Mental Rotation Characteristics Of Children With Chinese Dyslexia In Different Materials

Several studies have indicated that children with dyslexia have so far failed to develop effective visual processing strategies,and that some dyslexia are associated with visual-spatial deficits.Some dyslexia are associated with deficits of visual-spatial ability.Visual-spatial ability is divided into three main aspects:visualization,orientation and mental rotation(MR).However,the relationship between visual-spatial ability and reading ability is still a controversial issue.In this study,we selected children with Chinese dyslexia(the detection rate was 3.9%)and children with the age matching group from 1680 primary school students in grade 3,grade 4 and grade 5 in four primary schools in Urumqi,Xinjiang.Using the standard Ruiwen Intelligence Test,Literacy Test and The Attention Deficit Hyperactivity Disorder(ADHD)SNAP-IV Teacher Assessment Scale.We carried out the mental rotation tests of letters,Chinese characters and graphics to investigate the visual spatial cognitive ability of children with Chinese dyslexia and Normal children.The research is divided into three parts:The first study investigated on the characteristics and processing strategies of mental rotation of dyslexic children in alphabetic materials.These results indicated that when the rotation angles were0°,60°,and120°,both the dyslexia group and the control group showed that the speed of the global processing condition was faster than that the speed of the local processing condition,that is,the global processing advantage appeared.Under the global processing condition,when the rotation Angle was0°,60°,and120°,the speed of the dyslexia group and the control group decreased with the increase of the rotation Angle,that is,both groups showed mental rotation effect under the global processing condition,but the responses of the dyslexia group were markedly longer than those of the control group.Under the condition of local processing,there was no occur remarkable difference in the response of the dyslexia group and the control group with the increase of rotation Angle,and there was no significant difference in the response of the children in the two groups with the increase of rotation Angle.In addition,the speed of the control group on the global processing condition of180°,was slower than the local processing,that is,the local processing advantage appeared.However,there was no significant difference in the response of the dyslexia group under the two processing conditions.In terms of accuracy,and the accuracy of the dyslexia group was importantly lower than that of the control group.The second study investigated on the characteristics and processing strategies of mental rotation of dyslexic children in Chinese character materials.The results presented that when the rotation Angle was0°,60° and180°,the speed of global rotation of two groups were significantly faster than that of local rotation,showing global processing advantage.Under the global rotation condition,both the dyslexia group and the control group showed that the rotation Angle of 0° and 60° were significantly less than120° and180°,and both groups showed mental rotation effect under the condition of overall processing.Moreover,when the rotation Angle was0° and180°,the response time of the dyslexia group was obviously lower than those of the contrast group.Under the condition of local rotation,no matter what rotation Angle,the response time of the dyslexia group and the contrast group showed no significant difference with the increase of each rotation Angle,and the speed of the dyslexia group was significantly below than that of the contrast group.In terms of accuracy,the accuracy of the dyslexia group was obviously lower than that of the control group.The third study investigated on the characteristics and processing strategies of mental rotation of dyslexic children in graphic materials.The results revealed the global rotation of the graphic material increased significantly with the increase of the rotation Angle,while the local rotation of the graphic material showed no significant difference in the rotation Angle.The simple effect test found that the response time of global processing in the control group was less than that of local processing,that is,the global processing advantage appeared,while the response time of global processing in the dyslexia group was not significantly different from that of local processing.The main effect of the group was not significant,while other interactions were not significant.In terms of accuracy,the interaction between rotation Angle,rotation type and group was significant.When the rotation Angle was0° and60°,both groups showed that the accuracy rate of global rotation was significantly higher than that of local rotation,showing the advantage of overall processing.However,When the rotation Angle was 180°,the accuracy rate of global rotation in the dyslexic group was significantly lower than that of local rotation.Under the global rotation condition,when the rotation Angle was0° 、60° 、120° 、and180°,the accuracy rate of children in the two groups also decreased with the increase of the rotation Angle,that is,the mental rotation effect appeared,and the accuracy rate of the dyslexia group was significantly lower than that of the control group.Under the condition of local rotation,when the rotation Angle is0° 、60° 、120° 、and180°,the accuracy of the rotation Angle does not change with the increase of the rotation Angle,and no matter which rotation Angle,the accuracy of the dyslexia group is significantly lower than that of the control group.According to the above experimental results,the conclusions can be drawn:(1)Chinese dyslexic children show a lag in mental rotation processing in letters,Chinese characters and graphics,and this lag occurs in the stage of perceptual coding.(2)Chinese dyslexic children generally have backwarded mental rotation in all materials,but they have certain specificity in different writing materials.The ideographic characters,Chinese characters,which put more emphasis on the processing of glyphs,are the most backward.The second is more dependent on phonetic processing of pinyin characters-letters,only in the global processing there is backward.(3)Chinese dyslexic children,like normal children,have the global processing priority effect on the three materials of letters,Chinese characters and graphics,and the mental rotation effect is generated during the global processing,that is,the image is operated.In the local processing,there is no mental rotation effect,that is,there is no operation on the image.