Hemispheric asymmetries in language-related pathways: A combined functional MPI and tractography study
Hemispheric asymmetries in language-related pathways: A combined functional MPI and tractography study
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DOI：
10.1016/j.neuroimage.2006.03.011
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发表时间：
2006-08-01
期刊：
影响因子：
5.7
通讯作者：
Duncan, John S.
中科院分区：
文献类型：
--
作者：
Powell, H. W. Robert;Parker, Geoff J. M.;Duncan, John S.
功能偏侧化是人类大脑功能的一个特征，在典型的左半球语言专门化中最为明显。大量的解剖学和影像学研究已经研究了结构不对称是否是这种功能偏侧化的基础。我们结合功能磁共振成像（fMRI）和弥散加权成像（DWI）与纤维束成像研究10名健康的右利手受试者。三种语言功能磁共振成像模式被用来定义语言相关的区域在额叶下部和上级颞区。然后采用概率纤维束成像技术来描绘这些功能定义区域的连接。我们证明了布罗卡区和韦尼克区之间的一致连接沿着两侧的上级纵束，但更广泛的额颞连接左侧比右侧。左侧的束体积和平均各向异性分数（FA）均显著大于右侧。我们还证明了结构和功能的措施之间的相关性，与受试者更偏侧的功能磁共振成像激活有一个更高度偏侧的平均FA的连接。这些结构上的不对称性与语言功能的偏侧化是一致的，并表明了语言功能背后的主要结构联系。(c)2006年爱思唯尔公司All rights reserved.
Functional lateralization is a feature of human brain function, most apparent in the typical left-hemisphere specialization for language. A number of anatomical and imaging studies have examined whether structural asymmetries underlie this functional lateralization. We combined functional MRI (fMRI) and diffusion-weighted imaging (DWI) with tractography to study 10 healthy right-handed subjects. Three language fMRI paradigms were used to define language-related regions in inferior frontal and superior temporal regions. A probabilistic tractography technique was then employed to delineate the connections of these functionally defined regions. We demonstrated consistent connections between Broca's and Wernicke's areas along the superior longitudinal fasciculus bilaterally but more extensive frontotemporal connectivity on the left than the right. Both tract volumes and mean fractional anisotropy (FA) were significantly greater on the left than the right. We also demonstrated a correlation between measures of structure and function, with subjects with more lateralized fMRI activation having a more highly lateralized mean FA of their connections. These structural asymmetries are in keeping with the lateralization of language function and indicate the major structural connections underlying this function. (c) 2006 Elsevier Inc. All rights reserved.