CI Neural Mechanisms

项目总结/摘要 直接刺激听觉神经（AN）的耳蜗植入物（CI）被广泛认为是最有效的方法。 成功神经修复装置然而，CI患者不能像人一样理解语言 听力正常的患者，并且仍然存在未满足的临床需求，以改善已建立的CI用户的性能。 通过改变每个电极上的刺激参数（“编程”），为每个收听者调整CI; 然而，自从CI首次被批准以来，编程技术在很大程度上保持不变， 1984年FDA。研究表明1）AN纤维的估计密度影响语音识别 CI用户的结果，2）可以在CI用户的每个电极部位处估计AN密度，以及3）语音 当刺激具有更高AN密度的电极部位时，一些CI用户的识别得到改善。虽然这些 研究表明，语音识别似乎至少在某种程度上依赖于AN的能力， 精确地编码信号，在听觉皮层水平上的信息编码也很重要， 充分的言语理解。目前的研究将确定AN密度在精确编码中的作用， “定时”（时间）信息，并量化具有较高AN密度的刺激电极 影响听觉皮层对时间信息的编码。我们假设用户将 当使用具有更高AN的刺激电极的CI程序时， 密度，但这些改善将与更精确的编码时间内的线索 听觉皮层

PROJECT SUMMARY/ABSTRACT Cochlear implants (CIs), which directly stimulate the auditory nerve (AN), are widely considered to be the most successful neuroprosthetic device. However, patients with CIs do not understand speech as well as people with normal hearing, and there remains an unmet clinical need to improve performance in established CI users. CIs are adjusted for each listener by varying the stimulus parameters on each electrode (“programming”); however, programming techniques have largely remained unchanged since CIs were first approved by the FDA in 1984. Studies have shown that 1) the estimated density of AN fibers affects speech recognition outcomes in CI users, 2) AN density can be estimated at each electrode site in CI users, and 3) speech recognition improves for some CI users when stimulating electrode sites with higher AN density. While these studies show that speech recognition seems to be at least somewhat dependent on the ability of AN to precisely code the signal, encoding of information at the level of the auditory cortex is also important for adequate speech understanding. The present studies will define the role of AN density in the precise coding of “timing” (temporal) information and quantify the extent to which stimulating electrodes with higher AN density affects encoding of temporal information at the level of the auditory cortex. We hypothesize that users will show improved speech understanding when using a CI program that stimulates electrodes with higher AN density, but these improvements will be associated with more precise encoding of temporal cues within the auditory cortex.