Abstract
Dyslexia is a developmental disability affecting the acquisition of reading and writing skills, and its developmental nature makes longitudinal research of great importance. This study therefore investigated the cognitive-linguistic profiles of the typical-functioning dyslexics and high-functioning dyslexics with longitudinal cohorts of Chinese-speaking adolescents diagnosed with childhood dyslexia. These two dyslexic groups of fifty students (with 25 typical-functioning dyslexics) were assessed in Grade 2 (Time 1) and in Grade 8 (Time 2), whereas 25 typically developing controls were assessed at Time 2. Students were administered measures of phonological awareness, morphological skills, visual-orthographic knowledge, rapid naming, verbal working memory, and literacy skills. Results showed that, at Time 2, both dyslexic groups performed less well than the control group on most of the measures. Deficits in rapid naming were particularly salient in both dyslexic groups. Comparing the two dyslexic groups, the typical-functioning dyslexics had more multiple deficits than the high-functioning dyslexics. Findings highlight the importance of rapid naming deficits as potential universal causes of dyslexia and the utility of targeting visual-orthographic knowledge and morphological skills in supporting the development of dyslexic adolescents.