Embodiment matters when establishing eye contact with a robot

Eye contact constitutes a strong social signal in humans and affects various attentional processes. However, eye contact with another human evokes different responses compared with a direct gaze of an image on a screen. The question of interest is whether this holds also for eye contact with a robot. Previous experiments with physically present iCub humanoid robot showed that eye contact affects participants' orienting of attention. In the present study, we investigated whether a robot's eye contact on the screen could show similar effects. Specifically, in two experiments we examined the impact of eye contact on the gaze-cueing effect (orienting of attention in response to a directional gaze shift) while we varied the timing of the events within a trial sequence. Our results showed that the robot's eye contact did not modulate the gaze-cueing effect (gaze-cueing effect present in all conditions), thereby suggesting that eye contact gaze presented in a 2D format on the screen has less impact on observers than its 3D embodied version in a physically present robot. Overall, our findings stress the importance of embodied interactions for understanding the mechanisms of social cognition.