Department of Neurology, Medical University of Graz, Austria.
Neuropsychologia. 2012 Jun;50(7):1353-61. doi: 10.1016/j.neuropsychologia.2012.02.020. Epub 2012 Mar 1.
Studies investigating reading and spelling difficulties heavily focused on the neural correlates of reading impairments, whereas spelling impairments have been largely neglected so far. Hence, the aim of the present study was to investigate brain structure and function of children with isolated spelling difficulties. Therefore, 31 children, aged ten to 15 years, were investigated by means of functional MRI and DTI. This study revealed that children with isolated spelling impairment exhibit a stronger right hemispheric activation compared to children with reading and spelling difficulties and controls, when engaged in an orthographic decision task, presumably reflecting a highly efficient serial grapheme-phoneme decoding compensation strategy. In addition, children with spelling impairment activated bilateral inferior and middle frontal gyri during processing correctly spelled words and misspelled words, whereas the other two groups showed bilateral activation only in the misspelled condition, suggesting that additional right frontal engagement could be related to generally higher task demand and effort. DTI analyses revealed stronger frontal white matter integrity (fractional anisotropy) in controls (compared to spelling and reading impaired children), whereas no structural differences between controls and spelling impaired children were observed.
研究调查了阅读和拼写困难，重点关注阅读障碍的神经相关性，而拼写障碍迄今为止在很大程度上被忽视了。因此，本研究旨在调查孤立性拼写困难儿童的大脑结构和功能。为此，对 31 名 10 至 15 岁的儿童进行了功能磁共振成像和 DTI 研究。该研究表明，在进行正字法判断任务时，与阅读和拼写困难的儿童以及对照组相比，患有孤立性拼写障碍的儿童表现出更强的右侧半球激活，这可能反映了一种高效的串行字形-音位解码补偿策略。此外，拼写障碍儿童在处理正确拼写的单词和拼写错误的单词时会激活双侧额下回和额中回，而其他两组仅在拼写错误的情况下表现出双侧激活，这表明额外的右额叶参与可能与更高的任务需求和努力有关。DTI 分析显示，对照组（与阅读和拼写障碍儿童相比）的额白质完整性（各向异性分数）更强，而对照组和拼写障碍儿童之间没有观察到结构差异。
