公平加工的情境依赖性：来自ERP的证据

公平是人类社会生活的重要概念。大量研究采用最后通牒博弈, 发现人们具有不公平厌恶倾向, 即宁愿牺牲个人的经济利益, 也要拒绝不公平的分配提议。已有研究表明, 损失情境会增强不公平厌恶, 但其神经机制尚不清楚。本实验采用ERP技术, 运用最后通牒博弈范式, 考察两个情境因素：域(损失或获益)和博弈对象(人或计算机)对公平加工的影响。发现损失域下对不公平分配的拒绝率更高, 而博弈对象对决策行为无影响; 获益域下, 对家为人比对家为计算机诱发了更负的N1; 人机博弈时, 获益域比损失域诱发了更大的P2和LPP, 损失域比获益域、不公平提议比公平提议诱发了更大的N350, 而公平提议比不公平提议诱发了更大的LPP; 人际博弈时, 这些差异均不显著。这些结果表明, 对分配提议的大脑加工受博弈对象的调节, 人际博弈时, 对损益域、公平与不公平提议的加工类似, 而人机博弈时, 损失域和不公平提议涉及更多的抑制加工和冲突解决, 获益域和公平提议则更富动机性意义, 证实公平加工具有情境依赖性。     

公平加工的情境依赖性:来自行为的证据

采用最后通牒博弈范式,考察利益水平及社会距离对个体公平加工的影响,探讨公平加工的情境依赖性。实验结果表明:(1)对分配提议的加工受到利益水平的调节,不利不公平条件下被试更加注重公平。(2)提议的不同水平影响被试的拒绝行为,提议越不公平,拒绝率越高。(3)虽然社会距离的主效应不显著,但在实际情境中,较近的社会距离下人们对公平的要求更严格,证实公平加工具有情境依赖性。     

共情关怀对公平决策的影响——来自ERP的证据

本研究运用事件相关电位技术(event-related potential, ERP)和最后通牒博弈范式(ultimatum game, UG)考察了共情关怀对公平决策的影响。实验采用2 (状态共情关怀: 有共情关怀vs.无共情关怀) × 3 (分配公平性: 公平vs.劣势不公平vs.优势不公平)被试内设计, 共37名被试参与实验, 被试作为响应者选择是否接受提议者的分配提议。行为结果显示劣势不公平条件下, 有共情情境的接受率高于无共情情境; 优势不公平条件下呈现相反的结果。ERP结果显示: 对于他人提出的优势不公平提议, 无共情情境较有共情情境下诱发了更负的前部N1 (anterior N1, AN1), 有共情情境比无共情情境下诱发了更大的P2波幅; 有共情情境下, 他人提出的劣势不公平提议较优势不公平和公平提议诱发了更负的内侧额叶负波(medial frontal negativity, MFN); P3在公平条件下的波幅较劣势不公平条件下更大, 并未受到共情关怀的调节。这些结果表明共情关怀不仅调节了公平决策行为, 还调节了公平加工的早期注意和动机及之后的认知和情绪加工, 但由P3表征的高级认知过程仅受到公平性的调节而不受共情水平的影响。     

社会距离与分配差距对儿童有利不公平厌恶的影响

选取60名8-10岁儿童,采用迫选式独裁者游戏,考察个体与博弈对象的社会距离以及分配差距对儿童有利不公平厌恶的影响。结果发现：（1）在有利不公平条件下,与博弈对象社会距离越近,儿童对不公平分配提议的拒绝率越高;（2）分配差距越大,儿童对不公平分配提议的拒绝率越高;（3）社会距离和分配差距交互作用显著,在中等分配差距条件下,儿童对不公平分配提议拒绝率的社会距离效应最为明显。结果表明,社会距离和分配差距对儿童有利不公平厌恶有显著影响,在中度分配差距下社会距离具有更加明显的调节作用。     

社会距离与分配差距对儿童有利不公平厌恶的影响

选取60名8-10岁儿童,采用迫选式独裁者游戏,考察个体与博弈对象的社会距离以及分配差距对儿童有利不公平厌恶的影响。结果发现：（1）在有利不公平条件下,与博弈对象社会距离越近,儿童对不公平分配提议的拒绝率越高;（2）分配差距越大,儿童对不公平分配提议的拒绝率越高;（3）社会距离和分配差距交互作用显著,在中等分配差距条件下,儿童对不公平分配提议拒绝率的社会距离效应最为明显。结果表明,社会距离和分配差距对儿童有利不公平厌恶有显著影响,在中度分配差距下社会距离具有更加明显的调节作用。     

