Neurobiological Bases of Auditory Scene Analysis

描述(申请人提供)：这项建议的目标是检验非语言听觉对正常言语发展至关重要的假设。尽管有证据表明，患有发育性语言障碍(DLD)的儿童在处理低级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。该提案将调查对声学输入进行分段或分组的能力，因为组织声音的能力受损可能会导致糟糕的言语辨别技能，并干扰在常见的多源听力情况下的学习，如教室。最终目的是确定学龄儿童知觉健全组织正常发展的标准测量，以此来比较语言障碍儿童的测量结果。将研究学龄儿童(6-11岁)和青壮年(21-40岁)。将检查电生理和行为测量的组合。我们将分析事件相关脑电位(ERPs)的选定成分，这些成分指示听觉处理的不同阶段和注意力状态。脑电(EEG)中特定频率成分的分析将补充ERP分析。这一方法将使我们能够评估声音的皮质感觉表征如何影响对多个声流的感知的发展特征。评估典型语言发育(TLD)儿童的刺激驱动和注意力驱动过程之间的关系(通过本申请中提出的研究)对于设计未来的研究至关重要，这些研究将测试语言障碍是否可以归因于刺激驱动的皮质声音表征，并评估注意因素对声流感知的影响程度。我们将检验以下假设：1)决定声音分离的刺激参数随着年龄的变化而变化。(2)TLD儿童和成人的溪流分离电生理指标与行为指标相关。3)以电生理和行为测量的变化为指标，知觉训练促进了流分离。使用事件相关电位和脑电测量来评估健全组织的发育标志是有利的，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一种重要的非侵入性工具，用于诊断和评估导致语言受损的中枢听觉处理缺陷。

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.