发展性计算障碍儿童的数认知

发展性计算障碍作为一种特异性学习障碍,影响儿童的数学成就与数学学习观念,因而引起了多学科研究的关注和重视。文章分析了发展性计算障碍领域在数认知方面的已有研究,揭示了发展性计算障碍的数认知缺陷及内部差异,从一般认知加工障碍与数字加工模块障碍两个角度阐述了发展性计算障碍的可能成因,最后对当前研究进行了小结与展望,认为数认知缺陷的复杂关系、亚类型特征、成因之间的相互作用与机制还需进一步研究     

Prevalence of Attention-Deficit/Hyperactivity Disorder Symptoms in 4- to 17-Year-Old Children in the General Population

The purposes of this study were (a) to estimate the prevalence of Attention-Deficit/Hyperactivity Disorder (AD/HD) symptoms in the general preschool and school population; and (b) to analyze the influence of gender, age, and socioeconomic status (SES) variables on AD/HD symptoms. Out of the 80,000 preschool and schoolchildren living in Manizales, Colombia, a random sample of 540 children was selected. Two gender, three age (4- to 5-year olds, 6- to 11 -year olds, and 12- to 17-year olds), and three SES (low, middle, and high) groups were used. The 18 DSM-IV symptoms corresponding to AD/HD Criterion A were assessed on a scale of 0 (never) to 3 (almost always). All three demographic variables established statistically significant differences: AD/HD symptoms were more frequent in 6-to 11-year-old, low-SES, male participants. DSM-IV Criterion A for AD/HD was fulfilled by 19.8% of the boys and 12.3% of the girls. However, this difference was marginally significant only in the AD/HD Subtype I: Combined. It was concluded that demographic variables are significant correlates of the AD/HD diagnosis. The prevalence found in this study was higher than usually reported, even though only the symptomatic DSM-IV AD/HD criterion was analyzed. We failed to confirm the assumed AD/HD gender ratio.     

Neuropsychological status of French children with developmental dyslexia and/or developmental coordination disorder: Are both necessarily worse than one?

Developmental dyslexia (DD) and developmental coordination disorder (DCD) co-occur frequently, raising the underlying question of shared etiological bases. We investigated the cognitive profile of children with DD, children with DCD, and children with the dual association (DD + DCD) to determine the inherent characteristics of each disorder and explore the possible additional impact of co-morbidity on intellectual, attentional, and psychosocial functioning. The participants were 8- to 12-year-olds (20 DD, 22 DCD, and 23 DD + DCD). Cognitive abilities were assessed by the Wechsler Intelligence Scale for Children – Fourth Edition (WISC-IV) and the Continuous Performance Test – Second Edition (CPT-II) and behavioral impairments were evaluated by the Child Behavior Checklist (CBCL). No differences were found between the three groups on attention testing (CPT-II) or psychosocial characteristics (CBCL), but a higher percentage of DD + DCD children had pathological scores on psychosocial scales. Significant between-group differences were observed on Processing Speed Index scores and the block design and symbol search subtests, where DD children fared better than DCD children. No significant differences were evident between the co-morbid vs. the pure groups. Our results clearly show significant differences between children with DD only and children with DCD only. In particular, visuo-spatial disabilities and heterogeneity of intellectual profile seem to be good markers of DCD. However, it should be noted that despite these distinct and separate characteristics, a common cognitive profile (weaknesses and strengths) is likely shared by both neurodevelopmental disorders. Surprisingly, concerning co-morbidity, DD + DCD association is not associated with a decrease in intellectual or attentional capacities.     

Working memory deficits in developmental dyscalculia: The importance of serial order

Although a number of studies suggests a link between working memory (WM) storage capacity of short-term memory and calculation abilities, the nature of verbal WM deficits in children with developmental dyscalculia (DD) remains poorly understood. We explored verbal WM capacity in DD by focusing on the distinction between memory for item information (the items to be retained) and memory for order information (the order of the items within a list). We hypothesized that WM for order could be specifically related to impaired numerical abilities given that recent studies suggest close interactions between the representation of order information in WM and ordinal numerical processing. We investigated item and order WM abilities as well as basic numerical processing abilities in 16 children with DD (age: 8–11 years) and 16 typically developing children matched on age, IQ, and reading abilities. The DD group performed significantly poorer than controls in the order WM condition but not in the item WM condition. In addition, the DD group performed significantly slower than the control group on a numerical order judgment task. The present results show significantly reduced serial order WM abilities in DD coupled with less efficient numerical ordinal processing abilities, reflecting more general difficulties in explicit processing of ordinal information.     

