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1.
Using strict and lenient mathematics achievement cutoff scores to define a learning disability, respective groups of children who are math disabled (MLD, n=15) and low achieving (LA, n=44) were identified. These groups and a group of typically achieving (TA, n=46) children were administered a battery of mathematical cognition, working memory, and speed of processing measures (M=6 years). The children with MLD showed deficits across all math cognition tasks, many of which were partially or fully mediated by working memory or speed of processing. Compared with the TA group, the LA children were less fluent in processing numerical information and knew fewer addition facts. Implications for defining MLD and identifying underlying cognitive deficits are discussed.  相似文献   

2.
This study examines visual and spatial working memory skills in 35 third to fifth graders with both mathematics learning disabilities (MLD) and poor problem-solving skills and 35 of their peers with typical development (TD) on tasks involving both low and high attentional control. Results revealed that children with MLD, relative to TD children, failed spatial working memory tasks that had either low or high attentional demands but did not fail the visual tasks. In addition, children with MLD made more intrusion errors in the spatial working memory tasks requiring high attentional control than did their TD peers. Finally, as a post hoc analysis the sample of MLD was divided in two: children with severe MLD and children with low mathematical achievement. Results showed that only children with severe MLD failed in spatial working memory (WM) tasks if compared with children with low mathematical achievement and TD. The findings are discussed on the basis of their theoretical and clinical implications, in particular considering that children with MLD can benefit from spatial WM processes to solve arithmetic word problems, which involves the ability to both maintain and manipulate relevant information.  相似文献   

3.
Age-related change and patterns of individual differences in children's knowledge and skill in multiplication were investigated for students in Grades 4 and 6 (approximately ages 9 and 11, respectively) by examining multiple measures of computational skill, conceptual knowledge, and working memory. Regression analyses revealed that indexes reflecting probability of retrieval and special problem characteristics overshadow other, more general indexes (problem size and frequency of presentation) in predicting solution latencies. Some improvement in the use of conceptual knowledge was evident between Grades 4 and 6, but this change was neither strong nor uniform across tasks. Finally, patterns of individual differences across tasks differed as a function of grade level. The findings have implications for understanding developmental change and individual differences in mathematical cognition.  相似文献   

4.
Using 4 years of mathematics achievement scores, groups of typically achieving children (n = 101) and low achieving children with mild (LA-mild fact retrieval; n = 97) and severe (LA-severe fact retrieval; n = 18) fact retrieval deficits and mathematically learning disabled children (MLD; n = 15) were identified. Multilevel models contrasted developing retrieval competence from second to fourth grade with developing competence in executing arithmetic procedures, in fluency of processing quantities represented by Arabic numerals and sets of objects, and in representing quantity on a number line. The retrieval deficits of LA-severe fact retrieval children were at least as debilitating as those of the children with MLD and showed less across-grade improvement. The deficits were characterized by the retrieval of counting string associates while attempting to remember addition facts, suggesting poor inhibition of irrelevant information during the retrieval process. This suggests a very specific form of working memory deficit, one that is not captured by many typically used working memory tasks. Moreover, these deficits were not related to procedural competence or performance on the other mathematical tasks, nor were they related to verbal or nonverbal intelligence, reading ability, or speed of processing, nor would they be identifiable with standard untimed mathematics achievement tests.  相似文献   

5.
Children classified as hyperlexic learn to readwords spontaneously before age five, areimpaired in both reading and listeningcomprehension, and exhibit word recognitionskills above their linguistic and cognitiveabilities. Despite their strong wordrecognition skills, previous studies have shownthat the phonemic awareness skills ofhyperlexic children are low and notcommensurate with their word reading skill, inpart because of their limited comprehension of phonemic awareness tasks. Heretofore, a verylimited number of studies have investigateddirectly the orthographic processing, syntacticprocessing, and working memory skills ofchildren with hyperlexia. In the presentstudy, measures of orthographic processing,syntactic processing, and working memory skillwere administered to three hyperlexic childrenand three normally achieving readers; inaddition, measures of phonemic awareness,academic achievement, and cognitive abilitywere also administered. Results showed thatthe hyperlexic children performed aboveexpectations on the orthographic processingmeasures based on their cognitive andlinguistic abilities. The children withhyperlexia did not exhibit orthographic skillsthat were superior to the normally achievingreaders, although ceiling effects on theorthographic tasks may not have allowed them todemonstrate this skill. The three children withhyperlexia achieved lower scores than thenormally achieving readers on the syntacticprocessing measures and had great difficulty onthe phonemic awareness measures. Only one ofthe three hyperlexic children performed at alevel consistent with that of normallyachieving readers on the working memorymeasures. Findings suggest the hyperlexicchildren had levels of orthographic processingsimilar to that of normally achieving readers,read words using strategies similar to those ofnormal readers, and had phonemic awarenessskill that appears to be adequate for wordanalysis but could not be demonstrated ontraditional phonemic awareness measures.  相似文献   

