Straulino Elisa, Scarpazza Cristina, Spoto Andrea, Betti Sonia, Chozas Barrientos Beatriz, Sartori Luisa
Department of General Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy.
Translational Neuroimaging and Cognitive Lab, IRCCS San Camillo Hospital, Via Alberoni 70, 30126 Venice, Italy.
Biology (Basel). 2023 Aug 23;12(9):1160. doi: 10.3390/biology12091160.
Humans can recombine thousands of different facial expressions. This variability is due to the ability to voluntarily or involuntarily modulate emotional expressions, which, in turn, depends on the existence of two anatomically separate pathways. The Voluntary (VP) and Involuntary (IP) pathways mediate the production of posed and spontaneous facial expressions, respectively, and might also affect the left and right sides of the face differently. This is a neglected aspect in the literature on emotion, where posed expressions instead of genuine expressions are often used as stimuli. Two experiments with different induction methods were specifically designed to investigate the unfolding of spontaneous and posed facial expressions of happiness along the facial vertical axis (left, right) with a high-definition 3-D optoelectronic system. The results showed that spontaneous expressions were distinguished from posed facial movements as revealed by reliable spatial and speed key kinematic patterns in both experiments. Moreover, VP activation produced a lateralization effect: compared with the felt smile, the posed smile involved an initial acceleration of the left corner of the mouth, while an early deceleration of the right corner occurred in the second phase of the movement, after the velocity peak.
人类能够组合出数千种不同的面部表情。这种变异性源于能够主动或被动地调节情绪表达的能力，而这又取决于两条在解剖学上相互独立的通路的存在。自主通路（VP）和非自主通路（IP）分别介导刻意和自发面部表情的产生，并且可能对面部的左右两侧产生不同的影响。这是情绪文献中一个被忽视的方面，在该文献中，通常使用刻意表情而非真实表情作为刺激。专门设计了两个采用不同诱导方法的实验，以利用高清3D光电系统研究沿面部垂直轴（左侧、右侧）展开的自发和刻意的幸福面部表情。结果表明，在两个实验中，可靠的空间和速度关键运动学模式显示，自发表情与刻意的面部动作有所不同。此外，VP激活产生了一种偏侧化效应：与真实微笑相比，刻意微笑涉及嘴角左侧的初始加速，而在运动的第二阶段，即速度峰值之后，右侧嘴角出现早期减速。
