Sensory Integration for Heading Perception

描述（由申请人提供）：为了在我们的周围导航，我们必须准确地感知我们的自我运动方向（即，标题）。头部知觉是感觉整合中一个有趣的问题，需要将联合收割机视觉运动信号（光流）与前庭信号结合起来的神经回路，也许还有体感和本体感受的线索。头部感知的多感官性质可以通过部分的经验来理解，伴随着大视野视觉运动的强大的自我运动错觉（例如，IMAX影院）。虽然在视觉和顶叶皮质中已经对光流的处理进行了很好的研究，但是对于视觉和前庭信号如何或在哪里被整合用于航向感知知之甚少。区域MSTd和VIP似乎是有希望的候选者，因为已知这些区域参与处理光流，并且还发现包含关于头部平移的前庭信号。拟议的实验，采用定制设计的虚拟现实系统，解决了三个具体的目标，在经过训练的灵长类动物的头部知觉的神经基础。目的#1检查视觉和前庭线索的相对贡献，在MSTd/VIP标题选择性。具体来说，我们测试是否领导活动的神经元增强一致的视觉和前庭线索的组合。目标#2测试来自视觉和前庭线索的航向信号是否在共同的参考系（以眼为中心、以头为中心或中间）中编码，如果这些不同的感觉信号协同组合以提高航向选择性，则可以预期。在目标#3中，我们更直接地测试MSTd和VIP是否有助于通过在执行航向辨别任务期间从神经元记录航向感知。猴子将单独使用光流，前庭信号或两种线索的一致组合来执行这项任务。这将使我们能够测试MSTd/VIP神经元是否可以解释线索组合下所见的航向敏感性的改善。这些实验将提供一个全面的检查是否MSTd/VIP神经元参与感觉整合的航向知觉。在临床上，阿尔茨海默病患者的航向知觉可能严重受损，这可能导致空间定向障碍和导航困难。通过帮助阐明与航向感知有关的大脑区域，这项工作最终可能有助于将新的阿尔茨海默氏症疗法瞄准适当的大脑区域。

DESCRIPTION (provided by applicant): To navigate through our surroundings, we must accurately perceive our direction of self-motion (i.e., heading). Heading perception is an interesting problem in sensory integration, requiring neural circuits that combine visual motion signals (optic flow) with vestibular signals, and perhaps also somatosensory and proprioceptive cues. The multi-sensory nature of heading perception can be appreciated by the experience of section, the powerful illusion of self-motion that accompanies large-field visual motion (e.g., at an IMAX theater). Although the processing of optic flow has been well studied in visual and parietal cortices, little is known about how or where visual and vestibular signals are integrated for heading perception. Areas MSTd and VIP appear to be promising candidates, for these areas are known to be involved in processing optic flow and have also been found to contain vestibular signals regarding head translation. The proposed experiment, which employ a custom-designed virtual reality system, address three specific aims regarding the neural basis of heading perception in trained primates. Aim #1 examines the relative contributions of visual and vestibular cues to heading selectivity in MSTd/VIP. Specifically, we test whether the heading activity of neurons is enhanced by congruent combinations of visual and vestibular cues. Aim #2 tests whether heading signals derived from visual and vestibular cues are coded in a common reference frame (eye-centered, head-centered, or intermediate), as might be expected if these different sensory signals, are combined synergistically to improve heading selectivity. In Aim #3, we test more directly whether MSTd and VIP contribute to heading perception by recording from neurons during performance of a heading discrimination task. Monkeys will perform this task using optic flow alone, vestibular signals alone, or congruent combinations of the two cues. This will allow us to test whether MSTd/VIP neurons can account for the improvement in heading sensitivity seen under cue combination. These experiments will provide a comprehensive examination of whether MSTd/VIP neurons are involved in sensory integration for heading perception. Of clinical relevance, heading perception can be severely impaired in Alzheimer's disease, and this may contribute to spatial disorientation and navigational difficulties. By helping to elucidate the brain areas involved in heading perception, this work may eventually aid in targeting new Alzheimer's therapies to the appropriate brain regions.