Sun Peng, Zheng Li, Li Lin, Guo Xiuyan, Zhang Weidong, Zheng Yijie
School of Psychology and Cognitive Science, East China Normal University, Shanghai, China.
Key Laboratory of Brain Functional Genomics, Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics, School of Psychology and Cognitive Science, East China Normal University, Shanghai, China.
PLoS One. 2016 Aug 5;11(8):e0160503. doi: 10.1371/journal.pone.0160503. eCollection 2016.
Cooperation is pervasive and constitutes the core behavioral principle of human social life. Previous studies have revealed that mutual cooperation was reliably correlated with two reward-related brain regions, the ventral striatum and the orbitofrontal cortex. Using functional magnetic resonance imaging (fMRI), this study sought to investigate how the loss and gain contexts modulated the neural responses to mutual cooperation. Twenty-five female participants were scanned when they played a series of one-shot prisoner's dilemma games in the loss and gain contexts. Specifically, participants and partners independently chose to either cooperate with each other or not, and each was awarded or deprived of (in the gain context or the loss context, respectively) a sum of money which depended upon the interaction of their choices. Behavioral results indicated that participants cooperated in nearly half of the experiment trials and reported higher level of positive emotions for mutual cooperation in both contexts, but they cooperated more in the gain than in the loss context. At the neural level, stronger activities in the orbitofrontal cortex were observed for mutual cooperation compared with the other three outcomes in both contexts, while stronger activation in ventral striatum associated with mutual cooperation was observed in the gain context only. Together, our data indicated that, even in the one-shot interaction under loss context, participants still exhibited preference for cooperation and the rewarding experience from a mutually cooperative social interaction activated the ventral striatum and the orbitofrontal cortex, but the loss context weakened the association between the ventral striatum activation and mutual cooperation.
合作无处不在，是人类社会生活的核心行为准则。以往的研究表明，相互合作与两个与奖励相关的脑区——腹侧纹状体和眶额皮质——存在可靠的关联。本研究使用功能磁共振成像（fMRI），旨在探究损失和收益情境如何调节对相互合作的神经反应。25名女性参与者在损失和收益情境下进行一系列一次性囚徒困境游戏时接受了扫描。具体而言，参与者和伙伴各自独立选择是否相互合作，并且根据他们选择的相互作用，每人分别被给予或剥夺（在收益情境或损失情境中）一笔钱。行为结果表明，参与者在近一半的实验试验中选择合作，并且在两种情境下对相互合作都报告了更高水平的积极情绪，但他们在收益情境中比在损失情境中合作得更多。在神经层面，与其他三种结果相比，在两种情境下相互合作时眶额皮质均观察到更强的活动，而仅在收益情境中观察到与相互合作相关的腹侧纹状体更强的激活。总之，我们的数据表明，即使在损失情境下的一次性互动中，参与者仍然表现出对合作的偏好，并且相互合作的社会互动带来的奖励体验激活了腹侧纹状体和眶额皮质，但损失情境削弱了腹侧纹状体激活与相互合作之间的关联。
