Corrugator Supercilii Research Articles

Resolving the Controversy Surrounding the Function of the Corrugator Supercilii Muscle.

The corrugator supercilii muscle (CSM) has traditionally been recognized as a primary depressor of the eyebrows, playing a key role in expressing negative emotions and contributing to the formation of glabellar lines. However, recent studies indicate that the CSM may exhibit movements contrary to those previously documented, suggesting a more complex functional role. This research re-evaluates the anatomical and functional roles of the CSM and discusses their implications for botulinum toxin treatments. A prospective, intrapersonal comparative, and split-face study was conducted over a five-year period, from January 6, 2019, to January 6, 2024, involving 298 patients who underwent botulinum toxin injections. The study divided participants into seven groups, each targeting specific anatomical areas of the CSM and associated muscles. Injection techniques were varied to assess their impact on brow dynamics, with outcomes measured by changes in eyebrow position and expression lines. The study demonstrated that targeting specific portions of the CSM and depressor supercilii muscle (DSM) leads to distinct outcomes in brow elevation and the reduction of expression lines. However, this approach was also frequently associated with the development of omega-shaped wrinkles. Split-face evaluations further validated that the modified injection techniques achieved superior eyebrow elevation compared to traditional methods. This study challenges the traditional view of the CSM as primarily a brow depressor, highlighting its role in medial brow elevation. These findings underscore the need for a nuanced approach in esthetic medicine, particularly in botulinum toxin injections, to achieve balanced and natural facial expressions. Understanding the full range of CSM functions is crucial for optimizing esthetic outcomes and enhancing patient satisfaction. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Emotional contagion to vocal smile revealed by combined pupil reactivity and motor resonance

The interplay between the different components of emotional contagion (i.e. emotional state and facial motor resonance), both during implicit and explicit appraisal of emotion, remains controversial. The aims of this study were (i) to distinguish between these components thanks to vocal smile processing and (ii) to assess how they reflect implicit processes and/or an explicit appraisal loop. Emotional contagion to subtle vocal emotions was studied in 25 adults through motor resonance and Autonomic Nervous System (ANS) reactivity. Facial expressions (fEMG: facial electromyography) and pupil dilation were assessed during the processing and judgement of artificially emotionally modified sentences. fEMG revealed that Zygomaticus major was reactive to the perceived valence of sounds, whereas the activity of Corrugator supercilii reflected explicit judgement. Timing analysis of pupil dilation provided further insight into both the emotional state and the implicit and explicit processing of vocal emotion, showing earlier activity for emotional stimuli than for neutral stimuli, followed by valence-dependent variations and a late judgement-dependent increase in pupil diameter. This innovative combination of different electrophysiological measures shed new light on the debate between central and peripherical views within the framework of emotional contagion.

Simulating Upper Eyelid Ptosis During Neuromodulator Injections-An Exploratory Injection and Dissection Study.

Aesthetic neuromodulator injections of the upper face are frequently performed to temporarily block muscular actions of the periorbital muscles to ultimately reduce skin rhytids. However, the adverse event rate in the literature for toxin-induced blepharoptosis ranges from 0.51% to 5.4%. To identify access pathways by which injected neuromodulator product can travel from extra- to intra-orbital and therefore affect the levator palpebrae superioris muscle. Nine non-embalmed human body donors were investigated in this study with a mean age at death of 72.8 (16.1) years. The 18 supraorbital regions were injected in 28 times (14 for supratrochlear and 14 for supraorbital) with 0.5 cc, whereas eight cases (four for supratrochlear and four supraorbital) were injected with 0.1 cc of colored product. Anatomic dissections were conducted to identify structures stained by the injected color. The results of this injection- and dissection-based study revealed that both the supratrochlear and the supraorbital neurovascular bundles are access pathways for injected neuromodulator products to reach the intra-orbital space and affect the levator palpebrea superioris muscle. Out of 36 conducted injection passes, seven (19.44%) resulted in affection of the sole elevator of the eyelid of which 100% occurred only at an injection volume of 0.5 cc and not at 0.1 cc. Clinically, the results indicate that a low injection volume, a superficial injection for the supraorbital location, and angling the needle tip away from the supratrochlear foramen (toward the contralateral temple) when targeting the corrugator supercilii muscles, can increase the safety profile of an aesthetic toxin glabellar treatment.

