Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea.
Division of Computational Mathematics, National Institute for Mathematical Sciences (NIMS), Daejeon 34047, South Korea.
Neuroimage. 2017 Aug 15;157:263-274. doi: 10.1016/j.neuroimage.2017.06.024. Epub 2017 Jun 10.
Social interaction is a fundamental part of our daily lives; however, exactly how our brains use social cues to determine whether to cooperate without being exploited remains unclear. In this study, we used an electroencephalography (EEG) hyperscanning approach to investigate the effect of face-to-face contact on the brain mechanisms underlying the decision to cooperate or defect in an iterated version of the Prisoner's Dilemma Game. Participants played the game either in face-to-face or face-blocked conditions. The face-to-face interaction led players to cooperate more often, providing behavioral evidence for the use of these nonverbal cues in their social decision-making. In addition, the EEG hyperscanning identified temporal dynamics and inter-brain synchronization across the cortex, providing evidence for involvement of these regions in the processing of face-to-face cues to read each other's intent to cooperate. Most notably, the power of the alpha frequency band (8-13Hz) in the right temporoparietal region immediately after seeing a round outcome significantly differed between face-to-face and face-blocked conditions and predicted whether an individual would adopt a 'cooperation' or 'defection' strategy. Moreover, inter-brain synchronies within this time and frequency range reflected the use of these strategies. This study provides evidence for how the cortex uses nonverbal social cues to determine other's intentions, and highlights the significance of power in the alpha band and inter-brain phase synchronizations in high-level socio-cognitive processing.
社交互动是我们日常生活的重要组成部分，但大脑究竟如何利用社交线索来确定是否在不受剥削的情况下进行合作，这一点仍不清楚。在这项研究中，我们使用脑电图（EEG）超扫描方法来研究面对面接触对决策是否合作或背叛的大脑机制的影响，参与者在面对面或面部遮挡的情况下进行游戏。面对面的互动促使参与者更频繁地合作，为在社会决策中使用这些非言语线索提供了行为证据。此外，EEG 超扫描确定了大脑皮层的时间动态和大脑间同步，为这些区域参与处理面对面线索以了解彼此合作意图提供了证据。值得注意的是，在看到一轮结果后，右颞顶区域的 alpha 频带（8-13Hz）的功率在面对面和面部遮挡条件下有显著差异，这可以预测个体将采取“合作”还是“背叛”策略。此外，在此时间和频率范围内的大脑间同步反映了这些策略的使用。这项研究为大脑如何利用非言语社交线索来确定他人的意图提供了证据，并强调了 alpha 波段功率和大脑间相位同步在高级社会认知处理中的重要性。
