Virtual reality mediated brain-computer interface training improves sensorimotor neuromodulation in unimpaired and post spinal cord injury individuals

Real-time brain-computer interfaces (BCIs) that decode electroencephalograms (EEG) during motor imagery (MI) are a powerful adjunct to rehabilitation therapy after neurotrauma. Immersive virtual reality (VR) could complement BCIs by delivering multisensory feedback congruent to the users MI, enabling therapies that engage users in task-oriented scenarios. Yet, therapeutic outcomes rely on the users proficiency in evoking MI to attain volitional BCI-commanded VR interaction. While previous studies suggested that users could improve BCI-evoked MI within a single session, the effects of multiple training sessions on sensorimotor neuromodulation remain unknown. Here, we present a longitudinal study assessing the impact of VR-mediated BCI training on lower-limb sensorimotor neuromodulation, wherein an EEG-based BCI was coupled with congruent real-time multisensory feedback in immersive VR. We show that unimpaired individuals could learn to modulate their sensorimotor activations during MI virtual walking over multiple training sessions, also resulting in increased BCI control accuracy. Additionally, when extending the system to immersive VR cycling, four individuals with chronic complete spinal cord injury (SCI) showed similar improvements. This is the first study demonstrating that individuals could learn modulating sensorimotor activity associated with MI using BCI integrated with immersive VR over multiple training sessions, even after SCI-induced motor and sensory decline. These results suggest that VR-BCI training may facilitate neuroplasticity, potentially strengthening sensorimotor pathways and functional connectivity relevant to motor control and recovery.