Sensory Integration for Heading Perception

描述（由申请人提供）：为了在周围环境中导航，我们必须准确地感知我们的自我运动方向（即航向）。头球知觉是感觉统合中的一个有趣问题，它需要神经回路将视觉运动信号（光流）与前庭信号结合起来，也许还需要躯体感觉和本体感觉信号。头球感知的多感官特性可以通过分段体验来体会，这是伴随着大视场视觉运动的强大的自我运动幻觉（例如，在IMAX影院）。虽然光流在视觉和顶叶皮层的处理过程已经得到了很好的研究，但对于视觉和前庭信号如何或在哪里被整合以进行头部感知，我们知之甚少。MSTd和VIP区域似乎是有希望的候选者，因为已知这些区域参与处理光流，并且还发现包含有关头部翻译的前庭信号。该实验采用定制的虚拟现实系统，针对训练后灵长类动物头球感知的神经基础，提出了三个具体目标。目的1检查视觉和前庭线索对MSTd/VIP头球选择性的相对贡献。具体来说，我们测试了神经元的头部活动是否被视觉和前庭线索的一致组合所增强。目标2测试来自视觉和前庭线索的头球信号是否编码在一个共同的参考框架中（以眼睛为中心，以头部为中心，或中间），如果这些不同的感觉信号协同结合以提高头球选择性，这是可以预期的。在Aim #3中，我们通过记录神经元在头部识别任务中的表现，更直接地测试了MSTd和VIP是否有助于头部感知。猴子将单独使用光流、前庭信号或两种信号的一致组合来完成这项任务。这将允许我们测试MSTd/VIP神经元是否可以解释在线索组合下头部灵敏度的提高。这些实验将为MSTd/VIP神经元是否参与头球知觉的感觉整合提供全面的检验。与临床相关的是，阿尔茨海默病的头部知觉可能严重受损，这可能导致空间定向障碍和导航困难。通过帮助阐明参与头球感知的大脑区域，这项工作可能最终有助于针对适当的大脑区域进行新的阿尔茨海默氏症治疗。

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.