Neurophysiological basis of speech perception

我们建议继续研究言语感知的神经生理学基础，特别是 强调听觉和音素知觉在大脑中部和后部区域及其附近的作用 健康成人左额叶上沟(STS)的综合神经成像研究 还有孩子。 位于Heschl‘s回(HG)正前方和腹侧的左侧STS(MSTS)的中间部分 响应于包括诸如孤立音节和 音素，以及非语言熟悉的声音，如非语音人类发声和 动物的发声。我们的主要假设是从HG到MSTS的腹侧通路 高效地映射语音中按时间顺序排列的声音信息的过程 将波形转换为存储在MSTS中的语言相关、高度抽象和分类的表示形式。 我们建议研究这一途径的时空组织及其对音素的特异性 感知力。 HG后左侧STS(PSTS)与非母语言语的学习和学习有关。 其他新奇的声音，在语音的提取和排练(语音处理)和其他 听觉序列和发音规划。PSTS在双边方面也对这种看法做出了反应 对生物运动的影响。我们的主要假设是左侧pSTS的一个区域起工作记忆的作用 缓冲区，暂时存储具有低抽象级别的真实表示形式，这些表示形式保留 语音处理和发音所必需的声音的时间顺序特性 计划。类似地，pSTS的区域对生物运动有反应，因为 维度是其感知的核心。我们建议考察这一地区在演讲中的共同作用 和生物运动感知，以及形成对新声音的瞬时真实表示。 与成人相比，仍在发展语音感知的儿童表现出更浅的边界 在音素类别之间。儿童也会表现出对语音的激活模式，即 更多的分布，包括左额叶和运动前皮质，以及更多的后部受累 颞叶。然而，儿童在习得非本地语言方面表现出更大的可塑性 音素类别与成人的比较。我们建议比较儿童和成年人的能力 学习非母语的语音对比，大概最初是通过形成瞬变的实词 在pSTS中具有低级别抽象的表示，并最终通过形成长期 MSTS中高度抽象的、分类的神经表示。我们将研究正在开发的和 成熟大脑在音素范畴发展中的速度和局限性 表征与语音知觉习得的神经机制。

We propose to continue to study the neurophysiological basis of speech perception with particular emphasis on the role in auditory and phonemic perception of middle and posterior fields in and near the left superior temporal sulcus (STS), using a comprehensive neuroimaging approach in healthy adults and children. The middle portion of the left STS (mSTS), just anterior and ventral to Heschl's gyrus (HG), is responsive to speech utterances including prelexical segments such as isolated syllables and phonemes, as well as non linguistic familiar sounds such as nonspeech human vocalizations and animal vocalizations. Our principal hypothesis is that the ventral pathway from HG to mSTS mediates the highly-efficient process of mapping the sequential, chronological acoustic information in speech waveforms onto linguistically relevant, highly-abstract and categorical representations stored in mSTS. We propose to examine the spatiotemporal organization of this pathway and its specificity for phonemic perception. The left STS posterior to HG (pSTS) has been implicated in the learning of non-native speech and other novel sounds, in the retrieval and rehearsal of speech (phonological processing) and other auditory sequences and in articulatory planning. The pSTS, bilaterally, also responds to the perception of biological motion. Our principal hypothesis is that a region of the left pSTS acts as a working-memory buffer, transiently storing veridical representations with low-levels of abstraction, that retain the sequential, chronological properties of sounds necessary for phonological processing and articulatory planning. Similarly, regions of the pSTS are responsive to biological motion because of the temporal dimension central to its perception. We propose to examine the common role of this region in speech and biological motion perception and in forming transient veridical representations for novel sounds. Children still developing phonemic perception compared to adults display shallower boundaries between phonemic categories. Children also display a pattern of activation for speech sounds that is more distributed, including left frontal and premotor cortex and a more posterior involvement of the temporal lobes. However, children demonstrate greater plasticity in the acquisition of non-native phoneme categories compared to adults. We propose to compare the ability of children and adults to learn a non-native phonetic contrast, presumably initially through formation of transient veridical representations with low-levels of abstraction in pSTS and eventually through formation of long-term highly-abstract, categorical neural representations in mSTS. We will examine the developing and mature brain with regard to the rate and limitations in the development of phonemic category representations and the neural mechanisms underlying acquisition of phonemic perception.