Decision-making via monitoring others’ actions is a cornerstone of interpersonal exchanges. Although the ventral premotor cortex (PMv) and the medial prefrontal cortex (MPFC) are cortical nodes in social brain networks, the two areas are rarely concurrently active in neuroimaging, inviting the hypothesis that they are functionally independent. Here we show in macaques that the ability of the MPFC to monitor others’ actions depends on input from the PMv. We found that delta-band coherence between the two areas emerged during action execution and action observation. Information flow especially in the delta band increased from the PMv to the MPFC as the biological nature of observed actions increased. Furthermore, selective blockade of the PMv-to-MPFC pathway using a double viral vector infection technique impaired the processing of observed, but not executed, actions. These findings demonstrate that coordinated activity in the PMv-to-MPFC pathway has a causal role in social action monitoring.

通过监视他人的行为进行决策是人际交流的基石。尽管腹侧前运动皮层（PMv）和内侧前额叶皮层（MPFC）是社交脑网络中的皮质节点，但是这两个区域在神经成像中很少同时活跃，这提出了它们在功能上独立的假设。在这里，我们以猕猴的形式表明，MPFC监视他人行为的能力取决于PMv的输入。我们发现在动作执行和动作观察过程中出现了两个区域之间的三角带连贯性。随着观察到的动作的生物学性质的增加，尤其是在三角带中的信息流从PMv到MPFC增加。此外，使用双重病毒载体感染技术选择性阻断PMv-MPFC途径会损害观察到的，但未执行的动作。这些发现表明，PMv到MPFC途径中的协调活动在社会行为监测中具有因果作用。