Of all the muscles in the face, this isZygomaticus Majoris perhaps the most striking. It sits between the corners of our lips and the tops of our cheeks and controls the way we smile.
The muscle sits on the cheekbone, also called the zygomatic bone. Variations in the zygomatic muscle are also known to cause dimpling when smiling. All this means that this area has a lot to do with how we look when we are active or inactive.
Activation of these muscles (on either side of the face) creates a smile, both spontaneous and sincere (a "Duchenne" smile) or planned and deliberate (a "non-Duchenne" smile).
A true Duchenne smile is created by activating both the zygomatic and zygomatic musclesround eye(the muscle is around the lips and causes cheek lift) and the possible involvement of several other facial muscles. Activation of these two muscles results in a smile that also lifts the cheeks around the eye. A non-Duchenne smile activates the zygomatic muscle without activating the orbicularis oculi.
Image of the position of the zygomaticus major muscle. By: BodyParts3D, © The Database Center for Life Science, licensed under CC Attribution-Share Alike 2.1 Japan.
Of course, the muscle not only affects how we look and how we perceive it, but also how we emotionally interact with the world. Below you will learn how to measure the activity of this muscle and what this means for the person who shows activity in this region.
fEMG
The most common way to specifically measure activity in this region is to use fEMG (facial electromyography). By placing the electrodes along the muscle, the activity can be easily measured. Electrical impulses leading to muscle activation are detected by the electrodes. Research has shown that this measure is associated with positive emotions (not entirely surprising given its clear association with smiling) [1].
Other research using fEMG has also shown that zygomatic muscle activation is not necessarily associated exclusively with the generation of positive emotions. IfHart and others argue in a recent article"Especially in more complex environments... a smile can be difficult to interpret: a smile can be ironic, sarcastic, and smirking, and can also be an expression of really positive feelings" [2].
Interestingly, there are psychophysiological parameters that broadly determine whether the smile is considered real or not - spontaneous smiles are often presented for a shorter duration (about 4-6 seconds), have a slower progression, and are more symmetrical than intentional smiles [3]. This distinction can be made using fEMG images of the zygomatic muscle, which increases the significance of the mapping of facial expressions to emotions.
Because fEMG is such a sensitive measurement, it is able to detect the electrical activity underlying muscle movement even when there is no obvious muscle activation (i.e., when someone can be seen smiling).
One such study examining this in more detail came from Larsen and other researchers in 2003 [4]. Participants were presented with a series of stimuli previously found to elicit a range of specific emotions, while fEMG, respiration, etc.skin conductance (SCR)had been recorded. A self-assessment study was also conducted.
The researchers found that the activity of the zygomatic muscle is linearly related to the positive value of the stimulus - in fact, the more positive the stimulus, the more active this smiling muscle is. A negative relationship withActivity of Corrugator supercilii(the frown muscle) and positive stimuli.
The results suggest that these two facial muscles may serve as proxies for experiencing positive and negative emotional responses. Research also suggests that using fEMG can also provide clear answers when there is a clear explanation for the expected emotion.
Automatic analysis of facial expressions
Another method used to study zygomatic muscle activation is facial expression analysis, which visually captures the movements of the face and breaks down the movements into individual muscle movements, often called action units.
This method was originally performed by encoding facial expressions manually (bytie Facial Action Codeineg system [5] that we have already covered), but can now be performed by software such as Affectiva, which uses machine learning methods to effectively analyze facial muscle movements in real time.
A recent study compared facial muscle movements with fEMG and Affectiva by asking participants to display a range of emotions while using both modalities [6]. The researchers found that these methods are essentially similar when it comes to assessing the activity levels of the zygomaticus major, orbicularis orii, and corrugator supercilii.
Although the advantage of fEMG is its sensitivity, it is impractical to record the activity of many muscles at once (the norm is recording of 1-3 facial muscles). Automated facial expression analysis, on the other hand, makes it possible to detect all facial muscle movements and can even calculate how these combined movements result in complex facial expressions related to individual emotions (for example, a widened mouth and raised eyebrows). associated with surprise).
