Centre for Brain Research, School of Psychology, University of Auckland, New Zealand.
Department of Psychology, University of Canterbury, New Zealand.
Neuroimage Clin. 2018 Feb 5;18:356-366. doi: 10.1016/j.nicl.2018.02.004. eCollection 2018.
Learning disabilities such as dyslexia, dyscalculia and their comorbid manifestation are prevalent, affecting as much as 15% of the population. Structural neuroimaging studies have indicated that these disorders can be related to differences in white matter integrity, although findings remain disparate. In this study, we used a unique design composed of individuals with dyslexia, dyscalculia, both disorders and controls, to systematically explore differences in fractional anisotropy across groups using diffusion tensor imaging. Specifically, we focused on the corona radiata and the arcuate fasciculus, two tracts associated with reading and mathematics in a number of previous studies. Using Bayesian hypothesis testing, we show that the present data favor the null model of no differences between groups for these particular tracts-a finding that seems to go against the current view but might be representative of the disparities within this field of research. Together, these findings suggest that structural differences associated with dyslexia and dyscalculia might not be as reliable as previously thought, with potential ramifications in terms of remediation.
学习障碍，如诵读困难、计算障碍及其共病表现，较为常见，影响了多达 15%的人群。结构神经影像学研究表明，这些障碍可能与白质完整性的差异有关，但研究结果仍存在差异。在这项研究中，我们使用了一种独特的设计，由诵读困难、计算障碍、两种障碍和对照组的个体组成，使用弥散张量成像系统地探索了各组之间各向异性分数的差异。具体来说，我们集中研究了放射冠和弓状束，这两个束在之前的一些研究中与阅读和数学有关。使用贝叶斯假设检验，我们表明，目前的数据倾向于组间无差异的零假设——这一发现似乎与当前的观点相悖，但可能代表了该研究领域的差异。总之，这些发现表明，与诵读困难和计算障碍相关的结构差异可能不如以前认为的那样可靠，这可能会对矫正产生影响。
