Perceptual implications of cochlear implant electrode-neuron interfaces

项目概要/摘要 髋关节植入物是非常成功的神经假体，增强或恢复听力严重 听力受损的成人和儿童。来自环境的声音被转换成电脉冲， 通过电极阵列传送到听觉神经。耳蜗植入物提供重要的光谱和 时间信息给听众。然而，语音感知性能在不同的人之间变化很大。 人工耳蜗植入者，特别是在嘈杂的环境和复杂的刺激。这种可变性存在 即使对于在发育早期（<2岁）接受人工耳蜗植入的儿童也是如此。 最近的证据表明，儿童有更高密度的健康听觉神经元， 通过植入物刺激的目标。听觉发育可塑性也有一个关键期。 这些因素的相互作用和人工耳蜗植入的慢性电刺激并不好 特别是对于早期植入的儿童。尽管成年人和成年人之间存在这些已知的差异， 由于儿童的听觉系统不成熟，人工耳蜗的研究主要集中在成人身上。在成年人中， 用于优化编程策略的有前途的方法包括聚焦由每个 电极来刺激更有限的神经元群体并使不太有效的电极失活。非常 很少有人试图优化专门针对儿童的方案拟订战略， 有证据表明，儿童比成年人更能从集中刺激中受益。此外，当新 方案规划战略得到实施，但关于评估其 有效性 提出了三个目标：1）确定儿童光谱分辨率的潜在机制 和成年人与人工耳蜗植入通过比较周边的生理和行为调谐在整个 寿命; 2）量化儿童和成人在使用时言语感知的短期变化（超过小时） 具有选择性通道去激活的优化编程策略，具有和不具有聚焦刺激; 和3）使用相同的方法量化儿童和成人的言语感知的长期变化（数周内）。 目标2中的优化策略。 这些研究的结果有望促进我们对植入的 听觉系统的发展，人工耳蜗植入应该如何编程，以最好地提供频谱挑战 信号，以及适应方案拟订战略变化的时间进程。这些发现可能 指导临床决策，确定何时进行程控调整， 以及患者在调整后需要多长时间才能达到最佳表现。结果从这些 研究最终可能会改善儿童和成人人工耳蜗植入的功能结果。

Project Summary/Abstract Cochlear implants are highly successful neural prostheses that enhance or restore audition to severely hearing-impaired adults and children. Sound from the environment is converted into electrical pulses and conveyed to the auditory nerve by an array of electrodes. The cochlear implant provides important spectral and temporal information to the listener. However, speech perception performance varies considerably among cochlear implant listeners, particularly in noisy environments and for complex stimuli. This variability exists even for children who receive their cochlear implants early in development (<2 years old). Recent evidence suggests that children have a higher density of healthy auditory neurons, which are the target of stimulation through an implant. There is also a critical period for auditory developmental plasticity. The interaction of these factors and the chronic electrical stimulation of a cochlear implant are not well understood, especially for early-implanted children. Despite these known differences between adults and the immature auditory systems of children, cochlear implant research has focused on adults. In adults, the most promising methods for optimizing programming strategies include focusing the electrical field emitted by each electrode to stimulate a more restricted population of neurons and deactivating less effective electrodes. Very few attempts have been made to optimize programming strategies specifically for children, and recent evidence suggests children would benefit more than adults from focused stimulation. Moreover, when new programming strategies are implemented, there is limited data about the timecourse needed to assess their effectiveness. Three aims are proposed: 1) Determine the underlying mechanisms for spectral resolution in children and adults with cochlear implants by comparing peripheral physiological and behavioral tuning across the lifespan; 2) Quantify short-term changes (over hours) in speech perception in children and adults when using optimized programming strategies with selective channel deactivation with and without focused stimulation; and 3) Quantify long-term changes (over weeks) in speech perception in children and adults using the same optimized strategies as in Aim 2. The results of the proposed studies are expected to advance our understanding of how the implanted auditory system develops, how cochlear implants should be programmed to best deliver spectrally challenging signals, and the timecourse of acclimatization to changes in programming strategies. These findings could guide clinical decision making about when to make programming adjustments, what types of adjustments to make, and how long patients need to reach peak performance following adjustments. The results from these studies could ultimately lead to improved functional outcomes for children and adults with cochlear implants.