Study On Neuropsychological Characteristics Of Information Processing In Children With Developmental Dyscalculia

1.ObjectiveDevelopmental dyscalculia (DD) is a specific arithmetic difficulties with mathematical performance significantly lower than the normal level according to the age, education and intellectual potential. Epidemiological studies have shown that DD affects 3%-6.5% of school-age children.Studies about DD have attracted more attention since 20 century 70s. It has been widely documented that brain structure and function of children with DD are all different with their peers.DD is dynamic, which is associated with the development of children. DD will be improved with appropriate interventions. Otherwise, DD would be an enduring learning disorder persisting into adulthood. In order to carry out targeted intervention, we must thoroughly understand the mechanism ant cognitive characteristics of DD.In order to provide basic data for further studies and scientific basis for effective intervention, the main goal of this study was to shed further light on the features of information processing of children with DD by relevant neuropsychological testing. Therefore, this study has both the research value and sociological significance.2. Subjects and methods2.1 SubjectsTwo elementary schools were selected representatively according to randomized cluster sampling methods, in which 866 third to fifth graders were selected.2.1.1 DD group:34DD children (18 boys and 16 girls, mean age=10.38years, SD=1.04) participated in this study. Screener: ①PRS (The Pupil Rating Scale Revised Screening for Learning Disability)score of 65 or below; ② CRT(Combined Raven’s Test) score of 80 or above; ③ C-RSBMC(Rating scale for Basic Mathematical competences-Chinese revised)score of 50th percentile or below.2.1.2 Normal group:34 normal children (18 boys and 16 girls, mean age=10.43 years, SD=0.85) participated in this study, which were matched with DD group according to same grade and same gender. Screener:①PPRS (The Pupil Rating Scale Revised Screening for Learning Disability)score higher than 65; ② CRT(Combined Raven’s Test) score of 80 or above; ③ C-RSBMC(Rating scale for Basic Mathematical competences-Chinese revised)score higher than 50th percentile.All participants were right-handed and had normal auditory and normal or corrected-to-normal vision. Children with mental retardation, psychiatric disease, emotion disorder, neurological disease and somatic disease were excluded from this study. There are no significantly difference age and gender between DD group and normal group(P>0.05).2.2 Methods2.2.1 The Pupil Rating Scale Revised Screening for Learning Disability (PRS): to screen out the children with learning disability.2.2.2 Rating Scale for Basic Mathematical Competences-Chinese revised (C-RSBMC):to assess the mathematical disability.2.2.3 Combined Raven’s Test(CRT):to evaluate the capacity of observation identification, abstracting, analogism of children.2.2.4 Wisconsin Card Sorting Test(WCST):to evaluate the set shifting, working memory, response inhibition, cognitive conversion and abstraction ability of children.2.2.5 Mirror Trace Test:to assess the reasoning and visuo-motor ability of children.2.2.6 Stroop Test:to evaluate the capacity of response inhibition and selective attention of children.3.Results3.1 The total sample consisted of 866 children and 3.92% of them have developmental dyscalculia. Boy to girl ratio is 1.13:1, and there is no significantly difference gender. The results of C-RSBMC showed that Children in the DD group scored significantly lower than children in the normal group, indicating that DD children had deficits both in mathematical operation ability and logical thinking and spatial-visual function.3.2 In WCST, the performance of TA, TCP, TE, NE, CL, PR, UT in children with DD was significantly poorer than that of normal children, indicating DD children may have impairment in function of cognition, abstract, shifting, attention, and prefrontal cortex.3.3 In the mirror trace test,5.90% of DD group could not finish the test, but the completion rate was not significantly different when compared with normal group. When finished these tests, the DD group was remarkably slower than normal group.In addition, the DD group made more errors than normal group in counter-clockwise direction test. It suggested that DD children had poorer nonverbal reasoning and visual-motor coordinate than the normal children. There were negative correlations between mirror trace test indicators and factors of mathematical ability in children.3.4 In the stroop test, DD group spent more time than normal children in every test, and made more errors in the test required to read the color of words on the screen. It indicated that DD children reacted slower than normal children and had impairment in controlling interference. There were negative correlations between stroop test indicators and factors of mathematical ability in children.4.ConclusionIn summary, this study indicated that DD children had significant defects in the ability of information processing compared with normal children. First, DD children had impairment in function of abstract and logical reasoning, mainly in concept formation and cognitive conversion. Second, they had defects in the ability of visual-spatial information processing, and the performance of defects varies with the change of task. The defects may be reflected in processing time in general simple and intuitive information. However, It affects both speed and accuracy of information processing in analysis of abstract information and integration of a variety of information. We also found that visual-spatial ability had a specific influence on mathematical ability. In addition, DD children have impairments in function of cognition, attention, migration ability and so on.