Markett Sebastian, Bleek Benjamin, Reuter Martin, Prüss Holger, Richardt Kirsten, Müller Thilo, Yaruss J Scott, Montag Christian
Department of Psychology, University of Bonn, Germany; Center for Economics and Neuroscience, University of Bonn, Germany.
Department of Psychology, University of Bonn, Germany.
Neuropsychologia. 2016 Oct;91:444-450. doi: 10.1016/j.neuropsychologia.2016.09.008. Epub 2016 Sep 13.
Idiopathic stuttering is a fluency disorder characterized by impairments during speech production. Deficits in the motor control circuits of the basal ganglia have been implicated in idiopathic stuttering but it is unclear how these impairments relate to the disorder. Previous work has indicated a possible deficiency in motor inhibition in children who stutter. To extend these findings to adults, we designed two experiments to probe executive motor control in people who stutter using manual reaction time tasks that do not rely on speech production. We used two versions of the stop-signal reaction time task, a measure for inhibitory motor control that has been shown to rely on the basal ganglia circuits. We show increased stop-signal reaction times in two independent samples of adults who stutter compared to age- and sex-matched control groups. Additional measures involved simple reaction time measurements and a task-switching task where no group difference was detected. Results indicate a deficiency in inhibitory motor control in people who stutter in a task that does not rely on overt speech production and cannot be explained by general deficits in executive control or speeded motor execution. This finding establishes the stop-signal reaction time as a possible target for future experimental and neuroimaging studies on fluency disorders and is a further step towards unraveling the contribution of motor control deficits to idiopathic stuttering.
特发性口吃是一种流畅性障碍，其特征在于言语产生过程中的损伤。基底神经节运动控制回路的缺陷与特发性口吃有关，但尚不清楚这些损伤如何与该障碍相关联。先前的研究表明，口吃儿童可能存在运动抑制缺陷。为了将这些发现扩展到成年人，我们设计了两个实验，使用不依赖言语产生的手动反应时间任务来探究口吃者的执行运动控制。我们使用了两种版本的停止信号反应时间任务，这是一种已被证明依赖基底神经节回路的抑制性运动控制测量方法。与年龄和性别匹配的对照组相比，我们在两个独立的成年口吃者样本中发现停止信号反应时间增加。其他测量包括简单反应时间测量和任务切换任务，未检测到组间差异。结果表明，在不依赖明显言语产生的任务中，口吃者存在抑制性运动控制缺陷，且不能用执行控制或快速运动执行的一般缺陷来解释。这一发现确定了停止信号反应时间可能是未来关于流畅性障碍的实验和神经影像学研究的一个目标，并且是朝着揭示运动控制缺陷对特发性口吃的影响迈出的又一步。
