Upper limb Embodiment: Examining factors in the malleability of body representation

Human cognition is bonded inside a physical instance, allowing to connect the external environment to the internal world of beings, thus resulting in the experience of reality. The representation of the anatomical instance at disposition is highly complex and multi-faceted, as also proven by the different neural correlates concurring to the construction of a cohesive depiction of the body, both in visual and sensorimotor terms. Moreover, the physical representation is not static and fixed in time, but on the contrary is extremely plastic, incorporating external effectors inside the cognitive bodily depiction, so much so that an external effector can be considered as part “of my own self”. We see this with sport equipment, virtual avatars, prosthetic devices, and, lately, with supernumerary robotic limbs. Many factors play a crucial role on the incorporation of such external effectors: the visual appearance of the tool, its motor enhancing characteristics, the agent’s individual factors, the patient’s comfort in employing a prosthetic, the perception of usefulness of the tool in usage, and many more. It is clear then that this incorporation phenomenon is of extreme complexity, and more knowledge is required on the weighted impact of each singular factor over this embodiment process. The proposed doctoral thesis assesses the effect of bodily sense feedback, canonical body constraints violation, perception of usefulness and motor manoeuvrability and visual representation over the incorporation of external upper-limb effectors.