The influence of temporal asynchrony on character-speech integration in Chinese children with and without dyslexia: An ERP study

Dyslexic readers have been reported to show abnormal temporal acuity and multisensory integration deficiency. Here, we investigated the influence of temporal intervals on Chinese character-speech integration in children with and without dyslexia. Visual characters were presented synchronously to the onset of speech sounds (AV0) or before speech sound by 300 ms (AV300). Event-related potentials (ERP) evoked by congruent condition (speech sounds presented with congruent Chinese characters) and by baseline condition (speech sounds presented with Korean characters) were compared. Typically developing (TD) children exhibited congruency effect in AV0 condition, whereas dyslexic children exhibited congruency effect in AV300 condition. Moreover, congruency effect in TD children was due to enhanced neural activation to congruent trials, congruency effect in dyslexic children was contributed by neural suppression for baseline trials. These results suggested that different underlying mechanisms were involved in character-speech integration for typical and dyslexic children.