Wang Jing, Chen Zhaofeng, Peng Xiaozhe, Yang Tiantian, Li Peng, Cong Fengyu, Li Hong
Brain Function and Psychological Science Research Center, Shenzhen UniversityShenzhen, China; School of Psychology, South China Normal UniversityGuangzhou, China.
Department of Biomedical Engineering, Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology Dalian, China.
Front Psychol. 2016 Oct 6;7:1556. doi: 10.3389/fpsyg.2016.01556. eCollection 2016.
To investigate brain activity during the reinforcement learning process in social contexts is a topic of increasing research interest. Previous studies have mainly focused on using electroencephalograms (EEGs) for feedback evaluation in reinforcement learning tasks by measuring event-related potentials. Few studies have investigated the time-frequency (TF) profiles of a cue that manifested whether a following feedback is available or not after decision-making. Moreover, it remains unclear whether the TF profiles of the cue interact with different agents to whom the feedback related. In this study we used the TF approach to test EEG oscillations of the cue stimuli in three agents ('Self', 'Other', and 'Computer') conditions separately. The results showed that the increased central-posterior delta power was elicited by the feedback unavailable cues more so than with the feedback available cue within 200-350 ms after the onset of the cue, but only in the self-condition. Moreover, a frontal-central theta oscillation had enhanced power when following the feedback unavailable cue as opposed to the feedback available cue across three agencies. These findings demonstrated that the cue for knowing an outcome produced reward prediction error-like signals, which were mirrored by the delta and theta oscillations during decision-making. More importantly, the present study demonstrated that the theta and delta oscillations reflected separable components of the advanced cue processing before the feedback in decision-making.
研究社会环境中强化学习过程中的大脑活动是一个越来越受研究关注的课题。以往的研究主要集中在通过测量事件相关电位，使用脑电图（EEG）进行强化学习任务中的反馈评估。很少有研究调查决策后提示是否有后续反馈的时间频率（TF）特征。此外，提示的TF特征是否与反馈所涉及的不同主体相互作用仍不清楚。在本研究中，我们使用TF方法分别测试了三种主体（“自我”、“他人”和“计算机”）条件下提示刺激的EEG振荡。结果表明，在提示开始后200-350毫秒内，反馈不可用提示比反馈可用提示更能引起中央后δ功率增加，但仅在自我条件下。此外，与三种主体中的反馈可用提示相比，跟随反馈不可用提示时额中央θ振荡的功率增强。这些发现表明，用于知晓结果的提示产生了类似奖励预测误差的信号，在决策过程中由δ和θ振荡反映出来。更重要的是，本研究表明，θ和δ振荡反映了决策中反馈前高级提示处理的可分离成分。
