The vestibular system and the encoding of self-motion: from basic science to clinical applications

The vestibular system plays a fundamental role in stabilizing gaze, maintaining balance, and providing spatial orientation by encoding head motion in all 6 degrees of freedom. At the earliest stages of central processing, it integrates multimodal signals from proprioceptive, oculomotor, and predictive pathways, allowing for dynamic motor control and adaptive compensation for sensory deficits. This review examines the neural coding strategies underlying vestibular processing, with a focus on how the vestibular system encodes self-motion and contributes to multisensory integration and motor control. While traditional linear models have provided valuable insights into afferent response properties, these neural pathways encode head motion in a context-dependent manner, such that vestibular reflex pathways are suppressed during active behaviors. The vestibulocerebellum plays a crucial role in modulating vestibular reflexes through predictive mechanisms and experience-dependent plasticity, enabling accurate motor control as well as adaptation following vestibular injury or dysfunction. Beyond reflexive control, vestibular pathways also contribute to higher-order voluntary behaviors such as reaching, steering, and spatial navigation, integrating with cognitive and motor systems. Finally, this review explores the clinical implications of vestibular dysfunction in aging and neurodegenerative diseases, along with emerging vestibular prostheses that leverage neuroengineering advances to restore lost function. These innovations hold great promise for improving sensory encoding and rehabilitation strategies, offering new hope for individuals with balance and spatial orientation impairments.