Facial neuromuscular electrical stimulation (NMES) is the application of an electrical current to the skin to induce muscle contractions and has enormous potential for basic research and clinical intervention in psychology and neuroscience. Because the technique remains largely unknown, and the prospect of receiving electricity to the face can be daunting, willingness to receive facial NMES is likely to be low and gender differences might exist in the amount of concern for the sensation of pain and skin burns. We investigated these questions in 182 healthy participants. The likelihood of taking part (LOTP) in a hypothetical facial NMES study was measured both before and after presenting a detailed vignette about facial NMES including its risks. Results showed that LOTP was generally high and that participants remained more likely to participate than not to, despite a decrease in LOTP after the detailed vignette. LOTP was significantly predicted by participants’ previous knowledge about electrical stimulation and their tendency not to worry about the sensations of pain, and it was inversely related to concerns for burns and loss of muscle control. Fear of pain was also inversely related to LOTP, but its effect was mediated by the other concerns. We conclude that willingness to receive facial NMES is generally high across individuals in the studied age range (18–45) and that it is particularly important to reassure participants about facial NMES safety regarding burns and loss of muscle control. The findings are relevant for scholars considering using facial NMES in the laboratory.

Facial neuromuscular electrical stimulation (fNMES), which allows for the non-invasive and physiologically sound activation of facial muscles, has great potential for investigating fundamental questions in psychology and neuroscience, such as the role of proprioceptive facial feedback in emotion induction and emotion recognition, as well as for clinical applications, such as alleviating depression symptoms. However, despite illustrious origins in 19th century work of Duchenne de Boulogne, the practical application of fNMES remains largely unknown to researchers in psychology and human physiology. In addition, published studies vary dramatically in use and reporting of parameters, such as stimulation frequency, amplitude, duration, and electrode size. Because fNMES parameters impact the comfort and safety of volunteers, as well as its physiological (and psychological) effects, it is of paramount importance to establish recommendations of good practice. Here, we provide an introduction to fNMES, a systematic review of the existing literature focusing on stimulation parameters used, and we offer recommendations on how to safely and reliably deliver fNMES. In addition, we provide a free webpage, allowing to easily verify and compare the safety of fNMES parameters based on current density. As an example of a potential application, we focus on the use of fNMES for the investigation of the facial feedback hypothesis.

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Facial neuromuscular electrical stimulation (fNMES), which allows for the non-invasive and physiologically sound activation of facial muscles, has great potential for investigating fundamental questions in psychology and neuroscience, such as the role of proprioceptive facial feedback in emotion induction and emotion recognition, as well as for clinical applications, such as alleviating depression symptoms. However, despite illustrious origins in 19th century work of Duchenne de Boulogne, the practical application of fNMES remains largely unknown to researchers in psychology and human physiology. In addition, published studies vary dramatically in use and reporting of parameters, such as stimulation frequency, amplitude, duration, and electrode size. Because fNMES parameters impact the comfort and safety of volunteers, as well as its physiological (and psychological) effects, it is of paramount importance to establish recommendations of good practice. Here, we provide an introduction to fNMES, a systematic review of the existing literature focusing on stimulation parameters used, and we offer recommendations on how to safely and reliably deliver fNMES. In addition, we provide a free webpage, allowing to easily verify and compare the safety of fNMES parameters based on current density. As an example of a potential application, we focus on the use of fNMES for the investigation of the facial feedback hypothesis.

Facial neuromuscular electrical stimulation (NMES) is the application of an electrical current to the skin to induce muscle contractions and has enormous potential for basic research and clinical intervention in psychology and neuroscience. Because the technique remains largely unknown, and the prospect of receiving electricity to the face can be daunting, willingness to receive facial NMES is likely to be low and gender differences might exist in the amount of concern for the sensation of pain and skin burns. We investigated these questions in a pre-registered online study in 182 healthy participants. The likelihood of taking part (LOTP) in a hypothetical facial NMES study was measured with a 7-point Likert scale both before and after presenting a detailed vignette about facial NMES including its risks. Results showed that LOTP was generally high and that participants remained more likely to participate than not to, despite a decrease in LOTP after the detailed vignette. LOTP was significantly predicted by participants’ previous knowledge about electrical stimulation and their tendency not to worry about the sensations of pain, and it was inversely related to concerns for burns and loss of muscle control. Fear of pain was also inversely related to LOTP, but its effect was mediated by the other concerns. We conclude that willingness to receive facial NMES is generally high across individuals in the studied age range (18-45) and that it is particularly important to reassure participants about facial NMES safety regarding burns and loss of muscle control. The findings are relevant for scholars considering using facial NMES in the laboratory.