Reading-Related Functional Activity In Children With Isolated Spelling Deficits And Dyslexia

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.