Central and Peripheral Dynamics of Speech Production in Children Who Stutter

描述（由申请人提供）：本项目的总体目标是更好地了解导致口吃儿童语言不流畅的基本生理和神经机制。我们的研究策略结合了突破性和成熟的实验方法，包括功能近红外光谱（fNIRS -一种新兴的神经成像技术），关节的运动学测量和口吃严重程度的临床评估。该项目的总体目标是使用近红外光谱（fNIRS）研究在包括自然语音在内的一系列说话条件下，与语音产生有关的特定神经区域的激活。近20年来对口吃成人的功能性神经影像学研究的发现，为发展性口吃的神经学基础提供了更深入的了解。然而，由于对CWS的研究很少，因此尚不清楚在成人口吃患者中检测到的差异是在发病时存在还是在发病后出现，是终生补偿和/或治疗策略的结果。由于fMRI和PET技术固有的方法限制，早期神经成像研究的另一个限制是使用简短，不自然的说话任务。口吃发生在自然的、即兴的、连贯的讲话中。因此，在对CWS的言语运动系统提出最大要求的更生态有效的说话条件下评估神经激活是至关重要的。功能性近红外光谱可用于实现这一目标，因为它特别适合于记录自然说话条件下的脑血流动力学。本研究的另一个目的是探讨言语产生的中枢相关因子、外围运动言语动力学和口吃的行为指标之间的关系。我们将在一系列语言复杂性和听觉反馈被操纵的说话条件下，通过平行运动学和神经影像学实验来解决这一问题。将招募一个相对较大的CWS组，以确保代表一系列临床严重程度。通过结合一系列基于理论的实验，我们将确定口吃行为的潜在变化是否与CWS患者神经激活和言语运动协调的差异有关。该项目的研究结果将为未来使用这些非侵入性方法识别有持续性口吃风险的幼儿的神经特征提供关键的一步。

DESCRIPTION (provided by applicant): The overall goal of this project is to better understand the fundamental physiological and neural mechanisms that contribute to disfluencies in children who stutter (CWS). Our research strategy combines both ground-breaking and established experimental approaches including functional near-infrared spectroscopy (fNIRS - an emerging neuroimaging technology), kinematic measures of articulation, and clinical assessments of stuttering severity. An overall goal of this project is to examine activation of specific neural regions involved in speech production during a range of speaking conditions, including natural speech, using fNIRS. Findings from nearly 20 years of functional neuroimaging research in adults who stutter have provided greater insight into the neurological underpinnings of developmental stuttering. Because there have been few studies in CWS, however, it is unclear whether differences detected in adults who stutter are present at onset or emerge later, a consequence of a lifetime of compensation and/or therapeutic strategies. An additional limitation of earlier neuroimaging studies is the use of brief, unnatural speaking tasks due to methodological constraints inherent in fMRI and PET technologies. Stuttering occurs during natural, extemporaneous, connected speech. Therefore, it is critical to assess neural activation during more ecologically valid speaking conditions that place the greatest demands on the speech motor system of the CWS. Functional NIRS can be used to achieve this aim, because it is uniquely suited to record brain hemodynamics during natural speaking conditions. Another aim of this research is to examine relationships among central correlates of speech production, peripheral motor speech dynamics, and behavioral indices of stuttering. We will address this aim with parallel kinematic and neuroimaging experiments for a range of speaking conditions in which linguistic complexity and auditory feedback are manipulated. A relatively large group of CWS will be recruited to ensure that a range of clinical severity is represented. By incorporating a theoretically-grounded hierarchy of experiments designed to elicit a continuum of fluency, we will determine if potential changes in stuttering behavior are associated with differences in neural activation and speech motor coordination in CWS. Findings from this project will provide a critical step for future work using these noninvasive methods to identify neural characteristics of young children at risk for persistence in stuttering.