Speech Perception Impairments in Healthy Normal-Hearing Adults: Neural Mechanisms

项目描述（由申请人提供）：本项目的目标是研究听力正常、无发育障碍的健康青年言语知觉障碍的测量方法，并获得个体差异测量方法的数据库，以分析与实验测量方法的关系。患有语言感知障碍的健康成年人可能会在听力学诊所抱怨在听力退化的情况下难以感知语言，但在检查后发现他们的听力正常。但是语音噪音测试证实了他们的抱怨。然后，他们可能会被认为是中枢性听觉处理障碍（CAPD）的临床诊断，但如何诊断CAPD尚未达成一致；没有CAPD的标准测试；甚至不知道其原因是否是听觉处理障碍。没有神经基础被证实。认知神经科学提供了一个框架来研究语言感知障碍（SPI）的神经基础在其他健康的年轻人。我们假设那些抱怨言语感知困难的个体存在于个体差异的连续体中。我们假设，负责SPI的神经机制可能单独出现，也可能在刺激表征、注意和工作记忆水平上相互作用。一个

DESCRIPTION (provided by applicant): The goals of this project are to develop measures for studying speech perception impairments in healthy younger adults with normal hearing and without developmental disorders and to obtain a database of individual differences measures to analyze in relationship to experimental measures. Healthy adults with speech perception impairments may present at an audiology clinic complaining of difficulty perceiving speech under degraded listening conditions, yet upon examination they are found to be audiologically normal. But speech-in- noise testing confirms their complaint. They may then be considered for a clinical diagnosis of central auditory processing disorder (CAPD), but there is not agreement as to how to diagnosis CAPD; there are no standard tests of CAPD; and unknown even is whether its cause is a disorder of auditory processing. No neural bases have been confirmed. Cognitive neuroscience offers a framework for investigating the neural bases for speech perception impairment (SPI) in otherwise healthy young adults. We hypothesize those individuals who complain of speech perception difficulties exist on a continuum of individual differences. We hypothesize that the neural mechanisms responsible for the SPI could arise singly or in interaction at the levels of stimulus representation, attention, and working memory. A delayed recognition memory paradigm will be developed to investigate these mechanisms. The paradigm is designed to obtain behavioral and electrophysiological (EEG) measures in response to speech. Healthy adults with normal hearing and with SPI will be recruited for study and compared to similar age normal adults without speech perception impairments. All participants will undergo a battery of audiological tests and other screening, including tests for verbal intelligence, mental status, and phonological working memory. Then they will be tested in the proposed delayed recognition memory paradigm to gain behavioral and EEG results related to working memory, attention, and speech stimulus encoding. Stimuli will be nonsense syllables or real words that are either natural recordings or vocoded. Extensive individual differences and group statistical analyses will be carried out using the EEG, behavioral, and clinical measures. Individual differences scores will be sought across normal and SPI groups and as reliable predictors of group membership. With better understanding of neural mechanisms responsible for differences in speech perception across groups and individuals, clinical evaluations can become more accurate and treatments can be developed. We envision carrying this project forward to develop clinical tests for adults and also children.