State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, People's Republic of China.
PLoS One. 2012;7(6):e39747. doi: 10.1371/journal.pone.0039747. Epub 2012 Jun 25.
Among the non-fluencies seen in speech, some are more typical (MT) of stuttering speakers, whereas others are less typical (LT) and are common to both stuttering and fluent speakers. No neuroimaging work has evaluated the neural basis for grouping these symptom types. Another long-debated issue is which type (LT, MT) whole-word repetitions (WWR) should be placed in. In this study, a sentence completion task was performed by twenty stuttering patients who were scanned using an event-related design. This task elicited stuttering in these patients. Each stuttered trial from each patient was sorted into the MT or LT types with WWR put aside. Pattern classification was employed to train a patient-specific single trial model to automatically classify each trial as MT or LT using the corresponding fMRI data. This model was then validated by using test data that were independent of the training data. In a subsequent analysis, the classification model, just established, was used to determine which type the WWR should be placed in. The results showed that the LT and the MT could be separated with high accuracy based on their brain activity. The brain regions that made most contribution to the separation of the types were: the left inferior frontal cortex and bilateral precuneus, both of which showed higher activity in the MT than in the LT; and the left putamen and right cerebellum which showed the opposite activity pattern. The results also showed that the brain activity for WWR was more similar to that of the LT and fluent speech than to that of the MT. These findings provide a neurological basis for separating the MT and the LT types, and support the widely-used MT/LT symptom grouping scheme. In addition, WWR play a similar role as the LT, and thus should be placed in the LT type.
在言语不流畅中，有些是更典型的（MT）口吃者，而另一些则不那么典型（LT），并且在口吃者和流利者中都很常见。没有神经影像学研究评估将这些症状类型分组的神经基础。另一个长期争论的问题是哪种类型（LT、MT）的整词重复（WWR）应该归类。在这项研究中，二十名口吃患者使用事件相关设计进行了句子完成任务。该任务诱发了这些患者的口吃。每位患者的口吃试验都被分为 MT 或 LT 类型，而 WWR 则单独列出。模式分类用于训练患者特定的单次试验模型，该模型使用相应的 fMRI 数据自动将每个试验分类为 MT 或 LT。然后使用与训练数据独立的测试数据来验证该模型。在随后的分析中，刚刚建立的分类模型用于确定 WWR 应该归类的类型。结果表明，基于大脑活动，可以高精度地区分 LT 和 MT。对类型分离贡献最大的脑区为：左侧额下回和双侧楔前叶，MT 的活动高于 LT；左侧壳核和右侧小脑表现出相反的活动模式。结果还表明，WWR 的大脑活动与 LT 和流利言语的大脑活动更为相似，而与 MT 的大脑活动则不相似。这些发现为区分 MT 和 LT 类型提供了神经学基础，并支持广泛使用的 MT/LT 症状分组方案。此外，WWR 发挥与 LT 相似的作用，因此应归类于 LT 类型。
