What are the sign vehicles in the face and what messages do they send?
Subsequent questions and answers discuss what types of sign vehicles there are in the face, how they may be measured, and how they are validated as reflecting the concepts we are interested in measuring. First, consider again what is meant by sign vehicles in regard to the face. Ekman has classified the sign vehicles of the face into four types: static, slow, artificial, and rapid.
Static sign vehicles are the sign vehicles that are the basis of identity signals, such as bony structure, physical dimensions, permanent color and textures, and location of landmarks. These vehicles are the primary static sign vehicles in messages about identity, and are the basis of the signal. Other sign vehicles are noise. Identity sign vehicles remain invariant across many transformations, such as aging and transient expressions.
Slow sign vehicles are the basis of signals about health, physical activity, and aging. The condition of skin, depth and extent of wrinkles, and transient coloration are important slow sign vehicles.
Artificial sign vehicles are introduced by the person to alter or enhance other sign vehicles or to convey new messages. Cosmetics, prostheses, and jewelry are important artificial sign vehicles.
Rapid sign vehicles are the sign vehicles that are the basis for emotion signals and other messages of short duration. muscular actions and their effects on skin and facial tissues are the primary rapid sign vehicles.