Combining Facial and Postural Expressions of Emotions in a Virtual Character

Psychology suggests highly synchronized expressions of emotion across different modalities. Few experiments jointly studied the relative contribution of facial expression and body posture to the overall perception of emotion. Computational models for expressive virtual characters have to consider how such combinations will be perceived by users. This paper reports on two studies exploring how subjects perceived a virtual agent. The first study evaluates the contribution of the facial and postural expressions to the overall perception of basic emotion categories, as well as the valence and activation dimensions. The second study explores the impact of incongruent expressions on the perception of superposed emotions which are known to be frequent in everyday life. Our results suggest that the congruence of facial and bodily expression facilitates the recognition of emotion categories. Yet, judgments were mainly based on the emotion expressed in the face but were nevertheless affected by postures for the perception of the activation dimension.