Research indicates that we process others’ actions by simulating them in our own motor system. This means that we represent observed actions as if we executed them ourselves. However, in social life, we not only have to process actions but also interactions. Could this rely on motor simulation as well? In my PhD, I was able to show that we can simultaneously represent multiple observed actions in our motor system. However, representing multiple actions is not the same as representing interactions. Therefore, in the current project, I aim to investigate how motor simulation of multiple actions can lead to motor simulation of interactions. One way to represent interactions is to integrate the involved actions into composite actions. For example, two persons shaking hands could be represented as a single handshake in the motor system. Moreover, when
composite actions cannot be formed, representing multiple actions may produce motor conflict. In the first part of the project, I will address these two hypotheses. In the second part, I will then investigate whether interactions can be represented by processing interaction parameters such as synchronicity in the motor system. Finally, I will examine how the brain keeps track of which agent is doing what. That is, to represent interactions, it is also important that we can link the represented actions to their agent. Together, the current proposal is a crucial step in developing a simulation theory of interaction representation.