Department of Psychiatry, Erasmus MC, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.
Cogn Affect Behav Neurosci. 2011 Dec;11(4):516-25. doi: 10.3758/s13415-011-0050-1.
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.
在本研究中，我们考察了公平性和提议大小对最后通牒博弈（UG）中大脑和心脏反应的影响。20 名健康志愿者在计算机化的 UG 中扮演回应者的角色，其中提议的公平性和大小被系统地改变。公平性和提议的大小都以可预测的方式影响接受率，导致较少接受不公平和低的提议。只有不公平的高提议，而不是不公平的低提议，伴随着中额负向偏。令人惊讶的是，公平的提议会导致更强的心脏减速，而这与提议的大小无关。心脏和脑电的测量结果与表现有不同的关系，且这两种测量结果只有适度的相关性。这种心脏反应和脑电位之间的分离，被认为是对刺激概率和违反社会规则的影响的敏感性可能存在差异。
