No abstract

The present study was conducted to examine the cognitive profile and multiple-deficit hypothesis in Chinese developmental dyslexia. Thirty Chinese dyslexic children in Hong Kong were compared with 30 average readers of the same chronological age (CA controls) and 30 average readers of the same reading level (RL controls) in a number of rapid naming, visual, phonological, and orthographic tasks. Chinese dyslexic children performed significantly worse than the CA controls but similarly to the RL controls on most of the cognitive tasks. The rapid naming deficit was found to be the most dominant type of cognitive deficit in Chinese dyslexic children. Over half of the dyslexic children exhibited deficits in 3 or more cognitive areas, and there was a significant association between the number of cognitive deficits and the degree of reading and spelling impairment. The present findings support the multiple-deficit hypothesis in Chinese developmental dyslexia.

The present study sought to identify cognitive abilities that might distinguish Hong Kong Chinese adolescents with and without dyslexia and examined the cognitive profile of dyslexic adolescents in order to better understand this important problem. The performance of 27 Chinese adolescents with childhood diagnoses of dyslexia was compared with 27 adolescents of the same chronological age (CA) and 27 of matched reading level (RL) on measures of literacy and cognitive abilities: Chinese word reading, one-minute reading, reading comprehension, dictation, verbal short-term memory, rapid naming, visual-orthographic knowledge, morphological and phonological awareness. The results indicated that the dyslexic group scored lower than the CA group, but similar to the RL group, especially in the areas of rapid naming, visual-orthographic knowledge and morphological awareness, with over half having multiple deficits exhibited 2 or more cognitive areas. Furthermore, the number of cognitive deficits was associated with the degree of reading and spelling impairment. These findings suggest that adolescents with childhood diagnoses of dyslexia have persistent literacy difficulties and seem to have multiple causes for reading difficulties in Chinese.

Comparing the analyses based on the data of 1,235 Chinese children referred for government services and subsequently diagnosed as children with dyslexia in Hong Kong and those of 690 Chinese children in the sample for the normative study of the Hong Kong Test of Specific Learning Difficulties in Reading and Writing, we explored the reading-writing connection through a series of regression and correlation analyses. Specifically, orthographic knowledge, naming speed, and phonological memory were found to be salient predictors predicting both reading and writing, and when they were controlled and partialed out, the correlations between reading and writing were sizably attenuated, suggesting that these cognitive abilities or skills could act as third-variables contributing to the relationship between reading and writing. Issues related to causal inference, directionality of causality, and implications of the findings for intervention efforts and future research are discussed.

The present study sought to identify cognitive abilities that might distinguish Hong Kong Chinese adolescents with dyslexia and to assess how these abilities were associated with Chinese word reading, word dictation, and reading comprehension. The cognitive skills of interest were morphological awareness, visual-orthographic knowledge, rapid naming, and verbal working memory. A total of 90 junior secondary school students, 30 dyslexic, 30 chronological age controls, and 30 reading level controls was tested on a range of cognitive and literacy tasks. Dyslexic students were less competent than the control students in all cognitive and literacy measures. The regression analyses also showed that verbal working memory, rapid naming, morphological awareness, and visual-orthographic knowledge were significantly associated with literacy performance. Findings underscore the importance of these cognitive skills for Chinese literacy acquisition. Overall, this study highlights the persistent difficulties of Chinese dyslexic adolescents who seem to have multiple causes for reading and spelling difficulties.