Electrical Stimulation of Facial Muscles Alters Emotional Perception and Brain Responses

Recent research highlights the significant impact of facial muscle activity on how individuals perceive and interpret others' emotions. Scientists from the University of Essex conducted a comprehensive study using facial neuromuscular electrical stimulation (fNMES) to explore how stimulating facial muscles affects emotion recognition at different stages of visual processing. Published in *Communications Psychology, the study demonstrates that electrical stimulation of muscles involved in smiling can bias individuals toward perceiving faces as happier, especially during early visual interpretation.

Psychological theories have long suggested that our facial expressions feedback information to our brain, influencing our emotional understanding—a process known as 'facial feedback.' However, the precise timing and neural mechanisms of this influence have remained unclear. By integrating fNMES with EEG technology, researchers observed that stimulating smiling muscles not only increased happiness perceptions but also modulated brain activity related to face processing, specifically affecting the N170 neural marker associated with face recognition.

In experiments involving ambiguous facial images, stimulating the zygomaticus major (smile muscles) elicited a happiness bias in participants. EEG recordings showed that this stimulation decreased visual responses during early face processing stages, implying that facial feedback can reduce the brain's reliance on visual cues when decoding emotions. Notably, the timing of muscle activation played a critical role: stimulation during early visual stages and spontaneous mimicry was associated with altered brain responses and emotional judgments.

These findings suggest that our own facial expressions actively shape how we interpret social cues, influencing both perceptual and neural processes. This opens exciting possibilities for future applications, such as developing new interventions for mood disorders or improving emotion recognition through targeted facial muscle stimulation. Researchers aim to further refine their methods, exploring simultaneous muscle stimulation and combining fNMES with other neuroimaging techniques to deepen our understanding of facial feedback in emotion perception.

Overall, this study underscores the intertwined nature of body and mind in social cognition, highlighting that recognizing others' emotions involves not only visual perception but also our own bodily signals. The use of electric facial stimulation might pave the way for innovative approaches to emotional and social functioning in clinical and everyday contexts.

Source: https://medicalxpress.com/news/2025-07-electrical-facial-muscles-people-emotions.html