Audiovisual processing in specific language impairment

描述(申请人提供)：特定语言障碍的视听处理。越来越多的文献强烈表明，将听觉和视觉信息结合在一起的能力在正常的语言习得中发挥着重要作用。然而，这些感官融合的障碍是否会导致语言障碍的发展，如特定语言障碍(SLI)，目前尚不清楚。到目前为止，只有几项研究评估了SLI的视听加工。他们都使用了感觉冲突范式，也就是所谓的麦格克错觉，在这种模式下，“pa”的声音被配音到“ka”的视觉发音上，这通常会导致对“ta”的感知。这些研究报告了患有SLI的儿童和有SLI病史的成年人对这种错觉的易感性降低，结论是他们的视听整合受到了损害。然而，在音节知觉过程中不能解决听觉和视觉通道之间的感觉冲突并不意味着在语言加工的其他阶段，如语音的早期感觉编码或后来的词汇知觉，视听整合受到损害。此外，SLI儿童的视听处理障碍如何与言语-语言缺陷相互作用尚不清楚。这个项目旨在以多种方式促进我们对SLI中视听处理的理解。首先，我们借助事件相关脑电位(ERP)方法的优势，在语音感知的声学、音素和词汇水平上确定了SLI中视听加工的有效性，该方法出色的时间分辨率使其特别适合于评估SLI中视听知觉受挫的信息处理阶段。我们还在我们的范例中增加了更多生态上有效的刺激--没有感觉冲突的音节和单词--以检查对更真实的语音刺激的视听处理。最后，通过评估SLI儿童的视听整合行为指数和事件相关电位指数与一系列认知和语言技能之间的相关性，我们努力找出SLI儿童中最容易受到视听知觉困难影响的认知和语言缺陷。

DESCRIPTION (provided by applicant): Audiovisual Processing in Specific Language Impairment. A growing body of literature strongly suggests that the ability to combine auditory and visual information plays a significant role in normal language acquisition. However, whether a breakdown in the merging of these senses may contribute to the development of language disorders, such as specific language impairment (SLI), is unknown. So far, only a few studies have evaluated audiovisual processing in SLI. All of them used the sensory conflict paradigm - the so-called McGurk illusion - in which the sound of "pa" is dubbed onto the visual articulation of "ka" typically leading to the perception of "ta." These studies have reported a reduced susceptibility to this illusion in children with SLI and in adults with a history of SLI, concludin that their audiovisual integration is impaired. However, the inability to resolve a sensory conflic between auditory and visual modalities during syllable perception does not presuppose an impairment in audiovisual integration during other stages of linguistic processing, such as early sensory encoding of speech sounds or later lexical perception. Furthermore, how an impairment in audiovisual processing interacts with speech-language deficits of children with SLI is unknown. This project is designed to advance our understanding of audiovisual processing in SLI in multiple ways. First, we determine the effectiveness of audiovisual processing in SLI at the acoustic, phonemic, and lexical levels of speech perception by drawing on the strength of the event-related brain potentials (ERP) method, whose excellent temporal resolution makes it uniquely suited for evaluating the stage of information processing at which audiovisual perception falters in SLI. We also add more ecologically valid stimuli - syllables without a sensory conflict and words - to our paradigms in order to examine audiovisual processing in response to more realistic speech stimuli. Lastly, by evaluating correlations between, on the one hand, behavioral and ERP indices of audiovisual integration and, on the other hand, a range of cognitive and language skills in children with SLI, we strive to identify those cognitive and linguistic deficits of SLI that are most likely to be affected by audiovisual perception difficultis in this group.