The Negative BOLD Response in Speech Production and Persistent Stuttering

口吃是一种神经发育性语言障碍，影响儿童进入成年期，具有长期的心理社会和经济影响，口吃的核心是流利的语音。口吃症的一个特征是，即使在说出感觉上流利的语言时，口吃者的大脑和行为过程也与非口吃者有所不同。不幸的是，经过几十年的研究，涉及行为描述、结构和功能神经成像以及计算建模，目前还没有针对这种疾病的连贯的神经生物学框架。目前的提议是朝着开发口吃的神经机制模型迈出的第一步，并将其应用于其他口语产生的神经发育障碍。最重要的假设是，口吃与神经抑制水平的降低有关，这反映在负的血氧水平依赖(BOLD)信号反应(NBR)的减少。这种发育过程中抑制的减少对大脑结构和功能以及语言神经网络的稳定性和动力学产生了长期和广泛的影响，这些神经网络可能会影响全部或部分感觉运动、语言和认知行为。经验数据和概念框架将通过在言语产生方式中加入目前缺失的神经成分过程来影响言语产生模型和理论，并为神经发育性言语障碍的更多信息和神经生物学模型铺平道路。

Difficulty in producing fluent speech is the core of stuttering, a neurodevelopmental speech disorder affecting children into adulthood with long-term psychosocial and economic impact. A characteristic of the disorder is that even when producing perceptually fluent speech, there are differences in the brain and behavioural processes for individuals who stutter compared to those that do not. Unfortunately, after decades of research involving behavioral description, structural and functional neuroimaging and computational modeling, no coherent neurobiological framework for the disorder exists. The current proposal is a first step toward developing a neural mechanistic model for stuttering with application to other neurodevelopmental disorders of spoken language production. The over-arching hypothesis is that stuttering is associated with a reduced level of neural inhibition, as reflected in a reduction in the negative blood-oxygen-level-dependent (BOLD) signal response (NBR). This reduction in inhibition during development has long-term and wide-ranging effects on brain structure and function and the stability and dynamics of neural networks for speech potentially impacting all or some sensorimotor, linguistic and cognitive behaviours. The empirical data and conceptual framework will impact speech production models and theories by adding a currently missing neural component process to the manner in which speech is produced and pave the way for a more informed and neurobiological model of neurodevelopmental speech disorders.