The Cognitive Process Foundation Of The Chinese Developmental Dyslexia With Phonological And Orthographic Deficit

Developmental dyslexia is not only an important area in the learning disability research, but also a major topic in the field of language and reading cognitive research. Compared with the long history and remarkable achievement of the developmental dyslexia research in the west world, the Chinese developmental dyslexia research is a relatively new study with few researches focusing on the cognitive processing mechanism. As we all know that investigating the inner processing mechanism, subtypes and etiology of developmental dyslexia will be valuable for clarifying whether dyslexia is language specific or language free, and thus will be helpful in uncovering the factors resulting in dyslexia and providing the follow-up intervention for the dyslexic children. At present, the researchers have carried out many studies of Chinese developmental dyslexia from the point of liguisticits, but few study concerned the inner cognitve processing mechanism. Based on the theory of PASS cognitive processes, the Das and Naglieri Cognitive Assessment System (DN: CAS), the recomposed linguistic cognition tasks, this research aims to make systematic investigations of cognitive processing mechanisms of primary school students with Chinese developmental dyslexia.In study one, the author examined the reliability and validity of experiment tool-the Chinese version of DN: CAS. The results showed that this tool was reliable and had sound criterion related validity and construct validity. The four-factor-PASS model was better than three-factor-(PA)SS model no matter from the theoretic framework or from the statistical results, and the result was consistent with the theory put forward by Das et al. Meanwhile, the results of confirmatory factor analysis from the primary school students of grade 3 to 5 also provided statiscical support for the structure of DN: CAS in some sense, indicating both PASS theory and DN: CAS were suitable to the Chinese children.The first part of second study used the self-designed and recomposed linguistic programs in order to investigate the characteristics and differences of phonological processing and orthographic processing between the Chinese dyslexic children and the normal control group children. The results indicated that the control group children from grade 3 to 5 were capable to process phonologically and orthographically, however the dyslexic group performed worse than the control group in all of the linguistic tasks. In the second part of study two, children with dyslexia (DYS), grade 5 chronological age (CA) controls and grade 3 reading level (RL) controls were tested on measures of phonological processing and orthographic processing. The results indicated that the DYS group performed significantly poorer than the CA and RA groups on both measures of phonological awareness and the orthographic processing; the DYS group performed poorer than the CA group but comparably to the RA group on both measures of rapid naming and phonological memory. As a result, among the Chinese developmental dyslexic children, the phonological awareness and orthographic processing deficit were the two major deficits and the developmental delay resulted in the poor performance on measures of rapid naming and phonological memory. Meanwhile, the amount of dyslexic children with phonological awareness and orthographic processing deficits outweighed the ones with other deficits.In the third study, the dyslexic group and the normal control group from grade 3 to 5 were compared on the basis of PASS cognitive processing. The results showed that there were significant differences on PASS cognitive processing among grades, i.e. grade 3 children performed poorer than grade 4 and 5 children on all tasks of CAS. What is more, the dyslexic group performed worse than the control group on all of the measures of CAS. In the second part of study three, children with dyslexia (DYS), grade 5 chronological age (CA) controls and grade 3 reading level (RL) controls were tested on measures of PASS cognitive processing. The results indicated that the DYS group performed significantly poorer than the CA group but comparably to the RA group on measures of expressive attention, verbal-spatial relationship and the successive processing. Thus it could be concluded that the developmental delay led to the weakness of expressive attention, verbal-spatial relationship and the successive processing. Meanwhile, most dyslexic children had more than one kind of PASS cognitive processing deficit, i.e. Chinese developmental dyslexia was heterogeneous; among the dyslexic children, the problem on successive processing was most serious and the number of dyslexic children with successive deficit outweighed the ones with other deficits.The present study on PASS theory only examined the direct relationship between PASS process and English reading without including the phonological and orthographic processing. Few studies investigated the relation between PASS process and Chinese reading. Therefore, in the forth study, the author ran the regression analysis and built the structural equation model to examine the relationship among phonological processing, orthographic processing, PASS cognitive processing and Chinese reading. The results demonstrated that the phonological processing and orthographic processing significantly predicted Chinese reading and they played different roles in various reading processes. Phonological awareness explained the unique variance of reading fluency, Chinese character recognition and Chinese word dictation; the role of rapid naming was secondary to phonological awareness, and rapid naming could predict reading fluency and Chinese character recognition instead of Chinese word dictation; phonological memory predicted Chinese character recognition and Chinese word dictation, but its role was weaker compared with phonological awareness and rapid naming. Orthographic processing explained the unique variance of Chinese character recognition and Chinese word dictation, but had no direct effect to reading fluency. Thus, it could be concluded that both phonological and orthographic processing exerted direct impact to Chinese reading, which confirmed with the results from the English reading literature. PASS cognitive processing played different roles in predicting Chinese reading. Planning correlated with none of the tasks of Chinese reading, not even predict Chinese reading; Attention could well explain the unique variance of Chinese reading, directly predicting reading fluency and Chinese word dictation; Successive processing could predict reading fluency and Chinese character recognition; Simultaneous processing could predict Chinese character recognition and Chinese word dictation directly. Successive processing predicted phonological awareness as well. Simultaneous processing had unique contribution to orthographic processing, and it had some kind of influence to phonological awareness but the influence was weaker than the one exerted by successive processing. Finally, Successive processing predicted reading fluency, Chinese character recognition and Chinese word dictation indirectly through the effects of phonological awareness; Simultaneous processing predicted Chinese character recognition and Chinese word dictation indirectly through the effects of phonological awareness and orthographic knowledge.