Another study that showed the potential ofAutomatic facial expression analysis was performed with Affectivain 2013 [7]. The smile responses (cheekbone muscle activation) of more than 1500 participants were classified while viewing advertisements on the Internet. The large-scale data collection was made possible by the non-invasive nature of this methodology, which allowed much more data to be collected than most other studies (especially when compared to typical fEMG studies).
The researchers found that not only was it possible to classify the key activation/smile responses of the zygomaticus in most recordings (despite the inevitable problems associated with limited experimental control - poor lighting, increased participant movement, etc.), but also that accurate predictions about "Like" and "Want to see you again" can be derived from this data alone.
The future application of such methods opens up the possibility of extensive data collection and answering differentiated questions about emotional preferences, based on the activation of the zygomaticus major muscle (as well as other related facial muscle movements).
Despite being a single muscle, a great deal of information can be gleaned from zygomatic muscle activation, even more so when the full repertoire of facial expressions is considered. For researchers, this is certainly a reason to smile.
references
[1] Joyal, C., Jacob, L., Cigna, M., Guay, J. & Renaud, P. (2014). Virtual faces expressing emotions: a first companion and construct validity study.Frontiers of human neuroscience,8. two: 10.3389/fnhum.2014.00787
[2] Björn't Hart, B., Struiksma, M., van Boxtel, A. and van Berkum, J. (2018). Emotions in stories: facial EMG evidence for both mental simulation and moral evaluation.boundaries in psychology,9. twee: 10.3389/fpsyg.2018.00613
[3]Schmidt, K., Ambadar, Z., Cohn, J. & Reed, L. (2006). Movement differences between intentional and spontaneous facial expressions: main effect of the cheekbones in smiling.Journal of Nonverbal Behavior,30(1), 37-52. doi: 10.1007/s10919-005-0003-x
[4]Larsen, J., Norris, C. & Cacioppo, J. (2003). Effects of positive and negative effects on electromyographic activity on the zygomaticus major muscle and the corrugator supercilii muscle.Psychofysiologie,40(5), 776-785. doi: 10.1111/1469-8986.00078
[5]Ekman, P. & Rosenberg, E. (2005).What the face reveals. New York: Oxford University Pers.
[6] Kulke, L., Feyerabend, D. & Schacht, A. (2018). Comparison of facial expression analysis software Affectiva iMotions with EMG. https://doi.org/10.31234/osf.io/6c58y
[7]McDuff, D., El Kaliouby, R., Senechal, T., Demirdjian, D. & Picard, R. (2014). Automatic measurement of advertising preferences based on facial reactions collected from the internet.Image and image processing,32(10), 630-640. doi: 10.1016/j.imavis.2014.01.004
FAQs
What facial expression does the zygomaticus major do? ›
As zygomaticus major contracts, it pulls the angle of the mouth superolaterally. In synergy with risorius, zygomaticus major produces the expression of smiling.
What muscle is responsible for expressing sadness? ›However, when the muscles involved in making the sad expression (corrugator and depressor anguli oris) are considered, these muscles do not only contribute to a sad expression but also to other voluntary facial expressions.
Is zygomaticus a muscle of facial expression? ›The zygomaticus major muscle is a muscle that controls facial expression, drawing the mouth's angle upward and outward.
What 3 muscles are involved in smiling? ›The specific muscles are: Depressor anguli oris. Zygomaticus major.
What is the zygomaticus minor facial expression? ›The zygomaticus minor muscle is a muscle of facial expression. It originates from the zygomatic bone, lateral to the rest of the levator labii superioris muscle, and inserts into the outer part of the upper lip. It draws the upper lip backward, upward, and outward and is used in smiling.
How do you activate zygomaticus major? ›Pull the corners of the mouth upward, opposing the pressure of the fingers. Perform 20 reps. A tense smile or pinched lips can improve the wrinkles around and above your mouth. Perform a relaxation exercise with a gliding stroke to relax the zygomaticus major and zygomaticus minor muscles.
