Investigating mechanisms involved in vestibular substitution

前庭和其他感觉系统（视觉、体感和听觉）之间的相互作用对凝视稳定、姿势控制和身体表征等功能至关重要。当一种感觉被改变时，一种补偿现象允许至少部分地恢复与受损感觉系统相关的功能。前庭补偿是基于几个概念，如恢复，习惯化和适应。适应包括感觉替代，它依赖于使用完整的感觉系统来补偿减少的前庭输入。与前庭系统相关的反射和知觉功能为研究感觉替代提供了一个独特的窗口，因为这些功能大多涉及多感觉输入。尽管一些研究表明，感觉替代对某些个体是有效的，但观察到高度的个体间差异，这破坏了结果的泛化。因此，有必要进一步发展与前庭和其他感觉系统之间相互作用相关的基础知识，以更好地理解这一现象，并最终优化感觉替代。本研究计划的长期目标是揭示非前庭感官对前庭反射和知觉功能的贡献。在接下来的五年里，本项目将致力于在健康和听觉前庭损伤个体中研究控制听觉前庭和体感-前庭相互作用对身体表征的机制。通过观察前庭系统的可塑性程度，研究健康和听觉前庭受损的个体将加深我们对感觉替代机制的认识。为了完成所提出的研究，我们将使用前庭电刺激、生物力学分析（动作捕捉、力平台）、行为和感知方法。该计划的结果不仅将为前庭可塑性机制的研究提供必要的知识，而且还将为开发各种优化感觉替代的技术提供前庭替代的基本概念。

Interactions between the vestibular and other sensory systems (vision, somatosensory and auditory) are crucial to several functions such as gaze stabilization, postural control and body representation. When one of the senses is altered, a phenomenon of compensation allows to recover, at least in part, functions associated with the impaired sensory system. Vestibular compensation is based on several concepts such as restoration, habituation and adaptation. Adaptation comprise sensory substitution which relies on the use of intact sensory systems to compensate the reduced vestibular input. The reflexes and perceptual functions associated with the vestibular system offers a unique window to study sensory substitution as most of these functions involve multisensory input. Although some studies suggest that sensory substitution is effective for some individuals, a high degree of inter-individual variability is observed which yet undermines the generalization of the results. It becomes therefore imperative to further develop fundamental knowledge related to the interactions between the vestibular and other sensory systems to better understand this phenomenon and ultimately optimize sensory substitution. The long-term goal of this research program is to reveal the contribution of non-vestibular senses on vestibular reflexes and perceptual functions. In the next five years, this program will aim at studying the mechanisms governing audio-vestibular and somatosensory-vestibular interactions on body representation in both healthy and audio-vestibular lesioned individuals. Studying both healthy and audio-vestibular impaired individuals will deepen our knowledge of the mechanisms involved in sensory substitution by observing the extent of plasticity in the vestibular system. To complete the proposed set of studies, we will use electrical vestibular stimulation, biomechanical analysis (motion capture, force platform), behavioral and perceptual methods. The results stemming from this proposed program will not only provide essential knowledge required to pursue investigations on mechanisms involved in vestibular plasticity, but will also provide fundamental concepts on vestibular substitution to develop various technologies to optimize sensory substitution.