The Relationship Between Glabellar Contraction Patterns and Glabellar Muscle Anatomy: A Magnetic Resonance Imaging-based Study.

Glabellar contraction patterns were introduced to the scientific literature to help guide glabellar neuromodulator injection algorithms. However, the relationship between the underlying musculature and its influence on these glabellar contraction patterns is unclear. The aim of this study was to identify via Magnetic Resonance Imaging (MRI) glabellar muscle parameters that display an influence on the distribution of individual glabellar contraction patterns. Thirty-four healthy young individuals of Caucasian Polish descent were investigated (17 women, 17 men) with a mean age of 23.6 years and a mean BMI of 22.8 kg/m2. MRI-based measurements of length, thickness, width and surface area of procerus, corrugator supercilii, orbicularis oculi and frontalis muscles were conducted. Unadjusted models revealed that there was no statistically significant difference between the five glabellar contraction types and the investigated muscle parameters indicating that independent of the skin rhytid pattern, the underlying musculature was not different between the investigated groups in this sample with all p ≥ 0.102. Adjusted models revealed that sex was the most influential factor due to males displayed in general higher values for the investigated parameters when compared to females. The results of this study reveal that based on the MRI parameters investigated and based on the investigated cohort, there does not appear to be a strong relationship between glabellar contraction patterns and underlying glabella muscle anatomy. Utilizing glabellar contraction patterns to design neuromodulator treatment algorithms may be of variable clinical merit.

Anatomical Trajectory of the Corrugator Supercilii Muscle in Koreans: Implications for Aesthetic and Clinical Practices.

Understanding the attachment patterns of the corrugator supercilii muscle (CS) is vital for treatments designed to improve facial symmetry and functionality. The aim of this research was to elucidate the anatomical trajectory and intricate relationships of the CS within the upper face and midface, specifically focusing on its connections with the frontalis (FT) and orbicularis oculi (OOc) muscles. The CS was examined in 41 specimens of embalmed adult Korean cadavers using microdissection, histological analyses, and microcomputed tomography, an in-depth exploration of its anatomical positioning and intricate interactions with adjacent muscles. Some lower fibers of the CS extended to the upper orbital part of the OOc in 59.5% of cases, while the CS interdigitated or blended exclusively with the FT in 40.5% of cases. The fibers of the CS demonstrated diverse extensions towards the upper face and midface, exhibiting varied trajectories and lengths. Additionally, lower fibers of the CS extended to significant anatomical landmarks such as the OOc, malaris muscle, and the superficial musculoaponeurotic system (SMAS). This study demonstrates that precise understanding of the CS and its relationship with the FT and OOc is crucial for optimizing invasive or non-invasive treatment like botulinum toxin injection, SMAS lifting and browplasty surgery. The extension of lower fibers of the CS to significant anatomical landmarks indicates complex interactions with adjacent facial structures, highlighting the necessity of detailed anatomical knowledge for clinical applications.

Anatomie de la région frontale

The forehead is an anatomic region located between the frontal hairline cranially, the eyebrow and the glabella caudally, and the anterior border of the temporal fossa laterally on both sides. Its vertical situation, due to the telencephalon growth, is specific of the human species. From surface to deep planes, the skin and sub-cutaneous fat pads are described first. The muscular plane is constituted of the frontal muscles elevators of the forehead and the eyebrow, and the depressors which are the procerus and orbicularis oculi muscles superficially, the depressor supercilii muscle, and the corrugator supercilii in a deep plane. The galea aponeurotica, located deep to the frontal muscles, is a fibrous lamina on which the muscles of the skull insert. There is a sexual dimorphism of the frontal bone. The male forehead has extensive supraorbital bossing, and above this there is often a flat area, in teh femalethe supraorbital bossing is often nonexistent and above, there is a continous mild curvature. Blood supply to the forehead is given by an anterior pedicle constituted by the supraorbital and supratrochlear vessels and a lateral pedicle made of the anterior branches from the superficial temporal vessels. The sensory innervation of the forehead is given by the ophtalmic nerve which divides in frontal, nasociliar and lacrymal nerves. The motor innervation is given by the temporal ramus of the facial nerve which passes laterally to the zygomatic arch, and gives the innervation of the frontal, corrugator supercilii and procerus muscles.

