Cognitive processing deficits in poor readers with symptoms of reading disabilities and ADHD: More alike than different?

The cognitive differences among poor-reading children with characteristics of reading disabilities (RD) and attention deficit-hyperactivity disorder ( ADHD) when compared with children with comorbid symptoms (RD + ADHD) and sl ow learners (SL) on measures of phonological and executive processing were investigated. No significant differences in performance emerged between the ability groups in phonological processing. The SL + ADHD & slow learners p erformed better than RD groups (RD alone and RD + ADHD) on the visual-spati al working memory (WM) factor score and the RD-alone group was inferior to RD + ADHD, SL + ADHD, and SL-alone groups on the verbal WM factor score. Th e results support the notion that poor readers, whether suffering from RD o r ADHD symptoms, share a common phonological core deficit.