Simultaneous fMRI/ERP measures of Speech Perception

描述(由申请人提供)：是否存在一套独特的制度 语音处理是有争议的。这项建议的总体目标是 搜索专门的皮质语音模块的证据，与 普通听觉系统，使用先进的大脑成像方法的组合， 即同步功能磁共振成像(FMRI)和事件相关成像 潜在的(ERP)录制。将使用三种刺激类型来区分 语音和声学处理：(A)可作为语音或作为语音听到的声音 非言语，取决于受试者对声音性质的预期； (B)发音在语音上下文中变化，其中语音的关键提示为语音 感知被呈现；以及(C)语音声音在程度上逐渐变化 声学连贯性，因此在语音内容的程度上。一个 古怪的范式将被用来唤起特定的事件相关的听觉皮质 流程。由奇怪的检测引起的事件相关电位反应已被证明 取决于正在执行的听觉分析的类型，因此可以 用作声学的标记，与语音处理相反。同时进行 FMRI/ERP是一种新的、具有技术挑战性的方法。它涉及到记录脑电 使用非铁磁设备并且不干扰射频场和 磁共振成像采集，以及提取小的ERP信号从 磁性环境引起的背景噪声增加。高密度 电生理记录，使用电流密度图和 时空偶极子估计受fMRI数据的约束，将允许两者都很高 空间和高时间分辨率。FMRI/ERP同步实施 录音应该对言语和听力中使用的方法产生广泛的影响。 揭示言语和非言语知觉的时空组织 对于理解特定语言潜在的功能障碍很重要 减损。

DESCRIPTION (provided by applicant): The existence of a distinct system for speech processing is controversial. The general aim of this proposal is to search for evidence of a specialized cortical phonetic module, distinct from the general auditory system, using a combination of advanced brain imaging methods, i.e. simultaneous functional Magnetic Resonance Imaging (fMRI) and Event-Related Potential (ERP) recordings. Three stimulus types will be used to separate phonetic and acoustic processing: (a) sounds that can be heard as speech or as non-speech, depending on the subject's expectancy as to the nature of the sound; (b) sounds varying in the phonetic context in which the key cue for phonetic perception is presented; and (c) speech sounds gradually varying in the degree of acoustic coherence and therefore in the degree of phonetic content. An oddball paradigm will be used to evoke specific event-related auditory cortical processes. The ERP responses elicited by oddball detection have been shown to depend on the type of auditory analysis that is being performed and can hence be used as a marker for acoustic as opposed to phonetic processing. Simultaneous fMRI/ERP is a new and technically challenging method. It involves recording EEG with non-ferromagnetic equipment and without interfering with the RF field and the MRI acquisition, as well as extracting the small ERP signal from the increased noisy background caused by the magnetic environment. The high-density electrophysiologic recordings, analyzed using current density mapping and spatiotemporal dipole estimation constrained by fMRI data, will allow both high spatial and high temporal resolution. Implementation of simultaneous fMRI/ERP recordings should have a broad impact on methods used in speech and hearing. Revealing the spatial- temporal organization of speech and nonspeech perception is important for understanding dysfunction underlying specific language impairments.