Adaptive Prediction Error Coding in the Human Midbrain and Striatum Facilitates Behavioral Adaptation and Learning Efficiency.
Adaptive Prediction Error Coding in the Human Midbrain and Striatum Facilitates Behavioral Adaptation and Learning Efficiency.
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DOI：
10.1016/j.neuron.2016.04.019
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发表时间：
2016-06-01
期刊：
影响因子：
16.2
通讯作者：
Schultz W
中科院分区：
文献类型：
--
作者：
Diederen KM;Spencer T;Vestergaard MD;Fletcher PC;Schultz W
有效的错误驱动学习受益于预测误差的缩放以奖励可变性。这种行为适应可以通过神经元编码相对于奖励分布的标准偏差（SD）的预测误差来促进。为了研究这个假设，我们要求参与者预测即将到来的奖励的大小，这些奖励来自具有不同SD的分布。在每次预测之后，参与者都会得到奖励，产生一次又一次的预测错误。根据自适应编码的概念，黑质/腹侧被盖区（SN/VTA）和腹侧纹状体中的BOLD响应斜率对于在具有较小SD的分布中发生的预测误差更陡。SN/VTA适应不是瞬时的，而是在试验中发展的。自适应预测错误编码被行为适应所取代，这反映在学习率的SD依赖性变化上。重要的是，增加SN/VTA和腹侧纹状体适应与改善任务表现有关。这些结果表明，自适应编码促进行为适应和支持有效的学习。中脑和中脑纹状体编码预测错误相对于奖励变异性在试验中开发的中脑自适应预测错误编码自适应编码预测行为适应奖励变异性增加的适应性与改善的任务表现有关Diederen et al.显示，黑质/中脑被盖区复合体和纹状体编码预测错误相对于奖励的变化在学习过程中。这种适应的改善与上级任务表现有关，这表明自适应编码有利于学习。
Effective error-driven learning benefits from scaling of prediction errors to reward variability. Such behavioral adaptation may be facilitated by neurons coding prediction errors relative to the standard deviation (SD) of reward distributions. To investigate this hypothesis, we required participants to predict the magnitude of upcoming reward drawn from distributions with different SDs. After each prediction, participants received a reward, yielding trial-by-trial prediction errors. In line with the notion of adaptive coding, BOLD response slopes in the Substantia Nigra/Ventral Tegmental Area (SN/VTA) and ventral striatum were steeper for prediction errors occurring in distributions with smaller SDs. SN/VTA adaptation was not instantaneous but developed across trials. Adaptive prediction error coding was paralleled by behavioral adaptation, as reflected by SD-dependent changes in learning rate. Crucially, increased SN/VTA and ventral striatal adaptation was related to improved task performance. These results suggest that adaptive coding facilitates behavioral adaptation and supports efficient learning. Midbrain and Ventral Striatum code prediction errors relative to reward variability Adaptive prediction error coding in the midbrain developed across trials Adaptive coding predicts behavioral adaptation to reward variability Increased adaptation is associated with improved task performance Diederen et al. show that the Substantia Nigra/Ventral Tegmental Area complex and Ventral Striatum code prediction errors relative to reward variability during learning. Improvements in such adaptation are associated with superior task performance, suggesting that adaptive coding benefits learning.