Subcortical neural generators of the envelope-following response in sleeping children: A transfer function analysis
Subcortical neural generators of the envelope-following response in sleeping children: A transfer function analysis
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DOI：
10.1016/j.heares.2020.108157
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发表时间：
2021-03-01
期刊：
影响因子：
2.8
通讯作者：
Deltenre, Paul
中科院分区：
文献类型：
--
作者：
Lucchetti, Federico;Nonclercq, Antoine;Deltenre, Paul
从耳蜗到皮层的多种听觉结构，锁相到复杂刺激的包络。这些结构对人体表面记录的包络跟随响应（EFR）的相对贡献仍不确定。主动贡献者的识别由于以下事实而变得复杂：即使是针对其(f(2) - f(1))包络的最简单的双音(f(1)和f(2))刺激，也会引起额外的线性(f(1)和f(2))和非线性(2f(1) - f(2))锁相分量以及瞬态听觉脑干反应(ABR)。在这里，我们利用广义主音相位变化方法来隔离时域中的每个可预测分量，从而允许直接测量起始延迟、持续时间和相位不连续值，并从中推断出所涉及的发生器。针对多个包络频率 (0.22-1 kHz)，我们沿垂直顶点到颈部和水平耳垂到耳垂记录通道推导了 EFR 传递函数，分别产生 EFR-V 和 EFR-H 波形。受试者（N = 30）是具有正常电生理阈值和正常耳声发射的睡眠儿童。 EFR-H 和 EFR-V 锁相值 (PLV) 传递函数均具有低通曲线，EFR-V 的截止频率低于 EFR-H。我们还计算了两种 EFR 起始延迟的频率-延迟关系。 EFR-H 数据符合幂律函数，其中包含频率相关的行波延迟和总计 1.2 ms 的固定延迟。拟合函数很好地落在已发表的 ABR 波 I 潜伏期频率函数的五个估计范围内，从而指向耳蜗神经起源。不存在相位不连续性并且总体响应持续时间等于刺激的持续时间表明后来的发生器没有贡献。在一名患有严重脑干脑炎的患者中记录了完全相似的 EFR-H 反应，该患者具有正常、孤立的 ABR 波 I，但完全没有后续波，进一步证实了耳蜗神经起源。 EFR-V 潜伏期频率函数的建模表明，相对于 EFR-H 起始，固定传输时间为 2 ms，表明耳蜗核 (CN) 起源，此处也没有指示多个发生器。指向 CN 的 EFR-V 响应的其他特征是，至少对于低于传递函数截止值的 EFR 频率，更高的 PLV 以及增加的谐波失真。这种行为已经在所谓的高度同步的腹侧耳蜗核（VCN）神经元中得到了描述。本研究令人信服地证明了在时域中隔离 EFR 的优势，以便提取详细的光谱-时间参数，这些参数与正交记录通道相结合，为所涉及的神经发生器提供了新的线索。 (C) 2020 Elsevier B.V. 保留所有权利。
Multiple auditory structures, from cochlea to cortex, phase-lock to the envelope of complex stimuli. The relative contributions of these structures to the human surface-recorded envelope-following response (EFR) are still uncertain. Identification of the active contributor(s) is complicated by the fact that even the simplest two tone (f(1 )& f(2)) stimulus, targeting its (f(2) - f(1)) envelope, evokes additional linear (f(1) & f(2)) and non-linear (2f(1) - f(2)) phase-locked components as well as a transient auditory brainstem response (ABR). Here, we took advantage of the generalized primary tone phase variation method to isolate each predictable component in the time domain, allowing direct measurements of onset latency, duration and phase discontinuity values from which the involved generators were inferred. Targeting several envelope frequencies (0.22-1 kHz), we derived the EFR transfer functions along a vertical vertex-to-neck and a horizontal earlobe-to-earlobe recording channels, yielding respectively EFR-V and EFR-H waveforms. Subjects (N= 30) were sleeping children with normal electrophysiological thresholds and normal oto-acoustic emissions. Both EFR-H and EFR-V phase-locking values (PLV) transfer functions had a low-pass profile, EFR-V showing a lower cut-off frequency than EFR-H. We also computed the frequency-latency relationships of both EFRs onset latencies. EFR-H data fitted a power-law function incorporating a frequencydependent traveling wave delay and a fixed one amounting to 1.2 ms. The fitted function nicely fell within five published estimations of the latency-frequency function of the ABR wave-I, thus pointing to a cochlear nerve origin. The absence of phase discontinuity and overall response durations that were equal to that of the stimulus indicated no contribution from a later generator. The recording of an entirely similar EFR-H response in a patient who had severe brainstem encephalitis with a normal, isolated, ABR wave-I but complete absence of later waves, further substantiated a cochlear nerve origin. Modeling of the EFR-V latency-frequency functions indicated a fixed transport time of 2 ms with respect to EFR-H onset, suggesting a cochlear nucleus (CN) origin, here also, without indication for multiple generators. Other features of the EFR-V response pointing to the CN were, at least for the EFR frequency below the cut-off values of the transfer functions, higher PLVs coupled with increased harmonic distortion. Such a behavior has been described in the so-called highly-synchronized neurons of the ventral cochlear nucleus (VCN). The present study compellingly demonstrated the advantage of isolating the EFR in the temporal domain so as to extract detailed spectro-temporal parameters that, combined with orthogonal recording channels, shed new light on the involved neural generators. (C) 2020 Elsevier B.V. All rights reserved.