Predictive Action-perception Resonance and Mental Simulation (PARMS)

Mounting evidence suggests that even higher order socio-cognitive processes such as mind and intention reading, or action and perception understanding can be mapped onto modal sensorimotor cortices (1). The bodily instantiation of cognitive operations is called ‘embodiment’ and the internal reproduction of others’ mental, perceptuo-motor and emotional states is called ‘simulation’, a process which supposedly enables the interindividual sharing of experiences (2) and that may be linked to the striking functional property of the monkey premotor and parietal neurons (3, 4) activated during both action execution and observation (‘mirror neurons’). Behavioural and neural studies in healthy (5, 6) and brain damaged humans (7-9) indicate that action perception and execution rely upon largely overlapping neural substrates. Moreover, perceptuo-motor codes are tightly associated. Indeed, not only mere action observation strengthens the motor representation of the observed action (10), but also mere motor experience of a given action may improve its visual recognition (11). This inherent functional and anatomic bidirectional link may represent a deceivingly simple mechanism for the striking plastic abilities underlying social learning. Also quintessential to effective social interactions is the ability to predict and anticipate the actions of other individuals. One crucial but thus far scarcely explored question concerns the role played by the different nodes of the action observation network (AON) in understanding others’ actions and intentions on the basis of predictive coding algorithms (12, 13). We have previously demonstrated that cortico-spinal motor systems are mainly activated when making predictions on upcoming actions (14, 15). Here we plan to expand previous knowledge by investigating: i) the circumstances that induce an observer to represent actions in the future. Single-pulse transcranial magnetic stimulation (spTMS) and fMRI will be used; ii) the causative role played by specific nodes of the AON network in the predictive coding of observed actions as well as of higher-order linguistic action representation. To this aim we will use a) rTMS in healthy subjects to create specific ‘virtual lesions’ and b) state-of-the-art lesion mapping techniques in brain damaged patients; iii) the plastic and dynamic aspects of predictive abilities by testing children while they will learn specific perceptuo-motor skills (e.g. soccer actions) and motorically-visually expert individuals (e.g. elite basketball athletes). Particular attention will be paid to error prediction by testing expert and non-expert healthy subjects and brain damaged patients in observation tasks requiring to make early choices on which action is going to be performed by a model and whether the observed action is performed correctly in time and space. fMRI, spTMS, and psychophysics studies will be carried out. PARMS may have specific translational implications in different fields: i) robotics: our approach may be fundamentally important for applications aimed at reducing the comparative inability of current robotic systems to cope with the high prediction demands of real world social interactions and at increasing the competence of artificial agents to operate in natural, human-like environments and to produce meaningful behaviours by means of anticipatory simulation; ii) neurorehabilitation of motor deficits following stroke; iii) brain-based training procedures for optimizing sport performance and ultimately helping athletes to achieve excellence