Encoding of time-discounted rewards in orbitofrontal cortex is independent of value representation
Encoding of time-discounted rewards in orbitofrontal cortex is independent of value representation
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DOI：
10.1016/j.neuron.2006.06.027
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发表时间：
2006-08-17
期刊：
影响因子：
16.2
通讯作者：
Schoenbaum, Geoffrey
中科院分区：
文献类型：
--
作者：
Roesch, Matthew R.;Taylor, Adam R.;Schoenbaum, Geoffrey
我们监测大鼠眶额皮质的单神经元活动，执行时间折扣任务，奖励的空间位置预测奖励交付之前的延迟是短还是长。我们发现，在大多数神经元中，短时间延迟后传递的奖励引起的神经元反应比长时间延迟后传递的奖励更强烈。当延迟保持不变时，这些神经元的活动不受奖励大小的影响。这也适用于少数神经元，这些神经元在预期延迟奖励时表现出持续的放电增加。因此，眶额皮层对时间折扣奖励的编码与绝对奖励值的编码无关。这些结果是相反的建议，眶额神经元信号延迟奖励的价值在一个共同的货币，而是建议替代建议的作用，这一地区在指导反应延迟与即时奖励。
We monitored single-neuron activity in the orbitofrontal cortex of rats performing a time-discounting task in which the spatial location of the reward predicted whether the delay preceding reward delivery would be short or long. We found that rewards delivered after a short delay elicited a stronger neuronal response than those delivered after a long delay in most neurons. Activity in these neurons was not influenced by reward size when delays were held constant. This was also true for a minority of neurons that exhibited sustained increases in firing in anticipation of delayed reward. Thus, encoding of time-discounted rewards in orbitofrontal cortex is independent of the encoding of absolute reward value. These results are contrary to the proposal that orbitofrontal neurons signal the value of delayed rewards in a common currency and instead suggest alternative proposals for the role this region plays in guiding responses for delayed versus immediate rewards.