Analysis of the Sense of Embodiment in Virtual Co-embodiment Rehabilitation: A Structural Equation Modeling Approach.

Sense of embodiment (SoE) refers to the participant's perception of a virtual avatar as an extension of their own body, involving both physical and functional aspects. Research has highlighted the importance of SoE for the effectiveness of virtual rehabilitation. Virtual co-embodiment technology, an emerging virtual reality (VR) application, has the potential to enhance users' engagement and SoE, which demonstrates significant promise for motor rehabilitation. However, the exploration of factors influencing embodiment in virtual co-embodiment is still limited, particularly regarding both internal and external factors, which constrains its rehabilitation applications. This study investigates factors influencing SoE changes in Virtual Co-embodiment Rehabilitation by developing a theoretical model, based on 859 valid trials collected from 40 healthy participants, and analyzing the data using Structural Equation Modeling (SEM) and Partial Least Squares Structural Equation Modeling (PLS-SEM). The results suggest that both "visual consistency" (external factor) and "individual sensitivity" (internal factor) may influence changes in SoE, with "visual consistency" appearing to have a predominant effect. These findings contribute to understanding changes in SoE in virtual co-embodiment and offer insights for optimizing the technology in rehabilitation.