Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 291, Rome 00161, Italy; BrainSigns Srl, Via Tirso, 14, Rome 00198, Italy.
Department of Molecular Medicine, Sapienza University of Rome, Viale Regina Elena 291, Rome 00161, Italy; BrainSigns Srl, Via Tirso, 14, Rome 00198, Italy.
Hear Res. 2024 May;446:109007. doi: 10.1016/j.heares.2024.109007. Epub 2024 Apr 5.
Despite the proven effectiveness of cochlear implant (CI) in the hearing restoration of deaf or hard-of-hearing (DHH) children, to date, extreme variability in verbal working memory (VWM) abilities is observed in both unilateral and bilateral CI user children (CIs). Although clinical experience has long observed deficits in this fundamental executive function in CIs, the cause to date is still unknown. Here, we have set out to investigate differences in brain functioning regarding the impact of monaural and binaural listening in CIs compared with normal hearing (NH) peers during a three-level difficulty n-back task undertaken in two sensory modalities (auditory and visual). The objective of this pioneering study was to identify electroencephalographic (EEG) marker pattern differences in visual and auditory VWM performances in CIs compared to NH peers and possible differences between unilateral cochlear implant (UCI) and bilateral cochlear implant (BCI) users. The main results revealed differences in theta and gamma EEG bands. Compared with hearing controls and BCIs, UCIs showed hypoactivation of theta in the frontal area during the most complex condition of the auditory task and a correlation of the same activation with VWM performance. Hypoactivation in theta was also observed, again for UCIs, in the left hemisphere when compared to BCIs and in the gamma band in UCIs compared to both BCIs and NHs. For the latter two, a correlation was found between left hemispheric gamma oscillation and performance in the audio task. These findings, discussed in the light of recent research, suggest that unilateral CI is deficient in supporting auditory VWM in DHH. At the same time, bilateral CI would allow the DHH child to approach the VWM benchmark for NH children. The present study suggests the possible effectiveness of EEG in supporting, through a targeted approach, the diagnosis and rehabilitation of VWM in DHH children.
尽管耳蜗植入物 (CI) 在恢复聋或重听 (DHH) 儿童的听力方面已被证明是有效的，但迄今为止，单侧和双侧 CI 用户儿童 (CIs) 的言语工作记忆 (VWM) 能力存在极大的可变性。尽管临床经验长期以来一直观察到 CIs 中这种基本执行功能的缺陷，但迄今为止原因仍不清楚。在这里，我们着手研究在单耳和双耳聆听对 CI 的影响方面，CI 与正常听力 (NH) 同龄人在听觉和视觉两种感觉模式下进行的三级难度 n-back 任务中的大脑功能差异。这项开创性研究的目的是确定 CI 与 NH 同龄人在视觉和听觉 VWM 表现中与 EEG 标记模式的差异，以及单侧耳蜗植入物 (UCI) 和双侧耳蜗植入物 (BCI) 用户之间可能存在的差异。主要结果显示出 theta 和 gamma EEG 频段的差异。与听力对照组和 BCI 相比，UCI 在听觉任务最复杂条件下表现出额区 theta 活动减少，并且这种激活与 VWM 表现相关。当与 BCI 相比时，UCI 还观察到 theta 的活动减少，当与 BCI 和 NH 相比时，UCI 也观察到左半球的 gamma 带活动减少。对于后两者，发现左半球的 gamma 振荡与音频任务的表现之间存在相关性。这些发现，结合最近的研究讨论，表明单侧 CI 在支持 DHH 的听觉 VWM 方面存在不足。同时，双侧 CI 可以使 DHH 儿童接近 NH 儿童的 VWM 基准。本研究表明 EEG 可能通过靶向方法支持 DHH 儿童的 VWM 诊断和康复。