What muscles hold emotions? ›All of us have preferred places in our bodies where our pain, worry, and fears are most readily expressed in muscular tension. The three key areas in the body that have the potential to be most affected by emotional forces are the pelvic floor, the diaphragm, and the jaw.
Which muscles expresses negative emotions? ›Anger, fear, and sadness are associated with corrugator ("frown") muscle activity.
What are the facial muscles of expression? ›The muscles of facial expression (also known as the mimetic muscles) can generally be divided into three main functional categories: orbital, nasal and oral. These striated muscles broadly originate from the surface of the skull and insert onto facial skin.
What muscle changes facial expression? ›The craniofacial muscles are essential to chewing and making facial expressions. They originate from bone or fascia and insert into your skin. Craniofacial muscles work together to control movements in your: Cheeks.
What muscle creates smile expressions? ›
The risorius muscle's function is to aid in facial expression by pulling the corner of the mouth laterally via its contraction in an outward and upward motion. In conjunction with other facial muscles, this helps to create a smile or a frown, and myriad other expressions in-between.
How many muscles are used to cry? ›Crying: 17
You can thank the 12 muscles that screwed your face into a frown and the six intrinsic laryngeal muscles that caused your vocal chords to cough up that whimpering wail.
Orbicularis oris muscle along with the buccinator and pharyngeal constrictor form a functional unit, known as "buccinator mechanism" which has an important role in orofacial function (swallowing, sucking, whistling, chewing, vowel pronunciation, kissing).
What is the muscle of laughter? ›The diaphragm is a muscle that separates our abdominal cavity from our chest cavity, and it is the only muscle in our body that is attached to other muscles. When we laugh, our diaphragm convulsively pulls on our side muscles and shakes up our stomach and other vital organs.
How do you relax zygomaticus muscles? ›To stretch the Zygomaticus muscle, we must first revise the location. As we learned in the previous video, it runs from the cheekbone into the angles of the mouth. Using your fingers, gently pull along the course of the muscle from its origin to its attachment near the mouth. Do it slowly and repeat several times.
What is the zygomaticus process? ›The zygomatic process of the maxilla (malar process) is a rough triangular eminence, situated at the angle of separation of the anterior, zygomatic, and orbital surfaces. In front it forms part of the anterior surface. Behind it is concave, and forms part of the infratemporal fossa.
What are the 5 branches of facial expression? ›The branches are, from top to bottom: frontal (or temporal), zygomatic, buccal, marginal mandibular, and cervical. Each of these branches provides input to a group of muscles of facial expression.
What happens when zygomaticus major is damaged? ›The zygomaticus muscle presses on the blood vessels that are trapped, which causes the flow of blood to become restricted. In turn, the muscles will end up cramping from a lack of nourishment.
How do you strengthen your smile muscles? ›Start by smiling as wide as you can while keeping your mouth closed. It can help to visualize that your smile is extending from ear to ear. While smiling, try wiggling your nose until you feel your cheek muscles engaging. Hold the pose for about five seconds, and repeat 10 times.
How do you relax your cheek muscles? ›Bring the tip of your tongue to the highest point of the roof of your mouth. Hold this position for a count of 5, and then ease your jaw back into a resting closed mouth position. Do 10 reps per set.
What part of the body do emotions come from? ›
Three brain structures appear most closely linked with emotions: the amygdala, the insula or insular cortex, and a structure in the midbrain called the periaqueductal gray. A paired, almond-shaped structure deep within the brain, the amygdala integrates emotions, emotional behavior, and motivation.
Which part of our body can express our emotions? ›The researchers found that most basic emotions were tied to greater activity in the upper chest area, likely corresponding to the emotions' effects on breathing and heart rate. Sensations were also commonly felt in the head, likely reflecting facial expressions and mental activity.
Where is each emotion stored in the body? ›Emotional information is stored through “packages” in our organs, tissues, skin, and muscles. These “packages” allow the emotional information to stay in our body parts until we can “release” it. Negative emotions in particular have a long-lasting effect on the body.
Can muscles hold emotions? ›“Muscle tension emerges to create and maintain postures that keep oneself safe or unaware of unpleasant feelings,” he says. Certain postures and gestures also relate to specific feelings and social meanings.
