现实生活中人们通过社会比较获得对自身的认识。前人研究探讨了金钱收入的比较对个体结果评价的影响,而非金钱的社会比较效应的神经加工机制尚不清楚。本研究分离比较和金钱收入,使用双人合作的投骰子任务,先呈现“〉”或“〈”代表两人点数大小的比较结果,再呈现合作任务的输赢结果,考察非金钱的社会比较对合作任务结果加工的影响,记录任务表现的比较结果和最终合作任务结果的 ERP 数据。发现在任务表现比较结果阶段, FRN和 P300对代表行为表现好坏的社会比较信息敏感,呈现无金钱输赢提示的点数大小的比较结果时,点数小于他人比大于他人诱发更大的FRN和更小的P300;任务表现的比较结果对合作任务最终的金钱输赢结果的影响并没有反应在 FRN 上。这些表明,对非金钱的社会比较信息的加工始于结果快速评价的早期阶段。
Social comparison is a mental process through which people come to know themselves by evaluating their own abilities, attitudes, outcomes and believes in comparison with others. Previous studies found that social comparison influenced the evaluative process of the outcome in the brain. However, in all those studies, social comparison was manipulated as the comparison between the rewards of two participants, so it remains unclear whether the monetary value or the comparison affects the outcome evaluation. By dissociating the monetary value from comparison, the current study aimed to investigate how non-monetary social comparison affects the process of outcome evaluation in a cooperative task. 〈br〉 Eighteen healthy undergraduates (10 males, 8 females) took part in the EPR experiment. Participants cooperated with a confederate to complete a gambling game on two connected computers. Each of them chucked one dice sequentially and randomly. If the numbers on the two dices totaled greater than 6 in the trail, they would win 1 yuan in the trial; if not, they would lose 1 yuan. The final reward would be portioned out equally between them. After they chucked the two dices, a “>” or “<” between their name cueing comparison feedback indicates which one get a larger number. Then a feedback screen informed about whether they win or loss. However, unknown to the participants, the feedback was independent of their performance. Trails of each conditions were equal. Both social comparison feedback and monetary feedback were included in the final statistical analyses. For FRN analysis, we measured the average amplitude in the 250-350 ms time window for the social comparison feedback and the monetary feedback. P300 amplitude was quantified as the positive peak in the time window of 300-600 ms after feedback onset. 〈br〉 ERP results revealed that FRN and P300 were both sensitive to non-monetary social comparison. When compared with those who had a better performance, participants who got a smaller number