Editing Facial Action Coding System (section)

=== List of AUs and ADs (with underlying facial muscles) ===

==== Main codes ====
{| class="wikitable sortable"
|-
! AU number !! FACS name !! Muscular basis
|-
| 0 || Neutral face ||
|-
| 1 ||Inner brow raiser || ''[[frontalis muscle|frontalis]]'' (''[[pars medialis]]'')
|-
| 2 || Outer brow raiser || ''frontalis'' (''[[pars lateralis]]'')
|-
| 4 || Brow lowerer || ''[[depressor glabellae]]'', ''[[depressor supercilii]]'', ''[[corrugator supercilii]]''
|-
| 5 || Upper lid raiser || ''[[levator palpebrae superioris]]'', [[superior tarsal muscle]]
|-
| 6 || Cheek raiser || ''[[orbicularis oculi]]'' (''[[Orbital part of frontal bone|pars orbitalis]]'')
|-
| 7 || Lid tightener || ''orbicularis oculi'' (''[[pars palpebralis]]'')
|-
| 8 || Lips toward each other || ''[[orbicularis oris]]''
|-
| 9 || Nose wrinkler || ''[[levator labii superioris alaeque nasi]]''
|-
| 10 || Upper lip raiser || ''levator labii superioris'', ''[[levator labii superioris|caput infraorbitalis]]''
|-
| 11 || Nasolabial deepener || ''[[zygomaticus minor]]''
|-
| 12 || Lip corner puller || ''[[zygomaticus major]]''
|-
| 13 || Sharp lip puller || ''[[levator anguli oris]]'' (also known as ''[[caninus]]'')
|-
| 14 || Dimpler || ''[[buccinator]]''
|-
| 15 || Lip corner depressor || ''depressor anguli oris'' (also known as ''[[triangularis]]'')
|-
| 16 || Lower lip depressor || ''[[depressor labii inferioris]]''
|-
| 17 || Chin raiser || ''[[mentalis]]''
|-
| 18 || Lip pucker || ''[[incisivii labii superioris]]'' and ''[[incisivii labii inferioris]]''
|-
| 19 || Tongue show ||
|-
| 20 || Lip stretcher || ''[[risorius]]'' with ''[[platysma]]''
|-
| 21 || Neck tightener || ''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 [[Medial pterygoid muscle|internal ''pterygoid'']]
|-
| 27 || Mouth stretch || ''[[Pterygoid bone|pterygoids]]'', ''[[digastric]]''
|-
| 28 || Lip suck || ''orbicularis oris''
|}

==== Head movement codes ====
{| class="wikitable sortable"
|-
! AU number !! FACS name !! Action
|-
| 51 || Head turn left ||
|-
| 52 || Head turn right ||
|-
| 53 || Head up ||
|-
| 54 || Head down ||
|-
| 55 || Head tilt left ||
|-
| M55 || Head tilt left || The onset of the symmetrical 14 is immediately preceded or accompanied by a head tilt to the left.
|-
| 56 || Head tilt right ||
|-
| M56 || Head tilt right || The onset of the symmetrical 14 is immediately preceded or accompanied by a head tilt to the right.
|-
| 57 || Head forward ||
|-
| M57 || Head thrust forward || The onset of 17+24 is immediately preceded, accompanied, or followed by a head thrust forward.
|-
| 58 || Head back ||
|-
| M59 || Head shake up and down || The onset of 17+24 is immediately preceded, accompanied, or followed by an up-down head shake (nod).
|-
| M60 || Head shake side to side || The onset of 17+24 is immediately preceded, accompanied, or followed by a side to side head shake.
|-
| M83 || Head upward and to the side || The onset of the symmetrical 14 is immediately preceded or accompanied by a movement of the head, upward and turned or tilted to either the left or right.
|}

==== Eye movement codes ====
{| class="wikitable sortable"
|-
! AU number !! FACS name !! Action
|-
| 61 || Eyes turn left ||
|-
| M61 || Eyes left || The onset of the symmetrical 14 is immediately preceded or accompanied by eye movement to the left.
|-
| 62 || Eyes turn right ||
|-
| M62 || Eyes right || The onset of the symmetrical 14 is immediately preceded or accompanied by eye movement to the right.
|-
| 63 || Eyes up ||
|-
| 64 || Eyes down ||
|-
| 65 || [[Strabismus|Walleye]]||
|-
| 66 || Cross-eye ||
|-
| M68 || Upward rolling of eyes || The onset of the symmetrical 14 is immediately preceded or accompanied by an upward rolling of the eyes.
|-
| 69 || Eyes positioned to look at other person || The 4, 5, or 7, alone or in combination, occurs while the eye position is fixed on the other person in the conversation.
|-
| M69 || Head or eyes look at other person || The onset of the symmetrical 14 or AUs 4, 5, and 7, alone or in combination, is immediately preceded or accompanied by a movement of the eyes or of the head and eyes to look at the other person in the conversation.
|}

==== Visibility codes ====

{| class="wikitable sortable"
|-
! AU number !! FACS name
|-
| 70 || Brows and forehead not visible
|-
| 71 || Eyes not visible
|-
| 72 || Lower face not visible
|-
| 73 || Entire face not visible
|-
| 74 || Unscorable
|}

==== Gross behavior codes ====
These codes are reserved for recording information about gross behaviors that may be relevant to the facial actions that are scored.
{| class="wikitable sortable"
|-
! AU number !! FACS name !! Muscular basis
|-
| 29 || Jaw thrust ||
|-
| 30 || Jaw sideways ||
|-
| 31 || Jaw clencher || ''[[masseter]]''
|-
| 32 || [Lip] bite ||
|-
| 33 || [Cheek] blow ||
|-
| 34 || [Cheek] puff ||
|-
| 35 || [Cheek] suck ||
|-
| 36 || [Tongue] bulge ||
|-
| 37 || Lip wipe ||
|-
| 38 || Nostril dilator  || ''[[Nasalis muscle|nasalis (pars alaris)]]''
|-
| 39 || Nostril compressor || ''nasalis'' (''pars transversa'') and ''[[Depressor septi nasi muscle|depressor septi nasi]]''
|-
| 40 || Sniff
|-
| 41 || Lid droop || ''[[levator palpebrae superioris]]'' (relaxation)
|-
| 42 || Slit || ''[[orbicularis oculi muscle]]''
|-
| 43 || Eyes closed || relaxation of ''levator palpebrae superioris''
|-
| 44 || Squint || ''[[corrugator supercilii]]'' and ''orbicularis oculi'' muscle
|-
| 45 || Blink || relaxation of ''levator palpebrae superioris''; contraction of ''orbicularis oculi'' (''pars palpebralis'')
|-
| 46 || Wink || ''orbicularis oculi''
|-
| 50 || Speech
|-
| 80 || Swallow
|-
| 81 || Chewing
|-
| 82 || Shoulder shrug
|-
| 84 || Head shake back and forth
|-
| 85 || Head nod up and down
|-
| 91 || Flash
|-
| 92 || Partial flash
|-
| 97* || Shiver/tremble
|-
| 98* || Fast up-down look
|}