Audiovisual processing in specific language impairment

描述（由申请人提供）：特殊语言障碍的视听处理。越来越多的文献有力地表明，将听觉和视觉信息结合起来的能力在正常的语言习得中起着重要作用。然而，这些感官融合的崩溃是否会导致语言障碍的发展，如特殊语言障碍（SLI），尚不清楚。到目前为止，只有少数研究对特殊语言障碍的视听处理进行了评估。他们所有人都使用了感官冲突范式——即所谓的麦格克错觉——在这种范式中，“pa”的声音被配音到“ka”的视觉发音上，通常导致对“ta”的感知。这些研究报告了患有特殊语言障碍的儿童和有特殊语言障碍病史的成人对这种错觉的易感性降低，结论是他们的视听整合受损。然而，在音节感知过程中无法解决听觉和视觉之间的感觉冲突并不意味着在语言加工的其他阶段，如早期语音的感觉编码或后来的词汇感知，视听整合受到损害。此外，视听处理障碍如何与特殊语言障碍儿童的语言缺陷相互作用尚不清楚。本项目旨在通过多种方式促进我们对特殊语言中视听处理的理解。首先，我们利用事件相关脑电位（ERP）方法的优势，在语音感知的声学、音位和词汇层面确定了SLI中视听处理的有效性，该方法具有出色的时间分辨率，使其特别适合于评估SLI中视听感知出现问题的信息处理阶段。我们还添加了更多生态有效的刺激——没有感官冲突的音节和单词——到我们的范式中，以检验视听处理对更现实的语言刺激的反应。最后，通过评估SLI儿童视听整合的行为和ERP指数，以及一系列认知和语言技能之间的相关性，我们努力确定该群体中最有可能受到视听感知困难影响的SLI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.