Short-term temporal discounting of reward value in human ventral striatum.
Short-term temporal discounting of reward value in human ventral striatum.
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DOI：
10.1152/jn.90730.2008
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发表时间：
2009-03
影响因子：
2.5
通讯作者：
Schultz W
中科院分区：
文献类型：
--
作者：
Gregorios-Pippas L;Tobler PN;Schultz W
延迟的奖励失去了经济决策的价值，并构成了较弱的学习动机。奖励价值的时间折扣在动物中已经发生在几秒钟内，这使得研究潜在的神经生理机制成为可能。然而，很难将这些机制与人类的贴现行为联系起来，这通常需要几天或几个月的时间来研究，并且可能涉及不同的大脑过程。我们的研究旨在通过使用非常短的延迟和测量大脑中关键奖励中心之一腹侧纹状体的人类功能磁共振反应来弥合差距。我们使用心理测量学方法来评估延迟4.0-13.5秒的货币奖励的主观时间和价值。我们证明了双曲线和指数下降的纹状体反应奖励预测刺激在此时间范围内，无论奖励率的变化。较低的奖励幅度诱导陡峭的行为和纹状体折扣。相比之下，纹状体反应后，交付奖励反映了不确定性的主观时间与延迟奖励，而不是价值折扣。这些数据表明，几秒钟的延迟会影响腹侧纹状体预测奖励值的神经处理，并参与奖励反应的时间敏感性。与电生理动物数据的比较表明，腹侧纹状体奖励折扣可能涉及多巴胺能和眶额输入。
Delayed rewards lose their value for economic decisions and constitute weaker reinforcers for learning. Temporal discounting of reward value already occurs within a few seconds in animals, which allows investigations of the underlying neurophysiological mechanisms. However, it is difficult to relate these mechanisms to human discounting behavior, which is usually studied over days and months and may engage different brain processes. Our study aimed to bridge the gap by using very short delays and measuring human functional magnetic resonance responses in one of the key reward centers of the brain, the ventral striatum. We used psychometric methods to assess subjective timing and valuation of monetary rewards with delays of 4.0–13.5 s. We demonstrated hyperbolic and exponential decreases of striatal responses to reward predicting stimuli within this time range, irrespective of changes in reward rate. Lower reward magnitudes induced steeper behavioral and striatal discounting. By contrast, striatal responses following the delivery of reward reflected the uncertainty in subjective timing associated with delayed rewards rather than value discounting. These data suggest that delays of a few seconds affect the neural processing of predicted reward value in the ventral striatum and engage the temporal sensitivity of reward responses. Comparisons with electrophysiological animal data suggest that ventral striatal reward discounting may involve dopaminergic and orbitofrontal inputs.
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影响因子：
2.7
作者：
Johnson, MW;Bickel, WK
通讯作者：
Bickel, WK
影响因子：
2.4
作者：
Cardinal RN;Cheung TH
通讯作者：
Cheung TH
影响因子：
25
作者：
Kable, Joseph W.;Glimcher, Paul W.
通讯作者：
Glimcher, Paul W.
DOI：
10.1006/obhd.1995.1086
发表时间：
1995-10-01
影响因子：
4.6
作者：
KIRBY, KN;MARAKOVIC, NN
通讯作者：
MARAKOVIC, NN
DOI：
10.1111/j.2517-6161.1995.tb02031.x
发表时间：
1995-01-01
影响因子：
5.8
作者：
BENJAMINI, Y;HOCHBERG, Y
通讯作者：
HOCHBERG, Y