How does the Brain Represent Cooperative Actions? Investigating the Embodiment of a Two-person Grasping Task

Humans are capable of coordinating their actions with one another to achieve joint outcomes. In such joint actions, we must plan and execute our actions relative to those of our partners. Using a joint grasping task, this research examined the extent to which co-actors represent their partner’s actions during interpersonal coordination to facilitate cooperative actions. Two participants at a time worked together to grasp an object, such that each person used their index and middle fingers of one hand to push from opposite directions against the sides of the object to lift it. Results suggested that co-actors represented each other’s actions during the joint (cooperative) performance of the task, and that their kinematics were entrained into spatial and temporal synchrony. This supports the idea that during joint actions humans form task representations that specify not only their own part, but also the part to be performed by their partners.M.A