Infancy is the foundational period for learning from adults, and the dynamics of the social environment have long been considered central to children’s development. Here, we reveal a novel, naturalistic approach for studying live interactions between infants and adults. Using functional near-infrared spectroscopy (fNIRS), we simultaneously and continuously measured the brains of infants (N = 18; 9–15 months of age) and an adult while they communicated and played with each other. We found that time-locked neural coupling within dyads was significantly greater when dyad members interacted with each other than with control individuals. In addition, we characterized the dynamic relationship between neural activation and the moment-to-moment fluctuations of mutual gaze, joint attention to objects, infant emotion, and adult speech prosody. This investigation advances what is currently known about how the brains and behaviors of infants both shape and reflect those of adults during real-life communication.

中文翻译：

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婴儿和成人的大脑与自然交流的动态耦合

婴儿期是向成人学习的基础时期，社会环境的动态一直被认为是儿童发展的核心。在这里，我们揭示了一种新颖的、自然主义的方法来研究婴儿和成人之间的实时互动。使用功能性近红外光谱 (fNIRS)，我们同时连续测量婴儿（N = 18；9-15 个月大）和成年人在交流和玩耍时的大脑。我们发现当 dyad 成员彼此交互时，dyad 内的时间锁定神经耦合明显大于与控制个体的交互。此外，我们描述了神经激活与相互注视、对物体的共同注意、婴儿情绪和成人言语韵律的瞬时波动之间的动态关系。