Gender Differences and Cognitive Correlates of Mathematical Skills in School-Aged Children

Published information concerning the influence of gender on mathematical ability tests has been controversial. The present study examines the performance of school-aged boys and girls from two age groups on several mathematical tasks and analyzes the predictive value of a verbal fluency test and a spatial test on those mathematical tasks. More specifically, our research attempts to answer the following two questions: (1) Are gender differences in mathematical test performance among children interrelated with age and (2) do verbal and spatial nonmathematical tests mediate gender effects on mathematical test performance? Two hundred and seventy-eight 7- to 10-year-old children and 248 13- to 16-year-olds were selected from schools in Colombia and Mexico (231 boys and 295 girls). The age effect was found to be significant for all measures, with scores improving with age. Results showed that boys and girls in both age groups scored similarly in most subtests, but that differences emerged in the performance of mental mathematical operations and in resolving arithmetical problems. In the latter – but not in mental math – older boys outperformed older girls, whereas no gender differences were observed in the younger groups. After controlling for age, it was found that the spatial test was, indeed, a significant mediator of gender effects, while the verbal task was not.     

Probing the nature of deficits in the ‘Approximate Number System’ in children with persistent Developmental Dyscalculia

In the present study we examined whether children with Developmental Dyscalculia (DD) exhibit a deficit in the so‐called ‘Approximate Number System’ (ANS). To do so, we examined a group of elementary school children who demonstrated persistent low math achievement over 4 years and compared them to typically developing (TD), aged‐matched controls. The integrity of the ANS was measured using the Panamath ( www.panamath.org ) non‐symbolic numerical discrimination test. Children with DD demonstrated imprecise ANS acuity indexed by larger Weber fraction (w) compared to TD controls. Given recent findings showing that non‐symbolic numerical discrimination is affected by visual parameters, we went further and investigated whether children performed differently on trials on which number of dots and their overall area were either congruent or incongruent with each other. This analysis revealed that differences in w were only found between DD and TD children on the incongruent trials. In addition, visuo‐spatial working memory strongly predicts individual differences in ANS acuity (w) during the incongruent trials. Thus the purported ANS deficit in DD can be explained by a difficulty in extracting number from an array of dots when area is anti‐correlated with number. These data highlight the role of visuo‐spatial working memory during the extraction process, and demonstrate that close attention needs to be paid to perceptual processes invoked by tasks thought to represent measures of the ANS.     

Audio‐visual speech in noise perception in dyslexia

Individuals with developmental dyslexia (DD) may experience, besides reading problems, other speech‐related processing deficits. Here, we examined the influence of visual articulatory information (lip‐read speech) at various levels of background noise on auditory word recognition in children and adults with DD. We found that children with a documented history of DD have deficits in their ability to gain benefit from lip‐read information that disambiguates noise‐masked speech. We show with another group of adult individuals with DD that these deficits persist into adulthood. These deficits could not be attributed to impairments in unisensory auditory word recognition. Rather, the results indicate a specific deficit in audio‐visual speech processing and suggest that impaired multisensory integration might be an important aspect of DD.     

Cerebellar tasks do not distinguish between children with developmental dyslexia and children with intellectual disability.

This paper explored the claim that only children with developmental dyslexia, whose reading ability is discrepant from their average general reasoning ability show specific deficits in motor tasks assessing cerebellar functioning (Fawcett et al., 2001, Cerebellar tests differentiate between groups of poor readers with and without IQ discrepancy. J. Learning Disabilities, 34, 119) and rapid serial naming (RAN, Wolf & Bowers, 1999, The double deficit hypothesis for the developmental dyslexias. J. Educ. Psychol., 91, 1). All available children between the ages of 11 and 14 were recruited from two special schools for children with either (a) formally-diagnosed intellectual disabilities (N = 18); or (b) formal diagnoses of developmental dyslexia (N = 25). These two groups of children did not differ on gender, age, pseudoword decoding abilities, or on 7 of 8 literacy measures, but did differ significantly, as expected on verbal and non-verbal reasoning tasks. Importantly, there were no deficits in bead threading ability or postural stability in the children with developmental dyslexia compared to the children with intellectual disabilities. There were also no between-group differences in rapid naming measures. The present results therefore provide no support for the claim that cerebellar deficits or RAN distinguish between children with dyslexia and children with intellectual disabilities that include reading.     

