Same kinematics but different objects during action observation: Detection times and motor evoked potentials

Motor resonance refers to the fact that an observed action is online subliminally reenacted. The aim of the present paper was to verify if, on equal terms of kinematics, the to-be-grasped object's intrinsic properties are influencing the observers' motor behaviour. A detection time and a single pulse transcranial magnetic stimulation experiment were performed to verify the effects of a change of object's intrinsic properties artificially made on a video showing a grasping action. In particular, the object substituting the original one was not graspable by the showed movement. Results indicated an influence of object's intrinsic properties: Detection times were delayed and motor evoked potentials were reduced when the movement shown was not suitable to grasp the object. These results are interpreted as an evidence that during grasping action observation the motor system of the observer is influenced not only by the seen movements but also by the to-be-grasped object.