Auditory nerve responses to electric pulse trains

听觉神经对电脉冲序列的反应

• 批准号: 6983088
• 负责人: CHARLES A MILLER
• 金额: $ 37.68万
• 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/6983088
• 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.

耳蜗植入的一个趋势是使用更快的每通道脉冲载波速率，这是在增加信息容量的基础上促进的。然而，尚不清楚在大多数或患病个体中更高的比率是否实现了这一目标。临床研究提出了混合的结果和研究促进高（例如，5000 pps）罗音提出了重要的问题。例如，虽然在许多听觉神经纤维中已经报道了有益的、去刺激的效果，但相当数量的听觉神经纤维变得适应于无反应的程度。此外，生理性耳聋只能从完整的纤维中获得，而不能从慢性耳聋典型的退化神经元中获得。最后，虽然我们对听觉刺激的神经适应性有很多了解， 尽管电适应通常会产生更大的功能变化，但人们对电适应知之甚少。我们假设，至少有一部分的变异性能与高速率运营商是由于跨用户的差异，在听觉神经的反应，高速率的刺激。 这项研究计划旨在填补我们对听觉神经如何编码调制脉冲串信息的知识空白。提出了三个目标。目标1将评估调制载波激励的光纤中的信号编码，其速率与现代和拟议的语音处理器相关。将从完整和退化的神经中收集数据，以便更好地适用于临床病例。纤维追踪技术将有助于将生理学与解剖学状态联系起来。目标2将使用这些数据来帮助开发神经的计算模型，该模型考虑了许多纤维特性（例如，整合、不应性和适应性）。该模型可用于预测电诱发复合动作电位（EC'AP），以检验ECAP测量评估纤维功能的能力，这是一个临床相关问题。 最后，目标3将探讨将特定变换应用于调制脉冲串以补偿限制调制脉冲串所携带信息的适应和不应效应的可行性。我们希望这项工作的结果将指导未来的耳蜗植入语音处理器的设计，使调制的刺激可以更好地适应用户的听觉神经的编码能力。