Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5229, 69675 Bron, France.
Proc Natl Acad Sci U S A. 2011 Sep 20;108(38):16044-9. doi: 10.1073/pnas.1100892108. Epub 2011 Sep 6.
We compared private and social decision making to investigate the neural underpinnings of the effect of social comparison on risky choices. We measured brain activity using functional MRI while participants chose between two lotteries: in the private condition, they observed the outcome of the unchosen lottery, and in the social condition, the outcome of the lottery chosen by another person. The striatum, a reward-related brain structure, showed higher activity when participants won more than their counterpart (social gains) compared with winning in isolation and lower activity when they won less than their counterpart (social loss) compared with private loss. The medial prefrontal cortex, implicated in social reasoning, was more activated by social gains than all other events. Sensitivity to social gains influenced both brain activity and behavior during subsequent choices. Specifically, striatal activity associated with social gains predicted medial prefrontal cortex activity during social choices, and experienced social gains induced more risky and competitive behavior in later trials. These results show that interplay between reward and social reasoning networks mediates the influence of social comparison on the decision process.
我们比较了私人和社会决策，以研究社会比较对风险选择的影响的神经基础。我们使用功能磁共振成像测量参与者在两种彩票之间选择时的大脑活动：在私人条件下，他们观察未选中的彩票的结果，而在社会条件下，他们观察另一个人选择的彩票的结果。纹状体是与奖励相关的大脑结构，当参与者赢得比他们的对手更多的奖金（社会收益）时，纹状体的活动比单独获胜时更高，而当他们赢得比他们的对手更少的奖金（社会损失）时，纹状体的活动比私人损失时更低。内侧前额叶皮层，涉及社会推理，在社会收益方面比所有其他事件都更活跃。对社会收益的敏感性影响了随后选择过程中的大脑活动和行为。具体来说，与社会收益相关的纹状体活动预测了社会选择期间内侧前额叶皮层的活动，而经历的社会收益在后续试验中诱导了更冒险和竞争的行为。这些结果表明，奖励和社会推理网络之间的相互作用介导了社会比较对决策过程的影响。
