AUDITORY-VISUAL INTEGRATION AND AGE

描述(由申请人提供)：日常对话通常包括看到和听到我们的沟通伙伴，并提供了一个重要的方式，老年人通过它与他们的家庭和社区保持联系。我们之前的研究为年龄如何影响唇读能力和口语理解提供了基础知识。在这个资助周期中，我们将试图解释为什么一些人在视听时对说话者的演讲的认知度比基于他们仅能看得见和只能听得到的表现预测的要多得多，基于这一知识，我们的目标是开发干预措施来提高老年人的口语理解能力。这项研究的动机是视听整合模式，该模式同时考虑了信号和词汇因素，而大多数现有的模式都没有考虑到这些因素。重要的是，我们将使用一个方程来描述部分听觉和视觉信息的总和，以明确视听整合和单峰单词识别能力。为了实现我们的第一个特定目标，我们将操纵听觉和视觉语音信号的特性，以定位日常口语理解中与年龄相关的差异的来源。我们已经开发了矩阵式单词识别测试，这将使我们能够确定处理速度和工作记忆的年龄差异如何在音素和视位激活水平上影响AV整合。对于我们的第二个特定目标，我们开发了两个新的开放集单词测试，一个系统地改变激活的候选单词的数量，另一个系统地改变词频。使用这些测试，我们将操纵影响不同单词知觉混淆的词汇属性，并确定认知因素如何与竞争单词候选的激活水平相关。为了我们的最终具体目标，我们将使用我们实验室开发的视听口语理解测试，努力识别可以预测年龄和个体差异的变量，以预测从较慢的语言中获得的好处。我们的目标是确定放慢语速如何最好地提高老年人对延长的口语段落的理解，并预测谁将从这种干预中受益最大。这些目标的实现将具有理论和临床意义，使我们能够评估视听语音处理的理论模型，并测试提高老年人口语理解能力的方法。总体而言，这个项目是一个独特的机会，它将听力康复专家、认知心理学家和临床研究听力学家聚集在一起，目的是为老年人开发听力康复程序，这些程序的基础是经过充分测试的理论模型，并了解认知测量与视听言语理解的关系。 与公共健康相关：与只听不见相比，当个人既能看到又能听到说话者时，语音识别能力显著提高。对于老年人来说，这种改善通常等于或超过助听器和其他听力设备所获得的改善。我们提出了一个创新的视听整合理论模型，并将其作为一个框架，以确定衰老如何影响视听语音识别，以及确定如何最好地提高老年人的口语理解能力。

DESCRIPTION (provided by applicant): Everyday conversation typically involves both seeing and hearing our communication partners, and affords a vital means by which older adults stay engaged with their families and communities. Our previous research has contributed to fundamental knowledge of how aging affects both lipreading ability and spoken language comprehension. In this grant cycle, we will seek to explain why some individuals recognize much more of a talker's speech when it is presented audiovisually than would be predicted based on their vision-only and auditory-only performance, and based on this knowledge, we aim to develop interventions to enhance older adults' spoken language comprehension. The proposed studies are motivated by a model of audiovisual integration that takes into account both signal and lexical factors that are not incorporated into most existing models. Importantly, we will use an equation describing the summation of partial auditory and visual information to unconfound audiovisual integration and unimodal word recognition abilities. In order to accomplish our first Specific Aim, we will manipulate the properties of auditory and visual speech signals in order to localize the sources of age-related differences in everyday spoken language comprehension. We have developed matrix-style word recognition tests that will allow us to determine how age differences in processing speed and working memory affect AV integration at the level of phoneme and viseme activation. For our second Specific Aim, we have developed two new open-set word tests, one that systematically varies the number of activated word candidates and another that systematically varies word frequency. Using these tests, we will manipulate lexical properties affecting the perceptual confusability of different words and determine how cognitive factors relate to the activation levels of competing word candidates. For our final Specific Aim, we will use a test of audiovisual spoken language comprehension developed in our laboratory in our effort to identify variables that can predict age and individual differences in the benefits from slower speech. Our goal is to determine how slowed speech can best enhance older adults' comprehension of extended spoken passages and to predict who will benefit the most from such interventions. Accomplishment of these aims will have both theoretical and clinical significance, allowing us to assess a theoretical model of audiovisual speech processing and to test ways for enhancing spoken language comprehension in older adults. Overall, this project represents a unique opportunity that brings together an aural rehabilitation specialist, cognitive psychologists, and a clinical research audiologist for the purpose of developing aural rehabilitation procedures for older adults that are grounded in a well-tested theoretical model and in an understanding of how cognitive measures relate to audiovisual speech comprehension. PUBLIC HEALTH RELEVANCE: Speech recognition improves markedly when individuals can both see and hear a talker, compared with hearing alone. For older adults, the improvement often equals or exceeds that obtained from hearing aids and other listening devices. We propose an innovative theoretical model of audiovisual integration and will use it as a framework for establishing how aging affects audiovisual speech recognition, as well as to determine how best to enhance older adults' spoken language comprehension.