An "As Soon As Possible" Effect in Human Intertemporal Decision Making: Behavioral Evidence and Neural Mechanisms
An "As Soon As Possible" Effect in Human Intertemporal Decision Making: Behavioral Evidence and Neural Mechanisms
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DOI：
10.1152/jn.00177.2009
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发表时间：
2010-05-01
影响因子：
2.5
通讯作者：
Glimcher, Paul W.
中科院分区：
文献类型：
--
作者：
Kable, Joseph W.;Glimcher, Paul W.
Kable JW，Glimcher PW。人类跨期决策的“越快越好”效应：行为证据和神经机制。神经生理学杂志103：2513-2531,2010。2010年2月24日首次出版；DOI：10.1152/jn.00177.2009。许多决定涉及在结果的质量和收到该结果的时间之间进行权衡。在心理学和行为经济学中，研究最广泛的模型假设未来收益的价值下降是从现在开始的延迟的大致双曲线函数。最近，有人提出，这种双曲线式的价值下降是两个独立的神经系统相互作用的结果：一个专门评估即时回报，另一个专门评估延迟回报。在这里，我们报告了行为和功能磁共振成像结果，这些结果既不符合贴现的标准行为模型，也不符合分开的神经系统重视即时和延迟奖励的假设。在行为上，我们发现，人类受试者并不一定会做出双曲型贴现所预测的冲动性偏好逆转。我们还发现，腹侧纹状体、内侧前额叶和后扣带回皮质的血氧水平依赖活动并不像分离神经系统假说所提出的那样追踪是否存在即时奖励。这些区域的活动与即时和延迟奖励的主观价值相关。这些值不是只对一个奖励与另一个奖励的相对价值进行编码，而是以更绝对的尺度来表示。这些数据支持另一种行为神经模型(我们称之为ASAP)，在该模型中，主观价值相对于当前可获得的最快回报以双曲线方式下降，少数估值领域充当这些主观价值指导选择的最终共同路径。
Kable JW, Glimcher PW. An "as soon as possible" effect in human intertemporal decision making: behavioral evidence and neural mechanisms. J Neurophysiol 103: 2513-2531, 2010. First published February 24, 2010; doi: 10.1152/jn.00177.2009. Many decisions involve a trade-off between the quality of an outcome and the time at which that outcome is received. In psychology and behavioral economics, the most widely studied models hypothesize that the values of future gains decline as a roughly hyperbolic function of delay from the present. Recently, it has been proposed that this hyperbolic-like decline in value arises from the interaction of two separate neural systems: one specialized to value immediate rewards and the other specialized to value delayed rewards. Here we report behavioral and functional magnetic resonance imaging results that are inconsistent with both the standard behavioral models of discounting and the hypothesis that separate neural systems value immediate and delayed rewards. Behaviorally, we find that human subjects do not necessarily make the impulsive preference reversals predicted by hyperbolic-like discounting. We also find that blood oxygenation level dependent activity in ventral striatum, medial prefrontal, and posterior cingulate cortex does not track whether an immediate reward was present, as proposed by the separate neural systems hypothesis. Activity in these regions was correlated with the subjective value of both immediate and delayed rewards. Rather than encoding only the relative value of one reward compared with another, these values are represented on a more absolute scale. These data support an alternative behavioral neural model (which we call "ASAP"), in which subjective value declines hyperbolically relative to the soonest currently available reward and a small number of valuation areas serve as a final common pathway through which these subjective values guide choice.