Polezzi David, Daum Irene, Rubaltelli Enrico, Lotto Lorella, Civai Claudia, Sartori Giuseppe, Rumiati Rino
Department of Developmental Psychology and Socialization, University of Padova, via Venezia 8, 35131 Padova, Italy.
Behav Brain Res. 2008 Jul 19;190(2):218-23. doi: 10.1016/j.bbr.2008.03.003. Epub 2008 Mar 18.
In the Ultimatum Game, participants typically reject monetary offers they consider unfair even if the alternative is to gain no money at all. In the present study, ERPs were recorded while subjects processed different offers of a proposer. In addition to clearly fair and unfair offers, mid-value offers which cannot be easily classified as fair or unfair and therefore involve more elaborate decision making were analyzed. A fast initial distinction between fair and other kinds of offers was reflected by amplitude of the feedback related negativity (FRN). Mid-value offers were associated with longer RTs, and a larger N350 amplitude. In addition, source analyses revealed a specific involvement of the superior temporal gyrus and the inferior parietal lobule during processing of mid-value offers compared to offers categorized clearly as fair or unfair, suggesting a contribution of mentalizing about the intention of the proposer to the decision making process. Taken together, the present findings support the idea that economic decisions are significantly affected by non-rational factors, trying to narrow the gap between formal theory and the real decisional behaviour.
在最后通牒博弈中，参与者通常会拒绝他们认为不公平的金钱提议，即使 alternative 是根本得不到任何钱。在本研究中，当受试者处理提议者的不同提议时记录了事件相关电位（ERP）。除了明显公平和不公平的提议外，还分析了难以轻易归类为公平或不公平因而涉及更复杂决策的中等价值提议。公平提议与其他类型提议之间的快速初始区分由反馈相关负波（FRN）的幅度反映出来。中等价值提议与更长的反应时以及更大的N350幅度相关。此外，源分析显示，与明确归类为公平或不公平的提议相比，在处理中等价值提议期间颞上回和顶下小叶有特定参与，这表明对提议者意图进行心理化对决策过程有贡献。综上所述，本研究结果支持这样一种观点，即经济决策受到非理性因素的显著影响，试图缩小形式理论与实际决策行为之间的差距。
