Cross-modal reorganization and speech perception in cochlear implant users
Cross-modal reorganization and speech perception in cochlear implant users
复制标题
DOI：
10.1093/brain/awl264
复制
发表时间：
2006-12-01
期刊：
影响因子：
14.5
通讯作者：
Lepore, F.
中科院分区：
文献类型：
--
作者：
Doucet, M. E.;Bergeron, F.;Lepore, F.
最近的工作表明，一旦聋人的听觉皮层已经重组的跨模态可塑性，它可以不再响应从随后安装的人工耳蜗（CI）的信号。为了进一步研究这个问题，我们比较了诱发电位参与视觉刺激的处理之间的CI用户和听力控制。这些刺激是同心圆，被不同的重叠形状所取代，从而诱导形状转变，已知可以激活成年人的腹侧视觉通路。所有CI用户的设备植入时间均超过1年，但在培训后获得了不同水平的听觉表现，以建立语言理解能力。13名患者中有7名表现出良好的语音识别能力（表现良好），而其他6名表现出较差的语音识别能力（表现较差）。所有患者的诱发电位均显示较大的振幅，两组之间头皮激活的分布不同。表现不佳者表现出更广泛的，前部分布，高P2振幅的皮质，而表现良好者表现出显着较高的P2振幅的视觉枕叶区。这些结果表明，存在一个深刻的跨模态重组的表现不佳和模态内重组的表现良好。我们解释这些数据的基础上，增强视听耦合的关键，在CI用户的语音识别的长期功能改善。
Recent work suggests that once the auditory cortex of deaf persons has been reorganized by cross-modal plasticity, it can no longer respond to signals from a cochlear implant (CI) installed subsequently. To further examine this issue, we compared the evoked potentials involved in the processing of visual stimuli between CI users and hearing controls. The stimuli were concentric circles replaced by a different overlapping shape, inducing a shape transformation, known to activate the ventral visual pathway in human adults. All CI users had their device implanted for > 1 year, but obtained different levels of auditory performance following training to establish language comprehension. Seven of the 13 patients showed good capacities for speech recognition with the CI (good performers) while the six others demonstrated poor speech recognition abilities (poor performers). The evoked potentials of all patients showed larger amplitudes, with different distributions of scalp activations between the two groups. The poor performers exhibited broader, anteriorly distributed, high P2 amplitudes over the cortex whereas the good performers showed significantly higher P2 amplitudes over visual occipital areas. These results suggest the existence of a profound cross-modal reorganization in the poor performers and an intramodal reorganization in the good performers. We interpret these data on the basis of enhanced audiovisual coupling as the key to a long-term functional improvement in speech discrimination in CI users.