I have my eye on the emotion: a review of eye-tracking studies exploring processing of emotional facial expressions

Emotional facial expressions have a primary role in social interactions and in understanding another person’s emotions, moods, needs, intentions, and mental states. Studies employing stimuli in which facial areas are covered or altered faces have shown that the eyes and the mouth are the most informative when individuals process an emotional face. Nevertheless, in the literature there is varied evidence about which area between the eyes and the mouth is more informative for the processing of the specific emotions. The study of eye movements could contribute to an understanding of the processing of faces with specific emotional connotations. The aim of this study is to systematically review the evidence from the eye-tracking studies related to the characteristics of eye movements during the processing of different emotions. Moreover, factors influencing eye movements were also considered. Results from this systematic review suggest eye movements are predominantly directed toward the eye region when participants view anger and fear. Conversely, disgust, sadness and happiness are associated with increased gaze toward the mouth region. Surprise leads to fixations on both the mouth and the eyes. Furthermore, individual and cultural factors have been demonstrated to influence eye movement patterns during emotion processing. The implications of such studies and potential avenues for future research are explored.