想象一下驾驶一辆载有100公斤食物的卡车前往一个遭遇饥荒的地区。如果将食物递送给那里的每个人所花的时间会造成20公斤食物的损坏，而如果将食物只递送给那里一半的人仅会造成5公斤食物的损失。那么，是将食物递送给一半的人以使所提供食物的总量达到最大化，还是愿意牺牲15公斤的食物以使食物分配变得更加公平呢？
据5月8日在线发表于《科学》杂志的一篇论文报道，在一种高效率的选项和一种公平的选项之间进行权衡时，人类大脑的不同部位参与了这一过程。Ming Hsu及其同僚应用功能性核磁共振(fMRI)成像的方法来对自愿者的大脑活动进行监控，即在实际上是一种假设的条件下，当这些自愿者在做出如何将餐食在某个孤儿院的孩子中进行分配的决定的时候，他们的大脑活动被fMRI记录了下来。
他们的发现表明，一个被称作壳核的区域参与了倾向做出高效率决定的过程，而壳核已知参与处理奖励信号的过程。同样地，一个被称作脑岛的区域则参与做出倾向于公平的决定，而脑岛则连接着情绪处理系统。尾状核/中隔区则参与这两种类型的决定过程。每个自愿者侧重在公平方面所呈现的差异似乎比他们侧重在效率方面的差异要更多。
因此，文章的作者提示，我们对公平的判断更多地是植根于情绪而不是理性，而这一问题也是柏拉图、康德、休谟及其他哲学家们在各个时代都在冥思苦想的问题。（来源：Eurekalert！中文版）
生物谷推荐原始出处：
Science，DOI: 10.1126/science.1153651，Ming Hsu, Cédric Anen, Steven R. Quartz
The Right and the Good: Distributive Justice and Neural Encoding of Equity and Efficiency
Ming Hsu 1, Cédric Anen 2, Steven R. Quartz 2*
1 Beckman Institute for Advanced Science and Technology, and Department of Economics, University of Illinois at Urbana-Champaign
2 Social Cognitive Neuroscience Laboratory, Division of Humanities and Social Sciences 228-77, California Institute of Technology, Pasadena, CA 91125, USA.
* To whom correspondence should be addressed.
Steven R. Quartz , E-mail: steve@hss.caltech.edu
These authors contributed equally to this work.
Distributive justice concerns how individuals and societies distribute benefits and burdens in a just or moral manner. Combining distribution choices with functional magnetic resonance imaging (fMRI), we investigate the central problem of distributive justice: the tradeoff between equity and efficiency. We find that the putamen responds to efficiency, whereas the insula encodes inequity, and the caudate/septal subgenual region encodes a unified measure of efficiency and inequity (utility). Strikingly, individual differences in inequity aversion correlate with activity in inequity and utility regions. Against utilitarianism, our results support the deontological intuition that a sense of fairness is fundamental to distributive justice, but, as suggested by moral sentimentalists, is rooted in emotional processing. More generally, emotional responses related to norm violations may underlie individual differences in equity considerations and adherence to ethical rules.