Upper Blepharoplasty through Infrabrow Skin Excision to Treat Dermatochalasis with Lateral Hooding and Medial Orbital Fat Loss in Selected Patients.

Dermatochalasis with lateral hooding and medial orbital fat loss are common signs of aging in the upper eyelid. Removing the excess skin in this area through infrabrow skin excision can effectively lift the loose skin of the upper eyelid and minimizes visible scarring. Additionally, we have identified three compartments of orbital fat prolapse based on orbital anatomy. Transferring volume from the lateral compartment to the intermediate region can flatten the lateral upper eyelid and create medial fullness, which ultimately rejuvenates the upper eyelid. This study presents an operative method for correcting age-related changes in the upper eyelid using this technique. A total of 34 eyelids from 17 patients underwent a surgical procedure involving infrabrow skin excision, along with repositioning and lifting of lateral orbital fat. The inclusion criteria consisted of patients with moderate to severe upper eyelid dermatochalasis, coupled with middle fat loss and lateral hooding. To correct lateral hooding and restore midfacial fullness, lateral orbital fat was repositioned to an intermediate position, and the orbicularis oculi muscle was fold-sutured to the corrugator supercilii muscle. The mean age of the patients was 55.59 ± 3.20 years, with a range of 48 to 61 years. The mean follow-up period was 9.94 ± 1.35 months, ranging from 8 to 12 months. Patients were evaluated at 1-month, 3-month, and 6-month intervals. The Strasser system was used to evaluate the surgical outcomes at 3 months. All patients achieved good surgical outcomes, expressed through satisfactory cosmetic improvements, and improved visual field. The procedure effectively corrected lateral hooding and loss of middle orbital fat through infrabrow skin excision. No complications, such as wound dehiscence, lagophthalmos, noticeable scarring, ocular dyskinesia, or sensory changes, were observed. The combination of infrabrow skin excision, repositioning of lateral orbital fat, and lifting of the orbicularis oculi muscle effectively addresses moderate to severe dermatochalasis, lateral hooding, medial fat loss, and improves elasticity of the anterior wall of the upper lid in our patients. This procedure can produce satisfactory and long-lasting aesthetic results with an inconspicuous scar beneath the brow.

A Myxofibroma of the Soft Tissue of Face: A Rare Case Report

Myxoma is a locally invasive neoplasm usually involving the jaw bones, typically occurs between the second and fourth decades. This tumor may comprise 3%-6% of odontogenic tumors. Myxomas of the soft tissue of the face are very rare. We present an unusual case of myxofibroma occurring in a 13-year-old man involving the soft tissue of the face. It congenitally occurred and was a 1 cm sized, ovoid in shape, swelling located on the glabella without any symptoms. An excisional biopsy was performed. A well encapsulated ovoid mass was attached to the corrugator supercilli muscle below the frontalis muscle. It was measured 1.1 x 1 x 0.8 cm and completely excised. Histological examination revealed myxofibroma showing stellate and spinde-shaped cells throughout myxoid ground substance. The unusual features of this case are the site of the tumor, which was localized to the non-tooth bearing area of the mandible and its congenital occurrence history.

