Spatio-Temporal Properties of Amused, Embarrassed, and Pained Smiles

Abstract Smiles are universal but nuanced facial expressions that most frequently used in face-to-face communications, typically indicating amusement sometimes conveying negative emotions such as embarrassment and pain. Although previous studies have suggested spatial temporal properties could differ among these various types of smiles, no study has thoroughly analyzed properties. This aimed to clarify the spatiotemporal smiles amusement, embarrassment, pain using a spontaneous behavior database. The results regarding patterns revealed pained showed less eye constriction more overall tension than amused smiles; differences were identified between embarrassed smiles. Regarding properties, remained state higher Moreover, gradual change from states smile had lower probabilities staying or transitioning compared By comparing three types, this probability discrete help distinguish amused, embarrassed,