Multilevel Auditory Processing of Continuous Speech, from Acoustics to Language

项目摘要 为了使连续的语音被认为是可理解的，大脑采用了一系列扩展的表征 沿着听觉通路，强调不同的时间特征的讲话在每个阶段。脑干 到中脑，丘脑，并通过多个皮层区域，这些阶段支持快速音高的表征， 相关的周期性，对应于声道/包络调制的较慢的表示，并且最终， 语言和语义表示。此外，这些表示的强度不确定 这不仅是一种前馈的方式，也是由自上而下的过程，由注意力和倾听努力调节。 众所周知，语音信号的降级将以不同的方式干扰这些神经表示。 办法：有些损失是无法弥补的，但有些可以在以后阶段得到补偿。知识上的差距 因为不同的神经阶段，以及相应的连续语音表示， 很少有人将其作为纵向链来研究。在一个处理级别的部分故障可以在 补偿水平可以与后续水平相关联，并且补偿水平可以与倾听努力的水平相关联。 本申请的具体目标是确定连续语音是如何逐步 代表沿着和超越听觉通路，从中脑到语言区域，在年轻的正常人中， 倾听者。将采用脑电图（EEG）和脑磁图（MEG） 由于其高时间分辨率，同时记录皮层下和多个皮层区域 沿着行为和倾听努力的测量。不同语言的言语表征 神经阶段将通过时间锁定的神经处理和神经功能的特定测量来量化。 连通性。瞳孔测量将被用作听力努力的生理代理，除了自我， 报告的努力措施。我们的中心假设是，对疾病进展的基础理解 连续语音处理的表示，被视为具有前馈和反馈的网络 连通性（包括基于任务和与努力相关的连通性变化），将阐明声学和 连续语音最终被认为是可理解的神经条件。 目的1调查了一系列广泛的连续语音处理的神经措施，同时获得 沿着和超越听觉通路，以及它们可以预测可懂度的程度。目的2 调查在多大程度上也纳入持续倾听努力的措施，与 以上连续语音处理的神经测量，可以允许比 单独的神经测量。目的3研究神经连接在支持连续性的功能作用 语音处理沿着听觉通路和超越听觉通路。

PROJECT SUMMARY For continuous speech to be perceived as intelligible, the brain employs an extended series of representations along the auditory pathway, emphasizing different temporal features of speech at each stage. From brainstem to midbrain, thalamus, and through multiple cortical areas, these stages support representations of fast pitch- relevant periodicity, slower representations corresponding to vocal-tract/envelope modulations, and ultimately, linguistic and semantic representations. Furthermore, the strength of these representations is not determined solely in a feedforward way, but also by top-down processes, modulated by attention and listening effort. It is well known that degradation of a speech signal will interfere with these neural representations in different ways: some losses are irreparable, but others can be compensated for at a later stage. A gap in knowledge arises because the different neural stages, and the corresponding continuous speech representations, are rarely studied as a longitudinal chain. Partial failure at one processing level might be compensated for at a subsequent level, and the level of compensation might be associated with the level of listening effort. The specific objectives of this application are to determine how continuous speech is progressively represented along and beyond the auditory pathway, from midbrain to language areas, in young normal- hearing listeners. Both electroencephalography (EEG) and magnetoencephalography (MEG) will be employed for their high time resolution, simultaneously recording from subcortical and multiple cortical areas respectively, along with measures of behavior, and listening effort. The speech representations of different neural stages will be quantified by specified measures of time-locked neural processing and of neural connectivity. Pupillometry measures will be used as a physiological proxy for listening effort, in addition to self- reported effort measures. Our central hypothesis is that a grounded understanding of the progression of representations of continuous speech processing, viewed as a network with both feedforward and feedback connectivity (and including task-based and effort-linked connectivity changes), will elucidate the acoustic and neural conditions under which continuous speech is ultimately perceived as intelligible. Aim 1 investigates a broad set of neural measures of continuous speech processing, simultaneously obtained along and beyond the auditory pathway, and the extent to which they can predict intelligibility. Aim 2 investigates the extent to which also incorporating measures of sustained listening effort, in concert with the above neural measures of continuous speech processing, may allow better predictions of intelligibility than the neural measures alone. Aim 3 investigates the functional role of neural connectivity in supporting continuous speech processing along the auditory pathway and beyond.