Optimal processing of surface facial EMG to identify emotional expressions: A data-driven approach

Surface facial electromyography (EMG) is commonly used to detect emotions from subtle facial expressions. Although there are established procedures for collecting EMG data and some aspects of their processing, there is little agreement among researchers about the optimal way to process the EMG signal, so that the study-unrelated variability (noise) is removed, and the emotion-related variability is best detected. The aim of the current paper was to establish an optimal processing pipeline for EMG data for identifying emotional expressions in facial muscles. We identified the most common processing steps from existing literature and created 72 processing pipelines that represented all the different processing choices. We applied these pipelines to a previously published dataset from a facial mimicry experiment, where 100 adult participants observed happy and sad facial expressions, whilst the activity of their facial muscles, zygomaticus major and corrugator supercilii, was recorded with EMG. We used a resampling approach and subsets of the original data to investigate the effect and robustness of different processing choices on the performance of a logistic regression model that predicted the mimicked emotion (happy/sad) from the EMG signal. In addition, we used a random forest model to identify the most important processing steps for the sensitivity of the logistic regression model. Three processing steps were found to be most impactful: baseline correction, standardisation within muscles, and standardisation within subjects. The chosen feature of interest and the signal averaging had little influence on the sensitivity to the effect. We recommend an optimal processing pipeline, share our code and data, and provide a step-by-step walkthrough for researchers.

Temporal dynamics of positive emotion regulation: insights from facial electromyography.

Emotion regulation (ER) is a complex process that manifests gradually over time. This study investigated the temporal dynamics of ER in modifying positive emotions in terms of both negative affect (NA) and positive affect (PA) dimensions. After participants had been exposed to pleasant pictures for 8,000 ms, they received instructions to either continue viewing the picture (no regulation) or reappraise it with a neutral meaning (neutralize goal) or negative meaning (transform goal) for another 8,000 ms. We obtained corrugator supercilii and zygomaticus major electromyography (EMG) as objective measures of NA and PA. For the no-regulation condition, upon instruction onset, we observed maintained low levels of corrugator and high levels of zygomaticus EMG reactivity, indicating sustained PA activation. Compared to the no-regulation condition, for the neutralize goal, we observed no change in corrugator reactivity, which remained at a low level, while zygomaticus reduction started at 1,000 ms after instruction onset, indicating decreased PA and generation of a neutral emotional state. For the transform goal, we observed corrugator increase and zygomaticus decrease both starting at 1,500 ms after instruction onset and co-existing throughout the regulation period. These results indicate increased NA and decreased PA, relating to generation of a negative emotional state. The transform goal differed from the neutralize goal in terms of corrugator increase starting at 2,500 ms after instruction onset. Albeit simultaneous onset of changes on corrugator and zygomaticus reactivity under the transform goal, model-fitting analyses indicated that the best-fitting trajectory was one that first emphasized PA reduction until, at 3,000 ms, it turned into primary NA increase. These distinct temporal patterns highlight the possibility of effecting one-dimensional PA change with the neutralize goal and sequential two-dimensional change (first decreasing PA, then increasing NA) with the transform goal. This research sheds light on the time course of emotional change brought about by different regulatory goals.

Considering Cuteness Enhances Smiling Responses to Infant Faces1,2

AbstractLaboratory and field research has reported that the appearance of infants causes observers to smile. The current study examined whether this smiling response is modulated by the observer's task and evaluative dimension. Thirty‐nine young nulliparous women were asked to rate the cuteness or beauty levels of 6‐month‐old infants' faces using a 7‐point scale in different blocks. Facial electromyograms (EMGs) were recorded of participants' facial muscles related to both smiling (the zygomaticus major [ZM] and orbicularis oculi [OO]) and frowning (the corrugator supercilii [CS]). The results showed that cuteness and beauty ratings were highly correlated with each other (r = .90), indicating that these evaluations were based on similar attractiveness‐related physical features. Facial EMG responses on the smiling muscle sites, ZM and OO, increased significantly from the baseline when participants rated the faces' cuteness, and the responses were larger than when participants rated the faces' beauty. CS activity was not found to have any effect. The perceived cuteness level of the infant faces did not affect the facial EMG responses. Moreover, the magnitude of the smiling response was shown to be much smaller than that associated with voluntary smiling. These findings suggest that facial expressions while viewing infant faces do not exhibit a fixed pattern but are modulated by observers' tasks and that considering cuteness, which is based on more affective evaluations than beauty, can enhance smiling responses.

Comparing Neuromuscular Blockade Measurement Between Upper Arm (TOF Cuff®) and Eyelid (TOF Scan®) Using Mivacurium during General Anesthesia.

