结果评价中自我体验与替代体验的参照点效应:一项赌博游戏的ERPs研究

本研究采用"投注—反馈"的虚拟赌博游戏范式,通过2个实验分别检测个体在评价自己决策结果 (实验1)和观察他人决策结果 (实验2)过程中赌注大小(即参照点)对大脑活动的影响。结果发现:(1)体验自我决策结果时,输钱比赢钱诱发更负的FRN,仅有一个负反馈(-10元)表现出以赌注为界的分离,且相对效价一样的反馈值诱发的FRN差异不显著;(2)体验他人决策结果时,无论输赢,有赌注比无赌注诱发的FRN更负;而且相对效价相同的反馈值诱发的FRN差异不显著。据此可以认为,FRN一定程度上反映了以赌注为基准的主观标准对社会信息的评价判断:自我体验中的个体对损失的敏感度远高于收益;而替代体验中的个体更倾向于将"损失更多"看作一种负性结果。

Reference Point Effect of Self Experience and Vicarious Experience during Outcome Evaluation: An ERPs Study Using Gambling Game

Risky decision is commonplace. In a wide range of decision people are often faced with risky contexts. In the decisions which include both loss and benefit, individual must have a quick appraisal on the post-decision feedback so as to adjust and improve subsequent decision-making processes. Such feedbacks are not only from one’s own experience, but also from vicarious experience by observing others’ outcome. As the development of event-related potentials (ERPs), researchers are devoted to discovering and interpreting how appraisal of decision outcomes affects decision-making processes using ERPs, which helps to reduce the occurrence of irrational decision. Recently, feedback-related negativity (FRN) has been found to be one of the components that are closely related with appraisal of outcome. The existing studies concerning the representation of FRN on reference point effect are primarily based on the decision made by participants themselves. However, in daily life we may make decision for ourselves and for others; decision can be made not only by ourselves but it can also be made by others. Recently, it is found that when participants are observing others to get negative feedback, the neural activity is similar as when participants get negative feedback themselves. Such mirror processes indicate that FRN may be the same neural processes shared by self-reference and others-reference processes. Although few studies reported that FRN could be still evoked even when participants did not respond or observed others to respond, little is known about whether reference point effect of FRN still appears when decider changes. This topic warrants further investigation. Through two experiments, the current research investigated the influence of bet (i.e., reference point) on brain activity in the processes of appraising one’s own decision (experiment 1) and observing others’ decision (experiment 2). “Bet-feedback” virtual gamble paradigm was used. Two bet conditions (0 Yuan vs. 50 Yuan) and four feedback conditions (+110 Yuan, +60 Yuan, -10 Yuan, and -60 Yuan) were set to formulate an absolute outcome (based on absolute zero point) and a relative outcome (based on the amount of bet). In study 1, participants were required to participate in the gamble task with EEG recorded, whereas in study 2 participants were asked to observe others to gamble, also with EEG recorded. Results indicated that when subjects participated in the gamble task in person, the feedback of losing money evoked more negative FRN than winning money, and just one feedback (-10 Yuan) with bet evoked more negative FRN than without bet. However, when observing others to gamble, no matter losing or wining money with bet evoked more negative FRN than without bet. In conclusion, when behavior is self-relevant, people are more sensitive to loss regardless of losing money with or without bet. However, when behavior is others-relevant, negative appraisal as a result from losing money is affected by with or without bet; and at this moment monitoring does not reflect the feedback per se, but one’s own positive or negative emotion based on the outcome.