Deficits in basic numerical skills, calculation, and working memory have been found in children with developmental dyscalculia (DD) as well as children with attention-deficit/hyperactivity disorder ...(ADHD). This paper investigates cognitive profiles of children with DD and/or ADHD symptoms (AS) in a double dissociation design to obtain a better understanding of the comorbidity of DD and ADHD.
Children with DD-only (N = 33), AS-only (N = 16), comorbid DD+AS (N = 20), and typically developing controls (TD, N = 40) were assessed on measures of basic numerical processing, calculation, working memory, processing speed, and neurocognitive measures of attention.
Children with DD (DD, DD+AS) showed deficits in all basic numerical skills, calculation, working memory, and sustained attention. Children with AS (AS, DD+AS) displayed more selective difficulties in dot enumeration, subtraction, verbal working memory, and processing speed. Also, they generally performed more poorly in neurocognitive measures of attention, especially alertness. Children with DD+AS mostly showed an additive combination of the deficits associated with DD-only and A_Sonly, except for subtraction tasks, in which they were less impaired than expected.
DD and AS appear to be related to largely distinct patterns of cognitive deficits, which are present in combination in children with DD+AS.
Two hypotheses have been proposed about the etiology of neurodevelopmental learning disorders, such as dyslexia and dyscalculia: representation impairments and disrupted access to representations. We ...implemented a multi-method brain imaging approach to directly investigate these representation and access hypotheses in dyscalculia, a highly prevalent but understudied neurodevelopmental disorder in learning to calculate. We combined several magnetic resonance imaging methods and analyses, including univariate and multivariate analyses, functional and structural connectivity. Our sample comprised 24 adults with dyscalculia and 24 carefully matched controls. Results showed a clear deficit in the non-symbolic magnitude representations in parietal, temporal and frontal regions, as well as hyper-connectivity in visual brain regions in adults with dyscalculia. Dyscalculia in adults was thereby related to both impaired number representations and altered connectivity in the brain. We conclude that dyscalculia is related to impaired number representations as well as altered access to these representations.
•Dyscalculia affects 5–7% of population and is as prevalent as dyslexia.•We applied wide variety of neuroimaging techniques to investigate this hypothesis.•First neuroimaging study with adults diagnosed with dyscalculia.•Impaired non-symbolic number representations are observed across cortex.•Increased functional connectivity between temporo-occipital regions in dyscalculia.
Several studies have aimed to identify subtypes of dyscalculia. In many of these studies, either pre-defined groups (e.g., children with reading and mathematical difficulties vs. children with ...isolated mathematical difficulties) were analyzed regarding their cognitive profiles (top-down approach), or clusters of children with dyscalculia (CwD) were identified based on a narrow range of cognitive and mathematical skills (data-driven or bottom-up approach). However, it has remained difficult to establish robust subtypes of dyscalculia across studies. Against this background, we conducted a mixture model analysis in order to explore and identify subtypes of dyscalculia based on a broad range of variables (intelligence, reading fluency, working memory, attention, and various mathematical skills). The total sample comprised 174 elementary school CwD (IQ > 70; mathematical abilities: percentile rank <10), which consisted of two subsamples. The first subsample was based on a diagnostic test focusing on calculation (HRT 1–4;
n
= 71; 46 girls, 25 boys; age:
M
= 9.28 years,
SD
= 0.94) whereas the second subsample was based on a diagnostic test with a strong focus on basic numerical capacities (ZAREKI-R;
n
= 103; 78 girls, 25 boys; age:
M
= 8.94 years,
SD
= 1.05). Results provided convincing evidence for the existence of two subtypes in CwD: A slightly impaired subtype and a strongly impaired subtype. Subtypes differed most strongly regarding mathematical abilities, but the analyses suggest that differences in attention could also be a key factor. Therefore, comorbid attention difficulties seem to be a relevant factor that needs to be considered when establishing subtypes. Substantial intelligence differences between dyscalculia subtypes could not be found. Differences in working memory and reading fluency were negligible. Overall, the results seemed to be robust regardless of the diagnostic test used for assessing dyscalculia. When planning interventions for CwD, the existence of a subtype with substantial attention problems should be kept in mind.
The mechanisms underlying simple arithmetic difficulties in dyscalculia are unknown. Evidence suggests deficiencies may arise from basic processes supporting magnitude perception and arithmetic ...proficiency. We focused on ‘groupitizing’, the ability to decompose and recompose quantities into a whole, examining whether adults with dyscalculia could benefit from visuospatial grouping cues when asked to estimate the quantity of a given set of different number ranges. Results showed adults with dyscalculia tended to focus on individual items rather than grouping them, resulting in low estimation abilities in both small and large quantity ranges. However, the results highlight the importance of differentiating between large and small quantities in the groupitizing process: only where arithmetic was easy (small but not large quantities), were adults with dyscalculia able to demonstrate significant improvement when given grouping cues. Our findings suggest weaker groupitizing abilities play a significant role in magnitude perception and arithmetic proficiency levels in dyscalculia.
People with dyscalculia have difficulties in basic arithmetic that impact their life in many ways, from simple tasks such as calculating change, to life-changing events such as entering higher education or making financial decisions. They use immature counting strategies to solve simple arithmetic questions despite otherwise intact intellectual abilities. The reasons for this are unclear. We argued there may be a link between simple arithmetic proficiency and quantity perception processes. Our study investigated the mechanisms underlying quantity perception that play a role in dyscalculia deficiencies. We focused on ‘groupitizing,’ a process that enables a person to estimate a given quantity more efficiently by recomposing subgroups rather than simply using a counting strategy. The findings suggested a disadvantage in basic groupitizing in people with dyscalculia. Moreover, counting procedures interfered with groupitizing processes and hindered arithmetic proficiency.
