The parieto-frontal cortical circuit that is active during action observation is the
circuit with mirror properties that has been most extensively studied. Yet, there remains
controversy on its role in social cognition and its contribution to understanding the actions
and intentions of other individuals. Recent studies in monkeys and humans have shed light
on what the parieto-frontal cortical circuit encodes and its possible functional relevance for
cognition. We conclude that, although there are several mechanisms through which one can
understand the behaviour of other individuals, the parieto-frontal mechanism is the only one
that allows an individual to understand the action of others \u2018from the inside\u2019 and gives the
observer a first-person grasp of the motor goals and intentions of other individuals
