Purdue University, Department of Speech, Language, and Hearing Sciences, Heavilon Hall, 500 Oval Drive, West Lafayette, IN 47907-2038, USA.
J Fluency Disord. 2013 Jun;38(2):206-21. doi: 10.1016/j.jfludis.2013.01.001. Epub 2013 Jan 20.
We examined neural activity mediating semantic and syntactic processing in 27 preschool-age children who stutter (CWS) and 27 preschool-age children who do not stutter (CWNS) matched for age, nonverbal IQ and language abilities. All participants displayed language abilities and nonverbal IQ within the normal range. Event-related brain potentials (ERPs) were elicited while participants watched a cartoon video and heard naturally spoken sentences that were either correct or contained semantic or syntactic (phrase structure) violations. ERPs in CWS, compared to CWNS, were characterized by longer N400 peak latencies elicited by semantic processing. In the CWS, syntactic violations elicited greater negative amplitudes for the early time window (150-350 ms) over medial sites compared to CWNS. Additionally, the amplitude of the P600 elicited by syntactic violations relative to control words was significant over the left hemisphere for the CWNS but showed the reverse pattern in CWS, a robust effect only over the right hemisphere. Both groups of preschoolage children demonstrated marked and differential effects for neural processes elicited by semantic and phrase structure violations; however, a significant proportion of young CWS exhibit differences in the neural functions mediating language processing compared to CWNS despite normal language abilities. These results are the first to show that differences in event-related brain potentials reflecting language processing occur as early as the preschool years in CWS and provide the first evidence that atypical lateralization of hemispheric speech/language functions previously observed in the brains of adults who stutter begin to emerge near the onset of developmental stuttering.
The reader will be able to: (1) describe the role of language processing in current theoretical models of developmental stuttering; (2) summarize current evidence regarding language processing differences between individuals who do and do not stutter; (3) describe typical changes in neural indices of semantic and syntactic processing across development; (4) discuss the potential implications of the current findings in relation to theories of developmental stuttering.
我们研究了 27 名口吃儿童（CWS）和 27 名不口吃儿童（CWNS）在语义和句法处理中介导的神经活动，这些儿童在年龄、非言语智商和语言能力方面相匹配。所有参与者的语言能力和非言语智商均在正常范围内。参与者观看卡通视频并听到正确或包含语义或句法（短语结构）违规的自然语言句子时，会引出事件相关脑电位（ERPs）。与 CWNS 相比，CWS 的 N400 峰潜伏期更长，表明语义处理受到影响。在 CWS 中，与 CWNS 相比，句法违规引起的早期时间窗口（150-350ms）的负波幅更大，主要集中在内侧部位。此外，与控制词相比，句法违规引起的 P600 的振幅在 CWNS 中主要出现在左半球，但在 CWS 中出现相反的模式，仅在右半球出现强烈的效应。两组学龄前儿童的语义和短语结构违规引起的神经过程均表现出明显的差异；然而，尽管语言能力正常，但相当一部分年轻的 CWS 与 CWNS 相比，语言处理中介的神经功能存在差异。这些结果首次表明，CWS 中与语言处理相关的事件相关脑电位差异早在学龄前就出现，并首次提供证据表明，以前在口吃成年人大脑中观察到的半球言语/语言功能的异常侧化开始在发展性口吃的发病初期出现。
读者将能够：（1）描述语言处理在发展性口吃的当前理论模型中的作用；（2）总结关于口吃者和非口吃者之间语言处理差异的当前证据；（3）描述语义和句法处理的神经指数在整个发育过程中的典型变化；（4）讨论当前发现与发展性口吃理论的潜在关系。
