Abstract. Mutual gaze is a key element of human development, and constitutes an important factor in human interactions. In this study, we examined -through analysis of subjective reports-the influence of an online eyecontact of a humanoid robot on humans' reception of the robot. To this end, we manipulated the robot gaze, i.e., mutual (social) gaze and neutral (non-social) gaze, throughout an experiment involving letter identification. Our results suggest that people are sensitive to the mutual gaze of an artificial agent, they feel more engaged with the robot when a mutual gaze is established, and eye-contact supports attributing human-like characteristics to the robot. These findings are relevant both to the human-robot interaction (HRI) research -enhancing social behavior of robots, and also for cognitive neuroscience -studying mechanisms of social cognition in relatively realistic social interactive scenarios.
Keywords: Social Human-Robot interaction, iCub, Mutual Gaze
IntroductionOne of the major research topics in Human-Robot Interaction (HRI) research is designing robots that react to human needs, coordinate with humans by means of human-like actions, appear intentional, and behave like social agents. These features would allow for a better social attunement with humans and would facilitate their smooth integration into society. Besides design of robots for optimal adaptation in everyday environments, developments in HRI could benefit from investigation of social cognition in humans. More specifically, empirical findings in social neuroscience indicate the need for investigating social cognition during involvement in truly real-time interactive scenarios rather than through mere observation of social stimuli on a screen [1][2][3]. In order to examine mechanisms of social cognition in various naturalistic settings, humanoid robots consist an ideal trade-off between ecological validity and experimental control, for a review see [4]. In terms of ecological validity, humanoid robots increase perception of social presence due to their embodiment [5]. They can induce both low-level social cognition mechanisms (perceptual and motor processes) [6-8] and higher-order mechanisms, such as mentalizing [9]. In terms of experimental control, precise behavioral parameters of the robot can be manipulated, and subsequently, influence of these parameters on the social cognition mechanisms of humans can be examined [10]. Although lowlevel social processes are typically evoked when robots are used as interaction partners [6][7][8], they can be modulated by human-likeness of the robot, as people are sensitive to subtle human-like features in robot's behavior [11][12]. Therefore, increasing human-likeness of humanoid robots, should allow for more natural HRI on the one hand, and for understanding social cognition in more natural interactive scenarios on the other. One of the most crucial cues of typically human communication is mutual gaze or eye contact; a reciprocal exchange of gaze between two people. The effect of eye cont...