Department of Psychology, Vanderbilt University, Nashville, Tennessee 37240, USA.
J Neurosci. 2012 May 2;32(18):6170-6. doi: 10.1523/JNEUROSCI.6459-11.2012.
Preferences for different combinations of costs and benefits are a key source of variability in economic decision-making. However, the neurochemical basis of individual differences in these preferences is poorly understood. Studies in both animals and humans have demonstrated that direct manipulation of the neurotransmitter dopamine (DA) significantly impacts cost/benefit decision-making, but less is known about how naturally occurring variation in DA systems may relate to individual differences in economic behavior. In the present study, 25 healthy volunteers completed a dual-scan PET imaging protocol with [(18)F]fallypride and d-amphetamine to measure DA responsivity and separately completed the effort expenditure for rewards task, a behavioral measure of cost/benefit decision-making in humans. We found that individual differences in DA function in the left striatum and ventromedial prefrontal cortex were correlated with a willingness to expend greater effort for larger rewards, particularly when probability of reward receipt was low. Additionally, variability in DA responses in the bilateral insula was negatively correlated with willingness to expend effort for rewards, consistent with evidence implicating this region in the processing of response costs. These findings highlight the role of DA signaling in striatal, prefrontal, and insular regions as key neurochemical mechanisms underlying individual differences in cost/benefit decision-making.
偏好不同的成本和收益组合是经济决策中可变性的一个关键来源。然而，个体差异在这些偏好中的神经化学基础还知之甚少。动物和人类的研究都表明，直接操纵神经递质多巴胺 (DA) 会显著影响成本/收益决策，但对于 DA 系统中自然发生的变异如何与经济行为中的个体差异相关知之甚少。在本研究中，25 名健康志愿者完成了 [(18)F]fallypride 和 d-苯丙胺的双扫描 PET 成像方案，以测量 DA 反应性，并分别完成了努力支出奖励任务，这是人类成本/收益决策的行为测量。我们发现，左侧纹状体和腹内侧前额叶皮层中 DA 功能的个体差异与为更大的奖励付出更多努力的意愿相关，特别是在奖励获得概率较低时。此外，双侧脑岛的 DA 反应变异性与为奖励付出努力的意愿呈负相关，这与该区域参与反应成本处理的证据一致。这些发现强调了 DA 信号在纹状体、前额叶和脑岛区域中的作用，作为成本/收益决策中个体差异的关键神经化学机制。
