Understanding motor planning and action recognition of pantomimed grasps

The ability to manipulate objects with considerable skill is one of the defining features of primates. In both humans and non-human primates, grasping is typically directed toward a visible object and results in contact with the object. Humans - and perhaps some other species - are also capable of grasping imaginary objects in a pantomimed prehension. Pantomimed grasps are well studied, both for theoretical and clinical interests, to explore the double function of human hands, as instrumental as well as communicative devices. The present thesis aims to investigate both aspects of pantomimed grasps in terms of motor control, action understanding and neural activation during action observation. The first experiment explored whether the way pantomimed grasps are executed can convey weight information of imaginary objects. The second experiment tested whether observers can exploit movement kinematics to discriminate between real (i.e., movements directed toward a physically present object) and pantomimed grasps. The third study investigated if perception of real and pantomimed grasps might automatically drive object representation. The fourth experiment inspected whether having a motor expertise on pantomimed grasp execution impacts pantomimed grasp processing. The fifth experiment shed new insights on the neural underpinnings of action understanding mechanisms by exploring electroencephalography (EEG) signals during real and pantomimed grasp observation.