Feedback and Feedforward Mechanisms of Speech Perception

摘要/项目摘要 言语沟通在向他人传达我们的想法、维持社会联系以及 支持教育成就。因此，沟通障碍会影响言语感知，例如 自闭症、阅读障碍和听力损失可能给个人和社会带来高昂的代价。了解神经生物学 语音处理基础是侵入性颅内电生理学加速的一个重要目标 在神经外科背景下。然而，大量的行为证据表明， 将语音输入映射到神经生物学模型中尚未考虑的音素。这个 探索性/发展性 R21 项目追求的中心假设是聆听环境会系统地影响 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小组将通过脑内记录来使用 在神经外科背景下获得的立体脑电图（sEEG）来研究这一假设。喜欢 皮质电图 (ECoG)、sEEG 提供高时空分辨率，可以针对皮质表面， 包括颞上回（STG）。由于皮质内电极放置，sEEG 电极记录 通过颞上平面，专门针对深层脑沟和脑回灰质，包括上 颞沟 (STS) 和赫施尔回 (HG)。同时进行头皮脑电图 (EEG) 获得将这些皮质内测量与适合健康听众研究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，作为感知权重的函数 它们表示音素身份。这将为每个参与者提供基线响应以进行比较 对听力环境的实验操作会改变目标 2 中的感知权重，并将确定个体如何 知觉加权策略的差异可以预测皮质电生理反应。目标2将介绍两个 行之有效的操作，在行为上相对于基线改变感知权重：引入噪音 并引入“口音”，使短期语音输入偏离语音的分布规律 母语。对参与者内部实验操作的检查将提供一种敏感的方法 用于分析神经反应的变化作为聆听过程中感知权重变化的函数 上下文。参与者将在青春期后期（15-25 岁）进行抽样调查，在此期间，知觉 权重提供了信息异质性。该项目将通过填补一个重要空白来增强其影响力 对语音处理的理解，在与患者进行侵入性电生理学研究和 通过结合 sEEG 脑电图、婚礼经典和最先进的方式对人类听众进行头皮脑电图测量 计算方法来通知机制，并提供对动态、灵活本质的理解 言语处理对沟通障碍有重大影响。

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.