Multisensory Pathways and Plasticity Following Partial and Full Vision Loss

项目摘要 已知视觉皮层会改变其功能图和与其他皮层区域的连接， 部分或全部视力丧失，包括其他感官（如听觉）的重大再利用。是什么 目前尚不清楚这种跨通道侵入是否会改变多通道通路和多感觉整合， 各种感官。此外，目前还不知道在何种视力丧失条件下（如中央视力丧失）， 视网膜相关黄斑变性、色素性视网膜炎引起的周边视力丧失或 多种原因）促进（或抑制）多感觉整合，以及这些变化是否会改变 视网膜定位。这些知识对于发展一个更完整的多感觉理论模型至关重要 整合;更好地评估视力丧失患者的康复潜力;为 开发先进的视网膜假体、感觉辅助设备和感觉替代设备;并开发 视觉恢复后的最佳多感觉训练和康复模式。 为此，我们建议确定的空间和时间特性的记忆视觉（A-V） 低视力患者的整合（具体目标1）。更具体地说，我们将使用一组视觉 视错觉作为一种心理物理学工具来确定各种视网膜位置的A-V整合程度， 与中央凹的偏心度和与视力丧失区域的接近度两者的函数。我们亦建议 检查视力低下和晚期失明患者的视觉处理和跨通道整合的可行性 通过使用视听错觉和心理意象（具体目标2）。我们将确定多感官 在盲后期，来自想象的视觉刺激的整合可以与真实的听觉刺激的整合发生变化 听觉刺激的感知位置，包括水平平面和水平平面上的听觉空间感知， 深入从这两个目标的结果将提供一个评估的关键特征，视觉 盲人和视力低下者的相互作用，并将确定这些多感官相互作用的差异 这是专门针对视力丧失的原因。我们还计划识别这种跨模态的神经相关性， 使用fMRI成像的相互作用和整合（具体目标3）。我们将研究视觉上的关键差异， 皮层活动，以及听觉，视觉和多感觉皮层之间的连接模式， 将低视力和晚期失明的参与者与正常对照组进行比较。 全面了解低视力和晚盲的多感觉处理能力 个人将为人类大脑功能重组的后果提供重要见解， 也将为先进的多感官辅助设备、视觉假体和康复方案铺平道路。

Project Summary The visual cortex is known to change its functional map and connectivity with other cortical regions following partial or full vision loss, including significant repurposing among the other senses such as audition. What is unclear is whether such crossmodal incursion alters the multimodal pathways and multisensory integration of the various senses. Also, it is not yet known under what vision loss conditions (such as central vision loss with Age-Related Macular Degeneration, peripheral vision loss with Retinitis Pigmentosa, or full vision loss due to numerous causes) multisensory integration is facilitated (or suppressed), and whether these changes vary with retinal location. Such knowledge is critical to develop a more complete theoretical model of multisensory integration; to better evaluate potential for rehabilitation in those with vision loss; to provide a solid basis for the development of advanced retinal prostheses, sensory aids, and sensory substitution devices; and to develop optimal multisensory training and rehabilitation paradigms following visual restoration. To this end, we propose to determine the spatial and temporal characteristics of auditory-visual (A-V) integration in individuals with low vision (Specific Aim 1). More specifically, we will use a set of auditory-visual illusions as a psychophysical tool to determine the degree of A-V integration in various retinal locations as a function of both eccentricity from the fovea and proximity to regions of visual loss. We also propose to examine the viability of visual processing and crossmodal integration in those with low vision and the late blind by employing both A-V illusions and mental imagery (Specific Aim 2). We will determine whether multisensory integration from imagined visual stimuli can integrate with real auditory stimuli in the late blind to change the perceived location of auditory stimuli, including auditory spatial perception in the horizontal plane and in depth. The results from these two aims will provide an assessment of the key characteristics of auditory-visual interactions in the blind and those with low vision, and will identify differences in these multisensory interactions that are specific to the cause of vision loss. We also plan to identify the neural correlates of such crossmodal interactions and integrations using fMRI imaging (Specific Aim 3). We will examine key differences in visual cortical activity, as well as the connectivity patterns among auditory, visual, and multisensory cortices, by comparing low vision and late blind participants with sighted controls. A comprehensive understanding of the multisensory processing capabilities of low vision and late blind individuals will provide crucial insights into the consequences of functional reorganization in the human brain, and will also pave the way for advanced multisensory aids, visual prostheses, and rehabilitation protocols.