Can Machines Think? Interaction and Perspective Taking with Robots Investigated via fMRI

Background: When our PC goes on strike again we tend to curse it as if it were a human being.Why and under which circumstances do we attribute human-like properties to machines?Although humans increasingly interact directly with machines it remains unclear whether humans implicitly attribute intentions to them and, if so, whether such interactions resemble human-human interactions on a neural level.In social cognitive neuroscience the ability to attribute intentions and desires to others is being referred to as having a Theory of Mind (ToM).With the present study we investigated whether an increase of human-likeness of interaction partners modulates the participants’ ToM associated cortical activity.Methodology/Principal Findings: By means of functional magnetic resonance imaging (subjects n = 20) we investigated cortical activity modulation during highly interactive human-robot game.Increasing degrees of human-likeness for the game partner were introduced by means of a computer partner, a functional robot, an anthropomorphic robot and a human partner.The classical iterated prisoner’s dilemma game was applied as experimental task which allowed for an implicit detection of ToM associated cortical activity.During the experiment participants always played against a random sequence unknowingly to them.Irrespective of the surmised interaction partners’ responses participants indicated having experienced more fun and competition in the interaction with increasing human-like features of their partners.Parametric modulation of the functional imaging data revealed a highly significant linear increase of cortical activity in the medial frontal cortex as well as in the right temporo-parietal junction in correspondence with the increase of human-likeness of the interaction partner (computer,functional robot,anthropomorphic robot,human).Conclusions/Significance: Both regions correlating with the degree of human-likeness, the medial frontal cortex and the right temporo-parietal junction, have been associated with Theory-of-Mind.The results demonstrate that the tendency to build a model of another’s mind linearly increases with its perceived human-likeness.Moreover, the present data provides first evidence of a contribution of higher human cognitive functions such as ToM in direct interactions with artificial robots.Our results shed light on the long-lasting psychological and philosophical debate regarding human-machine interaction and the question of what makes humans being perceived as human.