The face is the muscular affective memory, a diary written in fibers.The muscles of the face are emotional reading units directly linked to the limbic system, functioning as printers of the brain affective state, and simultaneously as social interaction sensors. The facial muscle, that small fiber bundle, carries in itself a power that no algorithm can fully replicate: the authenticity of feeling, argues Prof. Freitas-Magalhães, the world's leading expert for Neuroscience and Biobehavioral Psychology and the Encyclopedia of Human Behavior, by Elsevier, Oxford, in his pioneering and extraordinary book on facial muscles.