Schäfer Eusebia, Vedoveli Ana-Elena, Righetti Giulia, Gamerdinger Philipp, Knipper Marlies, Tropitzsch Anke, Karnath Hans-Otto, Braun Christoph, Li Hegner Yiwen
MEG Center, University of Tübingen, Tübingen, Germany.
Department of Otolaryngology, Head and Neck Surgery, Tübingen Hearing Research Centre, University of Tübingen, Tübingen, Germany.
Front Neurosci. 2021 Mar 12;15:613101. doi: 10.3389/fnins.2021.613101. eCollection 2021.
Spatial hearing is critical for us not only to orient ourselves in space, but also to follow a conversation with multiple speakers involved in a complex sound environment. The hearing ability of people who suffered from severe sensorineural hearing loss can be restored by cochlear implants (CIs), however, with a large outcome variability. Yet, the causes of the CI performance variability remain incompletely understood. Despite the CI-based restoration of the peripheral auditory input, central auditory processing might still not function fully. Here we developed a multi-modal repetition suppression (MMRS) paradigm that is capable of capturing stimulus property-specific processing, in order to identify the neural correlates of spatial hearing and potential central neural indexes useful for the rehabilitation of sound localization in CI users. To this end, 17 normal hearing and 13 CI participants underwent the MMRS task while their brain activity was recorded with a 256-channel electroencephalography (EEG). The participants were required to discriminate between the probe sound location coming from a horizontal array of loudspeakers. The EEG MMRS response following the probe sound was elicited at various brain regions and at different stages of processing. Interestingly, the more similar this differential MMRS response in the right temporo-parieto-occipital (TPO) junction in CI users was to the normal hearing group, the better was the spatial hearing performance in individual CI users. Based on this finding, we suggest that the differential MMRS response at the right TPO junction could serve as a central neural index for intact or impaired sound localization abilities.
空间听觉对我们至关重要，它不仅能帮助我们在空间中定位自己，还能让我们在复杂的声音环境中跟上多个说话者的对话。患有严重感音神经性听力损失的人的听力可以通过人工耳蜗（CI）恢复，然而，结果差异很大。然而，人工耳蜗性能差异的原因仍未完全了解。尽管基于人工耳蜗恢复了外周听觉输入，但中枢听觉处理可能仍未完全发挥作用。在这里，我们开发了一种多模态重复抑制（MMRS）范式，该范式能够捕捉特定于刺激属性的处理过程，以识别空间听觉的神经关联以及对人工耳蜗使用者声音定位康复有用的潜在中枢神经指标。为此，17名听力正常的参与者和13名人工耳蜗使用者在进行MMRS任务时，用256通道脑电图（EEG）记录他们的大脑活动。参与者被要求区分来自水平排列扬声器阵列的探测声音的位置。探测声音后的脑电图MMRS反应在不同的脑区和处理的不同阶段被诱发。有趣的是，人工耳蜗使用者右侧颞顶枕（TPO）交界处的这种差异MMRS反应与听力正常组越相似，个体人工耳蜗使用者的空间听觉表现就越好。基于这一发现，我们认为右侧TPO交界处的差异MMRS反应可以作为完整或受损声音定位能力的中枢神经指标。
