Role of facial expressions in social interactions.

The expressions we see in the faces of others engage a number of different cognitive processes. Emotional expressions elicit rapid responses, which often imitate the emotion in the observed face. These effects can even occur for faces presented in such a way that the observer is not aware of them. We are also very good at explicitly recognizing and describing the emotion being expressed. A recent study, contrasting human and humanoid robot facial expressions, suggests that people can recognize the expressions made by the robot explicitly, but may not show the automatic, implicit response. The emotional expressions presented by faces are not simply reflexive, but also have a communicative component. For example, empathic expressions of pain are not simply a reflexive response to the sight of pain in another, since they are exaggerated when the empathizer knows he or she is being observed. It seems that we want people to know that we are empathic. Of especial importance among facial expressions are ostensive gestures such as the eyebrow flash, which indicate the intention to communicate. These gestures indicate, first, that the sender is to be trusted and, second, that any following signals are of importance to the receiver.