Functions of Learning Rate in Adaptive Reward Learning.
Functions of Learning Rate in Adaptive Reward Learning.
复制标题
学习率在自适应奖励学习中的作用
DOI：
10.3389/fnhum.2017.00592
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发表时间：
2017
影响因子：
2.9
通讯作者：
Zhou J
中科院分区：
文献类型：
--
作者：
Wu X;Wang T;Liu C;Wu T;Jiang J;Zhou D;Zhou J
作为一种重要的认知功能，学习运用预测误差（学习预测与世界状态之间的差异）来调整对未来的预测。预测误差对这种调整的影响程度也取决于学习率。我们对学习率的理解仍然有限，包括（1）它如何受到其他因素的调节，以及（2）学习率如何与预测误差相互作用以更新学习的具体机制。我们应用计算建模和功能磁共振成像来研究这些问题。我们发现，当人类参与者执行奖励学习任务时，奖励幅度会调节学习率。调制强度进一步预测了受试者在高与低奖励后的行为差异。成像结果进一步表明，这种调制反映在奖励反馈也被编码的大脑区域，如内侧前额叶皮层（MFC），楔前叶和后扣带皮层。此外，我们第一次观察到学习率和奖励预测误差的整合在MFC活动中表现出来。这些发现扩展了我们对适应性学习的理解，展示了它在预测更新的连锁反应中是如何发挥作用的。
As a crucial cognitive function, learning applies prediction error (the discrepancy between the prediction from learning and the world state) to adjust predictions of the future. How much prediction error affects this adjustment also depends on the learning rate. Our understanding to the learning rate is still limited, in terms of (1) how it is modulated by other factors, and (2) the specific mechanisms of how learning rate interacts with prediction error to update learning. We applied computational modeling and functional magnetic resonance imaging to investigate these issues. We found that, when human participants performed a reward learning task, reward magnitude modulated learning rate. Modulation strength further predicted the difference in behavior following high vs. low reward across subjects. Imaging results further showed that this modulation was reflected in brain regions where the reward feedback is also encoded, such as the medial prefrontal cortex (MFC), precuneus, and posterior cingulate cortex. Furthermore, for the first time, we observed that the integration of the learning rate and the reward prediction error was represented in MFC activity. These findings extend our understanding of adaptive learning by demonstrating how it functions in a chain reaction of prediction updating.
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影响因子：
5.3
作者：
Jocham, Gerhard;Klein, Tilmann A.;Ullsperger, Markus
通讯作者：
Ullsperger, Markus
DOI：
10.1098/rstb.2007.2098
发表时间：
2007-05-29
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6.3
作者：
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作者：
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影响因子：
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作者：
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影响因子：
16.2
作者：
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通讯作者：
Stephan, Klaas E.