Auditory nerve responses to electric pulse trains

听觉神经对电脉冲序列的反应

• 批准号: 7112401
• 负责人: CHARLES A MILLER
• 金额: $ 44.89万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7112401
• 关键词: acoustic nerve; action potentials; auditory stimulus; behavioral /social science research tag; cats; cochlear implants; electrophysiology; electrostimulus; mathematical model; medical implant science; neural degeneration; neural information processing; neurophysiology; sensory signal detection; sound perception; speech recognition

A trend in cochlear implants is the use of faster per-channel pulse carrier rates, promoted on the basis of increased information capacity. However, it is not clear that higher rates achieve this goal in most or ill individuals. Clinical studies present mixed results and research promoting high (e.g., 5000 pps) rales raises important questions. For example, while beneficial, desynchronizing, effects have been reported in many auditory nerve fibers, comparable numbers become adapted to the point of being unresponsive. Furthermore, physiologic dala have only been obtained from intact fibers, not from degenerated neurons typical of chronically deaf ears. Finally, while much is known about neural adaptation to acoustic stimuli, relatively little is known about electrical adaptation, even though the latter typically produces much larger functional changes. We hypothesize that at least part of the variability in performance with higher-rate carriers is due to across-user differences in the auditory nerve's response to high-rate stimuli. This research plan seeks to fill these gaps in our knowledge of how the auditory nerve encodes information presented as modulated pulse trains. Three Aims are proposed. Aim 1 will assess signal encoding in fibers excited by modulated carriers at rates relevant to modern and proposed speech processors. Data will be collected from intact and degenerated nerves for greater applicability to clinical cases. Fiber tracing techniques will help link physiology with anatomical status. Aim 2 will use that data to help develop a computational model of the nerve that accounts for many fiber properties (e.g., integration, refractoriness, and adaptation). This model wsll be used to predict the electrically evoked compound action potential (EC'AP) so that we can tesi: the capacity of ECAP measures to assess fiber functionality, a clinically relevant issue. Finally, Aim 3 will explore the feasibility of applying specific transforms to modulated trains to compensate for adaptation and refractory effects that limit information carried by modulated pulse trains. We expect the results of this work will guide future designs of cochlear-implant speech processors so that modulated stimuli can be better tailored to the encoding capacity of the user's auditory nerve.

人工耳蜗植入物的趋势是使用更快的每通道脉冲载体速率，并根据信息能力的增加而促进。但是，尚不清楚较高的利率在大多数人或生病的人中实现了这一目标。临床研究表现出混合的结果和促进高（例如5000 pps）的研究提出了重要的问题。例如，虽然在许多听觉神经纤维中报道了有益的，干燥的效果，但可比较的数字已适应不反应的点。此外，只有从完整的纤维中获得的生理dala，而不是从典型的慢性耳朵耳朵的神经元中获得的。最后，尽管对神经适应声刺激知之甚少，但相对 即使后者通常会产生更大的功能变化，但对电气适应性知之甚少。我们假设至少有一部分具有高速载体性能变异性是由于听觉神经对高速刺激的反应的跨用户差异。 该研究计划旨在填补这些空白，了解听觉神经如何编码作为调制脉冲火车提供的信息。提出了三个目标。 AIM 1将评估与现代和拟议语音处理器相关的调制载体激发的纤维中编码的信号。数据将从完整和退化神经中收集，以使对临床病例的适用性更大。纤维追踪技术将有助于将生理学与解剖状态联系起来。 AIM 2将使用该数据来帮助开发一个占多个纤维特性的神经的计算模型（例如，集成，耐火和适应）。该模型WS将用于预测电诱发的复合动作电位（EC'AP），以便我们可以：ECAP测量的能力评估纤维功能，这是临床上相关的问题。 最后，AIM 3将探索将特定变换应用于调制列车的可行性，以补偿适应性和难治效应，以限制由调制脉冲列车携带的信息。我们希望这项工作的结果将指导人工耳蜗语音处理器的未来设计，以便可以更好地根据用户听觉神经的编码能力量身定制刺激。