Identifying subtypes of reading disability in the Spanish language

This study was designed to examine the dyslexic subtypes in a transparent orthography (i.e., Spanish language). The subtyping procedure used comparison with chronological-age-matched and reading-level controls on reaction times (RTs) to high frequency words and to pseudowords. Using regression-based procedures, the authors identified 20 phonological and 48 surface dyslexics from a sample of 89 dyslexic third-grade children by comparing them to chronological-age-matched controls on RTs to high frequency and pseudoword reading. However, when the dyslexic subtypes were defined by reference to reading-level controls, the same 20 phonological dyslexics were defined, but only 19 surface dyslexics were identified. Nevertheless, the results of the phonological awareness tasks and error analysis do not validate the division of the dyslexic sample into these subgroups.