Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510, USA.
Neuron. 2011 Jan 13;69(1):170-82. doi: 10.1016/j.neuron.2010.11.041.
In choosing between different rewards expected after unequal delays, humans and animals often prefer the smaller but more immediate reward, indicating that the subjective value or utility of reward is depreciated according to its delay. Here, we show that neurons in the primate caudate nucleus and ventral striatum modulate their activity according to temporally discounted values of rewards with a similar time course. However, neurons in the caudate nucleus encoded the difference in the temporally discounted values of the two alternative targets more reliably than neurons in the ventral striatum. In contrast, neurons in the ventral striatum largely encoded the sum of the temporally discounted values, and therefore, the overall goodness of available options. These results suggest a more pivotal role for the dorsal striatum in action selection during intertemporal choice.
在选择不同延迟后的不同奖励时，人类和动物通常更喜欢较小但更即时的奖励，这表明奖励的主观价值或效用会根据其延迟而贬值。在这里，我们表明，灵长类动物尾状核和腹侧纹状体中的神经元根据奖励的时间折扣值进行调节，其时间过程相似。然而，与腹侧纹状体中的神经元相比，尾状核中的神经元更可靠地编码了两个替代目标的时间折扣值之间的差异。相比之下，腹侧纹状体中的神经元主要编码时间折扣值的总和，因此，可用选项的整体好坏。这些结果表明，在跨时选择期间，背侧纹状体在动作选择中起着更关键的作用。
