Individual differences in cochlear implant users' audiovisual integration and links to speech proficiency

项目总结 人工耳蜗可以让严重听力损失的人体验到声音，其中一些是第一次。 时间到了。这种非常成功的神经假体设备可以极大地提高一些人的语言理解能力 然而，术后言语熟练程度仍然高度不稳定，很难预测。 虽然视觉口面部发音在前后的言语交流中都起着至关重要的作用 人工耳蜗植入术、评估植入物可行性的临床措施及术后监测 目前，性能仅限于听觉语音测量。因此，当前的评估可能是 仅提供具有CI的听觉康复的部分图像。这项提议声称，降级的声音 CI提供给中枢神经系统带来了独特的计算挑战，对于 尤其是语音，视觉信息几乎肯定会被用来提高理解能力。我们相信 将绩效评估扩展到包括视觉领域增加了生态有效性 语言清晰度衡量并可能揭示成功结果的另一个变量-- 整合感官流，实现多感官增强。 我们的第一个目标是在一群语言后聋的CI用户中描述视听整合的特征。这 包括音素和单词层面的单感觉和多感觉语音感知。这样做使我们能够 将幻觉任务(即麦格克效应)与熟练理解语音中嵌入的单词联系起来 噪音-对于几乎所有CI用户来说，这是一个具有挑战性的倾听环境，也是一个有效整合感官的环境 才是关键。 我们的第二个目标是研究视听整合中可变性的神经基础，在我们的 在前期工作和文献中。功能近红外光谱(FNIRS)是一种无创成像技术 对所有CI用户都是安全的技术。用这种光学成像技术测量血流动力学反应 将使我们能够确定听觉、视觉和视听刺激是否以不同的方式激活颞叶 在1)CI用户和NH控制之间，2)熟练和非熟练CI用户之间，以及3)McGurk错觉之间 感知者和非感知者。 这项建议的目标是更好地理解非典型视听整合及其与可变性的关系 在人工耳蜗(CI)使用者的神经处理和语音理解方面。这一知识是 对于我们通过配置项理解语言熟练程度至关重要，最重要的是，对于用户如何最好地 利用所有感官信息来提高可理解性和改善生活质量。

PROJECT SUMMARY Cochlear implants (CIs) allow those with profound hearing loss to experience sound, some of them for the first time. This highly successful neuroprosthetic device can drastically improve speech comprehension for some individuals; however, postoperative speech proficiency remains highly variable and difficult to predict. Although visual orofacial articulations play a crucial role in verbal communication both before and after cochlear implantation, clinical measures assessing implant candidacy and monitoring postoperative performance are currently limited to auditory-only speech measures. As a result, current assessments may be providing only a partial picture of aural rehabilitation with a CI. This proposal asserts that the degraded sound provided by a CI presents a unique computational challenge for the central nervous system and that, for speech in particular, visual information is almost certainly recruited to increase comprehension. We believe that extending performance assessments to include the visual domain increases the ecological validity of speech intelligibility measures and may also reveal an additional variable in successful outcomes–the integration of sensory streams to achieve multisensory enhancement. Our first aim is to characterize audiovisual integration in a cohort of postlingually deafened CI users. This includes unisensory and multisensory speech perception at the phoneme and word level. Doing so enables us to relate illusory tasks (i.e. the McGurk effect) to proficiency at comprehending words embedded in speech-like noise–a challenging listening environment for nearly all CI users, and one where effective sensory integration is key. Our second aim is to investigate the neural basis of variability in audiovisual integration seen in both our preliminary work and in the literature. Functional Near Infrared Spectroscopy (fNIRS) is a noninvasive imaging technique that is safe for all CI users. Hemodynamic responses measured with this optical imaging technique will allow us to determine whether auditory, visual, and audiovisual stimuli activate the temporal lobe differently between 1) CI users and NH controls, 2) proficient and non-proficient CI users, and 3) McGurk illusion perceivers and non-perceivers. The goal of this proposal is to better understand atypical audiovisual integration and how it relates to variability in both neural processing and speech comprehension in cochlear implant (CI) users. This knowledge is essential for our understanding of speech proficiency with a CI and, most importantly, for how users can best utilize all sensory information to enhance intelligibility and improve quality of life.