Perceiving faces and understanding emotions are key components of human social cognition. Prior research with adults and infants suggests that these social cognitive functions are supported by superior temporal cortex (STC) and medial prefrontal cortex (MPFC). We used functional near-infrared spectroscopy (fNIRS) to characterize functional responses in these cortical regions to faces in early childhood. Three-year-old children (n = 88, M(SD) = 3.15(.16) years) passively viewed faces that varied in emotional content and valence (happy, angry, fearful, neutral) and, for fearful and angry faces, intensity (100%, 40%), while undergoing fNIRS. Bilateral STC and MPFC showed greater oxygenated hemoglobin concentration values to all faces relative to objects. MPFC additionally responded preferentially to happy faces relative to neutral faces. We did not detect preferential responses to angry or fearful faces, or overall differences in response magnitude by emotional valence (100% happy vs. fearful and angry) or intensity (100% vs. 40% fearful and angry). In exploratory analyses, preferential responses to faces in MPFC were not robustly correlated with performance on tasks of early social cognition. These results link and extend adult and infant research on functional responses to faces in STC and MPFC and contribute to the characterization of the neural correlates of early social cognition.

感知面孔和理解情绪是人类社会认知的关键组成部分。先前对成人和婴儿的研究表明，这些社会认知功能得到上颞叶皮层 (STC) 和内侧前额叶皮层 (MPFC) 的支持。我们使用功能近红外光谱 (fNIRS) 来表征这些皮质区域对儿童早期面部的功能反应。三岁儿童（n = 88，M(SD) = 3.15(.16) 岁）被动地观察情绪内容和效价（快乐、愤怒、恐惧、中性）不同的面孔，对于恐惧和愤怒的面孔，强度（100%、40%），同时进行 fNIRS。双侧 STC 和 MPFC 显示所有面部相对于物体的含氧血红蛋白浓度值更高。相对于中性面孔，MPFC 还优先响应快乐面孔。我们没有检测到对愤怒或恐惧面孔的优先反应，或情绪效价（100% 快乐与恐惧和愤怒）或强度（100% 与 40% 恐惧和愤怒）的反应幅度的总体差异。在探索性分析中，MPFC 中对面孔的偏好反应与早期社会认知任务的表现没有强相关性。这些结果连接并扩展了成人和婴儿对 STC 和 MPFC 面部功能反应的研究，并有助于表征早期社会认知的神经相关性。MPFC中对面孔的偏好反应与早期社会认知任务的表现没有强相关。这些结果连接并扩展了成人和婴儿对 STC 和 MPFC 面部功能反应的研究，并有助于表征早期社会认知的神经相关性。MPFC中对面孔的偏好反应与早期社会认知任务的表现没有强相关。这些结果连接并扩展了成人和婴儿对 STC 和 MPFC 面部功能反应的研究，并有助于表征早期社会认知的神经相关性。