Probing the Electrode-Neuron Interface With Focused Cochlear Implant Stimulation
Probing the Electrode-Neuron Interface With Focused Cochlear Implant Stimulation
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DOI：
10.1177/1084713810375249
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发表时间：
2010-06-01
影响因子：
--
通讯作者：
Bierer, Julie Arenberg
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文献类型：
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作者：
Bierer, Julie Arenberg
人工耳蜗是一种非常成功的神经假体，适用于严重或严重听力损失的人，他们从助听器放大中获益很少。尽管植入物能够为言语感知提供重要的光谱和时间线索，但言语测试的表现因听者而异。从单个植入对象获得的心理物理测量在不同的植入渠道中也可能有很大的差异。这篇综述讨论了这样的变异性反映了电极-神经元界面的偏差的证据，这指的是植入通道有效刺激听神经的能力。有人认为，聚焦电刺激非常适合于评估电极-神经元界面上的通道间不规则性。在植入听者中，用三极构型测量的相对高阈值的通道比相对低阈值的通道表现出更宽的心理物理调谐曲线和更小的动态范围。更广泛的调谐意味着，针对耳蜗中一组神经元的特定频率信息可能会激活更远的神经元，而压缩的动态范围可能会使基于强度的信息更难解析，特别是在存在竞争噪声的情况下。这两种线索的退化都会对言语感知产生负面影响。
Cochlear implants are highly successful neural prostheses for persons with severe or profound hearing loss who gain little benefit from hearing aid amplification. Although implants are capable of providing important spectral and temporal cues for speech perception, performance on speech tests is variable across listeners. Psychophysical measures obtained from individual implant subjects can also be highly variable across implant channels. This review discusses evidence that such variability reflects deviations in the electrode-neuron interface, which refers to an implant channel's ability to effectively stimulate the auditory nerve. It is proposed that focused electrical stimulation is ideally suited to assess channel-to-channel irregularities in the electrode-neuron interface. In implant listeners, it is demonstrated that channels with relatively high thresholds, as measured with the tripolar configuration, exhibit broader psychophysical tuning curves and smaller dynamic ranges than channels with relatively low thresholds. Broader tuning implies that frequency-specific information intended for one population of neurons in the cochlea may activate more distant neurons, and a compressed dynamic range could make it more difficult to resolve intensity-based information, particularly in the presence of competing noise. Degradation of both types of cues would negatively affect speech perception.