Joint action with a virtual robotic vs. human agent

Prior research has revealed that when performing joint action tasks with a human co-actor, we automatically form representations not only of our own action, but also of the action of the co-actor we are interacting with, creating an action discrimination problem. Studies suggest these processes are affected by the human/non-human nature of the agent the task is shared with. In two experiments (Experiments 1 and 2), we measured the Joint Simon Effect (JSE) as an index of action discrimination, using a virtual version of the joint go/no-go task in which the task was shared with a virtual robotic vs. human hand. Furthermore, both experiments tested whether the JSE was affected by sensorimotor experience during which the participant manipulated the virtual robotic hand via an exoskeleton (vs. passive observation of movements of the virtual robotic hand). Experiment 2 replicated Experiment 1, except that prior to the joint action task, participants were informed about the robotic vs. human nature of the two virtual hands (no such information was given in Experiment 1). Both experiments demonstrated a significant JSE, which did not differ between robotic and human partner. Analysis of the results further indicates that the JSE obtained in the robotic condition was not modified after manipulating the virtual robotic hand. These results suggest that the human vs. non-human appearance of the partner is not a determinant of joint action performance in virtual settings.