Perdue Meaghan V, Geeraert Bryce L, Manning Kathryn Y, Dewey Deborah, Lebel Catherine
University of Calgary, Department of Radiology, 28 Oki Drive NW, Calgary, Alberta T3B 6A8, Canada; Alberta Children's Hospital Research Institute, 28 Oki Drive NW, Calgary, Alberta T3B 6A8, Canada; University of Calgary, Hotchkiss Brain Institute, 28 Oki Drive NW, Calgary, Alberta T3B 6A8, Canada; University of Massachusetts Chan Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
University of Calgary, Department of Radiology, 28 Oki Drive NW, Calgary, Alberta T3B 6A8, Canada; Alberta Children's Hospital Research Institute, 28 Oki Drive NW, Calgary, Alberta T3B 6A8, Canada; University of Calgary, Hotchkiss Brain Institute, 28 Oki Drive NW, Calgary, Alberta T3B 6A8, Canada.
Dev Cogn Neurosci. 2025 Apr;72:101537. doi: 10.1016/j.dcn.2025.101537. Epub 2025 Feb 25.
Numerous studies have linked reading ability to white matter microstructure using diffusion tensor imaging, but findings have been inconsistent and lack specificity. Fiber-specific diffusion-weighted magnetic resonance imaging (dMRI) models offer enhanced precision in measuring specific microstructural features, but they have not yet been applied to examine associations between reading ability and white matter microstructure development as children learn to read. We applied constrained spherical deconvolution (CSD) and fiber-specific modelling to characterize developmental changes in fiber density of key white matter tracts of the reading network, and investigated associations between tract-wise fiber density and children's phonological decoding abilities. Fiber density was measured from ages 2-13 years, and decoding ability (pseudoword reading) was assessed at ages 6 years and older. Higher decoding ability was associated with greater fiber density in the left arcuate fasciculus, and effects remained consistent over time. Follow-up analysis revealed that asymmetry changes in the arcuate fasciculus were moderated by decoding ability: good decoders showed leftward asymmetry from early childhood onward, while poorer decoders shifted toward leftward asymmetry over time. These results suggest that densely organized fibers in the left arcuate fasciculus serve as a foundation for the development of reading skills from the pre-reading stage through fluent reading.
众多研究已使用扩散张量成像将阅读能力与白质微观结构联系起来，但研究结果并不一致且缺乏特异性。纤维特异性扩散加权磁共振成像（dMRI）模型在测量特定微观结构特征方面具有更高的精度，但尚未应用于研究儿童学习阅读时阅读能力与白质微观结构发育之间的关联。我们应用约束球面反卷积（CSD）和纤维特异性建模来表征阅读网络关键白质束纤维密度的发育变化，并研究逐束纤维密度与儿童语音解码能力之间的关联。在2至13岁测量纤维密度，并在6岁及以上评估解码能力（假词阅读）。较高的解码能力与左侧弓状束中更大的纤维密度相关，且随着时间推移这种效应保持一致。后续分析表明，弓状束的不对称变化受解码能力调节：阅读能力好的儿童从幼儿期开始就表现出向左不对称，而阅读能力较差的儿童随着时间推移逐渐转向向左不对称。这些结果表明，左侧弓状束中密集排列的纤维是从阅读前阶段到流畅阅读阶段阅读技能发展的基础。
