离的奖励和损失相关的预期。
与 HC 相比，PRG 在双侧腹侧纹状体对 5 欧元试验的激活强度大于对 1 欧元试验的激活强度。PRG 还显示出与收益相关的预期价值相关的双侧腹侧纹状体和左侧眶额皮层的更多激活，而 HC 则没有。此外，回归分析表明，赌博严重程度评分与与收益相关的预期价值编码相关的右侧杏仁核激活之间存在高度显著的负相关。对于损失相关的预期价值，两组之间没有大脑激活的差异。
PRG 在奖励预期期间的奖励系统中表现出比 HC 更高的活动，而我们在损失价值系统中没有观察到 PRG 和 HC 之间的差异。此外，赌博严重程度和杏仁核激活之间的负相关表明，更严重的 PRG 在赌博时不太可能回避风险。我们的研究提供了证据表明，PRG 的特点是异常增加的奖励预期编码，这可能使他们对赌博结果过于乐观。