6.
Turner syndrome is a common genetic disorder associated with select deficits in executive functions, working memory and mathematics. In Study 1, we examined growth trajectories of skills in these areas, from grades 1 to 6, among girls with or without Turner syndrome. Rates of growth and performance levels at 6th grade, on an untimed math achievement test, did not suggest that girls with Turner syndrome have math learning difficulty (MLD). However, analyses did reveal lower efficiency on timed executive function tasks, among girls with Turner syndrome, who traded accuracy for speed under mild to moderate working memory demands. In Study 2 we compared numerical processing skills of 6th graders who had either Turner syndrome, MLD, low math achievement, or typical achievement in math. A numerical decomposition task revealed numerical processing deficits for the Turner syndrome and MLD groups, relative to typically achieving students. The relative difficulties in how numerical processing vs. working memory demands affected performance accuracy differed among groups, with the former demands leading to more performance difficulties in the Turner syndrome group. Our findings support the notion that girls with Turner syndrome recruit different strategies than their peers during allegedly basic numerical processing, that numerical processing deficits vs. executive function deficits underlie their difficulties with mathematics, and that math difficulties among these girls may not be apparent on untimed tests. These finding have implications for a possible manifestation of MLD.  相似文献   

7.
BOOK REVIEWS     
Children with motor learning difficulties (MLD) tend to be less physically active than their coordinated peers and one likely consequence is a reduced level of physical fitness. In this study, 52 children with MLD, aged 5 to 8 years, were compared to 52 age‐ and gender‐matched control children across a range of health and skill related fitness components. Analyses of variance revealed significantly lower scores in the group with MLD on the tests for cardiorespiratory endurance, flexibility, abdominal strength, speed and power than the control group. Furthermore, the group with MLD had a significantly higher Body Mass Index (BMI). These findings have implications for educators and allied health professionals working with this age group. Programmes need to teach children with movement difficulties to perform tasks used in fitness assessment and also to work on the development of physical fitness.  相似文献   

8.
This study investigated the relationship between working memory (WM), declarative strategy knowledge, and math achievement in children with and without mathematical disabilities (MD). Experiment 1 examined the relationship between strategy knowledge, verbal WM, and visual-spatial WM in children with MD as a function of initial, gain, and maintenance conditions. The results showed that after partialing the influence of reading, stable strategy choices rather than specific strategy knowledge was related to verbal and visual-spatial WM span in high demand (maintenance) conditions. Experiment 2 compared children with MD to a group of chronological age-matched children and a group of math ability-matched children on the same conditions as Experiment 1. Age-matched children's verbal and visual-spatial WM performance was superior to that of children with MD, whereas WM performance was statistically comparable between children with MD and younger children matched on math ability. The selection of expert strategies was related to high WM span scores in the initial conditions. After controlling for reading achievement in a regression analysis, verbal and visual-spatial WM, stable verbal strategy choices, and expert strategy choices related to visual-spatial processing all contributed independent variance to math achievement. Overall, these results suggest that WM and math achievement are related to strategy knowledge.  相似文献   

9.
A longitudinal study was conducted on 82 children to investigate, firstly the numerical competence of young children and the predictive value of (pre)-numerical tests in kindergarten, and, secondly, whether children's knowledge of the numerical system and representation of the number size is related to their computation and logical knowledge and to their counting skills. In an additional cross-sectional study on 30 children with a clinical diagnosis of mathematical learning disability (MLD) of 8,5 years, age- and ability-matched with 2 × 30 children the same parameters of numerical competence were assessed. The longitudinal data showed individual differences in numerosity, as well as the relationship between a delay in arithmetics in grade l and problems on numerosity in kindergarten. In the cross-sectional results some evidence was found for the independence of numerical abilities in MLD-children. About 13% of them had still severe pre-numerical processing deficits (in number sequence production, cardinality skills and logical knowledge) in grade 3. About 67% had severe difficulties in executing calculation procedures and a lack of conceptual knowledge. A feature of 87% of the MLD-children was severe translation deficits, with a significantly worse knowledge of number words compared with the knowledge of Arab numerals. Finally a severe deficit in subitizing was found to be present in 33% of the MLD children. On a group level the processing deficits were linked to understanding numerosity, since the ability-matched younger children and the MLD-children had the same pre-numerical and numerical profile. Implications for the assessment of mathematical disabilities and the value of TEDI-MATH® as an instrument in this process are discussed.  相似文献   

