Covert facial mimicry involves subtle facial muscle activation in observers when they perceive the facial emotional expressions of others. It remains uncertain whether prototypical facial features in ...emotional expressions are being covertly mimicked and also whether covert facial mimicry involves distinct facial muscle activation patterns across muscles per emotion category, or simply distinguishes positive versus negative valence in observed facial emotions. To test whether covert facial mimicry is emotion-specific, we measured facial electromyography (EMG) from five muscle sites (corrugator supercilii, levator labii, frontalis lateralis, depressor anguli oris, zygomaticus major) whilst participants watched videos of people expressing 9 different basic and complex emotions and a neutral expression. This study builds upon previous research by including a greater number of facial muscle measures and emotional expressions. It is the first study to investigate activation patterns across muscles during facial mimicry and to provide evidence for distinct patterns of facial muscle activation when viewing individual emotion categories, suggesting that facial mimicry is emotion-specific, rather than just valence-based.
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, and may serve for clinical applications, such as alleviating symptoms of depression. However, despite illustrious origins in the 19th-century work of Duchenne de Boulogne, the practical application of fNMES remains largely unknown to today’s researchers in psychology. In addition, published studies vary dramatically in the stimulation parameters used, such as stimulation frequency, amplitude, duration, and electrode size, and in the way they reported them. 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 and to ensure studies can be better compared and integrated. Here, we provide an introduction to fNMES, systematically review the existing literature focusing on the stimulation parameters used, and offer recommendations on how to safely and reliably deliver fNMES and on how to report the fNMES parameters to allow better cross-study comparison. In addition, we provide a free webpage, to easily visualise fNMES parameters and verify their safety 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.
Compound facial expressions of emotion Du, Shichuan; Tao, Yong; Martinez, Aleix M
Proceedings of the National Academy of Sciences,
04/2014, Letnik:
111, Številka:
15
Journal Article
Recenzirano
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Understanding the different categories of facial expressions of emotion regularly used by us is essential to gain insights into human cognition and affect as well as for the design of computational ...models and perceptual interfaces. Past research on facial expressions of emotion has focused on the study of six basic categories—happiness, surprise, anger, sadness, fear, and disgust. However, many more facial expressions of emotion exist and are used regularly by humans. This paper describes an important group of expressions, which we call compound emotion categories. Compound emotions are those that can be constructed by combining basic component categories to create new ones. For instance, happily surprised and angrily surprised are two distinct compound emotion categories. The present work defines 21 distinct emotion categories. Sample images of their facial expressions were collected from 230 human subjects. A Facial Action Coding System analysis shows the production of these 21 categories is different but consistent with the subordinate categories they represent (e.g., a happily surprised expression combines muscle movements observed in happiness and surprised). We show that these differences are sufficient to distinguish between the 21 defined categories. We then use a computational model of face perception to demonstrate that most of these categories are also visually discriminable from one another.
BACKGROUND:Masseteric- or deep temporal–to-facial nerve transfer (five-to-seven nerve transfer) is increasingly used in facial reanimation; however, the indications and clinical variables affecting ...outcomes for five-to-seven nerve transfer have not been defined. The authors describe their early experience with five-to-seven nerve transfer, reporting function and patient-reported outcomes, to identify potential parameters that are predictive of outcome.
METHODS:The authors conducted a retrospective chart review of all patients who underwent five-to-seven nerve transfer for smile reanimation from 2012 to 2017. Age, sex, cause of facial paralysis, onset and duration of paralysis, history of adjuvant chemotherapy and/or radiation therapy, donor nerve used, adjunctive procedures, and final excursion were recorded. Standard photographs and videos, and data regarding clinical facial nerve function and patient-reported quality of life, were obtained preoperatively and postoperatively.
RESULTS:Sixty patients were identified. Forty-seven had flaccid facial paralysis and 13 had postparalysis facial palsy. Among flaccid facial paralysis patients, masseteric nerve transfer was successful in 30 patients (88 percent) and deep temporal nerve transfer was successful in three cases (60 percent). Among postparalysis facial palsy patients, five-to-seven nerve transfer was successful in two patients (20 percent). Average quality-of-life scores improved significantly from preoperatively (46) to postoperatively (59) among flaccid facial paralysis patients with successful five-to-seven nerve transfer.
CONCLUSIONS:Five-to-seven nerve transfer is a viable option in facial reanimation. Shorter denervation times and preoperative flaccidity are favorable predictors of outcome. Five-to-seven nerve transfer as an adjunct to primary repair appears highly effective for enhancing smile function. Five-to-seven nerve transfer results are not reliable in patients with postparalysis facial palsy.
CLINICAL QUESTION/LEVEL OF EVIDENCE:Therapeutic, IV.
