Neurobiological Bases of Auditory Scene Analysis

描述（由申请人提供）：本提案的目的是验证非语言听觉对正常语言发展至关重要的假设。尽管有证据表明发育性语言障碍（DLD）儿童在处理低水平声学信息方面存在缺陷，但听觉感知缺陷的具体性质尚不清楚。该提案将调查将声音输入分割或分组的能力，因为组织声音的能力受损可能导致语言辨别能力低下，并干扰在常见的多源听力情况下（如课堂）的学习。最终目的是确定学龄儿童知觉声音组织正常发展的标准测量方法，并与语言障碍儿童的测量方法进行比较。学龄儿童（6-11岁）和年轻人（21-40岁）将被研究。电生理和行为测量的结合将被检查。我们将分析事件相关脑电位（event- relevant brain potential, ERPs）的一些组成部分，这些组成部分反映了听觉加工的不同阶段和注意状态。ERP分析将由脑电图（EEG）中频率特异性成分的分析来补充。这种方法将使我们能够评估声音的皮层感觉表征如何影响对多个声音流的感知的发育特征。评估典型语言发展（TLD）儿童的刺激驱动和注意驱动过程之间的关系（通过当前应用程序中提出的研究）对于设计未来的研究至关重要，这些研究可以测试语言障碍是否可归因于刺激驱动的皮层声音表征，并评估注意因素影响声音流感知的程度。我们将检验以下假设：1)决定声音分离的刺激参数随年龄的变化而变化。2) TLD儿童和成人流隔离电生理指标与行为指标相关。3)通过电生理和行为测量指标的变化，感知训练促进了脑流分离。使用ERP和EEG测量来评估健全组织的发育标记是有利的，因为这些指标可以在幼儿和受损人群中获得。这种方法有可能成为诊断和评估导致语言障碍的中枢听觉处理缺陷的重要非侵入性工具。

DESCRIPTION (provided by applicant): The goal of this proposal is to test the hypothesis that nonlinguistic auditory perception is essential for normal speech development. Despite the evidence that children with developmental language disorders (DLD) have deficits in processing low-level acoustic information, the specific nature of the auditory perceptual deficits is not known. The proposal will investigate the ability to segment or group acoustic input because impairments in the ability to organize sound could contribute to poor speech discrimination skills and interfere with learning in common multi-source listening situations, such as the classroom. The ultimate purpose is to ascertain standard measures of the normal development of perceptual sound organization in school-aged children upon which measures in language-impaired children can be compared. School-aged children (6-11 years) and young adults (21-40 years) will be studied. A combination of electrophysiological and behavioral measures will be examined. We will analyze selected components of event-related brain potentials (ERPs) that index different stages and attentional states of auditory processing. ERP analysis will be supplemented by analysis of frequency-specific components in the electroencephalogram (EEG). This approach will enable us to assess developmental features of how cortical sensory representations of sound impact upon perception of multiple sound streams. Assessing the relationship between stimulus-driven and attention-driven processes in typically language developing (TLD) children (via the studies proposed in the current application) is crucial for designing future studies that test whether or not language impairments can be attributed to stimulus-driven cortical sound representations, and to assess the degree to which attentional factors influence perception of sound streams. We will test the following hypotheses: 1) Stimulus parameters determining the segregation of sounds change as a function of age. 2) Electrophysiological indices of stream segregation correlate with behavioral measures in TLD children and adults. 3) Perceptual training facilitates stream segregation, as indexed by changes in electrophysiological and behavioral measures. The use of the ERP and EEG measures to assess developmental markers of sound organization is advantageous because these indices can be obtained in young children and impaired populations. This methodological approach has the potential to be an important non-invasive tool for diagnosis and assessment of central auditory processing deficits that lead to impaired language.