Self-Avatar in Realtà Virtuale: studio preliminare sull' adattamento alla modifica del comportamento del corpo virtuale

The sense of embodiment is one of the key factors for enjoining a virtual reality (VR) experience. While proprioception is a well known component of the sense of embodiment, the way users adapt to external alterations of the self-avatar behavior is still unclear. Since the rubber hand illusion was shown to be effective, several studies were carried on to understand human response to virtual body modification. In this dissertation, we investigate the proprioception and the variation of the adaptation level in several experimental conditions. We developed a VR application that represents the hands of the self-avatar, and can modify the movement of the elbow, increasing or decreasing the rotation angle of the limbs. The development is made using Unity 3D and it is based on hand tracking features of the head mounted display Meta Quest 2. The experimental design includes two conditions: in the predictable condition, users initially experience a stable enhancement of their movements and then switch to a frequent change; in the non predictable conditions, users experienced the opposite, following an inverted pattern. We showed how the frequency of the variation of the alterations can affect the adaptation over time to new self-avatar behavior. The way we measure user experience and the sense of embodiment, is through questionnaires, whose reports are included in this thesis. The way we measure proprioception is through a proprioceptive test, performed at the end of every session, and the data are being analyzed. These studies are a starting point for realizing a system that optimizes neuro-rehabilitation strategies for post-stroke patients. This work was realized during my internship at the National Institute of Informatics in Tokyo, Japan, under the supervision of Professor Soccini and Professor Inamura. ​