Introduction: The aim of this study was to assess various smile line problems and treatments and to assess the patients’ satisfaction after treatment. Methods: This cross-sectional study assessed ...patients who had smile line problems. Various smile line problems included vertical maxillary excess (VME), muscle hyperactivity, gingival hyperplasia, short lip, bimaxillary protrusion, asymmetric muscle hyperactivity, maxillary canting, and tooth deformity. All patients filled out a questionnaire one year after the procedures for 23 assessments of satisfaction. The level of satisfaction was evaluated using a visual analog scale (VAS): 0-3 dissatisfaction, 4-7 acceptable, and 7-10 desirable. Results: One-hundred thirty-seven patients were included in this study. The highest level of satisfaction was noted in patients who had tooth deformity, VME with passive eruption, and gingival hyperplasia or passive supra-eruption (7.75±0.46, 7.66±0.72, and 7.50±0.55, respectively). The lowest level of satisfaction was noted in patients who had asymmetric muscle activity, muscle hyperactivity, and VME+ muscle hyperactivity (4.25±0.96, 4.33±0.78 and5.00±1.09, respectively). Conclusion: Patients with soft tissue problems of the smile line may have low 41satisfaction especially when temporary treatments such as botulinum toxin are used for treatment. Surgery of the hard tissues may result in moderate to high satisfaction in patients with smile line problems.
In this article, we elaborate a practical approach to superficial facial anatomy enabling easy identification of the facial mimic muscles by classifying them according to their shared common ...insertion sites.
The facial mimic muscles are often difficult to identify on imaging. By tracing them from their common group insertion sites back to their individual origins as well as understanding key anatomic relationships, radiologists can more accurately identify these muscles.
Electrical stimulation of the median nerve at the wrist may elicit a blink reflex hand blink reflex (HBR) mediated by a neural circuit at brain stem level. As, in a Sherringtonian sense, the blink ...reflex is a defensive response, in a series of experiments we tested, in healthy volunteers, whether and how the HBR is modulated by the proximity of the stimulated hand to the face. Electromyographic activity was recorded from the orbicularis oculi, bilaterally. We observed that the HBR is enhanced when the stimulated hand is inside the peripersonal space of the face, compared with when it is outside, irrespective of whether the proximity of the hand to the face is manipulated by changing the position of the arm (experiment 1) or by rotating the head while keeping the arm position constant (experiment 3). Experiment 2 showed that such HBR enhancement has similar magnitude when the participants have their eyes closed. Experiments 4 and 5 showed, respectively, that the blink reflex elicited by the electrical stimulation of the supraorbital nerve, as well as the N20 wave of the somatosensory evoked potentials elicited by the median nerve stimulation, are entirely unaffected by hand position. Taken together, our results provide compelling evidence that the brain stem circuits mediating the HBR in humans undergo tonic and selective top-down modulation from higher order cortical areas responsible for encoding the location of somatosensory stimuli in external space coordinates. These findings support the existence of a "defensive" peripersonal space, representing a safety margin advantageous for survival.
Viewing facial expressions often evokes facial responses in the observer. These spontaneous facial reactions (SFRs) are believed to play an important role for social interactions. However, their ...developmental trajectory and the underlying neurocognitive mechanisms are still little understood. In the current study, 4- and 7-month old infants were presented with facial expressions of happiness, anger, and fear. Electromyography (EMG) was used to measure activation in muscles relevant for forming these expressions: zygomaticus major (smiling), corrugator supercilii (frowning), and frontalis (forehead raising). The results indicated no selective activation of the facial muscles for the expressions in 4-month-old infants. For 7-month-old infants, evidence for selective facial reactions was found especially for happy (leading to increased zygomaticus major activation) and fearful faces (leading to increased frontalis activation), while angry faces did not show a clear differential response. These results suggest that emotional SFRs may be the result of complex neurocognitive mechanisms which lead to partial mimicry but are also likely to be influenced by evaluative processes. Such mechanisms seem to undergo important developments at least until the second half of the first year of life.
Abstract
Background
The tear trough is one of the most challenging facial regions for soft-tissue filler injections. A thorough understanding of the underlying facial, muscular, and vascular anatomy ...is crucial to perform safe and effective tear trough injectable treatments.
Objectives
The authors sought to evaluate the location and function of the angular vein in the tear trough in 3 different facial expressions: repose, smiling, and max. orbicularis oculi contraction.
Methods
Twenty study participants with a mean age of 48.3 years and mean BMI of 24.5 kg/m2 were investigated via functional ultrasound imaging. The diameter of the angular vein and the velocity and direction of venous blood flow were analyzed in repose, smiling, and during max. orbicularis oculi contraction.
Results
The angular vein was identified in 100% of the cases to travel inside the orbicularis oculi muscle (intra-muscular course) within the tear trough, whereas the angular artery was not identified in this location. The distance between the angular vein and the inferior orbital rim was (lateral to medial): 4.6 mm, 4.5 mm, 3.9 mm, and 3.8 mm. The caudally directed blood flow was in repose 10.2 cm/s and was 7.3 cm/s at max. orbicularis oculi muscle contraction; however, no blood flow was detectable during smiling.
Conclusions
The diameter and the venous blood flow of the angular vein varied between the 3 tested facial expressions. Based on these anatomical findings, the deep injection approach to the tear trough is recommended due to the intramuscular course of the angular vein.
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