Cortical delta activity reflects reward prediction error and related behavioral adjustments, but at different times
Cortical delta activity reflects reward prediction error and related behavioral adjustments, but at different times
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DOI：
10.1016/j.neuroimage.2015.02.007
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发表时间：
2015-04-15
期刊：
影响因子：
5.7
通讯作者：
Cavanagh, James F.
中科院分区：
文献类型：
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作者：
Cavanagh, James F.
最近的研究表明，奖励预测错误会在头皮记录的脑电图（EEG）中引起正电压偏转;这种事件有时被称为奖励积极性。然而，对这一拟议关系的有力检验仍有待确定。其他重要的问题仍然没有得到解决：例如奖励积极性在预测未来最大化奖励的行为调整中的作用。为了回答这些问题，一个三臂强盗任务被用来调查的作用，积极的预测错误，在试验的探索和任务集为基础的开发。反馈锁定的奖励积极性的特点是δ带活动，这些相关的EEG功能与计算得出的积极预测误差的程度成比例。然而，这些现象也是分离的：计算模型预测剥削性的动作选择和相关的响应时间加快，而反馈锁定的EEG功能没有。令人信服的是，时间锁定到随后的强盗（P3）的δ带动力学成功地预测了这些行为。这些强盗锁定的研究结果包括增强顶叶运动皮层δ相位滞后，与反应时间加快的程度，这表明δ带活动在激励行动选择的机制作用。反馈与强盗锁定EEG信号的这种分离被解释为分层不同类型的预测误差的差异，在强化学习和决策过程中产生关于这些可分离的δ带现象的新预测。(C)2015 Elsevier Inc. All rights reserved.
Recent work has suggested that reward prediction errors elicit a positive voltage deflection in the scalp-recorded electroencephalogram (EEG); an event sometimes termed a reward positivity. However, a strong test of this proposed relationship remains to be defined. Other important questions remain unaddressed: such as the role of the reward positivity in predicting future behavioral adjustments that maximize reward. To answer these questions, a three-armed bandit task was used to investigate the role of positive prediction errors during trial-by-trial exploration and task-set based exploitation. The feedback-locked reward positivity was characterized by delta band activities, and these related EEG features scaled with the degree of a computationally derived positive prediction error. However, these phenomena were also dissociated: the computational model predicted exploitative action selection and related response time speeding whereas the feedback-locked EEG features did not. Compellingly, delta band dynamics time-locked to the subsequent bandit (the P3) successfully predicted these behaviors. These bandit-locked findings included an enhanced parietal to motor cortex delta phase lag that correlated with the degree of response time speeding, suggesting a mechanistic role for delta band activities in motivating action selection. This dissociation in feedback vs. bandit locked EEG signals is interpreted as a differentiation in hierarchically distinct types of prediction error, yielding novel predictions about these dissociable delta band phenomena during reinforcement learning and decision making. (C) 2015 Elsevier Inc. All rights reserved.