Characteristics Of Visual Spatial Information Processing And Cognitive Control In Children With Developmental Dyslexia

There are various forms of dyslexia,its mechanism and causes are complex.Especially in the context of Chinese culture,there is no universally accepted unified concept or clear conclusion about dyslexia.In this paper,through three studies,the children with Chinese dyslexia and normal reading in the second grade and the fifth grade are taken as the research objects,and the two research paradigms of mental rotation and AX-CPT are combined to explore the characteristics of visual spatial information processing and cognitive control of children with Chinese dyslexia.Study 1: To compare the difference of mental rotation tasks between children with dyslexia in different grades and normal children of the same physiological age,and to explore the characteristics of visual spatial information processing in children with dyslexia in the second grade and the fifth grade.The results show that:(1)There is a linear relationship between reaction time and angles in children of two grades,and the reaction time increases with the increase of angle;(2)children with dyslexia in two grades spend less time and correct rate in completing tasks than children with normal reading in the same age;(3)children with dyslexia in the second grade have significantly slower mental rotation rate than children with normal reading in the same age(4)there was no significant difference between the mental rotation rate of the fifth grade dyslexic children and the normal children of the same age.Based on these results,the conclusion is as follows: the mental rotation effect also exists in children with dyslexia.In the mental rotation task involving Pinyin letters,the visual spatial information processing ability of children with dyslexia in the second grade is affected,while that of children with dyslexia in the fifth grade is not affected.Study 2: Using the mental rotation task of "real word" and "false word" as materials,to explore whether there is a relationship between the visual spatial information processing and content effect of children with dyslexia in different education stages.The results show that:(1)In the two kinds of material tasks,the time efficiency and accuracy of the fifth grade dyslexic children are better than that of the second grade;(2)the time efficiency and accuracy of the fifth grade children with dyslexia completed the task of "real words" are better than that of "false words",while the second grade children with dyslexia completed the task of "real words" are better than that of "false words" only in the accuracy.Based on these results,the conclusion is as follows: the visual-spatial information processing ability of children with dyslexia increases with the age in some ways.The content effect has a greater impact on children with the fifth grade children with dyslexia.Study 3: Using AX-CPT paradigm to explore the core components of cognitive control of dyslexic children from the perspective of time dynamic in control process,which revealed the characteristics of active control and reactive control of children with dyslexia.The results showed that:(1)The reaction time of children with dyslexia in reactive control and active control is significantly higher than that of children with normal reading,and the accuracy rate was significantly lower than that of children with normal reading;(2)the time interval had a significant impact on the inter group reaction time of reactive control task,while the inter group reaction time and accuracy rate of active control task had a significant impact.Based on these results,the conclusion is as follows: compared with normal reading children,children with dyslexia show insufficient active control and reactive control,and the effect of time interval on active control is greater than reactive control.Based on this,this study recognized that the characteristics of visual spatial information processing of dyslexic children are different in different age stages,which shows that the second grade children with dyslexia have difficulties in the "rotation stage" of mental rotation task,the fifth grade children with dyslexia have no difficulties in the "rotation stage" of mental rotation task,and their mental rotation ability is not damaged.Secondly,children with dyslexia are influenced by the content of materials and the stage of education in the visual spatial reading task,which shows that they are familiar with materials and promote the completion of the task of children with dyslexia in the stage of higher education.Finally,the completion of mental rotation task is closely related to cognitive control ability.Therefore,in the exploration of cognitive control function of children with dyslexia,we found that there are deficiencies in both cognitive mechanisms under the dual cognitive control mechanism.