Executive functions underlie word reading and reading fluency in Chinese children with attention deficit/hyperactivity disorder, reading disabilities, and comorbid attention deficit/hyperactivity disorder and reading disabilities.

The current study examined the executive function (EF) deficits and their roles in reading in one hundred and four Cantonese-speaking children with typical development, reading disabilities (RD), ADHD, and comorbid ADHD and RD (ADHD + RD). Children's EF and reading skills were measured. Analysis of variance results showed that all children with disorders manifested deficits in verbal and visuospatial short-term and working memory and behavioral inhibition. Moreover, children with ADHD and ADHD + RD also exhibited deficits in inhibition (IC and BI) and cognitive flexibility. These findings demonstrated that the EF deficits in Chinese children with RD, ADHD, and ADHD + RD are similar to those in their counterparts using alphabetic languages. However, children with ADHD + RD displayed more severe deficits in visuospatial working memory compared to children with RD and ADHD, which was inconsistent with that observed in children using alphabetic languages. Regression analysis results showed that verbal short-term memory was a significant predictor for both word reading and reading fluency in children with RD and ADHD + RD. Moreover, behavioral inhibition significantly predicted reading fluency in children with ADHD. These findings also agreed with previous studies. Collectively, the results of the current study showed that the EF deficits and their roles in reading found in Chinese children with RD, ADHD, and ADHD + RD are mainly consistent with children using alphabetic languages. However, more studies are still needed to confirm these findings, especially comparing the severity of working memory among these three disorders.

The role of rapid naming in reading development and dyslexia in Chinese.

We examined in a series of studies the mechanism that may underlie the relationship between Rapid Automatized Naming (RAN) and reading (accuracy and fluency) in Mandarin Chinese. Study 1 examined the "arbitrary" connections hypothesis in a sample of Grade 2 children (N=182). Study 2 contrasted the phonological processing, orthographic processing, and speed of processing hypotheses in a sample of Grade 2 children followed until Grade 5 (N=72). Finally, Study 3 contrasted the same hypotheses in a sample of Grade 4 children with dyslexia (n=30) and chronological-age controls (n=30). The results indicated that (a) RAN is unrelated to Paired Associate Learning (PAL) tasks that tap the ability to form arbitrary connections between characters and their pronunciation, (b) controlling for nonverbal IQ and orthographic processing was sufficient to explain the RAN-reading accuracy relationship but not the RAN-reading fluency relationship, and (c) the observed differences between dyslexics and controls in RAN diminished after controlling for orthographic processing. Taken together, these findings suggest that RAN is related to reading accuracy (and partly to reading fluency) because children must access orthographic representations from long-term memory. Although accessing these representations is sufficient for accurate word recognition, it is not sufficient for fluent reading, which also requires efficient parafoveal processing.