Intra- and Interpersonal Functions of Head Motion in Emotion Communication

In affective computing, head motion too often has been considered only a nuisance variable, something to control when aligning face images for analysis of facial expression or identity. Yet, recent research suggests that head motion is critical to the communication of emotion and the regulation of face-to-face interaction. Using a generic head tracker, strong relationships between head motion and emotion at both the individual and dyadic levels were found in studies of distressed couples and mother-infant dyads. These findings raise key research questions about head motion and other nonverbal displays: How extensively do they communicate emotion and psychological distress or disorder? What is their temporal coordination with facial expression? How are they coordinated interpersonally? Windowed cross-correlation and actor-partner analysis are proposed for the latter.