FACS - Facial Action Coding System
(2002 Revision is here)

(Ekman and Friesen 1978)

AU Description Facial muscle Example image
1

Inner Brow Raiser

Frontalis, pars medialis

2

Outer Brow Raiser

Frontalis, pars lateralis

4

Brow Lowerer

Corrugator supercilii, Depressor supercilii

5

Upper Lid Raiser

Levator palpebrae superioris

6

Cheek Raiser

Orbicularis oculi, pars orbitalis

7

Lid Tightener

Orbicularis oculi, pars palpebralis

9

Nose Wrinkler

Levator labii superioris alaquae nasi

10

Upper Lip Raiser

Levator labii superioris

11

Nasolabial Deepener

Zygomaticus minor

12

Lip Corner Puller

Zygomaticus major

13

Cheek Puffer

Levator anguli oris (a.k.a. Caninus)

14

Dimpler

Buccinator

15

Lip Corner Depressor

Depressor anguli oris (a.k.a. Triangularis)

16

Lower Lip Depressor

Depressor labii inferioris

17

Chin Raiser

Mentalis

18

Lip Puckerer

Incisivii labii superioris and Incisivii labii inferioris

20

Lip stretcher

Risorius w/ platysma

22

Lip Funneler

Orbicularis oris

23

Lip Tightener

Orbicularis oris

24

Lip Pressor

Orbicularis oris

25

Lips part**

Depressor labii inferioris or relaxation of Mentalis, or Orbicularis oris

26

Jaw Drop

Masseter, relaxed Temporalis and internal Pterygoid

27

Mouth Stretch

Pterygoids, Digastric

28

Lip Suck

Orbicularis oris

41

Lid droop**

Relaxation of Levator palpebrae superioris

42

Slit

Orbicularis oculi

43

Eyes Closed

Relaxation of Levator palpebrae superioris; Orbicularis oculi, pars palpebralis

44

Squint

Orbicularis oculi, pars palpebralis

45

Blink

Relaxation of Levator palpebrae superioris; Orbicularis oculi, pars palpebralis

 
46

Wink

Relaxation of Levator palpebrae superioris; Orbicularis oculi, pars palpebralis

 
51

Head turn left

 
52

Head turn right

 
53

Head up

 
54

Head down

 
55

Head tilt left

 
56

Head tilt right

 
57

Head forward

 
58

Head back

 
61

Eyes turn left

 
62

Eyes turn right

 
63

Eyes up

 
64

Eyes down

 

* AUs (Action Units) underlined bold are currently recognizable by AFA System when occurring alone or cooccurring.

** The criteria has changed for this AU, that is, AU 25, 26 and 27 are now coded according to criteria of intensity (25A-E) and also AU 41, 42 and 43 are now coded according to criteria of intensity