Neuropsychology Lab, Department of Psychology, European Medical School, Carl von Ossietzky University Oldenburg, Germany.
Cluster of Excellence Hearing4all Oldenburg, Germany.
Neuroimage Clin. 2017 Sep 4;16:514-523. doi: 10.1016/j.nicl.2017.09.001. eCollection 2017.
There is clear evidence for cross-modal cortical reorganization in the auditory system of post-lingually deafened cochlear implant (CI) users. A recent report suggests that moderate sensori-neural hearing loss is already sufficient to initiate corresponding cortical changes. To what extend these changes are deprivation-induced or related to sensory recovery is still debated. Moreover, the influence of cross-modal reorganization on CI benefit is also still unclear. While reorganization during deafness may impede speech recovery, reorganization also has beneficial influences on face recognition and lip-reading. As CI users were observed to show differences in multisensory integration, the question arises if cross-modal reorganization is related to audio-visual integration skills. The current electroencephalography study investigated cortical reorganization in experienced post-lingually deafened CI users ( = 18), untreated mild to moderately hearing impaired individuals (n = 18) and normal hearing controls ( = 17). Cross-modal activation of the auditory cortex by means of EEG source localization in response to human faces and audio-visual integration, quantified with the McGurk illusion, were measured. CI users revealed stronger cross-modal activations compared to age-matched normal hearing individuals. Furthermore, CI users showed a relationship between cross-modal activation and audio-visual integration strength. This may further support a beneficial relationship between cross-modal activation and daily-life communication skills that may not be fully captured by laboratory-based speech perception tests. Interestingly, hearing impaired individuals showed behavioral and neurophysiological results that were numerically between the other two groups, and they showed a moderate relationship between cross-modal activation and the degree of hearing loss. This further supports the notion that auditory deprivation evokes a reorganization of the auditory system even at early stages of hearing loss.
在后天失聪的人工耳蜗（CI）使用者的听觉系统中，存在明显的跨模态皮质重组的证据。最近的一份报告表明，中度感觉神经性听力损失足以引发相应的皮质变化。这些变化是剥夺诱导的还是与感觉恢复有关仍存在争议。此外，这种皮质重组对 CI 获益的影响仍不清楚。虽然失聪期间的重组可能会阻碍言语恢复，但它对人脸识别和唇读也有有益的影响。由于 CI 用户在多感觉整合方面表现出差异，因此出现了一个问题，即跨模态重组是否与视听整合技能有关。当前的脑电图研究调查了经验丰富的后天失聪的 CI 用户（n=18）、未经治疗的轻度至中度听力受损个体（n=18）和正常听力对照者（n=17）的皮质重组。通过 EEG 源定位测量听觉皮层对人脸的跨模态激活，以及使用 McGurk 错觉量化的视听整合。与年龄匹配的正常听力个体相比，CI 用户显示出更强的跨模态激活。此外，CI 用户显示出跨模态激活与视听整合强度之间的关系。这进一步支持了跨模态激活与日常生活交流技能之间的有益关系，而这些关系可能无法通过基于实验室的言语感知测试完全捕捉到。有趣的是，听力受损个体的行为和神经生理结果在数值上介于其他两组之间，并且他们的跨模态激活与听力损失程度之间存在中度关系。这进一步支持了听觉剥夺甚至在听力损失的早期阶段就会引起听觉系统重组的观点。
