Andrulyte Ieva, De Bezenac Christophe, Branzi Francesca, Forkel Stephanie J, Taylor Peter N, Keller Simon S
Departments of Pharmacology and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L3 9TA, United Kingdom
Departments of Pharmacology and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L3 9TA, United Kingdom.
J Neurosci. 2024 Dec 11;44(50):e0166242024. doi: 10.1523/JNEUROSCI.0166-24.2024.
Interhemispheric anatomical differences have long been thought to be related to language lateralization. Previous studies have explored whether asymmetries in the diffusion characteristics of white matter language tracts are consistent with language lateralization. These studies, typically with smaller cohorts, yielded mixed results. This study investigated whether connectomic analysis of quantitative anisotropy (QA) and shape features of white matter tracts across the whole brain are associated with language lateralization. We analyzed 1,040 healthy individuals (562 females) from the Human Connectome Project database. Hemispheric language dominance for each participant was quantified using a laterality quotient (LQ) derived from fMRI activation in regions of interest (ROIs) associated with a language comprehension task compared against a math task. A linear regression model was used to examine the relationship between structural asymmetry and functional lateralization. Connectometry revealed a significant negative correlation between LQs and QA of corpus callosum tracts, indicating that higher QA in these regions is associated with bilateral and right hemisphere language representation in frontal and temporal regions. Left language laterality in the temporal lobe was significantly associated with longer right inferior fronto-occipital fasciculus (IFOF) and forceps minor tracts. These results suggest that diffusion measures of microstructural architecture as well as geometrical features of reconstructed white matter tracts play a role in language lateralization. People with increased dependence on the right or both frontal hemispheres for language processing may have more developed commissural fibers, which may support more efficient interhemispheric communication.
长期以来，人们一直认为半球间的解剖学差异与语言侧化有关。以往的研究探讨了白质语言束扩散特征的不对称性是否与语言侧化一致。这些研究通常样本量较小，结果不一。本研究调查了全脑白质束的定量各向异性（QA）和形状特征的连接组分析是否与语言侧化相关。我们分析了来自人类连接组计划数据库的1040名健康个体（562名女性）。使用从与语言理解任务相关的感兴趣区域（ROI）的功能磁共振成像激活中得出的偏侧商（LQ），并与数学任务进行比较，来量化每个参与者的半球语言优势。使用线性回归模型来检验结构不对称性与功能侧化之间的关系。连接组学显示胼胝体束的LQ与QA之间存在显著负相关，表明这些区域较高的QA与额叶和颞叶的双侧及右半球语言表征相关。颞叶的左侧语言侧化与右侧下额枕束（IFOF）和小钳状束较长显著相关。这些结果表明，微观结构的扩散测量以及重建白质束的几何特征在语言侧化中发挥作用。在语言处理上对右侧或双侧额叶半球依赖增加的人可能有更发达的连合纤维，这可能支持更有效的半球间通信。
