The present thesis aimed to identify and examine children with late-emerging dyslexia (LED) in Chinese. They were a group of children who only met the diagnostic criteria of dyslexia in their later stage of development after Grade 3. Their cognitive profile in word level and text level skills were compared with those who were diagnosed as dyslexia at their early grades (ED), i.e., before Grade 3. This thesis also aimed to identify early predictors which could discriminate the two groups, the LED and ED groups. Study 1 was a cross-sectional study which aimed to identify a group of LED children in Grade 4 and to examine their cognitive profile. Four groups of participants were recruited. Two groups of Grade 4 dyslexic children participated—36 dyslexic children diagnosed before Grade 3 (the ED group) and 41 dyslexic children diagnosed in Grade 4 (the LED group). There were two control groups, age-equivalent (CA) and reading level equivalent (RA) control groups.
Totally 171 children were administered some word-level and text-level literacy and cognitive linguistic tasks. The LED group was found to be significantly higher than the ED group in word reading fluency and faster than the RA group in RAN, but poorer than the ED group in listening comprehension. Rapid naming, listening comprehension and age were able to predict correctly 73% membership of the LED group and 74.2% membership of the ED group. Subgroup analysis of both groups, with different word reading level, revealed the heterogeneity of the ED group which implied possible diversity in developmental changes prior Grade 4. As some children in the LED group of Study 1 might be unidentified but not late-emerging cases, a longitudinal study was necessary. Thus, Study 2 was a longitudinal study which followed 371 children from 4 local primary schools at Time 1 (Grade 2), Time 2 (Grade 3) and Time 3 (Grade 4). It aimed to identify early predictors which could discriminate the two groups, the ED and the LED who were diagnosed in Grade 3 and 4 respectively. The LED group was found to be similar to the CA group in text reading fluency and significantly better than the ED group in dictation at Time 1. Dictation and word reading fluency of Time 1 and text reading fluency of Time 2 were significant to predict 84.6% membership of the LED and the ED. Their late emerging difficulties were evident in word spelling and text reading fluency. The LED who were relatively superior in verbal memory and morphological awareness at Time 1, in orthographic skills and phonological retrieval at Time 2, are supposed to have acquired the basic skills necessary for word learning in the logographic, cipher and orthographic stage. But at Time 2 and 3, they were found to meet the criterion of dyslexia. Findings of the present study supported that Chinese word learning at the early stage, might only require few cognitive skills, such as phonological and semantic skills but at a later stage, it involved multiple cognitive skills of all three aspects, phonology, orthography and semantics. Overall speaking, a group of Chinese children with late-emerging dyslexia were identified in this study. The prevalence rate was estimated to be around 39% of the total number of dyslexic cases (including both with late-emerging and early diagnosed dyslexia). The LED groups in both studies were found to be better than the ED groups in reading fluency either of word only in Study 1 or both word and text in Study 2. In addition, the LED group of Study 2 was also found to have dictation better than the ED group in Grade 2 but not later. Despite the steady trend of deterioration in literacy skills, the cognitive linguistic skills of the LED group fluctuated. Thus, the present findings supported that younger Chinese learners, particularly in Hong Kong where pin-yin system was not adopted in most schools, could survive with strength in phonological memory and morphological awareness at the early stage. But mature Chinese learners have to acquire multiple cognitive skills of all three aspects phonology, orthography and semantics, in order to maintain adequacy in literacy skills. This was consistent with the multiple deficit model in previous Chinese studies (Ho et al, 2002 & 2004) in contrast with the double deficit model of English (Bowers & Wolf, 1993; Wolf, 1997; Wolf & Bowers, 1999). Such findings also suggested that the development of phonological pathway followed by the semantic pathway in English, proposed by Seidenberg, and McChelland (1989), was not found in Chinese. Instead, the connection between phonology and semantics was first developed followed by the triangular model of phonology, semantics and orthography. Besides, present findings have some implications for practice in assessment and intervention. Educational practitioners should be aware that the performance in dictation, among some children, could be deviated from their reading and that their performance fluctuated developmentally. Also, identification has to be done universally and timely with sensitive screening tools. Assessment tools may include word level such as dictation and word reading fluency and text level such as text level fluency and intervention has to be linked with assessment so as to strengthen the aspect which the children might be weak at a particular stage. / published_or_final_version / Educational Psychology / Doctoral / Doctor of Psychology
| Identifer | oai:union.ndltd.org:HKU/oai:hub.hku.hk:10722/191169 |
| Date | January 2013 |
| Creators | Chan, Sau-wai, Elaine., 陳秀慧. |
| Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
| Source Sets | Hong Kong University Theses |
| Language | English |
| Detected Language | English |
| Type | PG_Thesis |
| Source | http://hub.hku.hk/bib/B50638932 |
| Rights | The author retains all proprietary rights, (such as patent rights) and the right to use in future works., Creative Commons: Attribution 3.0 Hong Kong License |
| Relation | HKU Theses Online (HKUTO) |
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