Department of Psychology, McGill University, Montreal, Canada.
Columbia Business School, Columbia University, New York, USA.
Proc Biol Sci. 2020 May 27;287(1927):20192941. doi: 10.1098/rspb.2019.2941. Epub 2020 May 13.
Mimicry, and especially spontaneous facial mimicry, is a rudimentary element of social-emotional experience that is well-conserved across numerous species. Although such mimicry is thought to be a relatively automatic process, research indicates that contextual factors can influence mimicry, especially in humans. Here, we extend this work by investigating the effect of acute psychosocial stress on spontaneous facial mimicry. Participants performed a spontaneous facial mimicry task with facial electromyography (fEMG) at baseline and approximately one month later, following an acute psychosocial stressor (Trier Social Stress Test). Results show that the magnitude of the endocrine stress response reduced zygomaticus major reactivity, and specifically spontaneous facial mimicry for positive social stimuli (i.e. smiles). Individuals with higher levels of the stress hormone cortisol showed a more blunted fEMG response to smiles, but not to frowns. Conversely, stress had no effect on corrugator supercilii activation (i.e. frowning to frowns). These findings highlight the importance of the biological stress response system in this basic element of social-emotional experience.
模仿，特别是自发的面部模仿，是社会情感体验的一个基本要素，在许多物种中都得到了很好的保留。尽管这种模仿被认为是一个相对自动的过程，但研究表明，环境因素会影响模仿，尤其是在人类中。在这里，我们通过研究急性社会心理应激对自发面部模仿的影响来扩展这项工作。参与者在基线和大约一个月后进行了自发的面部模仿任务，同时进行了面部肌电图（fEMG）测量，在此期间参与者经历了急性社会心理应激源（特里尔社会应激测试）。结果表明，内分泌应激反应的幅度降低了颧大肌的反应性，特别是对积极社会刺激（即微笑）的自发面部模仿。皮质醇水平较高的个体对微笑的 fEMG 反应更迟钝，但对皱眉没有影响。相反，压力对皱眉肌（即皱眉对皱眉）的激活没有影响。这些发现强调了生物应激反应系统在社会情感体验这一基本要素中的重要性。