10.
The study sought out to extend our knowledge regarding the origin of mathematical learning disabilities (MLD) in children by testing different hypotheses in the same samples of children. Different aspects of cognitive functions and number processing were assessed in fifth- and sixth-graders (11–13 years old) with MLD and compared to controls. The MLD group displayed weaknesses with most aspects of number processing (e.g., subitizing, symbolic number comparison, number-line estimation) and two cognitive functions (e.g., visual–spatial working memory). These findings favor the defective approximate number system (ANS) hypothesis, but do not fit well with the access deficit hypothesis. Support is also provided for the defective object-tracking system (OTS) hypothesis, the domain general cognitive deficit hypothesis and to some extent the defective numerosity-coding hypothesis. The study suggests that MLD might be caused by multiple deficits and not a single core deficit.  相似文献   

11.
In the past years, an increasing number of studies have investigated executive functions as predictors of individual differences in mathematical abilities. The present longitudinal study was designed to investigate whether the executive functions shifting, inhibition, and working memory differ between low achieving and typically achieving children and whether these executive functions can be seen as precursors to math learning disabilities in children. Furthermore, the predictive value of working memory ability compared to preparatory mathematical abilities was examined. Two classifications were made based on (persistent) mathematical ability in first and second grade. Repeated measures analyses and discriminant analyses were used to investigate which functions predicted group membership best. Group differences in performance were found on one inhibition and three working memory tasks. The working memory tasks predicted math learning disabilities, even over and above the predictive value of preparatory mathematical abilities.  相似文献   

12.
小学数学学习困难儿童的工作记忆广度研究   总被引：1，自引：0，他引：1  
对数学学习困难儿童的工作记忆广度进行研究,结果发现数学学习困难儿童在言语和视觉空间工作记忆广度上都显著低于正常儿童,但这种不足主要是一种发展的延迟。对有无伴随阅读困难的数学学习困难儿童进行比较,发现二者的言语和视觉空间工作记忆广度都没有表现出显著差异。  相似文献   

13.
The current meta-analysis synthesized findings from profiling research on Chinese children with reading difficulties (RD). We reviewed a total of 81 studies published between 1964 and May 2015, representing a total of 9735 Chinese children. There are 982 effect sizes for the comparison between children with RD and age-matched typically developing (A-TD) children and 152 effect sizes for the comparison between children with RD and reading-level-matched typically developing (R-TD) children on multiple linguistic and cognitive skills. Results showed that compared to A-TD children, children with RD have severe deficits in morphological awareness, orthographic knowledge, phonological awareness, rapid naming, working memory, and visual skills and moderate deficits in short-term memory and motor skills. Compared to R-TD children, children with RD only have moderate deficits in rapid naming and mild deficits in orthographic knowledge. Moderation analyses for the comparison between RD and A-TD children revealed that children with more severe RD show more severe deficits in morphological awareness, phonological awareness, rapid naming, and visual skills. However, neither location (Mainland vs. Hong Kong) nor type of reading screening (character recognition vs. character recognition combined with reading comprehension) emerged as a moderator of the deficit profiles. These findings indicate that Chinese children with RD have deficits on a wide range of cognitive and linguistic skills. Deficits in rapid naming and orthographic knowledge may be potential causal factors for RD in Chinese based on existing evidence. Implications for the diagnosis and instructions of Chinese children with RD were discussed.  相似文献   

14.
This study was designed to investigate potential reading differences between low-achieving and typically achieving first-grade Korean-speaking children by (1) comparing their speed of lexical access on alphanumeric and non-alphanumeric tests of rapid automatized naming and (2) comparing relationships between the two groups’ performance on alphanumeric and non-alphanumeric tasks with their performance on component measures of reading. Twenty-seven low-achieving readers and 34 typically achieving readers participated in this study. The low-achieving readers performed significantly more slowly than their typically achieving reading peers on the four measures of rapid naming. The response rates for both alphanumeric naming tasks (digits and letters) showed strong negative correlations with oral reading fluency, while their response rates for the non-alphanumeric naming tasks (Color and Object naming) showed relatively weak relationships with reading measures for both groups. In regression equations, Letter naming tasks were uniquely associated with both word recognition and oral reading fluency. The utility of using alphanumeric naming tasks as indicators for identifying Korean Hangul readers who are at risk for reading disabilities is discussed.  相似文献   

