Decoupling facial expressions and head motions in complex emotions

Perception of emotion through facial expressions and head motion is of interest to both psychology and affective computing researchers. However, very little is known about the importance of each modality individually, as they are often treated together rather than separately. We present a study which isolates the effect of head motion from facial expression in the perception of complex emotions in videos. We demonstrate that head motions carry emotional information that is complementary rather than redundant to the emotion content in facial expressions. Finally, we show that emotional expressivity in head motion is not limited to nods and shakes and that additional gestures (such as head tilts, raises and general amount of motion) could be beneficial to automated recognition systems.