  Gaze cueing is a fundamental part of social interactions, and broadly studied
using Posner task based gaze cueing paradigms. While studies using human
stimuli consistently yield a gaze cueing effect, results from studies using
robotic stimuli are inconsistent. Typically, these studies use virtual agents
or pictures of robots. As previous research has pointed to the significance of
physical presence in human-robot interaction, it is of fundamental importance
to understand its yet unexplored role in interactions with gaze cues. This
paper investigates whether the physical presence of the iCub humanoid robot
affects the strength of the gaze cueing effect in human-robot interaction. We
exposed 42 participants to a gaze cueing task. We asked participants to react
as quickly and accurately as possible to the appearance of a target stimulus
that was either congruently or incongruently cued by the gaze of a copresent
iCub robot or a virtual version of the same robot. Analysis of the reaction
time measurements showed that participants were consistently affected by their
robot interaction partner's gaze, independently on the way the robot was
presented. Additional analyses of participants' ratings of the robot's
anthropomorphism, animacy and likeability further add to the impression that
presence does not play a significant role in simple gaze based interactions.
Together our findings open up interesting discussions about the possibility to
generalize results from studies using virtual agents to real life interactions
with copresent robots.
