Cortical processing of frequency changes in cochlear implant users

人工耳蜗植入术的主要挑战之一是脑梗塞患者言语知觉的大变异性。 性能。目前还没有可以在临床上用于预测言语结果的客观方法 不能可靠地执行需要行为反应的测试的CI用户。此外，缺乏 对CI结果的巨大变异性的理解是个性化康复的障碍。我们的长期合作 目的是了解CI言语结果的变异性的神经关联，并探索这些 神经反应可作为评估和预测脑梗塞预后的客观指标。之前的研究已经 显示了使用心理物理方法检测声音频率变化的能力是 与CI用户的语音结果高度相关。事实上，检测频率变化的能力可能会发挥作用 在与音调相关的任务中发挥重要作用，这些任务通常会对CI用户构成挑战，例如 在嘈杂环境中的语音感知。声学改变复合体(ACC)是一种皮层产生的 由声刺激的频率、幅度等的变化所引起的听觉诱发反应。 记录ACC不需要个体做出任何行为反应。本R15中的目标 该项目旨在检查ACC在CI成人用户中的预测价值。在这个项目中，我们将确定 听觉诱发电位与频率变化检测和语音行为表现的相关性 当刺激呈现时没有背景噪声(目标1)和有背景噪声时的知觉 (目标2)。成人CI用户和正常听力(NH)控制人员将拥有语音识别功能 评估他们的能力，并在他们进行 识别包含频率变化的刺激的心理声学任务。ACC测量(峰值幅度， 潜伏期和大脑激活模式)将与频率变化的行为测量进行比较 检测和语音结果。中心假设是，ACC的测量结果显著相关 以了解CI用户在频率变化检测和语音识别能力方面的行为表现。这 项目将产生重大影响：1)拟议研究的结果将提供重要的见解 脑梗塞患者言语理解的巨大变异性，2)拟议的研究将有助于识别 可用于客观评估CI益处的电生理测量。这些客观措施是 对于不能可靠地进行行为测试的人来说尤其有价值，3)这项研究可能会导致 未来努力改进CI用户的频率变化的皮质编码，以最大限度地提高CI 福利。

One of the major challenges in cochlear implants (CIs) is the large variability in CI patients’ speech perception performance. There are currently no objective measures that can be used clinically to predict speech outcomes of CI users who cannot reliably perform tests requiring behavioral responses. Moreover, the lack of understanding of the large variability on CI outcomes is a barrier to customized rehabilitation. Our long-term goal is to understand the neural correlates of the variability in CI speech outcomes and to explore if these neural responses can serve as objective measures to assess and predict CI outcomes. Previous studies have shown that the capability to detect frequency changes of sound measured using psychophysical methods is highly correlated with speech outcomes in CI users. In fact, the ability to detect frequency changes may play an important role in the performance on pitch-related tasks that typically challenging for CI users such as speech perception in noisy environments. The acoustic change complex (ACC) is a type of cortically-generated auditory evoked response evoked by the change in the frequency, amplitude etc. of an acoustic stimulus. Recording the ACC does not require any behavioral response from an individual. The objective in this R15 project is to examine the predictive value of the ACC in CI adult users. In this project, we will determine the correlation between the ACC and behavioral performance of frequency change detection and speech perception when the stimuli are presented without a background noise (Aim 1) and with a background noise (Aim 2), respectively. Adult CI users and normal hearing (NH) controls will have their speech recognition abilities assessed and they will undergo electroencephalographic recordings while they perform the psychoacoustic task of identifying stimuli containing frequency changes. The ACC measures (peak amplitude, latency, and brain activation patterns) will be compared with the behavioral measures of frequency change detection and speech outcomes. The central hypothesis is that the ACC measures are significantly correlated to CI users’ behavioral performance in frequency change detection and speech recognition abilities. This project will have significant implications: 1) the results from the proposed study will provide important insights into the large variability in CI patients’ speech understanding, 2) the proposed research will help to identify electrophysiological measures that can be used to objectively assess CI benefits. Such objective measures are especially valuable for individuals who cannot reliably perform behavioral tests, and 3) this research may lead to future efforts toward improving the cortical encoding of frequency changes in CI users to maximize CI benefits.