Left posterior-dorsal area 44 couples with parietal areas to promote speech fluency, while right area 44 activity promotes the stopping of motor responses
Left posterior-dorsal area 44 couples with parietal areas to promote speech fluency, while right area 44 activity promotes the stopping of motor responses
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DOI：
10.1016/j.neuroimage.2016.08.030
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发表时间：
2016-11-15
期刊：
影响因子：
5.7
通讯作者：
Sommer, Martin
中科院分区：
文献类型：
--
作者：
Neef, Nicole E.;Buetfering, Christoph;Sommer, Martin
44区是Broca区在细胞构筑上的独特部分。平行和重叠的大规模网络与该区域结合在一起，从而协调了不同的语言、认知和运动功能。在口吃的背景下，44区经常成为焦点，因为结构和生理上的异常会影响发展轨迹、口吃的严重性、持续性和病因。伴随口吃而来的一个显著现象是歌唱能力被保留下来。说话和唱歌是天生的行为，招募的大脑网络基本上是重叠的，包括左侧和右侧区域44。分析成年人口吃时44区的哪些潜在亚区有故障，以及是什么有效地抑制了歌唱过程中的口吃，可能会更好地理解大规模大脑网络的协调和重组，这些网络专门负责说话和唱歌。我们使用fMRI研究了15名口吃的右旋男性和17名匹配的对照组受试者在说话和想象哼唱旋律时44区功能不同的亚区。我们的结果是四倍的。首先，口吃与左侧后背侧区域44的激活减少有关，该区域参与语音产生，包括语音文字处理、音调处理、工作记忆处理、排序、运动规划、假词学习和动作抑制。第二，口吃患者左侧后区44区与左侧顶下小叶之间的功能耦合不足。第三，尽管保留了唱歌的能力，但口吃的男性在想象哼唱旋律时，双侧44区的激活减少，这表明这种提高流利性的条件似乎绕过了后背区44，以实现流利性。第四，44区后亚区的时间进程显示两组患者右侧大脑半球的峰值激活延迟，可能是偏移性反应的信号。因为在口吃的男性中，右脑的这些与抵消反应相关的激活相对较大，我们的数据表明，一种过度活跃的机制可以停止言语运动反应，因此可能反映了一种病理机制，到目前为止，这一机制一直被忽视。总体而言，目前的结果证实了最近描述的基于共激活的分割，支持左侧区域44的功能不同亚区的想法。(C)2016年提交人。由爱思唯尔公司出版。
Area 44 is a cytoarchitectonically distinct portion of Broca's region. Parallel and overlapping large-scale networks couple with this region thereby orchestrating heterogeneous language, cognitive, and motor functions. In the context of stuttering, area 44 frequently comes into focus because structural and physiological irregularities affect developmental trajectories, stuttering severity, persistency, and etiology. A remarkable phenomenon accompanying stuttering is the preserved ability to sing. Speaking and singing are connatural behaviours recruiting largely overlapping brain networks including left and right area 44. Analysing which potential subregions of area 44 are malfunctioning in adults who stutter, and what effectively suppresses stuttering during singing, may provide a better understanding of the coordination and reorganization of large-scale brain networks dedicated to speaking and singing in general. We used fMRI to investigate functionally distinct subregions of area 44 during imagery of speaking and imaginary of humming a melody in 15 dextral males who stutter and 17 matched control participants. Our results are fourfold. First, stuttering was specifically linked to a reduced activation of left posterior-dorsal area 44, a subregion that is involved in speech production, including phonological word processing, pitch processing, working memory processes, sequencing, motor planning, pseudoword learning, and action inhibition. Second, functional coupling between left posterior area 44 and left inferior parietal lobule was deficient in stuttering. Third, despite the preserved ability to sing, males who stutter showed bilaterally a reduced activation of area 44 when imagine humming a melody, suggesting that this fluency-enhancing condition seems to bypass posterior-dorsal area 44 to achieve fluency. Fourth, time courses of the posterior subregions in area 44 showed delayed peak activations in the right hemisphere in both groups, possibly signaling the offset response. Because these offset response-related activations in the right hemisphere were comparably large in males who stutter, our data suggest a hyperactive mechanism to stop speech motor responses and thus possibly reflect a pathomechanism, which, until now, has been neglected. Overall, the current results confirmed a recently described co-activation based parcellation supporting the idea of functionally distinct subregions of left area 44. (C) 2016 The Authors. Published by Elsevier Inc.