15.
Researchers of mathematics learning disability (MLD) commonly use cutoff scores to determine which participants have MLD. Some researchers apply more restrictive cutoffs than others (e.g., performance below the 10th vs. below the 35th percentile). Different cutoffs may lead to groups of children that differ in their profile of math and related skills, including reading, visual-spatial, and working memory skills. The present study assesses the characteristics of children with MLD based on varying MLD definitions of math performance either below the 10th percentile (n = 22) or between the 11th and 25th percentile (n = 42) on the Test of Early Math Ability, second edition (TEMA-2). Initial starting levels and growth rates for math and related skills were examined in these two MLD groups relative to a comparison group (n = 146) whose TEMA-2 performance exceeded the 25th percentile. Between kindergarten and third grade, differences emerged in the starting level and growth rate, suggesting qualitative differences among the three groups. Despite some similarities, qualitative group differences were also observed in the profiles of math-related skills across groups. These results highlight differences in student characteristics based on the definition of MLD and illustrate the value of examining skill areas associated with math performance in addition to math performance itself.  相似文献   

16.
Many children have significant mathematical learning disabilities (MLD, or dyscalculia) despite adequate schooling. The current study hypothesizes that MLD partly results from a deficiency in the Approximate Number System (ANS) that supports nonverbal numerical representations across species and throughout development. In this study of 71 ninth graders, it is shown that students with MLD have significantly poorer ANS precision than students in all other mathematics achievement groups (low, typically, and high achieving), as measured by psychophysical assessments of ANS acuity (w) and of the mappings between ANS representations and number words (cv). This relation persists even when controlling for domain-general abilities. Furthermore, this ANS precision does not differentiate low-achieving from typically achieving students, suggesting an ANS deficit that is specific to MLD.  相似文献   

17.
In a sample of 39 children with mathematical learning disabilities (MLD) and 106 typically developing controls belonging to three control groups of three different ages, we found that visual perception, motor skills and visual-motor integration explained a substantial proportion of the variance in either number fact retrieval or procedural calculation. Furthermore, children with MLD performed significantly worse on visual perception, motor skills and visual-motor integration in comparison with age-matched control children. A mild developmental delay in visual perception, visual-motor integration and (fine) motor coordination and a severe delay in motor skills were found in children with MLD. However, not all children with MLD have problems on these domains. They seem to be a heterogeneous group, not only with respect to their mathematical profile but also with respect to their visual perceptual, motor and visual-motor integration skills. Diagnostic implications are discussed.  相似文献   

18.
The extant literature on the social functioning of students with learning disabilities (LD) has indicated that whereas a majority belong to peer groups, a higher proportion are isolated and most have lower social status among peers in general than their typically achieving classmates. Although some work has examined these issues over short-term longitudinal studies, none to date have examined them over extensive time periods. Toward this end, the current study examined a sample of 1,361 students (678 girls and 683 boys; 55 with LD) using multiple measures of peer social functioning assessed each semester from spring of third grade through fall of sixth grade. The results indicated that whereas students with LD were similar to their typically achieving peers in terms of group functioning and characteristics, they were viewed as lower in social standing among their classmates as a whole. These effects were maintained over time, indicating that long-term inclusion may not substantially affect peer social functioning among students with LD.  相似文献   

19.
The current study aimed at identifying the difficulties experienced by children with mathematics learning disability (MLD) in the problem representation phase of arithmetic word problem solving using a novel problem types identification task. An MLD group (n = 66) and a typically achieving control group (n = 139) were recruited for an assessment on problem type identification as well as some domain-general and mathematics-related cognitive abilities. Results from ANCOVA showed that the MLD group scored significantly lower than the typically achieving control group on this assessment, after controlling for the effect of cognitive correlates, reading achievement and arithmetic performance. Furthermore, this assessment significantly predicted MLD membership even after taking children's arithmetic competency into account. The current study confirmed the difficulties in problem representation of arithmetic word problems experienced by students with MLD and provided evidence for the need to introduce schema instructions in mathematics classes.  相似文献   

20.
Working memory has been proposed as an important component of reading and arithmetic skills. The development of working memory was studied in normally achieving and subtypes of learning disabled children. The performance of reading disabled (RD), arithmetic disabled (ARITHD), and attentional deficit disordered (ADD) children, age 7-13, was compared to normal achievers (NA) on 2 working memory tasks, 1 involving sentences and the other involving counting. There was a significant growth of working memory as a function of age. In addition, the RD children had significantly lower scores on both tasks. The ARITHD children had significantly lower scores only on the Working Memory--Counting task, and the ADD group had scores similar to the normally achieving children except at the youngest age level in the Working Memory--Sentences task. Thus, a reading disability appears to involve a generalized deficit in working memory. Children with an arithmetic disability do not have a generalized language deficit but have a specific working memory deficit in relation to processing numerical information. As children with ADD did not have deficits in these tasks, working memory may not have significant attentional components. An important component of the development of reading and computational arithmetic skills appears to be the growth of working memory for language and numerical information.  相似文献   

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