What the human face tells the human mind: some challenges for the robot-human interface

The human face serves a variety of different communicative functions in social interaction. The face mediates person identification, the perception of emotional expressions and lipreading. Perceiving the direction of social attention, and facial attractiveness, also affect interpersonal behaviour. This paper reviews these different uses made of facial information, and considers their computational demands. The possible link between the perception of faces and deeper levels of social understanding is emphasised through a discussion of developmental deficits affecting social cognition. Finally, the implications for the development of communication between robots and humans is discussed. It is concluded that it could be useful both for robots to understand human faces, and also to display human-like facial gestures themselves