Theory of mind (ToM) on robots

Theory of Mind (ToM) is not only a key capability for cognitive development but also for successful social interaction. In order for a robot to interact successfully with a human both interaction partners need to have an adequate representation of the other's actions. In this paper we address the question of how a robot's actions are perceived and represented in a human subject interacting with the robot and how this perception is influenced by the appearance of the robot. We present the preliminary results of an fMRI-study in which participants had to play a version of the classical Prisoners' Dilemma Game (PDG) against four opponents: a human partner (HP), an anthropomorphic robot (AR), a functional robot (FR), and a computer (CP). The PDG scenario enables to implicitly measure mentalizing or Theory of Mind (ToM) abilities, a technique commonly applied in functional imaging. As the responses of each game partner were randomized unknowingly to the participants, the attribution of intention or will to an opponent (i.e. HP, AR, FR or CP) was based purely on differences in the perception of shape and embodiment.