the FACS study guide
a visual guide to the Facial Action Coding System (FACS)
The FACS Cheat Study Guide is a comprehensive visual guide to the facial expressions of the Facial Action Coding System – and beyond! Learn about FACS action units (AUs) and their corresponding muscles through animated GIFs, images, and descriptions.
SECTION GUIDE
*See AU 11 & AU 23 for rare reference shots of nasolabial furrow deepener & lip tightener.
eyebrows & forehead
– inner brow raiser (AU1) / frontalis, pars medialis
– outer brow raiser (AU2) / frontalis, pars lateralis
– brow lowerer (AU4) / varied
eyes & cheeks
– upper lid raiser (AU5) / levator palpebrae superioris
– cheek raiser (AU6) / orbicularis oculi, pars orbitalis
– lid tightener (AU7) / orbicularis oculi, pars palpebralis
– blink (AU45) / orbicularis oculi, pars palpebralis
– wink (AU46) / orbicularis oculi, pars orbitalis
nose & middle face
– nose wrinkler (AU9) / levator labii superioris, alaeque nasi
– upper lip raiser (AU10) / levator labii superioris
– nasolabial furrow deepener (AU11) / zygomaticus minor
– nostril dilator (AU38) / nasalis, pars alaris
– nostril compressor (AU39) / nasalis, pars transversa & depressor septi nasi
lip corner elevators & pinchers
– lip corner puller (AU12) / zygomaticus major
– sharp lip puller (AU13) / levator anguli oris
– dimpler (AU14) / buccinator
real & faux lip depressors
– lip corner depressor (AU15) / depressor anguli oris
– lower lip depressor (AU16) / depressor labii inferioris
– chin raiser (AU17) / mentalis
orbicularis oris I
– howler mouth (fAUx8) / orbicularis oris
– lip pucker (AU18) / incisivus labii superioris & interioris
– lip funneler (AU22) / orbicularis oris
orbicularis oris II
– lip tightener (AU23) / orbicularis oris
– lip presser (AU24) / orbicularis oris
– lips part (AU25)
– lips suck (AU28) / orbicularis oris
jaw actions
– jaw drop (AU26)
– mouth stretch (AU27)
eyebrows & forehead
stills
click tabs for GIFs & further info
AU1 – inner brow raiser
frontalis, pars medialis
for a deeper dive on AU1:
- The Secret Life of Inner Brow Raiser
- This post and video will walk you through the variations in inner brow raiser and how to identify each person’s unique inner brow raising style – including your own!
- (If you are not a subscriber, the free version of this video is on YouTube)
- Inner Brow Raiser Deep Dive
- This post covers fundamental features of inner brow raiser.
- It also goes over common misconceptions regarding inner brow raiser and how to recognize incorrect inner brow raiser references. (Spoiler alert: There are a lot of them.)
- Frontalis Variation
- This post covers under-researched topics in frontalis muscle structure.
- It covers anatomical differences of the frontalis muscle and how these differences look as well as what implications they may have in the areas of:
- face tracking
- mocap
- EMG recording
- FACS-based facial coding
- Compare AU1 to a full brow raise (1+2). Observe image below.
AU2 – outer brow raiser
frontalis, pars lateralis
for a deeper dive on AU2:
- In the context of AU1 vs. AU2: The Secret Life of Inner Brow Raiser (If you are not a subscriber, the free version of this video is on YouTube)
- While this post and video is primarily focused on AU1 (inner brow raiser), there is valuable information on AU2 here as well.
- Frontalis Variation
- This post covers under-researched topics in frontalis muscle structure.
- It covers anatomical differences of the frontalis muscle and how these differences look as well as what implications they may have in the areas of:
- face tracking
- mocap
- EMG recording
- FACS-based facial coding
- Compare AU2 to a full brow raise (1+2). Observe image below.
AU4 – brow lowerer
corrugator supercilii, procerus, depressor supercilii
for a deeper dive on AU4:
- The 3 muscles that make up AU4 can move independently.
- corrugator supercilii
- depressor supercilii
- procerus
- The 3 muscles that make up AU4 can move independently.
1. corrugator supercilii
GIF above shows posed. isolated (or mostly isolated) corrugator supercilii activation at mild/medium intensity.
- tends to push the brows toward each other
- can be referred to as “knitting” the brows
- causes vertical wrinkles above the nose
2. depressor supercilii
GIF above shows spontaneous. isolated (or mostly isolated) depressor supercilii activation at mild intensity.
GIF above shows posed. isolated (or mostly isolated) depressor supercilii activation at mild/medium intensity. NOTE 1: In the posed version, I was unable to symmetrically activate depressor supercilii, and it is dominant on the left side (screen right). NOTE 2: In the posed version, I activate nostril compressor, which accounts for the movement on the lower parts of the nose. Please ignore this movement, as it is not a part of depressor supercilii movement. Reference the spontaneous pose to see action without added movement from nostril compression.
- technically considered an eye muscle
- debated whether this muscle is its own distinct muscle or part of orbicularis oculi
***Many surgeons, dermatologists, ophthalmologists, and plastic surgeons argue strongly that depressor supercilii is a distinct muscle with its own movement. I’m with them on this one.
3. procerus
GIF above shows posed full brow raise (frontalis) + procerus activation. I cannot activate procerus without strong corrugator supercilii unless I raise my brows. Even in this example, besides the full brow raise, there appears to be mild to moderate intensity depressor supercilii and potentially mild corrugator supercilii; however, the strongest and most obvious AU4 action here comes from procerus, which you can observe creating U-shaped wrinkles in the medial area of the forehead. When occurring without brow raise, procerus wrinkles are typically straight and horizontal.
- technically considered a nasal muscle
- tends to push the down the medial portion of the brows, above the nose
- causes horizontal wrinkle above nasal root
#notFACS – ears up & back
auricular muscles (see NOTES)
NOTE1: This is not a FACS action. I have included this ear movement in the FACS Cheat Sheet, because I observe it happening relatively frequently.
NOTE 2: There are multiple auricular muscles. The superior auricular moves the ears up. The posterior auricular moves the ears back. The anterior auricular the moves ears forward. At present, I cannot separate these movements. The reference here shows posterior auricular + superior auricular movement.
eyes & cheeks Please subscribe to see this content.
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