Feedback and Feedforward Mechanisms of Speech Perception

摘要/项目摘要 言语交流在向他人传达我们的思想、维持社会关系以及 支持教育成果。因此，影响言语感知的沟通障碍，如 自闭症、阅读障碍和听力损失对个人和社会来说都可能是代价高昂的。了解神经生物学 语音处理基础是侵入性颅内电生理学催生的一个重要目标 在神经外科的情况下。然而，大量的行为证据表明， 将语音输入映射到尚未在神经生物学模型中解释的音素。这 探索性/发展性R21项目追求听力环境系统性影响这一中心假设 大脑皮质对语音的反应，因此影响信号音素中声学维度的编码。一个 新成立的跨学科研究团队将通过 在神经外科背景下获得的立体脑电信号(SEEG)来研究这一假说。喜欢 皮层脑电图术(ECoG)，sEEG提供高时空分辨率并可以靶向皮质表面， 包括颞上回(STG)。由于皮质内电极的放置，sEEG电极记录 经颞上平面，特别针对深沟和脑回灰质，包括SUBERVER 颞沟(STS)和赫氏回(HG)。同步头皮脑电(EEG)将 获得将这些皮质内测量与健康听者研究中适当的非侵入性方法联系起来。 目标1将建立对两个声学-语音维度的神经反应，作为知觉权重的函数 它们发出音素身份的信号。这将为每个参与者提供基准回答，以供比较 对听力语境的实验操作改变了目标2中的知觉权重，并将确定个体如何 知觉加权策略的不同可预测皮层电生理反应。AIM 2将引入两个 行为上相对于基线移动知觉权重的成熟操作：引入噪声 以及引入其短期语音输入偏离 母语。检查参与者内部的实验操作将提供一种敏感的手段，通过 用来分析神经反应的变化作为在听的过程中产生的知觉权重的变化的函数 上下文。参与者将在青春期后期(15-25岁)进行抽样，在这段时间里， 权重提供了信息量的异质性。该项目将通过填补一个重要的空白来扩大其影响 理解语音处理，搭建与患者进行有创电生理研究的桥梁 结合sEEG、婚礼经典和最新技术测量人类听者的头皮脑电 提供机制信息的计算方法，并提供对动态、灵活性质的理解 对沟通障碍有实质性影响的语音处理。

ABSTRACT / PROJECT SUMMARY Speech communication plays a crucial role in conveying our thoughts to others, maintaining social ties, and supporting educational achievement. As a result, communication disorders that impact speech perception like autism, dyslexia, and hearing loss can be costly to both individuals and society. Understanding the neurobiological bases of speech processing is an important goal that has been hastened by invasive intracranial electrophysiology in neurosurgical contexts. Yet, substantial behavioral evidence demonstrates dynamic, flexible aspects of the mapping of speech input to phonemes that is not yet accounted for in neurobiological models. This Exploratory/Developmental R21 project pursues the central hypothesis that listening context systematically impacts cortical response to speech and therefore affects the encoding of acoustic dimensions in signaling phonemes. A newly established cross-disciplinary research team will use intracerebral recording via stereoelectroencephalography (sEEG) obtained in a neurosurgical context to pursue this hypothesis. Like electrocorticography (ECoG), sEEG offers high spatiotemporal resolution and can target the cortical surface, including superior temporal gyrus (STG). Owing to the intracortical electrode placement, sEEG electrodes record through the supratemporal plane, specifically targeting both deep sulcal and gyral grey matter including superior temporal sulcus (STS) and Heschl’s gyrus (HG). Simultaneous scalp electroencephalography (EEG) will be acquired to link these intracortical measures with noninvasive approaches appropriate in studies of healthy listeners. Aim 1 will establish neural response to two acoustic-phonetic dimensions as a function of the perceptual weight with which they signal phoneme identity. This will provide a baseline response for each participant for comparison as experimental manipulations to listening context shift perceptual weights in Aim 2, and will establish how individual differences in perceptual weighting strategies predict cortical electrophysiological response. Aim 2 will introduce two well-established manipulations that, behaviorally, shift perceptual weights relative to baseline: introduction of noise and introduction of an ‘accent’ for which the short-term speech input deviates from distributional regularities of the native language. Examination of experimental manipulations within-participant will provide a sensitive means by which to assay changes in neural response as a function of changes in perceptual weights arising across listening contexts. Participants will be sampled across later adolescence (15-25 years), a period during which perceptual weights provide informative heterogeneity. The project will compound its impact by filling an important gap in understanding of speech processing, building a bridge from invasive electrophysiological studies with patients to scalp EEG measures of human listeners through combined sEEG+EEG, wedding classic and state-of-the-art computational approaches to inform mechanisms, and delivering an understanding of the dynamic, flexible nature of speech processing with substantial implications for communication disorders.