Corrugator supercilii and orbicularis oculi muscle. FACS is designed to be self-instructional. A review of the cross-cultural studies". Friesen, and Joseph C. American Journal of Physical Anthropology. An action which is unilateral occurs on only one side of the face but has no specific side is indicated with a "U" and an action which is unilateral but has a stronger side is indicated with an "A.
The recognition of emotion may also utilize the occipitotemporal neocortex, orbitofrontal cortex and right frontoparietal cortices.
Facial Action Coding System
Subsequent cross-cultural studies found similar results. A person's face, especially their eyes, creates the most obvious and immediate cues that lead to the formation of impressions. Facial Action Coding System 3. It can also show the manner in which something is done, such as carelessly or routinely. These muscles develop from the second pharyngeal arch in the embryo.