Do muscles control emotions? ›Our nervous system is hardwired to contract our mimetic muscles (facial muscles) in certain patterns to convey a range of emotions—like happiness, sadness, disgust, anger, surprise, and fear—as a means of communication.
What muscles are involved in crying? ›The facial muscles involved in crying are the M. frontalis, the M. corrugator, the M. orbicularis oculi, as well as the M.
How emotions affect your muscles? ›When the body is stressed, the muscles tense up. That's because muscle tension is a reflex reaction to stress, both physical and emotional. It's essentially the body's way of guarding against injury and pain. The shoulder area, particularly the trapezius muscle, tends to carry more tension than anywhere else.
What emotion is stored in the neck? ›The neck is one of the most common places to store emotion, with tension and tightness arising from fear, anxiety, grief, anger, and other strong emotional experiences. Neck tension can also be associated with trust issues, feelings of insecurity, and weak willpower.
What nerve is responsible for emotions? ›Emotional expression, which depends greatly on the sympathetic nervous system, is controlled by regions of the cerebral hemispheres above the hypothalamus and by the midbrain below it.
What are the 6 main facial expressions? ›Specifically, the universality hypothesis proposes that six basic internal human emotions (i.e., happy, surprise, fear, disgust, anger, and sad) are expressed using the same facial movements across all cultures (4–7), supporting universal recognition.
What are the facial nerves of expression? ›
Sensation on the face is innervated by the trigeminal nerves (V) as are the muscles of mastication, but the muscles of facial expression are innervated mainly by the facial nerve (VII) as is the sensation of taste.
What are the muscles of eye expression? ›The orbicularis oculi muscles circle the eyes and are located just under the skin. Parts of this muscle act to open and close the eyelids and are important muscles in facial expression.
How do facial expressions cause emotions? ›Facial emotional expressions are salient social cues in everyday interaction. Behavioral data suggest that human facial expressions communicate both the emotional state of the poser and behavioral intentions or action demands to the perceiver (Horstmann, 2003).
Why do emotions give rise to facial expressions? ›Facial expressions do not just give us away; they may also allow us to experience our own emotions more fully. This process is still not well understood, but it is possible that forcing your face to express happiness, sadness or anger may help you feel those emotions.
What controls facial expression? ›The facial nerve plays a key role in making facial expressions. It controls your facial muscles that help you smile, frown, scrunch up your nose and wrinkle your forehead.
What muscle is a true smile? ›All smiling involves contraction of the zygomatic major muscles, which lifts the corners of the mouth.
What is the muscle of fake smile? ›“These are produced by the action of a muscle called the orbicularis oculi, which rings the eye and contracts when people produce genuine, but not polite smiles.”
What muscle is used to wink? ›The orbicularis oculi muscle closes the eyelids and assists in pumping the tears from the eye into the nasolacrimal duct system. The orbital section of the orbicularis oculi is more involved in the voluntary closure of the eyelid, such as with winking and forced squeezing.
How do emotions trigger tears? ›Unlike basal tears, your body doesn't make them automatically. For emotional tears to kick in, your limbic system — the part of your brain that regulates emotions — sends a signal to your brain's message system to activate your lacrimal glands to produce tears. The result? A full-on cry-fest.
What muscle tears the most? ›Muscle Tear
Like a muscle strain, the most common muscle tears occur in the lower back, neck, shoulder, and hamstring. Muscle tears often cause a sudden onset of severe pain, as well as bruising, swelling, and weakness. Anyone who sustains this type of injury should seek urgent medical attention.
What gets released when you cry? ›
Researchers have established that crying releases oxytocin and endogenous opioids, also known as endorphins. These feel-good chemicals help ease both physical and emotional pain.
What is the hugging muscle? ›You want to make sure your "hugging muscles" are in good working order. We're talking about the pectoralis major and the pectoralis minor, commonly called the pecs. They are two large muscles in the chest, pec major being the bigger; in fact, it is very big, extending from the collarbone to the sternum.
