Simultaneous fMRI/ERP measures of Speech Perception

描述（由申请人提供）：存在一个独特的系统， 语音处理是有争议的本建议的总体目标是 寻找一个专门的皮层语音模块的证据，不同于 一般的听觉系统，使用先进的脑成像方法的组合， 即同时功能性磁共振成像（fMRI）和事件相关 电位（ERP）记录。将使用三种刺激类型来区分 语音和声学处理：（a）可以作为语音或 非言语，取决于受试者对声音性质的预期; (b)在语音语境中，语音的关键线索 感知呈现;（c）语音在程度上逐渐变化 声学连贯性，因此在语音内容的程度。一个 oddball范式将被用来唤起特定的事件相关的听觉皮层 流程.由古怪检测引起的ERP反应已经被证明是 取决于正在执行的听觉分析的类型，因此可以 用作声学标记，而不是语音处理。同时 fMRI/ERP是一种新的、技术上具有挑战性的方法。它包括记录脑电图 使用非铁磁设备且不干扰射频场， MRI采集，以及从 由磁性环境引起的噪声背景增加。高密度 电生理记录，使用电流密度图分析， 受fMRI数据约束的时空偶极子估计，将允许高 空间和高时间分辨率。同步fMRI/ERP的实现 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 对于理解特定语言下的功能障碍很重要 损伤

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.