Language-dependent plasticity in the encoding of pitch in the human brainstem

人类脑干音调编码中的语言依赖性可塑性

• 批准号: 7670253
• 负责人: ANANTHANARAYAN KRISHNAN
• 金额: $ 29.14万
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-15 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7670253
• 关键词: Address; Adopted; Algorithms; Attention; Auditory; Auditory area; Auricular prosthesis; Behavioral; Brain Stem; Chinese People; Classification; Cochlear Implants; Complement; Contralateral; Control Groups; Development; Dimensions; Ear; Electrophysiology (science); Frequencies; Handedness; Hearing; Hearing Aids; Homologous Gene; Human; Impairment; Inferior Colliculus; Knowledge; Language; Left; Linguistics; Mediating; Modeling; Monitor; Neurobiology; Noise; Outcome; Pathway interactions; Patients; Perception; Population; Process; Prosthesis; Public Health; Recovery; Relative (related person); Reporting; Role; Scalp structure; Scheme; Signal Transduction; Specificity; Speech; Staging; Stimulus; Structure; Target Populations; Training; Variant; auditory pathway; base; clinical practice; computerized data processing; design; experience; indexing; insight; lexical; neuromechanism; novel; relating to nervous system; response; sound

DESCRIPTION (provided by applicant): Crosslanguage studies of the perception of lexical tones have suggested that attention-modulated pitch processing at the cortical level may be influenced by language experience. We recently demonstrated that preattentive stages of pitch processing at the human brainstem level may also be influenced by language experience as reflected in the scalp-recorded human frequency following response. Our long term objective is to advance our knowledge of how pitch mechanisms in the auditory brainstem reorganize with experience to enhance encoding of behaviorally relevant sounds and to determine their role in the hierarchical processing of the temporal structure of sound. By adopting a crosslanguage approach (Mandarin, Thai, English) in tandem with a variety of speech and nonspeech stimuli varying in their lexical status and/or pitch contour, we are able to directly address questions of domain- as well as tone-specificity of the neural mechanisms mediating this pitch representation in the human brainstem. The specific aims are to assess: (1) language-dependent specificity of pitch representation for native f0 trajectories in a speech context; (2) language-dependent specificity of pitch representation for native f0 trajectories in a nonspeech context; (3) sensitivity of pitch representation to systematic temporal degradation in native f0 trajectories in a nonspeech context; (4) contour specificity of the pitch representation of native and nonnative contour f0 trajectories in a nonspeech context; (5) role of temporal- or spectral-based mechanisms underlying pitch extraction; and (6) laterality of experience- dependent brainstem reorganization for pitch representation. We hypothesize that temporal neural mechanisms mediating pitch representation are sensitive to a particular language and tonal dimensions; that this pitch representation in the native listeners is less susceptible to temporal degradation of pitch relevant information in the stimulus even when presented in a nonspeech context; that an ear advantage may even be evident at the brainstem since the inferior colliculus and auditory cortex share the same dominant contralateral pathway. Our findings promise to provide fresh insights as to how pitch processing at the brainstem level emerges from differential demands on auditory and linguistic processes that are shared by speech and nonspeech stimuli alike. Of relevance to the public health, a better understanding of how pitch encoding is influenced by language experience at the brainstem level will allow us to assess differentially the integrity of pitch representation in our increasingly multilingual population; to monitor non-invasively changes in pitch representation after retraining of language/hearing-impaired listeners from different language backgrounds; and to develop optimal, language-sensitive signal processing strategies for hearing prosthetic devices used by hearing-impaired listeners. Thus, auditory electrophysiology at the brainstem level can provide us with fresh insights into patients' difficulties in hearing and understanding speech and assist in the development of optimal signal processing strategies to remedy degraded neural representation. Our ability to favorably influence the recovery from hearing-related impairments will depend upon a better understanding of the neurobiological basis of language-dependent pitch processing in the human brainstem. The scalp recorded frequency following response (FFR) provides a noninvasive neural index of pitch representation at the brainstem level. If the aims of this project are achieved, FFRs can be incorporated into clinical practice to assess the integrity of pitch representation in a target population, to index changes in pitch representation before and after training, and to evaluate signal processing algorithms designed to recover degraded neural representation of pitch in conventional hearing aids and/or cochlear implants.

描述（由申请人提供）：对词汇声调感知的跨语言研究表明，皮层水平的注意力调节音调处理可能会受到语言经验的影响。我们最近证明，人类脑干水平的音调处理的前注意阶段也可能受到语言体验的影响，这反映在头皮记录的人类频率跟随反应中。我们的长期目标是增进我们对听觉脑干中的音调机制如何通过经验重组的了解，以增强行为相关声音的编码，并确定它们在声音时间结构的分层处理中的作用。通过采用跨语言方法（普通话、泰语、英语），结合各种词汇状态和/或音高轮廓不同的语音和非语音刺激，我们能够直接解决领域和语气特异性的问题。调节人类脑干中这种音调表征的神经机制。具体目标是评估：（1）语音环境中本地 f0 轨迹的音高表示的语言相关特异性； (2) 非语音环境中本地 f0 轨迹的音高表示的语言相关特异性； (3) 音调表示对非语音环境中本地 f0 轨迹的系统时间退化的敏感性； (4) 非语音上下文中本地和非本地轮廓 f0 轨迹的音调表示的轮廓特异性； (5) 基于时间或频谱的机制在基音提取中的作用； (6)音调表征的经验依赖脑干重组的侧向性。我们假设介导音调表征的时间神经机制对特定语言和音调维度敏感；即使在非语音环境中呈现，母语听众中的这种音调表示也不易受到刺激中音调相关信息的时间退化的影响；由于下丘和听觉皮层共享相同的主要对侧通路，因此在脑干处耳朵的优势甚至可能很明显。我们的研究结果有望为脑干水平的音调处理如何从语音和非语音刺激所共有的听觉和语言过程的不同需求中产生提供新的见解。与公共健康相关的是，更好地了解音调编码如何受到脑干水平的语言体验的影响将使我们能够对日益多语言的人口中音调表征的完整性进行差异化评估；在对来自不同语言背景的语言/听力障碍听众进行再训练后，以非侵入性方式监测音调表征的变化；并为听力受损听众使用的听力假肢设备开发最佳的、语言敏感的信号处理策略。因此，脑干水平的听觉电生理学可以为我们提供有关患者听力和理解言语困难的新见解，并帮助制定最佳信号处理策略来补救退化的神经表征。我们能否有利地影响听力相关损伤的恢复将取决于对人类脑干中语言依赖性音调处理的神经生物学基础的更好理解。头皮记录的频率跟随响应（FFR）提供了脑干水平音调表征的无创神经指数。如果该项目的目标得以实现，FFR 可以纳入临床实践，以评估目标人群中音调表征的完整性，索引训练前后音调表征的变化，并评估旨在恢复退化神经元的信号处理算法。传统助听器和/或人工耳蜗中音调的表示。