•Adults with dyscalculia show poorer quantity estimation than typically developed peers, even with very small quantities (4-6 dots).•Given grouping cues, adults with dyscalculia can estimate small quantities, but this ability is restricted to small amounts.•Arranging quantities into small subgroups ("groupitizing") is crucial for achieving proficiency in arithmetic.
Humans and other animals are able to make rough estimations of quantities using what has been termed the approximate number system (ANS). Much evidence suggests that sensitivity to numerosity ...correlates with symbolic math capacity, leading to the suggestion that the ANS may serve as a start-up tool to develop symbolic math. Many experiments have demonstrated that numerosity perception transcends the sensory modality of stimuli and their presentation format (sequential or simultaneous), but it remains an open question whether the relationship between numerosity and math generalizes over stimulus format and modality. Here we measured precision for estimating the numerosity of clouds of dots and sequences of flashes or clicks, as well as for paired comparisons of the numerosity of clouds of dots. Our results show that in children, formal math abilities correlate positively with sensitivity for estimation and paired-comparisons of the numerosity of visual arrays of dots. However, precision of numerosity estimation for sequences of flashes or sounds did not correlate with math, although sensitivities in all estimations tasks (for sequential or simultaneous stimuli) were strongly correlated with each other. In adults, we found no significant correlations between math scores and sensitivity to any of the psychophysical tasks. Taken together these results support the existence of a generalized number sense, and go on to demonstrate an intrinsic link between mathematics and perception of spatial, but not temporal numerosity.
A number of previous studies have identified cognitive deficits in developmental dyscalculia (DD). Yet, most of these studies were in alphabetic languages, whereas few of them examined Chinese DD. ...Here, we conducted a study aiming to determine the cognitive factors associated with DD in Chinese children. Five candidate cognitive factors of DD—phonological retrieval, phonological awareness, visual–spatial attention, spatial thinking, and pattern understanding—were examined in the present study. A total of 904 Chinese children ages 8 to 11 years participated in this study. From the sample, 97 children were identified with DD through tests of arithmetic ability, and 93 age- and IQ-matched typically developing children were selected as controls. Logistic regression analysis revealed that phonological retrieval, pattern understanding, visual–spatial attention, and phonological awareness significantly predicted DD, whereas spatial thinking failed to do so. Results of logistic relative weights analysis showed that all five factors explained statistically significant amounts of variance in arithmetic scores. Phonological retrieval had the most influence on DD, followed by pattern understanding, visual–spatial attention, phonological awareness, and spatial thinking. These findings have important clinical implications for diagnosis and intervention of Chinese DD.
Expert system for diagnosing learning disorders in children Andrade-Arenas, Laberiano; Yactayo-Arias, Cesar
International journal of electrical and computer engineering (Malacca, Malacca),
06/2024, Letnik:
14, Številka:
3
Journal Article
Odprti dostop
Given the urgent need for early detection of learning disorders such as dysgraphia, dyslexia, and dyscalculia in children, this study aimed to evaluate an expert system developed in Python to ...facilitate early diagnosis of these disorders. The background highlights the importance of providing parents, educators, and health professionals with an effective tool for early detection of these disorders. In 21 simulated cases, the system showed impressive performance with an accuracy rate of 95%, a precision of 100%, a sensitivity of 93%, and a specificity of 100%. Furthermore, the acceptability evaluation, conducted with 15 parents selected by convenience sampling, showed a high level of satisfaction, with an overall mean of 4.78 and a standard deviation of 0.45, indicating consistency in responses. In conclusion, this study confirms the effectiveness of the expert system in the early diagnosis of learning disabilities, providing parents, educators, and health professionals with a valuable tool. Despite these encouraging results, the need for additional research is recognized to address limitations and improve the external validity of the system to ensure its widespread utility and adaptability in real clinical settings.
This study examined visual, spatial‐sequential, and spatial‐simultaneous working memory (WM) performance in children with mathematical learning disability (MLD) and low mathematics achievement (LMA) ...compared with typically developing (TD) children. Groups were matched on reading decoding performance and verbal intelligence. Besides statistical significance testing, we used bootstrap confidence interval estimation and computed effect sizes. Children were individually tested with six computerized tasks, two for each visuospatial WM subcomponent. We found that both MLD and LMA children had low visuospatial WM function in both spatial‐simultaneous and spatial‐sequential WM tasks. The WM deficit was most expressed in MLD children and less in LMA children. This suggests that WM scores are distributed along a continuum with TD children achieving top scores and MLD children achieving low scores. The theoretical and practical significance of findings is discussed.
Statement of Contribution
What is already known on this subject?
Working memory plays an important role in mathematical achievement.
Children with mathematical learning disability (MLD) usually have low working memory resources.
Conflicting results have been reported concerning the role of VSWM in individuals with MLD.
What the present study adds?
Children with different degree of impairment in math achievement and typically developing children were tested.
Visual, spatial‐sequential, and spatial‐simultaneous working memory tasks were examined.
Only spatial‐sequential and spatial‐simultaneous working memory tasks discriminated the two impairments groups.
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.
In this study, children with persistent dyscalculia (DD) exhibited (a) larger Weber fraction and (b) greater error rates when the size of the individual dot stimuli were incongruent with the more numerous dot array during a non‐symbolic numerical discrimination task compared to typically developing children. These findings reveal that indices commonly used to assess internal numerical representations are affected by visual perceptual variables and affects children with DD to a greater extent than their typically developing peers. Multiple explanations for the present set of findings are discussed herein.
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