Facial Action Coding System (FACS) is a system to taxonomize human facial expressions, originally developed by Paul Ekman and Wallace Friesen in 1976.[1] It is a common standard to systematically categorize the physical expression of emotions, and it has proven useful to psychologists and to animators.
Contents |
Uses
Using FACS, human coders can manually code nearly any anatomically possible facial expression, deconstucting it into the specific Action Units (AU) and their temporal segments that produced the expression. As AUs are independent of any interpretation, they can be used for any higher order decision making process including recognition of basic emotions, or pre-programmed commands for an ambient intelligent environment. The FACS manual is over 1000 pages in length and provides the AUs, as well as Dr. Ekman's interpretation of their meaning.
FACS defines 32 AUs, which are a contraction or relaxation of one or more muscles. It also defines a number of Action Descriptors, which differ from AUs in that the authors of FACS have not specified the muscular basis for the action and have not distinguished specific behaviors as precisely as they have for the AUs.
For example, FACS can be used to distinguish two types of smiles as follows: [2]
- insincere and voluntary Pan American smile: contraction of zygomatic major alone
- sincere and involuntary Duchenne smile: contraction of zygomatic major and inferior part of orbicularis oculi.
Although the labeling of expressions currently requires trained experts, researchers have had some success in using computers to automatically identify FACS codes, and thus quickly identify emotions[3]. Computer graphical face models, such as CANDIDE or Artnatomy, allow expressions to be artificially posed by setting the desired action units.
The use of FACS has been proposed for use in the analysis of depression[4], and the measurement of pain in patients unable to express themselves verbally[5].
FACS is designed to be self-instructional. People can learn the technique from a number of sources[6], including manuals and workshops[7], and obtain certification through testing[8]. A variant of FACS has been developed to analyze facial expressions in chimpanzees[9].
Codes for action units
For clarification, FACS is an index of facial expressions, but does not actually provide any bio-mechanical information about the degree muscle activation. Though muscle activation is not part of FACS, the main muscles involved in the facial expression has been added here for the benefit of the reader.
(Also see the list of facial muscles.)
Action descriptors (with facial muscles)
- 1 Inner Brow Raiser -- 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
- 6 Cheek Raiser -- Orbicularis oculi (pars orbitalis)
- 7 Lid Tightener -- Orbicularis oculi (pars palpebralis)
- 9 Nose Wrinkler -- Levator labii superioris alaeque nasi
- 10 Upper Lip Raiser -- Levator labii superioris, caput infraorbitalis
- 11 Nasolabial Deepener -- Zygomaticus minor
- 12 Lip Corner Puller -- Zygomaticus major
- 13 Cheek Puffer -- 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 Puckerer -- Incisivii labii superioris and Incisivii labii inferioris
- 19 Tongue Out
- 20 Lip stretcher -- Risorius w/ 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 internal pterygoid
- 27 Mouth Stretch -- Pterygoids, Digastric
- 28 Lip Suck -- Orbicularis oris
- 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
- 39 Nostril Compressor
- 41 Lid Droop
- 42 Slit
- 43 Eyes Closed -- Relaxation of Levator palpebrae superioris; Orbicularis oculi (pars palpebralis)
- 44 Squint
- 45 Blink -- Relaxation of Levator palpebrae superioris; Orbicularis oculi (pars palpebralis)
- 46 Wink -- Relaxation of Levator palpebrae superioris; Orbicularis oculi (pars palpebralis)
See also
References
- ^ P. Ekman and W. Friesen. Facial Action Coding System: A Technique for the Measurement of Facial Movement. Consulting Psychologists Press, Palo Alto, 1978.
- ^ Del Giudice M, Colle L (2007). "Differences between children and adults in the recognition of enjoyment smiles". Developmental psychology 43 (3): 796–803. doi:. PMID 17484588.
- ^ Facial Action Coding System. Retrieved July 21, 2007.
- ^ Reed LI, Sayette MA, Cohn JF (2007). "Impact of depression on response to comedy: A dynamic facial coding analysis". Journal of abnormal psychology 116 (4): 804–9. doi:. PMID 18020726.
- ^ Lints-Martindale AC, Hadjistavropoulos T, Barber B, Gibson SJ (2007). "A Psychophysical Investigation of the Facial Action Coding System as an Index of Pain Variability among Older Adults with and without Alzheimer's Disease". Pain medicine (Malden, Mass.) 8 (8): 678–89. doi:. PMID 18028046.
- ^ http://www.google.com/search?q=facs+learning+facial+expressions&ie=utf-8&oe=utf-8&aq=t Google search for FACS Learning Facial Expressions
- ^ http://www.erikarosenberg.com/FACS.html Example and web site of one teaching professional: Erika L. Rosenberg, Ph.D
- ^ http://www.face-and-emotion.com/dataface/facs/fft.jsp
- ^ Parr LA, Waller BM, Vick SJ, Bard KA (2007). "Classifying chimpanzee facial expressions using muscle action". Emotion (Washington, D.C.) 7 (1): 172–81. doi:. PMID 17352572.
External links
- New Yorker article discussing FACS
- Details from 1978 edition of FACS
- overview Link is broken
- Site at WPI
- Article at About.com
- Sample of FACS Manual Link is broken
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