Synergistic Embodiment: A Framework for Shared Control and Multi-Limb Interaction in Virtual Reality

Abstract

Collaboration is moving beyond shared screens and virtual spaces toward shared bodily action. As VR, robotics, and AI-mediated systems reshape how people work, learn, care, play, and act at a distance, virtual and augmented bodies are becoming shared, programmable media for coordination. They may be co-controlled by multiple users, extended through supernumerary limbs, experienced from distributed viewpoints, or partly governed by semi-autonomous processes. These systems unsettle a foundational assumption in HCI and VR: that embodiment belongs to a single user, body, and perception-action loop. I term this emerging condition collaborative embodiment. This thesis investigates collaborative embodiment as a unified research problem. I first surveyed 137 studies to map methods in collaborative VR and identify gaps in shared control, perspective, and limb augmentation. I then designed and evaluated three VR systems: CoplayingVR for shared hand control, One Body, Two Minds for dynamic perspective switching, and Juggling Extra Limbs for coordination with semi-autonomous virtual arms. Using mixed methods, I show that shared control can improve novice performance and engagement when coordination costs are managed; flexible perspectives balance awareness, comfort, and embodiment; and increasing limb autonomy shifts users from manipulation toward delegation and supervision. This thesis advances Synergistic Embodiment as a conceptual lens and introduces the Interaction Elements Matrix as a design framework for control mapping, perspective strategy, feedback, and autonomy.