Reconceptualizing Presence (PI/PSI) as Mechanisms in VR Neurorehabilitation: There Is No Spoon, But Believing So Lets You Bend It

Virtual reality is widely used in stroke rehabilitation, but the field has focused on outcomes at the expense of mechanisms. This paper argues that VR works not because it delivers more practice, but because it deliberately manipulates Place Illusion (PI) and Plausibility Illusion (PSI) to recalibrate the stroke-damaged body schema. A qualitative systematic review of seven studies (2015–2025) revealed a dissociation that repetition alone cannot explain: Virtual Reality Mirror Therapy (VRMT) improved balance and gait, while immersive, gamified VR improved upper-limb function. We propose that VRMT targets PSI-driven body ownership and multisensory integration to update body schema, whereas immersive VR targets agency and PI-enhanced PSI to drive error-based motor learning. In this framework, PI and PSI are not passive correlates of experience but active perceptual processes that condition sensorimotor plasticity. This generates testable predictions linking presence measurements to neural and behavioral recovery markers. It also reframes stroke rehabilitation as a natural laboratory for studying the altered bodily self. If the framework holds, the field needs to stop asking whether VR works and start asking how the brain's capacity to believe in a virtual body becomes the very mechanism that repairs the physical one; and why restoring the illusion of a functioning limb may be as therapeutic as moving it.