Neurolinguistic differentiation of children with subtypes of dyslexia

A detailed analysis of the types of childhood dyslexia proposed by Boder (1973) and Bakker (1990) revealed characteristic patterns of organization of intellectual functions, of hemispheric specialization, and of reading errors in right-handed children with dyslexia. Children with L-type dyslexia (10 subjects) evidenced a large number of reading errors (e.g., substitutions of nouns and verbs), low scores in verbal short-term memory, and right-ear advantage (REA) in dichotic listening. Children with P-dyslexia (18 subjects) evidenced few reading errors, a short attention span, low performance in visual-motor coordination (WISC-R coding), and an absence of REA in dichotic listening. Children with M-type dyslexia (10 subjects) showed numerous reading errors (e.g., substitution of syllables and words), low performance in visual-motor coordination items (coding), and REA in dichotic listening.