Neural mechanisms of speech learning in older adults

描述（由申请人提供）：健康的老年听众表现出认知和复杂言语感知能力下降。在现实世界中的复杂的语音感知，包括听多个说话者产生的高度可变的语音声音（音素）和听噪音中的语音，已被证明需要认知资源。新提出的研究的总体目标是测试这一假设，即在复杂的语音训练之前进行认知训练将使健康的老年人具有更好的现实世界语音交流能力。这一假设基于大脑老化的衰退补偿模型，该模型假设感觉能力（听觉皮层）的下降可以通过增加一般认知皮层区域（如前额叶皮层）的参与来补偿，认知训练有望提供这种功能。PI的当前R 01正在检查年轻成人的言语学习，假设复杂言语学习（多说话者/高变异性声音到单词学习）的功效由认知脑区域（用于听觉注意的上级顶叶小叶和用于工作记忆的前额叶皮层）介导。该K 02奖项的目的是允许PI将其目前在年轻人中的工作扩展到老年人群，包括在噪声训练中进行多说话者声音到单词和言语之前规定认知训练的有效性的神经生理学基础检查。根据下降补偿模型，我们假设训练后认知大脑区域的参与对于复杂语音学习的成功至关重要。这项研究解决了两个关于老年人的重要问题，这一人群寻求认知刺激的退休后活动的趋势，包括有效的第二语言学习计划和克服中枢听觉缺陷的需要（噪音中的言语感知困难是主要的抱怨），以充分参与（嘈杂的）日常环境。该K 02奖项还将允许PI接受老年学（包括老年人神经影像学）和临床研究设计的教学和实验室培训，为他作为临床翻译研究员的终身职业生涯做好准备。 公共卫生相关性：许多老年人在餐馆等现实环境中难以理解言语。据报道，一些老年人避免社交（例如，在餐馆用餐），因为他们在这样的环境中很难交流。虽然这种困难可能与他们的耳朵有关，也可能与声音不够大而无法听到有关，但影响记忆和注意力的大脑功能下降也可能起着重要作用。我们的研究将试图探索在现实世界环境的言语感知训练之前，首先关注记忆和注意力的训练是否会导致老年人更好的整体口语交流;另一个目标是检查潜在的大脑对这种可能的改善的反应。

DESCRIPTION (provided by applicant): Healthy older listeners show decline in cognitive and complex speech perception abilities. Complex speech perception in the real-world, including listening to highly variable speech sounds (phonemes) produced by multiple talkers and listening to speech in noise, has been shown to require cognitive resources. The overarching goal of the newly proposed research is to test the hypothesis that cognitive training preceding complex speech training will result in better real-world speech communication abilities in healthy older adults. This hypothesis is grounded in the decline-compensation model of the aging brain, which postulates that decline in sensory abilities (auditory cortex) can be compensated by increased engagement of general cognitive cortical regions such as the prefrontal cortex, which cognitive training is expected to provide. The PI's current R01 is examining speech learning in younger adults, with the hypothesis that efficacy of complex speech learning (multi-talker/high-variability sound-to-word learning) is mediated by cognitive brain regions (superior parietal lobule for auditory attention and prefrontal cortex for working memory). The purpose of this K02 award is to allow the PI to extend his current work in younger adults to the elderly population, including examinations of the neurophysiological underpinnings of the efficacy of prescribing cognitive training before multi-talker sound-to-word and speech in noise training. Per the decline-compensation model, we hypothesize that the engagement of cognitive brain regions post-training is critical to the success in complex speech learning. The two important issues concerning older adults addressed by this research is the trend for this population to seek cognitively stimulating post-retirement activities including effective second language learning programs and the need to overcome central auditory deficits (with speech perception in noise difficulty being the chief complaint) in order to participate fully in (noisy) everyday environments. This K02 award will also allow the PI to receive didactic and laboratory training in gerontology (including neuroimaging in older adults) and clinical research designs to prepare him for a life-long career as a clinician-translational researcher. PUBLIC HEALTH RELEVANCE: Many older adults experience difficulty understanding speech in real-world environments such as restaurants. Some elderly individuals reportedly avoid socializing (e.g., dining in restaurants) because it is difficult for them to communicate in such environments. While this difficulty can be related to their ears and to the fact that sounds are not loud enough for them to hear, reduced brain functions affecting memory and attention might also be playing a major role. Our research will seek to explore whether training focusing first on memory and attention prior to speech perception training of real-world environments could result in better overall spoken language communication in older adults; an additional goal is to examine the underlying brain responses to such possible improvements.