BACKGROUND Mivacurium is a non-depolarizing neuromuscular blocking agent. TOF-Cuff® is a device that monitors intraoperative neuromuscular blockade and blood pressure. TOF-Scan® measures muscle relaxation status of an anaesthetized patient. This study included 36 patients aged 18 to 75 years presenting for elective surgery, to compare neuromuscular blockade measured using the TOF-Cuff of the upper arm and the TOF-Scan of the facial corrugator supercilii muscle during general anesthesia and following administration of mivacurium. MATERIAL AND METHODS Train-of-four (TOF) values were obtained every 30 s before intubation and successively every 5 min until extubation. RESULTS The median onset time for TOF-Cuff was longer than for TOF-Scan (210 s vs 90 s, P<0.00001). Multiplying the time to relaxation (according to TOF-Scan) by 1 to 8, respectively, provided concordance with the TOF-Cuff result for the following cumulative percentages of patients: 5.5%, 38.9%, 58.3%, 77.8%, 83.3%, 86.1%, 88.9%, and 91.7%. Analogue values for time to recovery from the last dose were 11.1%, 63.9%, 83.3%, 86.1%, 86.1%, 88.9%, 88.9%, and 91.7%. The proportion of patients who still had TOFratio=0 in the assessment performed at min 15 did not differ significantly between these 2 methods (P=0.088). Both TOF-Scan and TOF-Cuff showed a false-negative result in patients with clinical symptoms of preterm recovery; the numerical difference favored TOF-Cuff (1.6% vs 2.1%) but without statistical significance (P=0.2235). CONCLUSIONS When measurement on the limb is not possible, TOF-Scan on the eyelid can be an alternative for TOF-Cuff on the upper arm, if the time to relaxation is multiplied by at least 8, which is enough for 90% of patients.

Machine Learning-Based Interpretable Modeling for Subjective Emotional Dynamics Sensing Using Facial EMG.

Understanding the association between subjective emotional experiences and physiological signals is of practical and theoretical significance. Previous psychophysiological studies have shown a linear relationship between dynamic emotional valence experiences and facial electromyography (EMG) activities. However, whether and how subjective emotional valence dynamics relate to facial EMG changes nonlinearly remains unknown. To investigate this issue, we re-analyzed the data of two previous studies that measured dynamic valence ratings and facial EMG of the corrugator supercilii and zygomatic major muscles from 50 participants who viewed emotional film clips. We employed multilinear regression analyses and two nonlinear machine learning (ML) models: random forest and long short-term memory. In cross-validation, these ML models outperformed linear regression in terms of the mean squared error and correlation coefficient. Interpretation of the random forest model using the SHapley Additive exPlanation tool revealed nonlinear and interactive associations between several EMG features and subjective valence dynamics. These findings suggest that nonlinear ML models can better fit the relationship between subjective emotional valence dynamics and facial EMG than conventional linear models and highlight a nonlinear and complex relationship. The findings encourage emotion sensing using facial EMG and offer insight into the subjective-physiological association.

Infants' facial electromyographic responses to the sight of emotional interpersonal touch.

Adult studies have shown that observed interpersonal touch provides crucial information about others' emotional states. Yet, despite the unique communicative function of touch during development, very little is known about infants' sensitivity to the emotional valence of observed touches. To investigate this issue, we measured facial electromyographic (EMG) activity in response to positive (caress) and negative (scratches) observed touches in a sample of 11-month-old infants. Facial EMG activity was measured over the zygomaticus major (ZM) and corrugator supercilii muscles, respectively involved in positive (i.e., smiling) and negative (i.e., frowning) facial expressions. Results have shown distinct activations of the ZM during the observation of scratches and caresses. In particular, significantly greater activation of the ZM (smiling muscle) emerged specifically in response to the observation of caresses compared to scratches. Our finding suggests that, in infancy, observed affective touches can evoke emotional facial reactions.

Emotion dysregulation modulates visual perspective taking and spontaneous facial mimicry.

