Do children with dyslexia have general auditory or speech-specific deficits?

Abstract

Grounded on two widely-discussed hypotheses of dyslexia and growing evidence showing lexical tone perception deficits in children with dyslexia, this study examined pitch and tone perception in children with dyslexia to determine whether they exhibited general auditory processing or phonological deficits. Thirty eight- and ten-year-old Cantonese-speaking children with and without dyslexia and fifteen reading-matched controls to ten-year-old children with dyslexia were tested on nonverbal intelligence, short-term memory, working memory, reading and writing abilities, lexical tone identification, and discrimination of complex tones, synthetic speech tones, and lexical tones. Children with dyslexia performed comparably to the reading-matched group in all tasks, except tone identification, and performed significantly worse than age-matched peers in all measures, except for memory. Special difficulties in the perception of brief tones were found in lexical tone identification but not in pitch or tone discrimination. Lexical tone perception, but not pitch perception, is an important predictor of children’s reading and writing abilities and can reliably classify children with dyslexia. The findings showed that neither auditory processing nor pitch discrimination in speech signals can best explain the reading and writing difficulties in children with dyslexia. Children with dyslexia appear to have special difficulties with tasks involving lexical access.