Evaluating the effect of kinematic features in an action observation paradigm: a preliminary study for designing a motor priming in a BCI system

Brain-computer interfaces (BCIs) for neurological rehabilitation aim to restore impaired functional abilities by inducing neuroplasticity mechanisms. The presence of a feedback branch within the BCI loop provides the patients with real-time information about their brain performances, promoting patients’ motor re-learning and engagement. As a result, most studies have focused on feedback optimization overlooking the impact of patients’ motor planning residual abilities in accomplishing the task required by BCI-based training. Therefore, the inclusion of a visual motor priming (i.e. observed action prior to a task) in a BCI system could assist the patient to retrieve the forgotten motor scheme, thus inducing an increase in cortical excitability and favouring the closed-loop effect. The aim of this preliminary study was to investigate how individual motor style, measured by kinematics, affects the cortical excitability of the observer in an action observation task. EEG data were acquired from 10 healthy subjects during an action observation task in which different levels of motor distance between the observer and the agent were modulated. The results show a greater desynchronization over parietal areas in alpha and beta bands in case of more unpredictable kinematics, i.e., more dissimilar from the observers’ ones. The results would form the basis for the design of a kinematic-based visuomotor priming, considering the motor style of the post-stroke-patient, to be integrated into a BCI system for motor rehabilitation.