Performative faces

The paper presents a model for the construction of an artificial agent that can express performatives through facial expression. The performative of a speech act or communicative act is the particular communicative intention a Sender has to one's Addressee, the way one wants to socially relate oneself to the interlocutor. Performatives are decomposed both on the meaning and on the signal side: on the meaning side, a performative is represented as a cluster of cognitive units, that in turn include subclusters mentioning the Sender's general goal (informing, asking, requesting), the power relationship between Sender and Addressee, the Sender's affective state, and further information peculiar of specific performatives; on the signal side, facial expressions are decomposed into Action Units. The proposed system computes the appropriate performative of one's communicative acts through consideration of the context of communication, particularly of the Addressee's cognitive capacity, social relationship and personality traits, and then expresses the computed performatives through 3D facial displays.