Perceptual implications of cochlear implant electrode-neuron interfaces

描述(申请人提供)：人工耳蜗是一种非常成功的神经假体，可以增强或恢复严重听力受损的人的听力。然而，不同的人工耳蜗听者的表现差异很大，特别是在嘈杂的环境中，以及对于音乐等频谱复杂的刺激。病理学和影像研究表明，螺旋神经节存活神经元的分布和它们与单个CI电极的距离是表现可变性的两个来源。这项建议使用心理物理测量、计算机断层成像和计算机建模来评估这些因素如何影响单个人工耳蜗通道的功能。这些信息将被应用于对植入处理器进行重新编程，以便将功能不佳的通道的影响降至最低。提出了三个目标：1)确定使用空间聚焦电极配置获得的阈值与频谱分辨率、响度增长和耳蜗内电极位置的单通道测量的相关程度；2)量化具有高阈值的通道对语音刺激识别的贡献；以及3)确定根据目标1估计的电极-神经元接口定制的听者特定映射是否可以改善对复杂听力任务的感知。这些研究的结果有望促进该领域对人工耳蜗植入通道位置和神经存活如何影响单通道和语音感知的理解。这一发现有可能改变临床实践，为患者特定的通道映射提供指导，并最终提高人工耳蜗听者的语音感知能力。

DESCRIPTION (provided by applicant): Cochlear implants are highly successful neural prostheses that enhance or restore hearing to the severely hearing impaired. However, performance varies considerably among cochlear implant listeners, particularly in noisy environments and for spectrally complex stimuli like music. Pathology and imaging studies suggest that two sources of performance variability are the distribution of surviving spiral ganglion neurons and their distance from individual CI electrodes. This proposal uses psychophysical measures, computed tomography imaging, and computer modeling to assess how such factors affect the function of individual cochlear implant channels. That information will be applied to reprogram the implant processor in order to minimize the influence of poorly functioning channels. Three aims are proposed: 1) To determine the degree to which thresholds obtained using a spatially focused electrode configuration correlate with single-channel measures of spectral resolution, loudness growth, and electrode position within the cochlea; 2) To quantify the contributions of channels with high thresholds on the discrimination of speech stimuli; and 3) To determine if listener-specific mapping tailored to the estimated electrode-neuron interface from Aim 1 can improve perception on complex listening tasks. The results of these studies are expected to advance the field's understanding of how cochlear implant channel position and neural survival affect single-channel and speech perception. The findings have the potential to shift clinical practice by providing a guide for patient-specific channel mapping and ultimately lead to improved speech perception abilities in cochlear implant listeners.