Exploring the Social Environment with the Eyes: A Review of the Impact of Facial Stimuli on Saccadic Trajectories

Abstract

Eye movement parameters can be highly informative regarding how people explore the social environment around them. This theoretical review examines how human faces and their features (e.g., eye-gaze direction, emotional expressions) can modulate saccadic trajectories. In the first part, studies in which facial stimuli were presented in a central location, such as during a face-to-face social interaction, are illustrated. The second part focuses on studies in which facial stimuli were placed in the periphery. Together, these works confirm the presence of an intriguing link between eye movements and facial processing, and invite consideration of saccadic trajectories as a useful (and still underused) opportunity to track ongoing mechanisms that support the social vision. Some directions for future research are also discussed.

Keywords: eye movements; faces; saccadic trajectory; social cognition; visual attention.

Figure 1

Examples of the two main paradigms used to explore the impact of facial stimuli on saccadic curvatures. A central fixation spot is typically followed by a distracting face and a symbolic target stimulus. In (A), a central distracting face with its eye gaze averted leftwards is presented, while (B) shows a peripheral distracting face with a direct gaze. The dotted lines represent potential saccadic trajectories. Stimuli are not drawn to scale. SOA = stimulus onset asynchrony.