Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Graduate Program in Neuroscience, University of British Columbia, Vancouver, British Columbia, Canada.
J Neuroimaging. 2020 Sep;30(5):648-657. doi: 10.1111/jon.12741. Epub 2020 Jun 13.
Differences in the microstructure of fronto-parietal white matter tracts have been associated with mathematical achievement. However, much of the supporting evidence relies on nonspecific diffusion-weighted magnetic resonance imaging, making it difficult to isolate the role of myelin in math ability.
We used myelin water imaging to measure brain myelin. We related myelin water fraction (MWF) to Woodcock-Johnson III (WJ-III) basic math scores using region of interest (ROI) and tract-based spatial statistics (TBSS) analyses, in 14 typically developing and 36 learning challenged youth aged 9-17 years.
The ROI analysis found a positive relationship between fronto-parietal MWF and math in typically developing youth, but not in learning challenged youth. The relationship between fronto-parietal MWF and math observed in typically developing youth was fully mediated by age. No group differences in fronto-parietal MWF were found between typically developing and learning challenged youth. TBSS also found no group differences in MWF values. TBSS indicated math-MWF relationships extend beyond fronto-parietal tracts to descending and ascending projection tracts in typically developing youth. TBSS identified math-MWF relationships in the cerebral peduncles of learning challenged youth.
Our results suggest that in typically developing youth, brain myelination contributes to individual differences in basic math achievement. In contrast, youth with learning challenges appear to have less capacity to leverage myelin to improve math achievement.
额顶叶白质束的微观结构差异与数学成绩有关。然而，大部分支持证据依赖于非特异性弥散加权磁共振成像，因此难以分离髓鞘在数学能力中的作用。
我们使用髓鞘水成像来测量脑髓鞘。我们使用感兴趣区（ROI）和基于束的空间统计学（TBSS）分析，将髓鞘水分数（MWF）与 Woodcock-Johnson III（WJ-III）基本数学成绩相关联，共纳入 14 名典型发育和 36 名学习困难的 9-17 岁青少年。
ROI 分析发现，在典型发育的青少年中，额顶叶 MWF 与数学成绩呈正相关，但在学习困难的青少年中则无此关系。在典型发育的青少年中，MWF 与数学成绩之间的关系完全由年龄介导。在典型发育和学习困难的青少年之间，额顶叶 MWF 无组间差异。TBSS 也未发现 MWF 值的组间差异。TBSS 表明，在典型发育的青少年中，数学与 MWF 的关系不仅局限于额顶叶束，还延伸至下行和上行投射束。TBSS 确定了学习困难的青少年大脑脚中数学与 MWF 的关系。
我们的研究结果表明，在典型发育的青少年中，大脑髓鞘化有助于个体之间基本数学成绩的差异。相比之下，有学习障碍的青少年似乎利用髓鞘来提高数学成绩的能力较低。
