Ortmann Magdalene, Zwitserlood Pienie, Knief Arne, Baare Johanna, Brinkheetker Stephanie, Am Zehnhoff-Dinnesen Antoinette, Dobel Christian
Institute for Biomagnetism and Biosignalanalysis, Muenster University Hospital, Muenster, Germany.
Jean-Uhrmacher-Institute for Clinical ENT-Research, University of Cologne, Cologne, Germany.
PLoS One. 2017 Jan 5;12(1):e0168655. doi: 10.1371/journal.pone.0168655. eCollection 2017.
Cochlear implants provide individuals who are deaf with access to speech. Although substantial advancements have been made by novel technologies, there still is high variability in language development during childhood, depending on adaptation and neural plasticity. These factors have often been investigated in the auditory domain, with the mismatch negativity as an index for sensory and phonological processing. Several studies have demonstrated that the MMN is an electrophysiological correlate for hearing improvement with cochlear implants. In this study, two groups of cochlear implant users, both with very good basic hearing abilities but with non-overlapping speech performance (very good or very poor speech performance), were matched according to device experience and age at implantation. We tested the perception of phonemes in the context of specific other phonemes from which they were very hard to discriminate (e.g., the vowels in /bu/ vs. /bo/). The most difficult pair was individually determined for each participant. Using behavioral measures, both cochlear implants groups performed worse than matched controls, and the good performers performed better than the poor performers. Cochlear implant groups and controls did not differ during time intervals typically used for the mismatch negativity, but earlier: source analyses revealed increased activity in the region of the right supramarginal gyrus (220-260 ms) in good performers. Poor performers showed increased activity in the left occipital cortex (220-290 ms), which may be an index for cross-modal perception. The time course and the neural generators differ from data from our earlier studies, in which the same phonemes were assessed in an easy-to-discriminate context. The results demonstrate that the groups used different language processing strategies, depending on the success of language development and the particular language context. Overall, our data emphasize the role of neural plasticity and use of adaptive strategies for successful language development with cochlear implants.
人工耳蜗为失聪者提供了聆听言语的机会。尽管新技术取得了重大进展，但儿童时期的语言发展仍存在很大差异，这取决于适应性和神经可塑性。这些因素通常在听觉领域进行研究，将失配负波作为感觉和语音处理的指标。多项研究表明，失配负波是人工耳蜗听力改善的电生理相关指标。在本研究中，两组人工耳蜗使用者，他们都具有非常好的基本听力能力，但言语表现不重叠（非常好或非常差的言语表现），根据设备使用经验和植入时的年龄进行匹配。我们测试了在特定的其他音素背景下对音素的感知，这些音素很难区分（例如，/bu/与/bo/中的元音）。为每个参与者单独确定最难的一对。使用行为测量方法，两个人工耳蜗组的表现均比匹配的对照组差，表现好的组比表现差的组表现更好。人工耳蜗组和对照组在通常用于测量失配负波的时间间隔内没有差异，但更早的时候：源分析显示，表现好的参与者右侧缘上回区域（220 - 260毫秒）的活动增加。表现差的参与者左侧枕叶皮质活动增加（220 - 290毫秒），这可能是跨模态感知的一个指标。时间进程和神经发生器与我们早期研究的数据不同，在早期研究中，相同的音素是在易于区分的背景下进行评估的。结果表明，根据语言发展的成功程度和特定的语言背景，两组使用了不同的语言处理策略。总体而言，我们的数据强调了神经可塑性以及使用适应性策略对人工耳蜗成功语言发展的作用。
