Implicit and explicit motor learning in children and adults who stutter

发展性口吃是一种语言流畅性障碍，通常在青春期前的儿童中发病。有重要证据表明，言语运动缺陷是这种疾病的核心。这些缺陷，可能是遗传和神经的性质，被认为是我们理解口吃的发病，发展和恢复的基础。在我们之前的研究中，我们调查了口吃的成年人在获得新的运动技能方面的能力不足的程度。我们的研究结果表明，这些成年人是不熟练的非口吃的扬声器获得新的语音序列，即使经过广泛的实践。早期的证据表明，口吃和非口吃成年人之间的技能巩固的差异表明，这种缺陷可能反映了运动执行和运动学习过程。重要的是，我们的研究结果还表明，言语和非言语（手指排序）运动技能的表现缺陷之间存在明显的相似之处，支持了这一假设，即影响口吃的人的这些缺陷不仅限于言语清晰度，而且可能反映了一般的运动缺陷。* 学习运动技能是一个程序性的学习过程，在此过程中，表现会随着任务的多次重复而逐渐提高。这个过程可以是显性的，也可以是隐性的。 内隐运动学习是指学习是偶然的，参与者没有意识到他们已经学到了什么，以及他们如何执行任务。外显运动学习可以是有意的，参与者意识到他们的知识，并可以报告it.These两种学习策略，建议反映不同的学习机制，依赖于不同的神经基板。我们假设内隐和外显学习都可能参与口吃的发展，但这两个过程的相对权重还没有调查。内隐运动学习在言语的早期发展过程中显然是重要的，有人认为口吃的人可能在很大程度上依赖于外显策略。此外，内隐和外显学习都可能受到不稳定的感觉运动言语系统的影响。重要的是，已经有人提出，外显学习依赖于建立稳定的内部运动模型。如果不这样做，可能会导致言语流畅性中断。揭示内隐和外显运动学习在口吃发展中的独特作用对理解这种言语流畅性障碍至关重要。拟议的项目概述了旨在调查口吃儿童和成人的运动学习技能的研究。该项目将大大有助于我们理解口吃的本质和发展，并将为正在进行的言语运动控制模型的改进提供信息。

Developmental stuttering is a speech fluency disorder, which typically has its onset in pre-pubescent children. There is significant evidence that speech motor deficits are at the core of the disorder. These deficits, which likely are genetic and neural in nature, are considered fundamental to our understanding of the onset, development and recovery from stuttering. In our previous research, we have investigated the extent to which adults who stutter are deficient in their ability to acquire novel motor skills. Our results have demonstrated that these adults are less proficient than nonstuttering speakers acquiring new speech sequences, even after extensive practice. Early evidence of differences in skill consolidation between the stuttering and nonstuttering adults has suggested that this deficit may reflect both motor execution and motor learning processes. Importantly, our results also have shown clear parallels between deficient performance in both speech and non-speech (finger sequencing) motor skills, supporting the hypothesis that these deficiencies affecting people who stutter are not limited to speech articulation but may reflect a general motor deficit. ***Learning a motor skill is a procedural learning process during which performance improves gradually over many repetitions of the task. This process can be both explicit and implicit. Implicit motor learning refers to learning that is incidental, and in which participants are not aware of what they have learned and of how they perform the task. Explicit motor learning can be intentional, and participants are conscious of their knowledge and can report it. These two learning strategies are suggested to reflect different learning mechanisms that rely on distinct neural substrates. We have hypothesized that both implicit and explicit learning may be involved in the development of stuttering but the relative weight of these two processes has not been investigated. Implicit motor learning clearly is important during the early development of speech and it has been suggested that people who stutter may rely to a larger extent on explicit strategies. In addition, both implicit and explicit learning may be affected by the presence of an unstable sensorimotor speech system. Importantly, it has been proposed that explicit learning relies on the establishment of stable internal motor models. The failure to do so for speech may lead to disrupted speech fluency. Unraveling the unique contributions of implicit and explicit motor learning in the development of stuttering is critical to understanding this speech fluency disorder. The proposed project outlines studies aimed at investigating motor learning skills in children and adults who stutter. The project will contribute significantly to our understanding of the nature and development of stuttering and will inform the ongoing refinement of motor control models for speech.**