Which part is sensitive for kiss? ›Lips are the most exposed erogenous zone, which makes kissing feel very good.
What muscle makes you pout? ›5. Mentalis. Sometimes called the 'pouting muscle', contraction of the Mentalis raises and thrusts out the lower lip to make us pout.
What is the muscle of surprise? ›Frontalis muscle – lifts the eyebrows, makes horizontal forehead wrinkles when we are surprised.
Which muscle assists in smiling and blowing? ›- Prevents you from biting your cheek as you eat.
- Controls airflow through the mouth to whistle and suck in/blow out air, essential for meditative breathing and playing some musical instruments.
- Form your smile with the help of other muscles.
frontalis and M. corrugator supercilii are characteristic of pathological laughing and crying in addition to an increase of EMG discharges of M.
What is the major muscle of facial expression? ›The muscles of facial expressions are: Auriculars, which allow some people to move their ears. Corrugator supercilii, which is near the eyebrow and enables frowning. Depressor anguli oris, which is on each side of your chin and works with other muscles to produce a frown.
What is a major role of facial expression? ›Facial expressions are one of the more important aspects of human communication. The face is responsible for communicating not only thoughts or ideas, but also emotions.
What type of muscle is used for facial expression? ›The nasal muscle group includes the nasalis and procerus muscles. These muscles are primarily involved in creating facial expressions, but they also contribute to respiration.
Which facial nerve allows smiling and facial expression? ›
Within the motor system, although the muscles of mastication are innervated by the trigeminal nerve (V), the muscles of facial expression are innervated mainly by the facial nerve (VII).
What muscles are used in anger? ›The biceps, deltoids, and triceps are recruited strongly for the expression of anger and fear expression predominantly depends on the biceps and the deltoids. During passive viewing, all muscles automatically activate during the passive viewing of anger.
What muscles are involved in contempt expression? ›The mentalis muscle is involved in expressing doubt and contempt, as it elevates, everts and protrudes the lower lip, and wrinkles the skin of the chin. This article will discuss the anatomy and function of mentalis muscle.
Which cervical muscle is considered a muscle of facial expression? ›The platysma is often an overlooked muscle of facial expression due to its location on the neck, but it contributes nonetheless.
What are the movements of the face that convey emotional meaning called? ›A facial expression is one or more motions or positions of the muscles beneath the skin of the face. According to one set of controversial theories, these movements convey the emotional state of an individual to observers. Facial expressions are a form of nonverbal communication.
What is the power of facial expression and emotion? ›The ability to understand facial expressions is an important part of nonverbal communication. If you only listen to what a person says and ignore what their face is telling you, then you really won't get the whole story. Often, words do not match emotions, and the face betrays what a person is actually feeling.
What role do facial expressions play in the process of emotion? ›Facial expressions can display personal emotions and indicate an individual's intentions within a social situation and, hence, are extremely important for social interaction.
How do facial muscles create expressions? ›These striated muscles broadly originate from the surface of the skull and insert onto facial skin. Their contraction uniquely pulls on facial skin in order to exhibit various facial expressions.
What nerves are involved in facial expression? ›The facial nerve is the 7th cranial nerve and carries nerve fibers that control facial movement and expression. The facial nerve also carries nerves that are involved in taste to the anterior 2/3 of the tongue and producing tears (lacrimal gland).
What is the antagonist of the Zygomaticus major? ›The zygomaticus major is less efficient on her left side, and the balance between weakened zygomaticus major and its antagonist, DAO, has been lost.
What nerve controls muscles of facial expression? ›
The muscles of facial expression are innervated by the facial nerve (cranial nerve VII), and the muscles of mastication are innervated by the mandibular division of the trigeminal nerve (cranial nerve V3).
What part of the brain responds to facial expressions? ›Identifying facial expressions is crucial for social interactions. Functional neuroimaging studies show that a set of brain areas, such as the fusiform gyrus and amygdala, become active when viewing emotional facial expressions.
What part of the brain is responsible for facial movements? ›The midbrain is an important center for ocular motion while the pons is involved with coordinating eye and facial movements, facial sensation, hearing and balance.