Unselfishness is admired, especially when collaborations between groups of various scales are urgently needed. However, its neural mechanisms remain elusive. In a tri‐MRI dyad‐hyperscanning experiment involving 26 groups, each containing 4 participants as two rotating pairs in a coordination game, we sought to achieve reciprocity, or “winning in turn by the two interacting players,” as the precursor to unselfishness. Due to its critical role in social processing, the right temporal–parietal junction (rTPJ) was the seed for both time domain (connectivity) and frequency domain (i.e., coherence) analyses. For the former, negative connectivity between the rTPJ and the mentalizing network areas (e.g., the right inferior parietal lobule, rIPL) was identified, and such connectivity was further negatively correlated with the individual's final gain, supporting our task design that “rewarded” the reciprocal participants. For the latter, cerebral coherences of the rTPJs emerged between the interacting pairs (i.e., within‐group interacting pairs), and the coupling between the rTPJ and the right superior temporal gyrus (rSTG) between the players who were not interacting with each other (i.e., within‐group noninteracting pairs). These coherences reinforce the hypotheses that the rTPJ–rTPJ coupling tracks the collaboration processes and the rTPJ–rSTG coupling for the emergence of decontextualized shared meaning. Our results underpin two social roles (inferring others’ behavior and interpreting social outcomes) subserved by the rTPJ‐related network and highlight its interaction with other‐self/other‐concerning brain areas in reaching co‐benefits among unselfish players.

中文翻译：

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当“多为他人，少为自己”带来共同利益时：一项三核磁共振二元超扫描研究

无私是令人钦佩的，尤其是当不同规模的团体之间迫切需要合作时。然而，其神经机制仍然难以捉摸。在一项涉及 26 个组的三核磁共振二元超扫描实验中，每个组有 4 名参与者，作为协调游戏中的两个轮流对，我们寻求实现互惠，或者“两个互动的玩家轮流获胜”，作为无私的先兆。由于其在社会处理中的关键作用，右颞顶叶连接处 (rTPJ) 是时域（连接性）和频域（即相干性）分析的基础。对于前者，rTPJ 和心智化网络区域（例如，右顶下小叶，rIPL）之间的负连接被确定，并且这种连接进一步与个体的最终收益负相关，支持我们“奖励”相互的参与者。对于后者，rTPJ 的大脑一致性出现在相互作用对（即组内相互作用对）之间，以及 rTPJ 和右颞上回（rSTG）之间的耦合在没有相互作用的玩家之间出现。即，组内不相互作用的对）。这些连贯性强化了这样的假设：rTPJ-rTPJ 耦合追踪协作过程，而 rTPJ-rSTG 耦合则导致脱离语境的共享意义的出现。我们的结果支持了 rTPJ 相关网络所维护的两种社会角色（推断他人行为和解释社会结果），并强调了它与其他自我/其他相关大脑区域的相互作用，以实现无私参与者之间的共同利益。