Neural Correlates of Facial Mimicry: Simultaneous Measurements of EMG and BOLD Responses during Perception of Dynamic Compared to Static Facial Expressions

Abstract

Facial mimicry (FM) is an automatic response to imitate the facial expressions of others. However, neural correlates of the phenomenon are as yet not well established. We investigated this issue using simultaneously recorded EMG and BOLD signals during perception of dynamic and static emotional facial expressions of happiness and anger. During display presentations, BOLD signals and zygomaticus major (ZM), corrugator supercilii (CS) and orbicularis oculi (OO) EMG responses were recorded simultaneously from 46 healthy individuals. Subjects reacted spontaneously to happy facial expressions with increased EMG activity in ZM and OO muscles and decreased CS activity, which was interpreted as FM. Facial muscle responses correlated with BOLD activity in regions associated with motor simulation of facial expressions [i.e., inferior frontal gyrus, a classical Mirror Neuron System (MNS)]. Further, we also found correlations for regions associated with emotional processing (i.e., insula, part of the extended MNS). It is concluded that FM involves both motor and emotional brain structures, especially during perception of natural emotional expressions.

Widespread and lateralized social brain activity for processing dynamic facial expressions

“…For example, three previous studies (Badzakova‐Trajkov et al, ; Fox et al, ; Sato et al, ) indicated that observation of dynamic facial expressions activated the dorsomedial prefrontal cortex (dmPFC), which could be involved in attributing the intentions and other mental states from the faces of others (Frith & Frith, ). One possible reason for these inconsistent findings is sample size, which was less than 30 in all previous individual experiments with only a few exceptions (Badzakova‐Trajkov et al, ; Kessler et al, ; Rymarczyk et al, ), because studies involving small sample sizes may have low statistical power and a reduced chance of detecting effects (Button et al, ). This issue could be relevant even to meta‐analyses (Arsalidou et al, ; Zinchenko et al, ) because these studies employed coordinate‐based meta‐analytical methods, which assess the convergence of the locations of activation foci reported in individual studies and have difficulty detecting small effects with underpowered individual studies (Acar, Seurinck, Eickhoff, & Moerkerke, ).…”

“…A number of neuroimaging studies using functional magnetic resonance imaging (fMRI) and positron emission tomography have been performed to gain insight into the neural mechanisms underlying the processing of dynamic facial expressions (Arnold, Iaria, & Goghari, ; Arsalidou, Morris, & Taylor, ; Badzakova‐Trajkov, Haberling, Roberts, & Corballis, ; De Winter et al, ; Faivre, Charron, Roux, Lehéricy, & Kouider, ; Foley, Rippon, Thai, Longe, & Senior, ; Fox, Iaria, & Barton, ; Furl, Henson, Friston, & Calder, ; Grosbras & Paus, ; Johnston, Mayes, Hughes, & Young, ; Kessler et al, ; Kilts, Egan, Gideon, Ely, & Hoffman, ; Kret, Pichon, Grezes, & de Gelder, ; LaBar, Crupain, Voyvodic, & McCarthy, ; Pelphrey, Morris, McCarthy, & Labar, ; Pentón et al, ; Polosecki et al, ; Rahko et al, ; Reinl & Bartles, ; Rymarczyk, Zurawski, Jankowiak‐Siuda, & Szatkowska, ; Sato, Kochiyama, Uono, & Yoshikawa, ; Sato, Kochiyama, Yoshikawa, Naito, & Matsumura, ; Sato, Toichi, Uono, & Kochiyama, ; Schobert, Corradi‐Dell'Acqua, Frühholz, van der Zwaag, & Vuilleumier, ; Schultz, Brockhaus, Bülthoff, & Pilz, ; Schultz & Pilz, ; Trautmann, Fehr, & Herrmann, ; van der Gaag, Minderaa, & Keysers, ; for reviews, see Arsalidou et al, ; Zinchenko, Yaple, & Arsalidou, ). These studies contrasted brain activation during observation of dynamic emotional facial expressions with that during observation of control stimuli matched for visual motion or form with the dynamic expressions, such as dynamic mosaics, dynamic objects, nonemotional facial movements, and static emotional facial expressions.…”

Blocking facial mimicry affects recognition of facial and body expressions

“…Within this theoretical framework, facial mimicry has been conceived as linked to an internal simulation process that the observer would spontaneously put in place during the observation of others' facial expressions and that, ultimately, would support their recognition [27][28][29][30][31]. In line with this proposal, neuroimaging techniques have shown that (pre)motor and somatosensory regions representing the face are active during the perception of emotional face [32][33][34][35], and neural activity in these regions correlates with the degree of facial mimicry [36][37][38]. Moreover, damage to, or transcranial magnetic stimulation (TMS) interference with, the face representations in motor and somatosensory areas disrupts facial mimicry and impairs the recognition and interpretation of emotional expressions [39][40][41][42][43][44] (see also [45]).…”

Neural correlates of communicating emotion through facial expressions: A simultaneous fMRI and facial EMG study

“…Previous neuroimaging research has generated some support for these predictions but this evidence has faced technological and experimental constraints. Participants have viewed emotional images and faces while undergoing combined fMRI scanning and facial EMG recording (Heller et al, 2011;Likowski et al, 2012;Rymarczyk et al, 2018). However, technological constraints have previously prevented researchers from directly relating time-locked brain and facial muscle activity on a trial-by-trial basis.…”

“…Several research teams have recorded targets' brain and facial muscle activity by combining fMRI with facial electromyography (EMG). Targets in these studies produced facial EMG responses, and recruited brain structures broadly associated with experiencing emotion and mentalizing, when they viewed emotional images and faces (Heller et al, 2011;Likowski et al, 2012;Rymarczyk et al, 2018). Although revealing, this work does not isolate brain activity that "tracks" simultaneous facial movement on a trial-by-trial basis.…”