Markers of Auditory-Cognitive Aging: Evidence from Normal Hearing Listeners and Cochlear Implant Recipients

大约三分之一的65岁以上的人和近一半的75岁以上的人患有需要康复的听力损失（NIDCD，2017）。随着年龄的增长，耳蜗和中枢神经系统的退行性变化导致精确检测、分辨和表示语音的区别性物理特性的能力逐渐下降。随着认知能力的衰退，老年人在交流中表现出障碍，特别是在背景噪音中，这可能会驱使衰老的大脑使用补偿性的认知策略。最近的数据表明，听力损失会加速老年人的认知能力下降，并增加患痴呆症的风险。虽然因果关系尚不清楚，但通过助听器和人工耳蜗植入物（CI）进行听力恢复可能会减轻衰老的一些有害影响。然而，年龄与听力损失之间的相互作用以及相应的听力策略仍然是未知的，在本项目中，我们的目标是调查年龄，听力状况，以及增加知觉和认知负荷如何影响听力策略及其神经基础。为此目的，行为措施和皮层神经元的反应将获得从年轻和老年人的正常听力和听力受损的听众在元音识别任务和听觉Stroop任务期间，在安静和背景噪声中植入人工耳蜗。这种方法将揭示感知（安静与噪音）和语音认知（元音识别与Stroop）负荷的单独和组合效应。在时域和频域中分析的EEG活动以及利用源定位算法可以揭示听觉处理任务中涉及的神经机制和大脑结构，这些任务施加增加的感知和/或认知负荷。这些数据可以解释一些变异的性能CI收件人识别EEG标记的听觉认知老化。据我们所知，目前的建议是独特的，在使用多测量对象内的方法与组间比较的方法在听觉老化的领域。拟议的合作包括一个德国研究小组，最大的临床人口的老年人与CI和专业知识，在脑电图记录和分析（汉诺威医科大学）和一个在脑电图记录和衰老的认知影响方面具有丰富经验的以色列团队（特拉维夫大学）。互补的专业知识，可用的临床人口和共同的研究兴趣，为实质性的协同作用奠定了基础。开发的研究工具可能是更有价值的早期客观筛选的认知功能下降之前，它成为临床上明显的。

Approximately one in three people over 65 years and nearly half of those older than 75 have hearing loss that requires rehabilitation (NIDCD, 2017). With increasing age degenerative changes in the cochlea and central nervous system lead to gradual decrements in the ability to precisely detect, resolve, and represent the distinguishing physical properties of speech sounds. Together with the deterioration in cognitive abilities older adults show detriments in communication, especially in background noise that may drive the aging brain towards the use of compensatory auditory-cognitive strategies. Recent data indicate that hearing loss accelerates cognitive decline in older adults and increases the risk for developing dementia. While the causal relationship is not yet clear, hearing restoration by means of hearing aids and cochlear implants (CIs) may alleviate some of the deleterious effects of aging. The interaction between aging and hearing loss habilitated by a CI together with the corresponding listening strategies, however, are still unknown.In the present project we aim to investigate how age, hearing status, and increased perceptual and auditory-cognitive loads affect listening strategies and their neural underpinnings. For this purpose, behavioral measures and cortical neuronal responses will be acquired from young and older normal hearing and hearing-impaired listeners habilitated by cochlear implants during a vowel identification task and an auditory Stroop task presented in quiet and in background noise. This approach will uncover the separate and combined effects of perceptual (quiet vs. noise) and auditory-cognitive (vowel identification vs. Stroop) loads. EEG activity analyzed in the time and frequency domains as well as utilization of source localization algorithms may reveal the neural mechanisms and brain structures involved in auditory processing tasks that impose increasing perceptual and/or cognitive load. These data may explain some of the variability in performance of CI recipients by identifying EEG markers of auditory cognitive aging. To the best of our knowledge, the present proposal is unique in the use of a multi-measure-within-subject approach together with a between-group comparison approach in the domain of auditory aging.The proposed collaboration consists of a German research team with the largest clinical population of older adults with CIs and expertise in EEG recordings and analysis (Medical University Hannover) and an Israeli team with extensive experience in EEG recordings and in auditory-cognitive effects of aging (Tel Aviv University). The complementary expertise, available clinical population, and mutual research interest, set the grounds for substantial synergy. The developed research tools may be further valuable for early objective screening of auditory-cognitive decline before it becomes clinically overt.