| Developmental dyslexia refers to an individual who has no differences with other individuals in general intelligence,motivation,living environment and educational conditions,as well as no obvious visual and auditory disorders and neurological disorders,but whose reading performance is significantly lower than the appropriate level for the corresponding age.Many studies have shown that there are developmental dyslexics in the Chinese language system.As a cognitive factor,visual attention span refers to the ability to process multiple elements simultaneously.Some domestic and foreign research results on this kind of children show that these children have defects in visual attention span ability.Therefore,the purpose of this study is to explore the characteristics of visual attention span of children with developmental Chinese dyslexia and the significance of visual attention span for children with developmental Chinese dyslexia.Based on the above purposes,this study consists of three research contents.This study first explores the visual attention span characteristics of Chinese children with developmental dyslexia.The "component model" was used to divide the dyslexics into three groups,and a partial reporting task was used to compare the differences between the three groups of children with dyslexia and the age-matched group in visual attention span tests based on symbols,numbers,Chinese characters and letters,and to explore the trend of visual attention span deficits with grade changes.The results showed that the accuracy of visual attention span of Chinese dyslexic children was significantly different from that of the age-matched children.Children with Chinese dyslexic children had visual attention span deficit,which gradually increased with the improvement of grade.Secondly,on the basis of study one,the differences in phonological awareness,morpheme awareness,rapid automatic naming and visual attention span among children with different types of dyslexia were explored.The differences between the three types of children and ordinary children in morpheme awareness,phonological awareness,quick naming and visual attention span were calculated,and 1.5standard deviations below the average were taken as the criteria for defect determination.On the basis of determining the impairment,the differences in the degree and proportion of the four cognitive abilities of children with different kinds of dyslexia were compared.The results showed that there were many defects in Chinese dyslexic children,mainly morpheme and phonological awareness.Visual attention span deficits of children with three types of dyslexia show different manifestations under different materials.Children with word recognition impairment and children with reading comprehension impairment show greater visual attention span deficits when the stimulus materials are numbers;children with cognitive impairment have more severe visual attention span deficits.More dyslexic children had visual attention span deficits when the stimulus materials were numbers,letters and symbols.Finally,children with dyslexia have defects in visual attention span,a cognitive ability.Different kinds of children with dyslexia show different proportions and degrees of defects in visual attention span under different stimulus materials.Therefore,study 3 further explored the effectiveness of these four cognitive factors in distinguishing dyslexic children from ordinary children.Two Logistic regressions showed that rapid naming,morpheme awareness,phonological awareness and visual attention span were significant predictors for distinguishing dyslexia in the first regression,but only phonological awareness was retained after the second regression.This indicates that visual attention span is one of the variables affecting Chinese dyslexia,but it is not the most important predictive variable.Phonological awareness ability is still more effective in distinguishing dyslexic children from ordinary children.In general,children with Chinese developmental dyslexia have visual attention span deficits,which increase with the improvement of grade level.Different types of children with Chinese dyslexia have different degrees,proportions and types of visual attention span deficits.However,visual attention span is limited in distinguishing dyslexic children from ordinary children.Phonological awareness was more effective in distinguishing dyslexic children from ordinary children. |
