Buianova Irina, Istomina Asya, Manzhurtsev Andrei, Ublinskiy Maxim, Karpychev Victor, Arsalidou Marie
Department of Psychology, University of Otago, Dunedin, New Zealand.
Center for Language and Brain, HSE University, Moscow, Russian Federation.
PLoS One. 2025 Jun 11;20(6):e0324802. doi: 10.1371/journal.pone.0324802. eCollection 2025.
Functional neuroimaging studies have identified distributed brain networks involved in arithmetic problem-solving. However, it is still poorly understood to what extent microstructural properties of the underlying white matter contribute to mathematical performance. We investigate microstructural characteristics of one of the least studied white matter tracts, the bilateral middle longitudinal fasciculus (MdLF), reconstructed from diffusion-weighted MRI data, and their relations with mathematical performance in arithmetic tasks of varying complexity, in 56 individuals aged 10-29 years (22 children: 10-13 years; 20 adolescents: 14-17 years; 14 adults: 18-29 years). We identify group differences in math performance and diffusivity measures. We highlight linear relations with age in left fractional anisotropy and right radial diffusivity, which can serve as developmental markers. Further, we document for the first time that diffusivity values in the right MdLF are significantly lower than in the left MdLF for all groups, suggesting hemispheric asymmetry. Importantly, associations between math performance in the right MdLF favoured easier tasks and in the left MdLF favoured harder tasks. This finding is a deviation from the classic hemisphere dominance hypothesis. We propose that the observed patterns may be explained by the right-left-right hemispheric dominance hypothesis proposed by a theory of cognitive development. Our results provide new insights into the microstructural properties of the MdLF and their role in mathematical ability, with implications for understanding brain-behaviour relations.
功能神经影像学研究已经确定了参与算术问题解决的分布式脑网络。然而，对于潜在白质的微观结构特性在多大程度上影响数学表现，我们仍然知之甚少。我们研究了56名年龄在10 - 29岁（22名儿童：10 - 13岁；20名青少年：14 - 17岁；14名成年人：18 - 29岁）个体中，从扩散加权磁共振成像（MRI）数据重建的研究最少的白质束之一——双侧中纵束（MdLF）的微观结构特征，以及它们与不同复杂程度算术任务中数学表现的关系。我们确定了数学表现和扩散率测量方面的组间差异。我们强调了左侧分数各向异性和右侧径向扩散率与年龄的线性关系，这可以作为发育标志物。此外，我们首次记录到，所有组右侧MdLF的扩散率值均显著低于左侧MdLF，表明存在半球不对称性。重要的是，右侧MdLF的扩散率值与较简单任务的数学表现相关，而左侧MdLF的扩散率值与较难任务的数学表现相关。这一发现与经典的半球优势假说不同。我们提出，观察到的模式可能由认知发展理论提出的右 -左 -右半球优势假说所解释。我们的研究结果为MdLF的微观结构特性及其在数学能力中的作用提供了新的见解，对理解脑 -行为关系具有启示意义。
