An Electrically Induced Smile Can Alter Emotional Perception, Groundbreaking Study Finds
Researchers have made a groundbreaking discovery in the field of emotional perception, showing that a brief, electrically induced smile can significantly change how neutral faces are perceived. This novel approach, inspired by Charles Darwin’s work and known as facial electrical stimulation, holds promise for a deeper understanding of emotional perception and potential treatments for affective disorders, such as depression, Parkinson’s, and autism.
Key Facts
- Innovative Experimentation: This study utilized electrical stimulation to activate smile muscles, demonstrating that it can make neutral faces appear more joyful, offering the first evidence of its kind.
- Historical Inspiration: The technique draws inspiration from methods pioneered by Duchenne de Boulogne and featured by Charles Darwin, applying controlled electrical currents to induce precise smiles.
- Potential Clinical Applications: The findings open doors for exploring new treatment approaches for mood disorders and conditions affecting emotional expression, like Parkinson’s and autism, by enhancing facial emotion recognition through a greater understanding of facial feedback.
A recent study conducted at the University of Essex has revealed that a fleeting, electrically induced smile can profoundly alter how people interpret neutral facial expressions. The research, led by Dr. Sebastian Korb from the Department of Psychology, utilized facial electrical stimulation, a technique inspired by Charles Darwin’s pioneering work on emotions and expressions.
Inspired by the groundbreaking photographs taken by Duchenne de Boulogne and featured by Darwin, the study represented the first successful attempt to modernize this technique by applying controlled electrical currents to specific facial muscles. The results were astonishing, as even a brief, weak grin caused the participants to perceive the neutral faces as more joyful.
For the first time, the study demonstrated the significant impact of facial electrical stimulation on emotional perception. By manipulating facial muscles through painless electrical currents, the researchers were able to create momentary uncontrollable smiles, which, in turn, altered the perception of happiness in neutral or slightly sad-looking faces.
Dr. Korb, the lead researcher, emphasized the ground-breaking nature of the finding, stating, “The controlled, brief, and weak activation of facial muscles, creating the illusion of happiness in otherwise neutral or slightly sad-looking faces, holds immense significance.” Moreover, this finding bears relevance in ongoing theoretical debates regarding the role of facial feedback in emotions and possesses vast potential for future clinical applications.
Dr. Korb’s modernized technique builds upon the methodology first developed in the 19th century by the French physician Duchenne de Boulogne. Featured extensively in Darwin’s “The Expression of the Emotions in Man and Animals,” this technique underwent adjustments to ensure participant safety and optimize smile control. Using computer technology, the team precisely controlled the onset of smiles, down to the millisecond.
A total of 47 participants took part in the groundbreaking study, which was published in the esteemed journal Social Cognitive and Affective Neuroscience. During the experiments, the participants assessed digital avatars and determined whether they appeared happy or sad. In half of the trials, smiling muscles were activated at the onset of viewing the face, resulting in the perception of increased happiness.
The research sheds light on the intricacies of facial feedback and paves the way for further exploration of emotional perception in healthy individuals. Dr. Korb and his team aim to extend the study’s scope, focusing on facial emotion recognition for individuals with conditions like Parkinson’s, known to have impaired facial mimicry and recognition. Additionally, the team has published guidelines to allow other researchers to safely employ the technique of electrical facial muscle stimulation in their investigations.
About This Emotional Processing Research News
Author: Ben Hall
Source: University of Essex
Original Research: Closed access. “Zygomaticus activation through facial neuromuscular electrical stimulation (fNMES) induces happiness perception in ambiguous facial expressions and affects neural correlates of face processing” by Sebastian Korb et al. Social Cognitive and Affective Neuroscience.
Abstract
Zygomaticus activation through facial neuromuscular electrical stimulation (fNMES) induces happiness perception in ambiguous facial expressions and affects neural correlates of face processing
The role of facial feedback in facial emotion recognition remains controversial, partially due to the limitations of current methods for manipulating facial muscle activation, such as voluntarily posing expressions or holding a pen in the mouth. These methods have limited control over which muscles are activated or deactivated, when, and to what extent.
To overcome these limitations and examine the influence of facial muscle activity on facial emotion recognition in a more controlled manner, researchers employed computer-controlled facial neuromuscular electrical stimulation (fNMES). In a pre-registered electroencephalography (EEG) experiment, 47 participants categorised ambiguous facial expressions as happy or sad.
In half of the trials, weak smiling was induced by delivering fNMES to the bilateral Zygomaticus Major muscle for 500 milliseconds. Both frequentist and Bayesian linear mixed models demonstrated a significant increase in the likelihood of categorising ambiguous facial expressions as happy with fNMES. Additionally, fNMES resulted in reduced brainwave amplitudes associated with various stages of face processing.
These findings suggest that fNMES-induced facial feedback can bias facial emotion recognition and modulate the neural correlates of face processing. Researchers conclude that fNMES holds significant potential as a tool for studying the effects of facial feedback.
