Value and probability coding in a feedback-based learning task utilizing food rewards.
Value and probability coding in a feedback-based learning task utilizing food rewards.
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DOI：
10.1152/jn.00086.2014
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发表时间：
2015
影响因子：
2.5
通讯作者：
E. Tricomi;Karolina M. Lempert
中科院分区：
文献类型：
--
作者：
E. Tricomi;Karolina M. Lempert
对于我们引导行为的行为的后果，大脑必须代表不同类型的与结果相关的信息。例如，一个结果可以被解释为负面的，因为预期的奖励没有交付，或者因为交付了低价值的结果。因此，行为后果可以根据它们提供的关于结果概率和价值的信息而有所不同。我们研究了纹状体在处理基于概率和基于价值的负面反馈中的作用，方法是训练参与者将线索与食物奖励联系起来，然后使用选择性饱腹感程序来降低一种食物结果的价值。使用功能磁共振成像，我们检查了与接受预期奖励、接收贬值结果、遗漏预期奖励、遗漏贬值结果以及预期遗漏结果相关的大脑活动。对于奖赏结果，伏隔核的激活比贬值的结果更大，但该区域的活动与获得奖赏的概率无关。然而，与预期的奖赏遗漏相比，右侧尾状核和壳核的激活是对奖赏结果的最大反应。反馈时的背侧纹状体(尾状核和壳核)也显示出与获得奖励的三次概率相关的参数增加。我们的结果表明，腹侧纹状体对结果的动机相关性或主观价值很敏感，而背侧纹状体编码的是包含奖励概率的更复杂的信号。价值和概率信息可以整合在背侧纹状体中，以促进行动计划和努力的分配。
For the consequences of our actions to guide behavior, the brain must represent different types of outcome-related information. For example, an outcome can be construed as negative because an expected reward was not delivered or because an outcome of low value was delivered. Thus behavioral consequences can differ in terms of the information they provide about outcome probability and value. We investigated the role of the striatum in processing probability-based and value-based negative feedback by training participants to associate cues with food rewards and then employing a selective satiety procedure to devalue one food outcome. Using functional magnetic resonance imaging, we examined brain activity related to receipt of expected rewards, receipt of devalued outcomes, omission of expected rewards, omission of devalued outcomes, and expected omissions of an outcome. Nucleus accumbens activation was greater for rewarding outcomes than devalued outcomes, but activity in this region did not correlate with the probability of reward receipt. Activation of the right caudate and putamen, however, was largest in response to rewarding outcomes relative to expected omissions of reward. The dorsal striatum (caudate and putamen) at the time of feedback also showed a parametric increase correlating with the trialwise probability of reward receipt. Our results suggest that the ventral striatum is sensitive to the motivational relevance, or subjective value, of the outcome, while the dorsal striatum codes for a more complex signal that incorporates reward probability. Value and probability information may be integrated in the dorsal striatum, to facilitate action planning and allocation of effort.