Altering facial movements abolishes neural mirroring of facial expressions

Birch-Hurst, Kayley; Rychlowska, Magdalena; Lewis, Michael B.; Vanderwert, Ross E.

Abstract

People tend to automatically imitate others’ facial expressions of emotion. That reaction, termed “facial mimicry” has been linked to sensorimotor simulation—a process in which the observer’s brain recreates and mirrors the emotional experience of the other person, potentially enabling empathy and deep, motivated processing of social signals. However, the neural mechanisms that underlie sensorimotor simulation remain unclear. This study tests how interfering with facial mimicry by asking participants to hold a pen in their mouth influences the activity of the human mirror neuron system, indexed by the desynchronization of the EEG mu rhythm. This response arises from sensorimotor brain areas during observed and executed movements and has been linked with empathy. We recorded EEG during passive viewing of dynamic facial expressions of anger, fear, and happiness, as well as nonbiological moving objects. We examine mu desynchronization under conditions of free versus altered facial mimicry and show that desynchronization is present when adult participants can freely move but not when their facial movements are inhibited. Our findings highlight the importance of motor activity and facial expression in emotion communication. They also have important implications for behaviors that involve occupying or hiding the lower part of the face.

• Journal Article Type: Article
• Acceptance Date: Sep 14, 2021
• Online Publication Date: Oct 12, 2021
• Publication Date: 2022-04
• Deposit Date: Feb 18, 2022
• Publicly Available Date: Apr 13, 2022
• Journal: Cognitive, Affective and Behavioral Neuroscience
• Print ISSN: 1530-7026
• Electronic ISSN: 1531-135X
• Publisher: Springer (part of Springer Nature)
• Peer Reviewed: Peer Reviewed
• Volume: 22
• Pages: 316–327
• DOI: https://doi.org/10.3758/s13415-021-00956-z
• Keywords: Behavioral Neuroscience; Cognitive Neuroscience
• Public URL: https://uwe-repository.worktribe.com/output/8175718
• Additional Information: Accepted: 14 September 2021; First Online: 12 October 2021