Kucian Karin, Loenneker Thomas, Dietrich Thomas, Dosch Mengia, Martin Ernst, von Aster Michael
MR-Center, University Children's Hospital, Zurich, Switzerland.
Behav Brain Funct. 2006 Sep 5;2:31. doi: 10.1186/1744-9081-2-31.
Developmental dyscalculia (DD) is a specific learning disability affecting the acquisition of mathematical skills in children with otherwise normal general intelligence. The goal of the present study was to examine cerebral mechanisms underlying DD.
Eighteen children with DD aged 11.2 +/- 1.3 years and twenty age-matched typically achieving schoolchildren were investigated using functional magnetic resonance imaging (fMRI) during trials testing approximate and exact mathematical calculation, as well as magnitude comparison.
Children with DD showed greater inter-individual variability and had weaker activation in almost the entire neuronal network for approximate calculation including the intraparietal sulcus, and the middle and inferior frontal gyrus of both hemispheres. In particular, the left intraparietal sulcus, the left inferior frontal gyrus and the right middle frontal gyrus seem to play crucial roles in correct approximate calculation, since brain activation correlated with accuracy rate in these regions. In contrast, no differences between groups could be found for exact calculation and magnitude comparison. In general, fMRI revealed similar parietal and prefrontal activation patterns in DD children compared to controls for all conditions.
In conclusion, there is evidence for a deficient recruitment of neural resources in children with DD when processing analog magnitudes of numbers.
发育性计算障碍（DD）是一种特殊的学习障碍，影响着智力正常儿童数学技能的习得。本研究的目的是探究DD潜在的大脑机制。
对18名年龄为11.2±1.3岁的DD儿童和20名年龄匹配的数学成绩正常的学童，在进行近似和精确数学计算以及数量比较测试时使用功能磁共振成像（fMRI）进行研究。
DD儿童个体间差异更大，在几乎整个用于近似计算的神经网络中激活较弱，包括顶内沟以及双侧半球的额中回和额下回。特别是，左侧顶内沟、左侧额下回和右侧额中回似乎在正确的近似计算中起关键作用，因为这些区域的大脑激活与准确率相关。相比之下，在精确计算和数量比较方面未发现组间差异。总体而言，fMRI显示在所有情况下，DD儿童与对照组相比，顶叶和前额叶的激活模式相似。
总之，有证据表明DD儿童在处理数字的类似数量时神经资源募集不足。