Both non-symbolic and symbolic quantity processing are important for arithmetical computation but not for mathematical reasoning

This study investigated whether numerical processing was important for two types of mathematical competence: arithmetical computation and mathematical reasoning. Thousand eight hundred and fifty-seven Chinese primary school children in third through sixth grades took eight computerised tasks: numerical processing (numerosity comparison, digit comparison), arithmetical computation, number series completion, non-verbal matrix reasoning, mental rotation, choice reaction time, and word rhyming. Hierarchical regressions showed that both non-symbolic numerical processing (numerosity comparison) and symbolic numerical processing (digit comparison) were independent predictors of arithmetical computation but neither was a predictor of mathematical reasoning (assessed by number series completion). These findings suggest that the cognitive basis of mathematical performance varies depending on the type of mathematical competence measured.     

Individual differences in trajectories of arithmetical development in typically achieving 5- to 7-year-olds

The arithmetical performance of typically achieving 5- to 7-year-olds (N = 29) was measured at four 6-month intervals. The same seven tasks were used at each time point: exact calculation, story problems, approximate arithmetic, place value, calculation principles, forced retrieval, and written problems. Although group analysis showed mostly linear growth over the 18-month period, analysis of individual differences revealed a much more complex picture. Some children exhibited marked variation in performance across the seven tasks, including evidence of difficulty in some cases. Individual growth patterns also showed differences in developmental trajectories between children on each task and within children across tasks. The findings support the idea of the componential nature of arithmetical ability and underscore the need for further longitudinal research on typically achieving children and of careful consideration of individual differences.     

注意缺陷多动障碍-发展性阅读障碍共患儿童的干预效果及其内在机理

注意缺陷多动障碍和发展性阅读障碍是两类常见的儿童神经发育障碍, 二者共患率高达25%~48%。共患问题不仅使儿童自身面临着严重的认知、行为和心理损害, 还给家庭、学校和社会带来了沉重的负担, 对共患儿童的干预是极为必要且重要的。以共患病理机制假说为基础, 可将既往共患儿童的干预研究划分为以下两大类：(1)基于表型假说的干预方案, 如药物干预、阅读干预以及二者联合干预, 相应方案干预效果的迁移性和稳定性均有待深入考究; (2)基于共同缺陷假说的干预方案, 如针对核心共同认知缺陷之一的加工速度问题的干预已初显成效, 但相关研究较少, 干预效果需更多研究进一步系统性地考察。最后就共患儿童的干预方案现状进行了反思和展望。     

Children with Autism and Their Friends: A Multidimensional Study of Friendship in High-Functioning Autism Spectrum Disorder

This study of Israeli and American preadolescent children examined characteristics of friendship in 44 children with high-functioning autism spectrum disorder (HFASD) compared to 38 typically developing children (TYP), as they interacted with a close friend Participants were 8-12 years of age (HFASD: Israel, n = 24; USA, n = 20; TYP: Israel, n = 23; USA, n = 15), and were matched on SES, receptive language vocabulary, child age, and gender (each study group included one girl). Multidimensional assessments included: individual behaviors of target children and observed child-friend interactions during construction and drawing scenarios; target child's and friend's self-perceived mutual friendship qualities; and mother-reported characteristics (friendship's duration/frequency; friend's age/gender/disability status). Overall, children with HFASD displayed a number of differences on individual and dyadic friendship measures. Both age and verbal abilities affected friendship behaviors. Children with HFASD and their friends perceived friendship qualities similarly, suggesting that preadolescents with HFASD have capacities for interpersonal awareness. Between-group similarities also emerged on several complex social behaviors, suggesting that friendship follows a developmental trajectory in autism and may enhance social interaction skills in autism.     

