In humans and macaque monkeys, socially relevant face processing is accomplished via a distributed functional network that includes specialized patches in frontal cortex. It is unclear whether a similar network exists in New World primates, who diverged ~35 million years from Old World primates. The common marmoset is a New World primate species ideally placed to address this question given their complex social repertoire. Here, we demonstrate the existence of a putative high-level face processing network in marmosets. Like Old World primates, marmosets show differential activation in anterior cingulate and lateral prefrontal cortices while they view socially relevant videos of marmoset faces. We corroborate the locations of these frontal regions by demonstrating functional and structural connectivity between these regions and temporal lobe face patches. Given the evolutionary separation between macaques and marmosets, our results suggest this frontal network specialized for social face processing predates the separation between Platyrrhini and Catarrhini.

在人类和猕猴中，社交相关的面部处理是通过分布式功能网络完成的，该网络包括额叶皮层中的专门补丁。目前尚不清楚新世界灵长类动物是否存在类似的网络，新世界灵长类动物与旧世界灵长类动物分化了约 3500 万年。普通狨猴是一种新世界灵长类动物，鉴于其复杂的社会特征，因此非常适合解决这个问题。在这里，我们证明了在狨猴中存在一个假定的高级人脸处理网络。像旧世界灵长类动物一样，狨猴在观看狨猴面部的社交相关视频时，在前扣带回和外侧前额叶皮质中表现出不同的激活。我们通过展示这些区域和颞叶面部斑块之间的功能和结构连接来证实这些额叶区域的位置。鉴于猕猴和狨猴之间的进化分离，我们的结果表明，这个专门用于社交面部处理的额叶网络早于 Platyrrhini 和 Catarrhini 之间的分离。