Department of Psychology, University of Essex, Essex CO4 3SQ, UK; Centre for Brain and Cognitive Development, Department of Psychological Sciences, Birkbeck College, University of London, London WC1E 7HX, UK.
Centre for Brain and Cognitive Development, Department of Psychological Sciences, Birkbeck College, University of London, London WC1E 7HX, UK; Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, UK.
J Exp Child Psychol. 2019 Jul;183:33-47. doi: 10.1016/j.jecp.2019.01.015. Epub 2019 Mar 8.
Mimicry, the spontaneous copying of others' behaviors, plays an important role in social affiliation, with adults selectively mimicking in-group members over out-group members. Despite infants' early documented sensitivity to cues to group membership, previous work suggests that it is not until 4 years of age that spontaneous mimicry is modulated by group status. Here we demonstrate that mimicry is sensitive to cues to group membership at a much earlier age if the cues presented are more relevant to infants. 11-month-old infants observed videos of facial actions (e.g., mouth opening, eyebrow raising) performed by models who either spoke the infants' native language or an unfamiliar foreign language while we measured activation of the infants' mouth and eyebrow muscle regions using electromyography to obtain an index of mimicry. We simultaneously used functional near-infrared spectroscopy to investigate the neural mechanisms underlying differential mimicry responses. We found that infants showed greater facial mimicry of the native speaker compared to the foreign speaker and that the left temporal parietal cortex was activated more strongly during the observation of facial actions performed by the native speaker compared to the foreign speaker. Although the exact mechanisms underlying this selective mimicry response will need to be investigated in future research, these findings provide the first demonstration of the modulation of facial mimicry by cues to group status in preverbal infants and suggest that the foundations for the role that mimicry plays in facilitating social bonds seem to be present during the first year of life.
模仿，即自发地复制他人的行为，在社会联系中起着重要作用，成年人会选择性地模仿内群体成员而不是外群体成员。尽管婴儿对群体归属的线索有早期的记录敏感性，但之前的研究表明，直到 4 岁，自发模仿才会受到群体地位的调节。在这里，我们证明，如果呈现的线索与婴儿更相关，那么模仿对群体归属的线索就会更早变得敏感。11 个月大的婴儿观察到由模特进行的面部动作（例如张嘴、挑眉）的视频，模特说的是婴儿的母语或一种不熟悉的外语，而我们则使用肌电图测量婴儿的嘴和眉毛肌肉区域的激活情况，以获得模仿指数。我们同时使用功能近红外光谱技术来研究不同模仿反应的神经机制。我们发现，与外国说话者相比，婴儿对口音说话者的面部模仿更多，与外国说话者相比，在观察母语说话者进行的面部动作时，左颞顶叶皮层的激活更强。尽管未来的研究需要调查这种选择性模仿反应的具体机制，但这些发现首次证明了在言语前婴儿中，群体状态线索可以调节面部模仿，并且表明模仿在促进社会联系中所起的作用的基础似乎在生命的第一年就存在了。