群体身份调节最后通牒博弈的公平关注

群际互动是社会互动的一种重要形式, 在人类社会发展中起着重要作用。已有的行为研究表明个体参与群际互动时, 互动对象的群体身份会影响其心理加工和行为决策。但目前关于群体身份如何影响公平加工的动态时间过程尚不清楚。为了研究群体身份对最后通牒任务(Ultimatum Game, UG)中反应者公平关注的影响, 15名健康成人作为反应者与组内和组外提议者进行UG博弈, 提议包括极端不公平、中等不公平或公平提议三种。事件相关电位结果发现, 组外互动时公平提议和中等不公平提议比极端不公平提议诱发更负的AN1, 组内互动时不同提议诱发的AN1无显著差异。来自组内成员的中等和极端不公平提议比公平提议引起更负的内侧额叶负波(MFN), 但来自组外成员的不同提议则没有导致MFN波幅的变化。这些结果表明在群体互动情境下, 互动成员的群体身份能够影响个体的早期注意资源分配和公平关注加工。     

第三方情境的结果公平效应:来自ERP的证据

公平是人类社会的永恒主题。已有研究表明,个体在目睹他人遭受不公平对待时会谴责和惩罚违规者,但其神经机制尚不清楚。该研究运用第三方最后通牒博弈任务和ERP技术,在不涉及利益相关性和分配动机的情况下,考察第三方情境的结果公平效应。行为结果发现,不公平方案比公平方案引起了第三方更多的拒绝行为和更偏向负性的情绪体验。脑电结果也发现,结果公平性的不同水平诱发了不同波幅的FRN和P300,与公平方案相比,不公平方案诱发了更大的FRN和更小的P300。这表明即使与自身收益无关,个体加工他人利益分配过程中的结果信息时会受到公平准则的影响。     

最后通牒博弈中回应者的情绪唤醒和决策行为研究

运用心理生理实验法,探讨自主神经唤醒对最后通牒博弈中回应者决策行为的影响。结果发现:(1)不公平提议引起被试更大的皮肤电活动变化,表明他们对不公平提议产生更强的情绪反应。(2)情绪唤醒状态可以预示决策行为,被试做出拒绝行为前的皮肤电变化显著大于接受行为前的活动变化。(3)在最后通牒博弈中,博弈双方的性别配对差异影响回应者的决策行为。     

最后通牒游戏中接收者拒绝行为的情绪义务模型

公平偏好使人们在面对不公平的分配时通常会有所表示,在最后通牒游戏中具体表现为对不公平报价的拒绝,有很多研究把拒绝的原因归结为不公平厌恶和互惠主义等社会偏好,但这并不能解释一些最后通牒变体游戏中的拒绝行为。但这恰恰支持了情绪义务模型。     

公平行为的认知神经机制

大量研究采用最后通牒博弈发现人们愿意牺牲自身利益来维护公平,普遍具有不公平厌恶倾向。本文基于行为博弈任务对个体处于不同角色时的公平行为,从神经学层面做出新的解释,并对现存理论模型做了梳理。脑成像的研究发现,公平行为的相关脑区主要有负责情绪加工的脑岛和与认知控制相关的背外侧前额叶,内侧眶额皮层。前脑岛激活越大,个体拒绝不公平方案的可能性越大,而腹外侧前额叶可以调节前脑岛的活动,使个体采取更理性的方式,接受不公平分配方案。另外,睾酮素和催产素作为神经调节的激素,可以对公平行为起到调节作用,睾酮素通过抑制内侧眶额皮层的激活,增加对不公平方案的拒绝率,相反,催产素可以降低个体对于不公平方案的拒绝率,并增加个体的公平行为。     

公平偏好的电生理测量：来自脑电、皮肤电和心电的证据

研究发现,人们普遍具有追求公平的偏好,即人们在追求个人收益时也会关注收益分配的公平性。随着电生理技术的发展,越来越多的研究者采用电生理技术对公平偏好进行深入探讨。本研究从脑电、皮肤电、心电等方面梳理公平偏好的电生理机制。脑电的研究发现,公平偏好相关的脑电主要涉及反馈相关负波和P300;皮肤电的研究发现,相比于公平分配,个体在不公平分配情况下其皮肤电的激活水平更高;心率的研究发现,相比于公平分配,个体遭遇不公平分配时其心率降低。研究公平偏好电生理机制有助于更深入地揭示公平偏好的产生根源与形成过程。未来可从公平偏好电生理的整合研究、公平偏好的脑成像与电生理的整合性探索,以及拓展公平偏好电生理的外部效度和研究范式等方面展开进一步探究。     

