Sensory Integration for Heading Perception

描述(申请人提供)：为了在我们周围的环境中导航，我们必须准确地感知我们的自我运动方向(即航向)。航向知觉是感觉整合中一个有趣的问题，需要神经回路将视觉运动信号(光流)与前庭信号结合起来，或许还需要躯体感觉和本体感觉线索。航向感知的多感官本质可以通过切面体验来欣赏，这是伴随着大视场视觉运动的强大的自我运动错觉(例如，在IMAX影院)。虽然视觉和顶叶皮质对光流的处理已经有了很好的研究，但关于视觉和前庭信号如何或在哪里整合以实现航向知觉的研究还很少。MSTd区和VIP区似乎是很有希望的候选区域，因为已知这些区域参与处理视流，也被发现包含与头部平移有关的前庭信号。这项拟议的实验采用了定制设计的虚拟现实系统，解决了关于训练过的灵长类动物头部感知的神经基础的三个具体目标。目的#1研究视觉线索和前庭线索对MSTd/VIP的标题选择性的相对贡献。具体地说，我们测试了视觉和前庭线索的一致组合是否增强了神经元的标题活动。目标2测试从视觉和前庭线索获得的航向信号是否在共同的参考系(以眼睛为中心、以头部为中心或中间)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，则可能是预期的。在目标3中，我们更直接地测试了MSTd和VIP是否通过在执行标题辨别任务时从神经元记录来促进标题知觉。猴子将单独使用视流、前庭信号或两种信号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方向敏感性的改善。这些实验将对MSTd/VIP神经元是否参与航向知觉的感觉整合提供一个全面的检验。与临床相关的是，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。通过帮助阐明与头部知觉相关的大脑区域，这项工作最终可能有助于将新的阿尔茨海默氏症疗法定位于适当的大脑区域。

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.