Effects of feedback reliability on feedback-related brain activity: A feedback valuation account
Effects of feedback reliability on feedback-related brain activity: A feedback valuation account
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DOI：
10.3758/s13415-018-0591-7
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发表时间：
2018-06-01
影响因子：
2.9
通讯作者：
Steinhauser, Marco
中科院分区：
文献类型：
--
作者：
Ernst, Benjamin;Steinhauser, Marco
适应性决策依赖于从反馈中学习。由于反馈有时可能会误导，最佳学习需要利用反馈的可靠性知识来调整反馈处理。虽然先前的研究已经表明，反馈可靠性确实影响反馈处理，通过它来实现这一点的潜在机制仍然不清楚。在这里，我们建议，反馈处理的自适应调整，自上而下的评价反馈。我们假设不可靠的反馈相对于可靠的反馈是贬值的，从而减少了反馈相关的大脑活动和学习的奖励预测错误。这个帐户的一个重要预测是，反馈可靠性的影响容易受到对比效应。也就是说，与仅经历一个水平的反馈可靠性时相比，当在相同上下文内经历可靠和不可靠反馈两者时，反馈可靠性的效果应当增强。为了评估这一预测，我们测量了事件相关电位引起的反馈在两个实验中，反馈的可靠性是不同的块内或之间。我们发现，额中央效价效应，在强化学习过程中的奖励预测错误的相关性，减少了不可靠的反馈。但是，只有当反馈可靠性在块内变化时，才能得到这个结果，因此表明了对比效应。这表明反馈的适应性评价是反馈可靠性影响反馈加工的一种机制。
Adaptive decision making relies on learning from feedback. Because feedback sometimes can be misleading, optimal learning requires that knowledge about the feedback's reliability be utilized to adjust feedback processing. Although previous research has shown that feedback reliability indeed influences feedback processing, the underlying mechanisms through which this is accomplished remain unclear. Here we propose that feedback processing is adjusted by the adaptive, top-down valuation of feedback. We assume that unreliable feedback is devalued relative to reliable feedback, thus reducing the reward prediction errors that underlie feedback-related brain activity and learning. A crucial prediction of this account is that the effects of feedback reliability are susceptible to contrast effects. That is, the effects of feedback reliability should be enhanced when both reliable and unreliable feedback are experienced within the same context, as compared to when only one level of feedback reliability is experienced. To evaluate this prediction, we measured the event-related potentials elicited by feedback in two experiments in which feedback reliability was varied either within or between blocks. We found that the fronto-central valence effect, a correlate of reward prediction errors during reinforcement learning, was reduced for unreliable feedback. But this result was obtained only when feedback reliability was varied within blocks, thus indicating a contrast effect. This suggests that the adaptive valuation of feedback is one mechanism underlying the effects of feedback reliability on feedback processing.