The Negative BOLD Response in Speech Production and Persistent Stuttering

口吃是一种影响儿童直至成年的神经发育性语言障碍，具有长期的社会心理和经济影响。这种障碍的一个特点是，即使在产生感知流利的语言时，口吃者的大脑和行为过程与不口吃者相比也存在差异。不幸的是，经过几十年的研究，包括行为描述、结构和功能神经成像以及计算模型，没有关于这种疾病的连贯的神经生物学框架。目前的建议是朝着发展口吃的神经机制模型并将其应用于口语产生的其他神经发育障碍迈出的第一步。最重要的假设是，口吃与神经抑制水平降低有关，这反映在负血氧水平依赖性（BOLD）信号反应（NBR）的降低上。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态具有长期和广泛的影响，可能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的方式中添加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知情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.