Facial Deception in Humans and ECAs

Deception is an intriguing and relevant issue for the theory of both cognition and social interaction. When we deceive, we influence other people through manipulating their beliefs. This paper presents a definition of deception and of its functions in terms of a model of cognition and social action. We can define as deceptive any act, or even non-act (omission) of an agent aimed at having another agent believe something false or not believe something true about the environment, the agent’s identity or its mental and emotional states. A typology of ways to deceive is outlined (omission, concealment, falsification, masking, negation, and false confirmation), and applied to deception in facial and bodily expression. Some of possibilities generated by this typology are then applied to the construction of an ECA that can simulate, mask, or suppress facial expressions of emotions. The relationship of deception and politeness is investigated both on a theoretical ground and through the empirical analysis of a video corpus. The results of the analysis are used to determine when an ECA masks, suppresses or simulates emotional expression.