Guidance Framework for Selecting Virtual Hand Illusion Paradigms to Enhance Motor Imagery via Sense of Ownership in Stroke Rehabilitation

Virtual hand illusion (VHI)-based motor imagery (MI) guidance systems are a promising approach for enhancing MI by reinforcing the sense of ownership (SoO), a key factor in effective neurorehabilitation. Although VHI-based guidance has shown potential, most prior studies have relied on fixed paradigms, limiting individual adaptability. This study investigates the mechanistic feasibility of a guidance framework for VHI paradigm selection based on patients' clinical characteristics and SoO responses to enhance MI-related neural activity in stroke patients. Twelve subacute stroke patients completed a two-visit protocol. During the initial visit, paradigm feasibility was assessed, and galvanic skin response (GSR) was recorded to support VHI selection when multiple paradigms were feasible. The final paradigm determined by the proposed framework was termed the guidance-selected VHI (GS-VHI). To validate the proposed method, SoO and MI enhancement were evaluated and compared under pure MI, action observation (AO), and GS-VHI conditions. In participants with multiple feasible VHI paradigms, the paradigm associated with stronger GSR-based SoO also elicited greater MI-related event-related desynchronization (ERD). GS-VHI outperformed conventional conditions in both SoO and MI enhancement, supported by EEG beta attenuation for SoO and by both channel- and source-level ERD analyses for MI. Additional relationship analyses further suggested that ownership-related indices were associated with MI enhancement. These findings highlight the potential of tailoring VHI paradigms using objective neurophysiological markers and support the mechanistic link between SoO and MI modulation. This study serves as a mechanistic feasibility study rather than a clinical efficacy trial.