STUDY
Facial Action Coding System (FACS)
FACS(Facial Action Coding System)
The Facial Action Coding System (FACS) is a system to taxonomize human facial movements by their appearance on the face, based on a system originally developed by a Swedish anatomist named Carl-Herman Hjortsjö. It was later adopted by Paul Ekman and Wallace V. Friesen, and published in 1978. Ekman, Friesen, and Joseph C. Hager published a significant update to FACS in 2002.
Its the process by which someone describes obseravable facial behavior in terms of the AUs(Action Units) that comprise it.Coders usually analyze video-recorded bejavior,using both frame-by-frame and real time viewing.
FACS coders rely on direct observation of muscle movement as well as observed changes in facial morphology (e.g,Furrows,Creases,Bulges of skin,etc.), to determine which AUs occured.
FACS coders rely on direct observation of muscle movement as well as observed changes in facial morphology (e.g,Furrows,Creases,Bulges of skin,etc.), to determine which AUs occured.
Action Units (AUs)
Action units (AUs) are the fundamental actions of individual muscles or groups of muscles. Ekman and Friesen analyzed the relationship between AU movement and facial expressions in the Emotion Facial Action Coding System (EMFACS) and claimed that all AUs are external representations of muscle movements. The measurements in EMFACS are AUs, not muscles, for two reasons. First, for a few appearances, two or more muscles are combined into a single AU because the changes in appearance they produce cannot be distinguished. Second, the appearance changes produced by one muscle are sometimes separated into two or more AUs to represent the relatively independent actions of different parts of the muscle.
AUs can be described in two ways, Presence and Intensity
- Presence – If AU is visible in the face (for example AU01_c)
- Intensity – How intense is the AU (minimal to maximal) on a 5 point scale which can also be defined as Intensity Scoring
Intensity scoring – Intensities of the FACS are annotated by appending letters A\u2013E (for minimal-maximal intensity) to the action unit number (e.g. AU 1A is the weakest trace of AU 1 and AU 1E is the maximum intensity possible for the individual person).
- A Trace
- B Slight
- C Marked or pronounced
- D Severe or extreme
- E Maximum
Main Action Units
| Action Units | Description |
|---|---|
|
1 |
Inner Brow Raiser |
|
2 |
Outer Brow Raiser (unilateral, right side) |
|
4 |
Brow Lowerer |
|
5 |
Upper Lid Raiser |
|
6 |
Cheek Raiser |
|
7 |
Lid Tightener |
|
9 |
Nose Wrinkler |
|
10 |
Upper Lip Raiser |
|
11 |
Nasolabial Deepener |
|
12 |
Lip Corner Puller |
|
13 |
Cheek Puffer |
|
14 |
Dimpler |
|
15 |
Lip Corner Depressor |
|
16 |
Lower Lip Depressor |
|
17 |
Chin Raiser |
|
18 |
Lip Puckerer |
|
20 |
Lip stretcher |
|
22 |
Lip Funneler |
|
23 |
Lip Tightener |
|
24 |
Lip Pressor |
|
25 |
Lips part |
|
26 |
Jaw Drop |
|
28 |
Mouth Stretch |
|
41 |
Lid drop |
|
42 |
Slit |
|
43 |
Eyes Closed |
|
44 |
Squint |
|
45 |
Blink |
|
46 |
Wink |
What are emotions?
Emotions are a process, a particular kind of automatic appraisal influenced by our evolutionary and personal past, in which we sense that something important to our welfare is occurring, and a set of psychological changes and emotional behaviors begins to deal with the situation.” – Paul Ekman, PhD
There are seven universal emotions.
| No. | Emotion | Action Units |
|---|---|---|
|
1 |
Anger |
6+12 |
|
2 |
Contempt |
1+4+15 |
|
3 |
Disgust |
1+2+5B+26 |
|
4 |
Enjoyment |
1+2+4+5+7+20+26 |
|
5 |
Fear |
4+5+7+23 |
|
6 |
Sadness |
9+15+17 |
|
7 |
Surprise |
R12A+R14A |
Hand muscles test in Ziva Dynamics
