Phonetic influences on auditory feedback control

描述（由申请人提供）：言语研究的一个基本问题是产生和感知之间的相互作用。这种相互作用的性质对理解和建模语音发展，生产缺陷和康复策略具有深远的影响。我们的目标是描述如何感知他人的言语，特别是在音素边界，影响指导自我产生的言语的大脑-运动反馈过程。一方面，说话者可以以听者感知它的分类方式感知他自己的语音，从而允许快速、鲁棒的听觉处理。另一方面，在高级听觉皮层对声学信号施加语音结构之前，说话者可以在子类别级别上监视他的输出。我们的目标是区分这些假设，通过检查语音条件下的听觉变化和探测神经信号的增加反应的变化时，它是语音相关的。 我们的项目结合心理物理学和脑磁图实验来研究说话者听觉反馈突然改变所引起的神经动力学。拟议的实验旨在实现两个具体目标。首先，我们的目标是测量实时语音类别变化的神经反应。借鉴过去的研究结果，我们假设，跨类别或“语音”的转变会导致更大的神经反应比类内或“非语音”相同幅度的转变，但这种反应的动力学仍然是未知的。我们的目标是使用脑磁图检查时变神经反应意外的反馈扰动，语音和非语音变化的条件下的反应进行对比。其次，我们旨在评估言语训练对听觉反馈控制的影响。在共振峰空间中学习一个新的元音目标具有在新的元音和学习良好的母语元音之间添加新的类别边界的效果。拟议的实验评估这些新学到的类别影响现有元音扰动的反应的程度。 建议的研究增加了现有的反馈文献，通过引入有意义的语言变化和仅仅是声学变化之间的区别施加在反馈。我们的目标是通过确定听觉反馈控制是否受到分类感知的影响，从而改善言语运动控制模型，以及它是否发生在听觉皮层的高或低水平。这项研究直接适用于口吃，这是一种运动控制障碍，被认为反映了反馈处理的异常。这些研究也将最终有助于改善帕金森氏病或痉挛性发声障碍等沟通障碍的诊断和治疗，因为反馈控制的神经成像可以用于诊断，以探测涉及感知和生产的大脑网络中的特定异常。最后，这里提出的训练研究可能是有用的，在开发反馈相关的各种言语障碍的训练策略。

DESCRIPTION (provided by applicant): A fundamental issue in speech research is the interaction between production and perception. The nature of this interaction has profound implications for understanding and modeling speech development, production deficits, and rehabilitation strategies. Our goal is to characterize how perception of others' speech, particularly at the phoneme boundary, influences the auditory-motor feedback processes that guide self- produced speech. On the one hand, a speaker may perceive his own speech in the categorical manner in which listeners perceive it, allowing for rapid, robust auditory processing. On the other hand, a speaker may monitor his output at a sub-categorical level, before high-level auditory cortex imposes phonetic structure on the acoustic signal. We aim to distinguish these hypotheses by examining speech under conditions of auditory change and probing the neural signal for an increased response to that change when it is phonetically relevant. Our project combines psychophysical and magnetoencephalography experiments to investigate the neural dynamics elicited by a sudden modification of speakers' auditory feedback. The proposed experiments were designed to achieve two specific aims. First, we aim to measure the neural responses to real-time phonetic category changes. Drawing on the results of past studies, we hypothesize that a cross-category or "phonetic" shift causes a greater neural response than a within-category or "non-phonetic" shift of the same magnitude, but the dynamics of this response are still unknown. The goal is to use MEG to examine the time- varying neural response to unexpected feedback perturbation, contrasting that response under conditions of phonetic and non-phonetic change. Secondly, we aim to assess the effects of speech training on auditory feedback control. Learning a novel vowel target in formant space has the effect of adding new category boundaries between the novel vowel and the well-learned native vowels. The proposed experiments evaluate the degree to which these newly-learned categories affect the responses to perturbation of an existing vowel. The proposed research adds to the existing feedback literature by introducing the distinction between meaningful linguistic changes and mere acoustic variations imposed in feedback. We aim to improve models of speech motor control by determining whether auditory feedback control is influenced by categorical perception, and therefore whether it occurs at a high or low level in auditory cortex. This research is directly applicable to stuttering, a motor control disorder thought to reflect abnormalities in feedback processing. These studies will also ultimately contribute to improved diagnosis and treatment of communication disorders such as Parkinsons' Disease or spasmodic dysphonia, since neuroimaging of feedback control can be used diagnostically to probe the specific abnormalities in brain networks involved in perception and production. Finally, the training studies proposed here could potentially be useful in developing feedback-related training strategies for a variety of speech disorders.