THE SHARED SPACE OF ACTIONS. MIRROR NEURONS AND MOTOR INTENTIONALITY

Biological movements, especially those performed by our conspecifics, are very crucial stimuli for us. How do we recognize them? How do we grasp their possible meaning? How do we understand them not only as bodily movements but also as intentional actions?
According to a philosophically and psychologically influential view, in order to understand the intentional behaviour of others we have to attribute them with “propositional attitudes”, i.e. the mental states such as beliefs, desires, intentions etc. that would drive that behaviour, make it comprehensible and eventually predictable. Our intentional understanding of the actions of others would therefore be rooted in our ability to mentalize or to read their minds, in other words to represent them as having mental states. Without this meta-representational ability, the actions of others could not have any intentional meaning for us and this would prevent us from interacting with our peers and performing adequately in even most simple social situations.
Over the last few years, however, this view has been radically challenged by the neurophysiological analysis of the cortical mechanisms involved both in producing our own actions and in understanding those performed by others. The study of the functional properties of the cortical motor system and the discovery of a specific class of visuomotor neurons (mirror neurons) has suggested that our understanding of the actions of others is primarily based on a mechanism that directly matches the visual representation of observed actions with our own motor representation of the same actions. According to this hypothesis, we understand the actions of others by means of our own “motor knowledge”: it is this type of knowledge that would enable us to immediately attribute an intentional meaning to the movements of others. This does not exclude, of course, that other more complex processes, such as those that characterize our meta-representational abilities, may be at work and play a role in these functions. It simply underlines that this mentalizing is neither the sole nor the primary way to intentionally understand the actions of others.
In my talk I will briefly summarize the basic properties of the mirror system in monkeys and humans, and will focus on the implications of its matching mechanism for intentional understanding. This will help me to demonstrate the extent to which intentional and motor components of action are intertwined and how they can both be fully appreciated exclusively on the basis of a motor approach to intentionality, thus going beyond a merely mentalistic view of action understanding, which reduces the intentional content of an action to that of the pure (i.e. propositional, no-motor) mental states that are thought to cause such action, and a hyper-simplified view of motor behaviour that relegates the motor content of an action to the mere (i.e. non intentional) bodily movements needed to execute it.