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.

人工耳蜗植入物的一个趋势是使用更快的每通道脉冲载波率，这是在信息容量增加的基础上推广的。然而，目前还不清楚，在大多数或患病的个人中，较高的比率是否能实现这一目标。临床研究呈现出喜忧参半的结果，而促进高(例如，5000 PPS)比率的研究提出了重要的问题。例如，虽然在许多听神经纤维中已经报道了有益的、去同步化的影响，但类似的数字变得适应了无反应的点。此外，生理性DALA只能从完整的纤维中获得，而不是从慢性聋耳典型的退化神经元中获得。最后，虽然关于神经对声音刺激的适应了解很多，但相对来说 人们对电适应知之甚少，尽管后者通常会产生更大的功能变化。我们假设，在较高频率携带者的表现中，至少部分差异是由于不同用户对高频率刺激的听神经反应的差异。 这项研究计划试图填补我们在听神经如何编码以调制脉冲序列形式呈现的信息方面的知识空白。提出了三个目标。AIM 1将评估由调制载波以与现代和拟议的语音处理器相关的速率激励的光纤中的信号编码。数据将从完整和退化的神经中收集，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状态联系起来。Aim 2将使用这些数据来帮助开发神经的计算模型，该模型可以解释许多纤维特性(例如，整合、不稳定和适应)。这个模型将被用来预测电诱发复合动作电位(EC‘AP)，这样我们就可以测试ECAP测量评估纤维功能的能力，这是一个与临床相关的问题。 最后，目标3将探索将特定变换应用于调制序列的可行性，以补偿限制调制脉冲序列携带的信息的适应和顽固效应。我们希望这项工作的结果将指导未来的人工耳蜗式语音处理器的设计，以便调制刺激可以更好地适应用户听神经的编码能力。