Research On Cognitive Processing Of Chinese Developmental Dyslexia

This study is aimed to explore the psychological characteristics of Chinese developmental dyslexia on two different levels, namely the Chinese linguistic processing and basic cognitive processing, and to seek relatively steady diagnostic criterion to identify possible subtypes and then profile the psychological characteristics of each subtype.Pupils from of a primary school in Shanghai participated in the research, which was separated into three sections. The purpose of the first study was to examine the linguistic processing of different dyslexic groups that have been selected by different reading tasks, so that a proper reading diagnostic task could also be decided. Dyslexia Pre-selection group (N=40) and Control group (N=127) were selected by using Chinese achievement, Motivation Questionnaire and Conners Teachers Questionnaire among all students from Grade 2 to Grade 5 (N=406). Different reading measures (including reading accuracy, reading fluency, lexical capacity and dictation) were utilized to diagnose Dyslexic group, the performances on different linguistic tasks (including phonological awareness, orthographic knowledge and rapid automatized naming) of which were than compared with those of the Control group. Results suggested that the Dyslexia diagnosed by the three reading measures, to some degree, all had the same deficit pattern on phonological awareness, orthographic knowledge and rapid automatized naming (see Page 29 to 32 for detailed data information), almost all of whom were boys. Reading accuracy seemed to have the highest prevalent rate in diagnosis of above 3%, while the other reading tasks all selected too few children as dyslexia.In Study 2, the performances on basic cognitive processing of dyslexic group (N=13) that were diagnosed through reading accuracy were examined. Comparison was made between the performances of the dyslexic group (N=13) and those of the control group (N=93) by using phonological measures (including digit repetition, character repetition and backward digit repetition), visual skill measures (containing visual attention, visual-spatial relationship and visual-spatial memory), as well as the 12 tests of the PASS (Planning-Attention-Simultaneous-Successive) model. Results showed that the differences between the two groups existed in visual skills (visual attention t=-4.076, P≤0.01; visual-spatial relationship t=-3.210, P≤0.01; visual-spatial memory t=-2.338, P≤0.05), Planning (t=-3.189, P≤0.01), Attention (t=-4.620, P≤0.01), Simultaneous processing (t=-3.425, P≤0.01) and Successive processing (t=-3.397, P≤0.01), among which only the mean of Z score in Attention was less than-1. It suggested that although the dyslexic group did no better than the control group in the cognitive skills mentioned as above, they may not statistically have real deficits, while a deficit could only existed in Attention.In the third study, we tried to make validation to all measures (exclusive of CAS) that were utilized in the previous two parts of this research and explore the diagnostic criterion to identify different subtypes, and then profiled the deficit patterns of each subtype. Validity analysis of relevant indices was carried on by utilizing the data of the control group (N=93) from Grade 3 to Grade 5 that included the data of both linguistic processing (containing rime identification, onset identification and tone identification; reversed character identification and non-character identification; digital rapid automatized naming and color rapid automatized naming) and cognitive processing (including digit repetition, character repetition and digit backward repetition; visual attention, visual-spatial relationship and visual-spatial memory). The modified model (X2/df=1.149, P=0.244, GFI=0.921, IFI=0.975, CFI=.973, RMSEA=.040) consisted of 4 indices on both linguistic processing level and cognitive processing level, namely phonological awareness, rapid automatized naming, phonological memory and visual skills. Among all indices of the model, two orthographic tasks and four cognitive processes of the PASS model, phonological awareness and Simultaneous processing were chosen to be the predictors of the literacy skills by stepwise regression analysis, and then these two indices were used to differentiate possible subtypes among the whole dyslexic family. Results indicated that the phonological deficit subtype (N=3) mainly had impairment in skills that are more relevant to phonological processing (M of phonological awareness=-1.94, M of rapid automatized naming=-2.26); the Simultaneous processing deficit type (N=1) had more deficits on basic cognitive level (M of visual skills=-1.99, M of Planning=-1.87, M of Attention=-1.90, M of Simultaneous processing=-2.34, M of Successive processing=-1.62); the mixed type (N=6) had widespread impairment on all indices of both linguistic processing and cognitive processing; and that other type (N=2) did not manifest the same impairment pattern.