The Study of a Five-Dimensional Emotional Model for Facial Emotion Recognition
Table 3
Single activity unit (AU) of FACS (except from P. Ekman and W. V. Friesen, “Measuring Facial Movement,” Environmental Psychology and Nonverbal Behavior, vol. 1, pp. 56–75, 1976).
AU number
Description
Facial muscle
1
Inner brow raiser
Frontalis (pars medialis)
2
Outer brow raiser (unilateral, right side)
Frontalis (pars lateralis)
4
Brow lowered
Depressor glabellae, depressor supercilii, and corrugator supercilii
5
Upper lid raiser
Levator palpebrae superioris
6
Cheek raiser
Orbicularis oculi (pars orbitalis)
7
Lid tightener
Orbicularis oculi (pars palpebralis)
10
Upper lip raiser
Levator labii superioris and caput infraorbitalis
12
Lip corner puller
Zygomatic major
14
Dimpler
Buccinator
15
Lip corner depressor
Depressor anguli oris (triangularis)
16
Lower lip depressor
Depressor labii inferioris
25
Lips part
Depressor labii or relaxation of mentalis (AU17) or orbicularis oris
26
Jaw drop
Masseter; temporalis and internal pterygoid relaxed
