The neuro-electrophysiological basis of reading in Chinese children with dyslexia : an ERP study investigating phonological processing using delayed naming task

Abstract

In contrast to reading alphabetic scripts, the importance of phonological processing for reading Chinese has often been contested. This study aims to investigate the impact of different phonological processing skills on Chinese reading between typically developing children and children with dyslexia. Oral language, reading and phonological awareness tests, and an event related potential (ERP) delayed naming task were administrated to Grade four Cantonesespeaking children. Results showed that both groups of children read regular characters better than irregular characters. Children with dyslexia also found it more difficult to read irregular characters accurately. At the neural level, regular characters elicited greater positive P200 in both groups, but regularity effect at the N170 was only seen in typically developing children, suggesting that children with dyslexia have reduced sensitivity to the extraction of phonological information from the orthographic forms. Further stepwise regression analysis highlighted that oral language ability, phonological awareness and sensitivity to regularity at the N170 predicted children’s reading ability. However, no phonetic radical consistency effects were observed. Together, the findings support the core phonological processing deficit hypothesis of developmental dyslexia, and that the phonological awareness and awareness of orthography to phonology rules in Chinese independently contribute to reading ability.