Department of Cognitive Science, ARC Centre of Excellence for Cognition and its Disorders, Macquarie University , Sydney, NSW , Australia ; Perception and Action Research Centre (PARC), Faculty of Human Sciences, Macquarie University , Sydney, NSW , Australia.
Department of Linguistics, ARC Centre of Excellence for Cognition and its Disorders, Macquarie University , Sydney, NSW , Australia.
Front Hum Neurosci. 2014 May 28;8:354. doi: 10.3389/fnhum.2014.00354. eCollection 2014.
The neural causes of stuttering remain unknown. One explanation comes from neuroimaging studies that have reported abnormal lateralization of activation in the brains of people who stutter. However, these findings are generally based on data from adults with a long history of stuttering, raising the possibility that the observed lateralization anomalies are compensatory rather than causal. The current study investigated lateralization of brain activity in language-related regions of interest in young children soon after the onset of stuttering. We tested 24 preschool-aged children, half of whom had a positive diagnosis of stuttering. All children participated in a picture-naming experiment whilst their brain activity was recorded by magnetoencephalography. Source analysis performed during an epoch prior to speech onset was used to assess lateralized activation in three regions of interest. Activation was significantly lateralized to the left hemisphere in both groups and not different between groups. This study shows for the first time that significant speech preparatory brain activation can be identified in young children during picture-naming and supports the contention that, in stutterers, aberrant lateralization of brain function may be the result of neuroplastic adaptation that occurs as the condition becomes chronic.
口吃的神经原因尚不清楚。一种解释来自神经影像学研究，这些研究报告称，口吃者大脑的激活存在异常侧化。然而，这些发现通常基于有长期口吃史的成年人的数据，这使得人们认为观察到的侧化异常是代偿性的，而不是因果性的。本研究调查了口吃发作后不久的语言相关感兴趣区域的大脑活动的侧化。我们测试了 24 名学龄前儿童，其中一半被诊断为口吃。所有儿童在进行图片命名实验时，其大脑活动都通过脑磁图记录下来。在说话前的一个时段进行的源分析用于评估三个感兴趣区域的侧化激活。两组的激活都明显偏向于左侧半球，两组之间没有差异。这项研究首次表明，在图片命名过程中，可以在年幼的孩子身上识别出与言语准备相关的显著大脑激活，并支持这样一种观点，即口吃者的大脑功能异常侧化可能是随着病情发展为慢性而发生的神经可塑性适应的结果。
