ExpORL, Department of Neurosciences, Leuven Brain Institute, KU Leuven, Leuven, Belgium.
Cambridge Hearing Group, MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
Sci Rep. 2024 Mar 14;14(1):6158. doi: 10.1038/s41598-024-56047-9.
Electrically evoked frequency-following responses (eFFRs) provide insight in the phase-locking ability of brainstem of cochlear-implant (CI) users. eFFRs can potentially be used to gain insight in the individual differences in the biological limitation on temporal encoding of the electrically stimulated auditory pathway, which can be inherent to the electrical stimulation itself and/or the degenerative processes associated with hearing loss. One of the major challenge of measuring eFFRs in CI users is the process of isolating the stimulation artifact from the neural response, as both the response and the artifact overlap in time and have similar frequency characteristics. Here we introduce a new artifact removal method based on template subtraction that successfully removes the stimulation artifacts from the recordings when CI users are stimulated with pulse trains from 128 to 300 pulses per second in a monopolar configuration. Our results show that, although artifact removal was successful in all CI users, the phase-locking ability of the brainstem to the different pulse rates, as assessed with the eFFR differed substantially across participants. These results show that the eFFR can be measured, free from artifacts, in CI users and that they can be used to gain insight in individual differences in temporal processing of the electrically stimulated auditory pathway.
电诱发频率跟随反应（eFFR）提供了关于人工耳蜗（CI）使用者脑干锁相能力的深入了解。eFFR 可用于深入了解电刺激听觉通路的时间编码的生物学限制的个体差异，这可能是电刺激本身固有的，也可能与听力损失相关的退行性过程有关。在 CI 用户中测量 eFFR 的主要挑战之一是从神经反应中分离刺激伪影的过程，因为反应和伪影在时间上重叠，并且具有相似的频率特征。在这里，我们介绍了一种基于模板相减的新的伪影去除方法，当 CI 用户以单极模式每秒 128 到 300 个脉冲的脉冲串进行刺激时，该方法可成功地从记录中去除刺激伪影。我们的结果表明，尽管在所有 CI 用户中都成功地去除了伪影，但大脑对不同脉冲率的锁相能力，如通过 eFFR 评估的，在参与者之间有很大的差异。这些结果表明，可以在 CI 用户中测量无伪影的 eFFR，并且可以使用它来深入了解电刺激听觉通路的时间处理的个体差异。