Can we predict mathematical learning disabilities from symbolic and non‐symbolic comparison tasks in kindergarten? Findings from a longitudinal study

Background. The ability to compare numbers, as the most basic form of number sense, has been related to arithmetical achievement. Aims. The current study addressed the predictive value of non‐symbolic and symbolic (number word (NW) and Arabic number (AN)) comparison for arithmetics by means of a longitudinal design. Sample. Sixteen children with mathematical disabilities (MD), 64 low achievers (LA), and 315 typical achieving (TA) children were followed from kindergarten till grade 2. Method. The association of comparison skills with arithmetical skills in grades l and 2 was studied. The performances of MD, LA and TA children were compared. Results. Regression analyses showed that non‐symbolic skills in kindergarten were predictively related to arithmetical achievement 1 year later and fact retrieval 2 years later. AN comparison was predictively related to procedural calculation 2 years later. In grade 2, there was an association between both symbolic tasks and arithmetical achievement. Children with MD already had deficits in non‐symbolic and symbolic AN comparison in kindergarten, whereas in grade 2 the deficits in processing symbolic information remained. Conclusions. The combination of non‐symbolic and symbolic deficits represents a risk of developing MD.     

Representation and retrieval of arithmetical facts: Developmental difficulties

One form of developmental difficulty with arithmetic affects the storage or retrieval of arithmetical facts, such as tables, which are required to implement arithmetical computations (Temple, 1991, 1994). Such difficulties may arise because of impairment in a specialized system for the storage of arithmetical facts or as a result of causally linked impairment in another cognitive domain. This study explored issues concerning the representation and retrieval of arithmetical facts in children with number fact disorders (NF) and in normal children, in particular the status of hypothesized linked impairments: short-term memory (STM) spans, counting skills, speed of speech, and speed of number fact and lexical retrieval. There was no evidence that NF children had weak STM spans on any span measure or that STM spans related to arithmetical fact skills. There was also no evidence that NF children had weak counting abilities or free counting speeds. The NF children were slower in speeded counting, which also correlated with number fact skill. The significance or not of this is discussed. The NF children were also slower than controls in speed of speech and on some measures of speed of access. However, the absence of correlation with number fact skill, the absence of generality across tasks, and the possibility that delayed speeds in fact retrieval reflect the use of alternative strategies, together suggest that the increased speeds are not causally linked to number fact skill. The results are consistent with modular accounts, in which there is a specialized system for the storage and retrieval of arithmetical facts.     

Early Developmental Screening for Children in Foster Care

Limited data exist about the ideal timing of developmental screening for young children entering foster care, and current best practice recommends screening by 1 month into care to prioritize resources for evaluation. Therefore, we aimed to: (1) compare detection rates for potential developmental delay (DD) at foster care entry before and after implementation of a developmental screen and (2) examine accuracy of developmental screening when performed at entry and 1 month into care. Charts of 124 children <6 years evaluated for an initial foster care health assessment (IFCHA) were reviewed to determine baseline detection rates for potential DD. The Parents’ Evaluation of Developmental Status (PEDS) screening tool was then prospectively administered to 167 children <6 years during their IFCHA to determine detection rates. One month following the IFCHA, caregivers were re-contacted, and the screen was re-administered. Accuracy of the initial PEDS screen was compared to the 1 month PEDS screen by calculation of sensitivity and specificity. At baseline, potential DD was detected in 34 % of children at the IFCHA compared to 46 % after implementation of the PEDS (P = 0.041). Compared to the 1 month screen, the early screen had a sensitivity of 75 % and specificity of 88 %. Use of a developmental screening tool at foster care entry increased detection of potential DD, and the results remained consistent with screening 1 month later. These results support use of a developmental screen for children in foster care and suggest that screening be performed as early as possible to expedite necessary evaluations and referrals.     

Do subitizing deficits in developmental dyscalculia involve pattern recognition weakness?

The abilities of children diagnosed with developmental dyscalculia (DD) were examined in two types of object enumeration: subitizing, and small estimation (5–9 dots). Subitizing is usually defined as a fast and accurate assessment of a number of small dots (range 1 to 4 dots), and estimation is an imprecise process to assess a large number of items (range 5 dots or more). Based on reaction time (RT) and accuracy analysis, our results indicated a deficit in the subitizing and small estimation range among DD participants in relation to controls. There are indications that subitizing is based on pattern recognition, thus presenting dots in a canonical shape in the estimation range should result in a subitizing‐like pattern. In line with this theory, our control group presented a subitizing‐like pattern in the small estimation range for canonically arranged dots, whereas the DD participants presented a deficit in the estimation of canonically arranged dots. The present finding indicates that pattern recognition difficulties may play a significant role in both subitizing and subitizing deficits among those with DD.     