Understanding and sharing others' emotions (i.e., empathy) requires the ability to manage one's own emotions (i.e., emotion regulation). Indeed, empirical evidence suggests that empathy and emotion regulation are related. This evidence is largely based on self-report measures of both constructs. The current study examined how task measures that assess processes related to empathy are associated with self-reported emotion dysregulation in a young adult sample. An eye-tracking-based perspective-taking task was used as a proxy measure of cognitive empathy. A spontaneous facial mimicry (SFM) task, wherein the activation of the Zygomaticus Major and the Corrugator Supercilii was measured during the passive viewing of happy and angry faces, was used as a proxy measure of affective empathy. The perspective-taking task metric showed a negative relationship with emotion dysregulation. The overall SFM metric was not significantly associated with emotion dysregulation. Follow-up analyses revealed that SFM for angry faces was inversely proportional to emotion dysregulation; no such relationship was observed for SFM for happy faces. These findings build upon prior work by demonstrating a positive relationship between adaptive emotion regulation and a behavioral measure of cognitive empathy. The findings for affective empathy are suggestive of a valence-specific relationship between SFM and emotion regulation. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Altered emotional mind-body coherence in older adults.

Coherence between subjective experience and bodily responses in emotion is assumed to have a positive influence on well-being, which might be particularly valuable in late adulthood. Previous studies of young adults' continuous subjective, behavioral, and physiological responses to emotional films reported emotional mind-body coherence. In contrast, research regarding emotional coherence in older adults has been scarce. In this study, we examined emotional coherence in older adults between continuous valence ratings and behavioral responses (facial electromyography [EMG] of the corrugator supercilii and zygomatic major muscles), as well as between continuous arousal ratings and physiological measures (electrodermal activity [EDA] and fingertip temperature), in response to four emotion-eliciting film clips (anger, sadness, contentment, and amusement) film clips and an emotionally neutral clip. Intraindividual cross-correlation analyses revealed that the coherence between valence ratings and corrugator EMG activity for the anger-eliciting film was weaker in older adults than in young adults, who completed an identical experiment. Age differences also emerged in the coherence of arousal ratings with EDA and fingertip temperature measures, respectively, while participants watched the anger-eliciting and contentment-eliciting films; while negative correlations were found for older adults, positive correlations were found for young adults. These results indicate that emotional mind-body coherence somewhat differs quantitatively and qualitatively between older and young adults. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Facial disgust in response to touches, smells, and tastes.

Disgust serves to defend the body from the entry of toxins and disease. Central to this function is a strong relationship with the proximate senses of smell, taste, and touch. Theory suggests that distinct and reflexive facial movements should be evoked by gustatory and olfactory disgusts, serving to impede bodily entry. While this hypothesis has received some support from facial recognition studies, whether smell and taste disgusts actually produce distinct facial responses, is unknown. Moreover, there has been no assessment of the facial response evoked by contact with disgusting objects. To address these issues, this study compared facial responses to touch, smell, and taste disgusts. Sixty-four participants were asked to touch, smell, and taste disgust-evoking and neutral control stimuli, and rate them on disgust, on two occasions-first, while they were video recorded and second, with facial electromyography (EMG) applied (measuring levator labii and corrugator supercilii activity). Videos were coded for facial expressions by humans and for facial action units (FAUs) by machines. Self-report data confirmed the disgust stimuli as highly disgusting. Comparison of the overall pattern of FAUs evoked by touch, smell, and taste disgusts, indicated two distinct facial disgusts for the proximate senses-a chemosensory and a tactile-disgust face. The nose wrinkle and upper lip raise were central to all facial disgusts, indicating their centrality to the disgust face. Several facial disgusts appear to exist, each with different functional goals. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Heightened facial muscle reactivity in preadolescent girls with pathological anxiety

