Figure 2.

Two ‘agents’ interact with each another by reciprocally perceiving and performing the handwriting of digits. Each agent is based on a hierarchy of nested generative processes, spanning main sensorimotor levels (M, V, S, C) as well as levels associated with mentalizing (CS, G, PM). Across these levels, the generative processes predict the activity of the next-lower level, while prediction errors determined from visual input (V) and proprioceptive feedback traverse the hierarchy back upwards. By coupling these models through their interaction, agents reciprocate by writing what they believe they have understood and that way coordinate their beliefs dynamically and incrementally until they reach a mutual understanding. (Online version in colour.)