Does the human motor system simulate Pinocchio's actions? Coacting with a human hand versus a wooden hand in a dyadic interaction.

Corepresenting actions performed by conspecifics is essential to understanding their goals, inferring their mental states, and cooperating with them. It has recently been demonstrated that joint-action effects in a Simon task provide a good index for corepresentation. In the present study, we investigated whether corepresentation is restricted to biological agents or also occurs for nonbiological events. Participants performed a Simon task either with an image of a human hand or with a wooden analogue. The Simon-like effect emerged only when participants coacted with a biological agent. The lack of the joint-action effect when participants interacted with a wooden hand indicates that the human corepresentation system is biologically tuned.