Individual differences in main idea identification: An EEG study of monolinguals and bilinguals with dyslexia

Individuals differ in a range of processes related to reading comprehension, including working memory capacity, decoding skills, inference making and main idea identification. In this exploratory study, we examined evoked potential N400 amplitude during reading comprehension tasks and focused on identifying the main idea in the text, modulated by working memory capacity. Participants included monolinguals or bilinguals who were either typical readers (n = 33) or had been diagnosed with dyslexia (n = 19). Analyses revealed significant group differences for main idea conditions. Participants with dyslexia showed greater N400 amplitude than typical readers, particularly in the right hemisphere, when the main idea was in the last position in the paragraph. There were no significant differences in performance between bilinguals and monolinguals, which does not support the idea of a cognitive advantage for bilingualism. It was noteworthy that, if they had dyslexia, they were similarly negatively impacted by their reading disability. Findings highlight the processing advantages typical readers have relative to dyslexia.