Study On Characteristics Of Cognitive Processing Of Subtypes Of Chinese Dyslexia

Developmental dyslexia, refers to an individual who demonstrates observant low grades in reading levels and state of reading difficulties compared to his same age group under the conditions of:(1)no obvious differences in mental intelligence, motivation, living and educational environment. (2)no obvious deficiencies in eyesight, hearing and neural systems. In recent years, developmental dyslexia has been arousing researchers' great interest and attachment.Both domestic and international studies give evidence that dyslexia is not homogeneous population and can be caused by several cognitive deficits. The western researchers pay more attention to the heterogeneity of dyslexia. Whereas, the domestic research findings and results have been inconsistent and fragmented due to the inborn distinct characteristics of Chinese ideograph being different from phoneticism and late steps in this area. Based on systematically summarizing and analyzing the previous recognized research, the major researchers view the developmental dyslexia as homogeneous population, there are few care about the heterogeneity of dyslexia. Nowadays, because of psychologist's penetrating study on reading pattern and the influence of cognitive psychology, researchers tend to illustrate reading difficulties from the point of cognitive features, most of researchers focused on a certain perspective study on a certain part, hardly any systematic researches about kinds of dyslexia children's cognitive defaults. So the dissertation has put forward the developmental dyslexia differences exist in children inner group, the different cognitive deficits under different group. Some problems may happen in the phonetic, some dyslexia appear morphological. This study aims to explore the characteristic of cognitive processing of subtypes of developmental dyslexia.The test groups are sampled from children with developmental at Grade three of elementary, and being divided into three groups (the poor decoding; the poor comprehension and a combination of poor decoding and poor comprehension) based on simple view of reading. While the comparison groups are chosen from the normal children with the matching physiological age, intelligence level and educational environment. The_dissertation has discussed the characteristics of cognitive processing of different subtypes children in the six following aspects: phonological awareness, morphological processing, orthographic processing, naming speed, short-term memory and working memory processing.The first study is going to find the cognitive dissertation of different subtypes. we gave the normal children and three subtypes dyslexia six cognitive measures including phonological test, orthographic processing, naming speed, short term memory and working memory processing which have been testified to have relationship with dyslexia, most important is that we include a special cognitive test that has been considered more and more important to Chinese children's reading -morphological test. The result of study one tells us that three subtypes dyslexia show different cognitive deficits in all tests.The second test wants to find the well index of distinguishing the different subtypes from normal children and the dyslexia from normal by logistic regression. the result of study one is got by means of groups and we wonder what the relationship between these cognitive deficits and different subtypes and want to find the well index of distinguishing the different subtypes from normal children and the dyslexia from normal, so we using the logistic to explore the cognitive tests to distinguish the different subtype, the result of study two shows that different factor's effect are different when distinguish the subtypes dyslexia from the normal children. When we put the three subtypes together, find that in the six cognitive factors there are just two factors can do this well, morphological test and working memory.The third study explores heterogeneity of different subtypes dyslexia of cognitive deficits. We use the Standard Deviation ways. The results show that in terms of proportion and degree of every kind of cognitive deficits are different, and the morphological deficit is the largest in scale and the deepest in degree. Form the inner of different subtypes, there are different scale and degree of cognitive deficits in three subtypes, the cognitive deficits are the largest in scale and the deepest in degree in the subtype who were the combination of poor decoding and poor comprehension.The forth study explores the subtypes of Chinese dyslexia. First we used the cluster analysis to explore the cognitive subtypes of dyslexia and got five relative homogeneous subgroups. Then we explore the relationship between the two subtypes which got from two different aspects. The result shows that the group of working memory deficits was compared by the poor comprehension and the controlled, the group of morphologic deficit and phonological deficits was compared by the poor decoding and the combination of poor decoding and poor comprehension, the poor comprehension take larger proportion in the group of morphologic - phonological -short memory and working memory' deficits, the group which has no deficits was formed by the controlled. The group with all cognitive deficits was formed by the poor decoding and the combination of poor decoding and poor comprehension.