A State-Feedback Neurodynamic Model of Echolocation in Blind Humans

项目摘要 对于全世界4000万盲人来说，日常活动，如导航房间，识别 建造或赶上公共汽车是一个重大挑战，特别是在不熟悉的地区。一些盲人 通过积极的回声定位来增强他们的感知能力，用他们的声音产生一种“点击”的声音。 舌头来感知物体和编码在返回的回波中的空间数据。回声定位是一种有用的 为盲人提供知觉和移动辅助设备，以及研究基本神经和 知觉机制然而，它仍然不完全理解，研究不足，因此很少教， 使大多数未受过训练的盲人或视力受损者无法使用。 这项研究的目的是描述主动回声定位的神经动力学特征。这是一个 独特的感知方式，持续激活盲人的各种枕“视觉”皮层区域， 回声定位器，但大脑活动的动力学，以及它与活跃的点击生产的关系， 明白在这里，我们建议利用脑磁图的细粒度时间分辨率 (MEG)跟踪回声定位处理的动态，并确定角色和处理电路， 主动回声定位信号我们将招募盲人和有视力的参与者，并在他们听的时候记录MEG。 回声刺激并主动声穿透扫描仪中的虚拟反射对象。我们将利用这些数据提出一个 回声定位模型，包括主动点击生产，回声的感官反馈， 与行为目标的相关性。这些结果将为主动感知理论提供信息，目前还缺乏很好的方法。 听觉中的定义模型;失明中的神经可塑性，这低估了时间动态;以及 最后是定向和移动训练，缺乏证据来激励基于回声定位的干预。 在方法上，在执行拟议的工作，我们将开拓时间解决神经科学的， 回声定位，扩大应用的伪影减少算法，并介绍了一个新的框架， 研究听觉感觉-运动耦合模式。

PROJECT SUMMARY For the 40 million people worldwide who are blind, everyday activities like navigating a room, identifying a building, or catching a bus present major challenges, especially in unfamiliar areas. Some blind individuals augment their perception to a remarkable degree via active echolocation, producing a “click” sound with their tongues to perceive the object and spatial data encoded in the returning echoes. Echolocation is a useful perceptual and mobility aid for blind persons and a unique scientific model to studying fundamental neural and perceptual mechanisms. Yet it remains incompletely understood, understudied, and thus rarely taught, rendering it inaccessible to the majority of untrained people who are blind or visually impaired. The goal of the proposed research is to characterize the neural dynamics underlying active echolocation. It is a unique sensing modality that consistently activates various occipital “visual” cortical regions in blind echolocators, but the dynamics of that brain activity, and its relationship to active click production, is poorly understood. Here we propose to leverage the fine-grained temporal resolution of magnetoencephalography (MEG) to trace the dynamics of echolocation processing and to determine the roles and processing circuits for active echolocation signals. We will recruit blind and sighted participants and record MEG as they listen to echo stimuli and actively ensonify virtual reflecting objects in the scanner. We will use these data to propose a model of echolocation incorporating the active click production, sensory feedback from the echoes, and relevance to a behavioral goal. The results will inform theories of active perception, which currently lack well defined models in audition; neuroplasticity in blindness, which underrepresents temporal dynamics; and eventually orientation and mobility training, which lacks evidence to motivate echolocation-based interventions. Methodologically, in performing the proposed work, we will pioneer temporally resolved neuroscience of echolocation, expand the application of artifact-reduction algorithms, and introduce a novel framework for studying auditory sensory-motor coupling paradigms.