ABSTRACT

There is increasing evidence showing distinct neurocognitive underpinnings of different deficits of written language processing. This study investigated whether functional brain mechanisms related to isolated spelling problems can be distinguished from those observed for the combined profile of reading and spelling deficits (dyslexia). Two cognitive accounts explaining isolated spelling deficits were tested. Twenty-two children with typical development, 16 children with isolated spelling deficits and 20 children with dyslexia performed a reading-aloud task with words and pseudohomophones during fMRI. The whole-brain analysis for each condition revealed differential patterns of brain activity in the two deficit groups. No reliable differences between typically developing children and children with isolated spelling deficits could be observed in critical regions of the brain’s reading network. Children with dyslexia showed lower brain activity and reduced word-pseudohomophone effects in these regions. Our findings suggest that children with isolated spelling deficits can rely on (degraded) orthographic representations during reading.

摘要

越来越多的证据表明，不同的书面语言处理缺陷存在明显的神经认知基础。这项研究调查了是否可以将与孤立的拼写问题相关的功能性脑机制与阅读和拼写缺陷（阅读困难）的综合特征所观察到的脑机制区分开。测试了两个解释孤立的拼写缺陷的认知描述。在fMRI期间，有22名典型发育的儿童，16名患有孤立的拼写缺陷的儿童和20名阅读困难的儿童执行了单词和伪谐音的朗读任务。每种情况的全脑分析揭示了两个缺陷组的大脑活动的差异模式。在大脑阅读网络的关键区域，通常发育的儿童与孤立的拼写缺陷儿童之间没有可靠的差异。患有阅读障碍的儿童在这些地区表现出较低的大脑活动能力和单词伪谐音效果。我们的研究结果表明，患有拼写缺陷的儿童在阅读过程中可以依靠（降级的）拼字法表示形式。