AbstractObjectivesAnticipatory anxiety and heightened responses to uncertainty are central features of anxiety disorders (ADs) that contribute to clinical impairment. Anxiety symptoms typically emerge during childhood, and even subthreshold‐AD symptoms are associated with distress and risk for future psychopathology. This study compared facial emotional response to threat and uncertainty between preadolescent girls with ADs, girls with subthreshold‐AD symptoms, and controls.MethodsFacial emotional responding was characterized in preadolescent girls (age 8–11) with a range of anxiety symptoms: no/low anxiety (controls, n = 41), subthreshold‐AD (n = 73), and DSM‐5 diagnoses of separation, social, and/or generalized ADs (n = 45). A threat anticipation paradigm examined how image valence (negative/neutral) and image anticipation (uncertain/certain timing) impacted activity of the corrugator supercilii, a forehead muscle implicated in the “frown” response that is modulated by emotional stimuli (negative &gt; neutral). Corrugator magnitude and corrugator timecourse were compared between groups.ResultsFindings demonstrate greater corrugator activity during anticipation and viewing of negative stimuli, as well as increased corrugator reactivity in subthreshold‐AD and AD girls. Timecourse analyses of negative versus neutral stimuli revealed that AD and subthreshold‐AD girls had greater uncertainty‐related increases in corrugator activity compared to controls.ConclusionResults extend the physiological characterization of childhood pathological anxiety, highlighting the impact of subthreshold‐AD symptoms.

An investigation of the modulatory effects of empathic and autistic traits on emotional and facial motor responses during live social interactions.

A close relationship between emotional contagion and spontaneous facial mimicry has been theoretically proposed and is supported by empirical data. Facial expressions are essential in terms of both emotional and motor synchrony. Previous studies have demonstrated that trait emotional empathy enhanced spontaneous facial mimicry, but the relationship between autistic traits and spontaneous mimicry remained controversial. Moreover, previous studies presented faces that were static or videotaped, which may lack the "liveliness" of real-life social interactions. We addressed this limitation by using an image relay system to present live performances and pre-recorded videos of smiling or frowning dynamic facial expressions to 94 healthy female participants. We assessed their subjective experiential valence and arousal ratings to infer the amplitude of emotional contagion. We measured the electromyographic activities of the zygomaticus major and corrugator supercilii muscles to estimate spontaneous facial mimicry. Individual differences measures included trait emotional empathy (empathic concern) and the autism-spectrum quotient. We did not find that live performances enhanced the modulatory effect of trait differences on emotional contagion or spontaneous facial mimicry. However, we found that a high trait empathic concern was associated with stronger emotional contagion and corrugator mimicry. We found no two-way interaction between the autism spectrum quotient and emotional condition, suggesting that autistic traits did not modulate emotional contagion or spontaneous facial mimicry. Our findings imply that previous findings regarding the relationship between emotional empathy and emotional contagion/spontaneous facial mimicry using videos and photos could be generalized to real-life interactions.

Measuring facial mimicry: Affdex vs. EMG.

Facial mimicry is the automatic imitation of the facial affect expressions of others. It serves as an important component of interpersonal communication and affective co-experience. Facial mimicry has so far been measured by Electromyography (EMG), which requires a complex measuring apparatus. Recently, software for measuring facial expressions have become available, but it is still unclear how well it is suited for measuring facial mimicry. This study investigates the comparability of the automated facial coding software Affdex with EMG for measuring facial mimicry. For this purpose, facial mimicry was induced in 33 subjects by presenting naturalistic affect-expressive video sequences (anger, joy). The response of the subjects is measured simultaneously by facial EMG (corrugator supercilii muscle, zygomaticus major muscle) and by Affdex (action units lip corner puller and brow lowerer and affects joy and anger). Subsequently, the correlations between the measurement results of EMG and Affdex were calculated. After the presentation of the joy stimulus, there was an increase in zygomaticus muscle activity (EMG) about 400 ms after stimulus onset and an increase in joy and lip corner puller activity (Affdex) about 1200 ms after stimulus onset. The joy and the lip corner puller activity detected by Affdex correlate significantly with the EMG activity. After presentation of the anger stimulus, corrugator muscle activity (EMG) also increased approximately 400 ms after stimulus onset, whereas anger and brow lowerer activity (Affdex) showed no response. During the entire measurement interval, anger activity and brow lowerer activity (Affdex) did not correlate with corrugator muscle activity (EMG). Using Affdex, the facial mimicry response to a joy stimulus can be measured, but it is detected approximately 800 ms later compared to the EMG. Thus, electromyography remains the tool of choice for studying subtle mimic processes like facial mimicry.