The facial expression recognition is aimed to the automatic detection of micro-expressions, so facial expressions of short duration, from which emotions such as anger, fear, sadness, joy, surprise and contempt can be derived. The detection takes place either visually via a camera, which films the subjects during the experiment, or electrically by using electrodes on the face muscles. The latter brings more meaningful results, but however it requires a considerably higher effort.
Significance for the emotional intensity: medium
Informative value on the kind of emotion: high
Informative value on the mental workload: low
Effort: simple but with less significance if video recordings are used, higher significance by using electrical activity of the facial muscles