Assessing Neurophysiological States Through the BioVRsea Paradigm

Abstract

Introduction: Postural control is a complex sensorimotor function that de- pends on the integration of visual, vestibular, somatosensory, muscular, and cortical mechanisms. Impairments in this system are particularly relevant in Parkinson’s disease, where postural instability may emerge even in the early stages and contribute to reduced mobility, impaired adaptation, and increased fall risk. This doctoral thesis investigates postural control through the BioVRSea paradigm, an immersive virtual-reality and moving-platform protocol designed to elicit controlled sensory conflict while simultaneously recording neurophysiological and biomechanical responses. Results: The BioVRSea paradigm revealed distinct postural-control profiles across populations and experimental phases. In Parkinson’s disease, CoP results indicated a more constrained sway pattern, particularly after perturbation, suggesting reduced postural flexibility rather than improved stability. EMG findings showed muscle-specific alterations, with the gastrocnemius lateralis, tibialis anterior, and soleus contributing differently to postural regulation. EEG analyses revealed frequency-specific reorganization of brain dynamics, with alterations in alpha-band connectivity and distinct delta, theta, and beta Brain Network State patterns. These changes suggest that Parkinson’s disease affects both peripheral neuromuscular strategies and large-scale cortical network organization during postural control. In seafarers, BioVRSea further highlighted habituation and adaptation mechanisms related to repeated exposure to unstable environments. Conclusion: This thesis demonstrates that BioVRSea is a sensitive multimodal framework for investigating postural control under controlled sensory-conflict conditions. By integrating EEG, EMG, and CoP, the paradigm captures complementary aspects of balance regulation, from cortical network dynamics to muscular activation and sway behavior. The findings support the potential of BioVRSea as an advanced assessment tool for detecting altered postural strategies in Parkinson’s disease and for studying adaptive mechanisms in healthy and occupationally exposed populations.