Sharing losses and sharing gains: Increased demand for fairness under adversity

There is ample experimental evidence showing that people have a strong preference for equity in wealth allocation and social interaction. Although the behavior of gain sharing and responses to (un)fairness in allocation of wealth has been extensively investigated in studies employing economic exchange games, few studies have focused on how people respond to an unfair division of loss between individuals. In this study we developed a new variant of the ultimatum game and examined the participants' reactions to (un)fairness in both gain and loss sharing. Results from three experiments showed that the rejection rates to unfair offers were generally higher in the loss than in the gain domain. Moreover, participants were inclined to associate loss with “unfair” and gain with “fair”, with stronger associations leading to higher rejection rates in the ultimatum game. Furthermore, in subjective rating, unfair offers were perceived as being more unfair in the loss than in the gain domain. These results demonstrate an increased demand for fairness under adversity and the importance of justice in liability sharing.     

Dissociation between medial frontal negativity and cardiac responses in the ultimatum game: Effects of offer size and fairness

In the present study, we examined the role of fairness and offer size on brain and cardiac responses in the ultimatum game (UG). Twenty healthy volunteers played the role of responder in a computerized version of the UG in which the fairness and size of the offers were systematically varied. Both fairness and size of the offer influenced the acceptance rates in a predictable way, leading to fewer accepted unfair and low offers. Only unfair high, but not unfair low offers were accompanied by a medial frontal negativity. An unexpected stronger cardiac deceleration to fairer offers was found, which was not affected by the size of the offers. Cardiac and electrocortical measures showed a different relation with performance, and both measures were correlated only modestly. This dissociation between cardiac responses and brain potentials is discussed in terms of a possible differential sensitivity to effects of stimulus probability and violation of the social rules.     

两人和三人最后通牒博弈任务中嗓音吸引力对决策的影响

本研究用两人和三人最后通牒博弈任务探究男性嗓音吸引力对决策的影响。实验1发现, 高吸引力的嗓音会提高被试对不公平分配方案的接受率。实验2发现, 即使分配方案对第三方接受者公平, 对被试不公平, 第三方接受者的高吸引力嗓音仍然会提高被试对方案的接受率。综上, 嗓音吸引力可以诱发类似面孔吸引力的“美貌津贴”效应。     

最后通牒博弈任务中的印象调控过程

通过操纵最后通牒博弈任务中的提议者方案类型的设计,探索了在连续重复的博弈任务中提议者印象对回应者决策行为的影响,结果表明：（1）在与同一提议者完成的多轮最后通牒博弈任务中,回应者会自发地对提议者印象进行调控,提议者印象影响了回应者的决策思考过程;（2）提议方案影响回应者的决策结果,在过度受益与过度受损两种不公平方案下,回应者的决策行为相反;（3）最后通牒博弈任务中表现出的公平是一种策略性公平,而非真正信念水平的公平。     

The hidden side of the Ultimatum Game: The role of motivations and mind-reading in a two-level one-shot Ultimatum Game

The main aim of our study is to investigate the role of motivations and mind-reading in a two-level one-shot Ultimatum Game with three players. Our intention is to analyse subjects’ behaviour in both the responder and proposer roles. In the responder role, we found that the difference between the subjects’ expectations and the actual offers was the major factor that influenced their decisions and motivations in receiving money. In the proposer role, our results showed a significant influence of mind-reading, with a positive association between the fairness of subjects’ offers and the subjects’ expectations about the recipients’ willingness to accept. Although a shared concept of fairness exists findings suggest that decisions and motivations seem to depend on expectations, either when they are directly experienced or when they are ascribed to the counterpart.     

Counterfactual comparison modulates fairness consideration in the mini‐ultimatum game: An event‐related potentials study

Existing literature on the mini‐ultimatum game indicates that counterfactual comparison between chosen and unchosen alternatives is of great importance for individual's fairness consideration. However, it is still unclear how counterfactual comparison influences the electrophysiological responses to unfair chosen offers. In conjunction with event‐related potentials’ (ERPs) technique, the current study aimed to explore the issue by employing a modified version of the mini‐ultimatum game where a fixed set of two alternatives (unfair offer vs. fair alternative, unfair vs. hyperfair alternative, unfair offer vs. hyperunfair alternative) was presented before the chosen offer. The behavioral results showed that participants were more likely to accept unfair chosen offers when the unchosen alternative was hyperunfair than when the unchosen alternative was fair or hyperfair. The ERPs results showed that the feedback‐related negativity (FRN) elicited by unfair chosen offers was insensitive to the type of unchosen alternative when correcting for possible overlap with other components. In contrast, unfair chosen offers elicited larger P300 amplitudes when the unchosen alternative was hyperunfair than when the unchosen alternative was fair or hyperfair. These findings suggest that counterfactual comparison may take effect at later stages of fairness consideration as reflected by the P300.