Evidence for a deficit in orthographic structure processing in Chinese developmental dyslexia: an event-related potential study.

The present event-related potential (ERP) study aimed to examine group differences in processing of orthographic information in Chinese children with dyslexia and typically developing children. Twelve dyslexic (ages 100-125 months) and 11 control (ages 104-124 months) children were given a character decision task (similar to a lexical decision task). For the control group, the radical position information influenced the character processing at a later stage of semantic information processing as reflected by a more negative N400 component in the pseudocharacter condition, in which the semantic and phonetic radical were combined following correct orthographic rules, as compared to the noncharacter condition, in which the structure of the semantic and phonetic radicals was reversed from that for each real character. In contrast, the dyslexic group showed no such differences across the experimental conditions for the N400 component. Results suggest that Chinese children with dyslexia may have a deficit in processing orthographic information (specifically, radical position). Furthermore, a late positive component (LPC) was elicited in both groups, suggesting that children may have to back track on their earlier semantic memory in order to make a final decision as to whether the character is real or not.