Effects of social setting on the friendship formation of young children differing in developmental status

This study examined the effects of social setting on the friendship formation of preschool-aged children differing in developmental status. Normally developing children (ND), children with communication disorders (CD), and children with developmental (cognitive) delays (DD) participated in a series of short-term play groups. Each of the 21 play groups consisted of children similar in developmental status (ND, CD, or DD play groups; specialized social settings) or contained primarily ND children with a small number of either CD or DD children (mainstreamed social settings). All children initially were unacquainted with one another and were carefully matched on a variety of family demographic and child characteristic measures. Results revealed that high proportions of unilateral friendships were established for all developmental status groups, but proportions were smaller when employing an index of reciprocal friendships. The proportions of unilateral and reciprocal friendships varied in accordance with a child's developmental status, but were not affected by social setting. In mainstreamed settings, the friendship choices of ND children were affected by peers' developmental status. Moreover, children with reciprocal friends were more socially interactive overall than children without reciprocal friends. The implications of these results for arranging social settings that support friendship formation for children with and without disabilities are discussed.     

Which Executive Functioning Deficits Are Associated With AD/HD,ODD/CD and Comorbid AD/HD+ODD/CD?

This study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associated with executive functioning (EF) deficits while controlling for oppositional defiant disorder/conduct disorder (ODD/CD), (2) whether ODD/CD is associated with EF deficits while controlling for AD/HD, and (3)~whether a combination of AD/HD and ODD/CD is associated with EF deficits (and the possibility that there is no association between EF deficits and AD/HD or ODD/CD in isolation). Subjects were 99~children ages 6–12 years. Three putative domains of EF were investigated using well-validated tests: verbal fluency, working memory, and planning. Independent of ODD/CD, AD/HD was associated with deficits in planning and working memory, but not in verbal fluency. Only teacher rated AD/HD, but not parent rated AD/HD, significantly contributed to the prediction of EF task performance. No EF deficits were associated with ODD/CD. The presence of comorbid AD/HD accounts for the EF deficits in children with comorbid AD/HD+ODD/CD. These results suggest that EF deficits are unique to AD/HD and support the model proposed by R. A. Barkley (1997).     

‘I Remember When I Learned That!’ developmental and gender differences in children's memories of learning episodes

Eighty 4‐ to 9‐year‐old children answered factual knowledge questions in math, science and social studies during one‐on‐one interviews. Children indicated whether they had known or guessed each answer, and whether they (a) remembered the moment they learned the answer (episodic response) or (b) did not remember. For episodic responses, children provided memory narratives of learning episodes. One third of children's responses identified a learning episode. There was a developmental trend in which older children were more episodic than younger children, and when children knew and provided correct answers, there was a gender difference in which females were more episodic than males. Developmental and gender differences in the characteristics of memory narratives were also apparent. Copyright © 2010 John Wiley & Sons, Ltd.     

When the mental number line involves a delay: the writing of numbers by children of different arithmetical abilities

Our study focused on number transcoding in children. It investigated how 9-year-olds with and without arithmetical disabilities wrote Arabic digits after they had heard them as number words. Planning time before writing each digit was registered. Analyses revealed that the two groups differed not only in arithmetical abilities but also in verbal and reading abilities. Children with arithmetical disabilities were overall slower in planning Arabic digits than were control children with normal arithmetical abilities. In addition, they showed a number size effect for numbers smaller than 10, suggesting a semantically mediated route in number processing. Control children did not need more planning time for large numbers (e.g., 8) than for small numbers (e.g., 3), suggesting a direct nonsemantic route. For both two- and three-digit numbers, both groups of children showed a number size effect, although the effect was smaller each time for control children. The presence of the stronger number size effect for children with arithmetical disabilities was seen as a delay in the development of quick and direct transcoding. The relation between transcoding problems and arithmetical disabilities is discussed. A defect in the linking of numerical symbols to analog numerical representations is proposed as an explanation for the transcoding problems found in some children.