Dyscalculic Children Research Articles

Ordinal processing differences between children with persistent dyscalculia and typically performing children.

Ordinal number processing skills are important for adults and children. Recent work demonstrates that children have difficulty with judging the ordinality of sequences that are in-order but do not match the typical count-list (i.e., in-order non-adjacent sequences, such as 2-4-6). Limited evidence in the literature suggests that dyscalculic children show a similar pattern of behavior. In the present study, we sought to explicitly test the hypothesis that children with developmental dyscalculia struggle primarily with extending notions of ordinality to sequences outside of the count-list. We test this hypothesis using a sample of children with persistent developmental dyscalculia, and a comparison group of typically performing children. Both groups completed an ordinality judgment task, in which triplet sequences were judged as being in-order (e.g., 3-4-5; 2-4-6) or in mixed-order (e.g., 3-5-4; 2-6-4). In line with our prediction, results demonstrate that children with persistent developmental dyscalculia make more errors, compared to typically performing children, but only on the in-order non-adjacent trials (e.g., 2-4-6). Broadly, this finding suggests that ordinality processing abilities are impaired in children with developmental dyscalculia, and that this characteristic appears primarily in extending notions of ordinality beyond adjacent sequences. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Performance on curriculum-based mathematics assessments in developmental dyscalculia: the effect of content domain and question format

Developmental Dyscalculia (DD) is characterised by persistent difficulties in learning mathematical skills, which usually becomes apparent in the early years of schooling. Traditionally, DD is known to affect children’s arithmetic processing, whilst other domains of mathematics receive much less research attention. Nevertheless, contemporary diagnostic guidelines suggest that DD is linked to widespread and diverse difficulties, both within and outside of the domain of numbers. This study examined the performance (i.e., accuracy and number of questions attempted) of children on a curriculum-based mathematics assessment, considering the effect of content domains, question format (i.e., multiple-choice questions vs. constructed response questions) and test half. Participants were forty children aged 8 to 11 years old with DD (n = 20) and a carefully matched control group of typically developing children (n = 20) from primary schools in Northern Ireland. Results revealed that the DD group achieved significantly lower scores than the control group across all areas of the curriculum, and the magnitude of group differences was similar across all content domains. These findings indicate that performance in content domains other than in arithmetic may be equally informative in supporting the identification of children with DD. In addition, we found that using multiple-choice questions may support learners with DD in achieving the best outcome, and, thus, could be useful for assessing mathematics skills in dyscalculic children in classroom contexts. Nevertheless, constructed response questions may show the greatest sensitivity to identifying learners at risk, and could be the most useful in diagnostic settings.

Weaker number sense accounts for impaired numerosity perception in dyscalculia: Behavioral and computational evidence.

Impaired numerosity perception in developmental dyscalculia (low "number acuity") has been interpreted as evidence of reduced representational precision in the neurocognitive system supporting non-symbolic number sense. However, recent studies suggest that poor numerosity judgments might stem from stronger interference from non-numerical visual information, in line with alternative accounts that highlight impairments in executive functions and visuospatial abilities in the etiology of dyscalculia. To resolve this debate, we used a psychophysical method designed to disentangle the contribution of numerical and non-numerical features to explicit numerosity judgments in a dot comparison task and we assessed the relative saliency of numerosity in a spontaneous categorization task. Children with dyscalculia were compared to control children with average mathematical skills matched for age, IQ, and visuospatial memory. In the comparison task, the lower accuracy of dyscalculics compared to controls was linked to weaker encoding of numerosity, but not to the strength of non-numerical biases. Similarly, in the spontaneous categorization task, children with dyscalculia showed a weaker number-based categorization compared to the control group, with no evidence of a stronger influence of non-numerical information on category choice. Simulations with a neurocomputational model of numerosity perception showed that the reduction of representational resources affected the progressive refinement of number acuity, with little effect on non-numerical bias in numerosity judgments. Together, these results suggest that impaired numerosity perception in dyscalculia cannot be explained by increased interference from non-numerical visual cues, thereby supporting the hypothesis of a core number sense deficit. RESEARCH HIGHLIGHTS: A strongly debated issue is whether impaired numerosity perception in dyscalculia stems from a deficit in number sense or from poor executive and visuospatial functions. Dyscalculic children show reduced precision in visual numerosity judgments and weaker number-based spontaneous categorization, but no increasing reliance on continuous visual properties. Simulations with deep neural networks demonstrate that reduced neural/computational resources affect the developmental trajectory of number acuity and account for impaired numerosity judgments. Our findings show that weaker number acuity in developmental dyscalculia is not necessarily related to increased interference from non-numerical visual cues.

WE ASKED TEACHERS: DO YOU KNOW WHAT DYSCALCULIA IS?

This study aims to determine the knowledge levels of primary school, mathematics, special education, and Psychological Counseling & Guidance (PCG) teachers on Dyscalculia. A descriptive survey model was used for the research. Four hundred eighty-nine teachers were selected for the study, including 254 primary school teachers, 130 high school math teachers, 53 psychologists, 28 special educators, and 24 secondary school math teachers. A survey form devised by Dias, Pereira, and Van Borsel (2013) during the research, including 18 questions, 2 of which were open-ended and 16 were closed-ended, was used. The obtained data reveal that most participating teachers do not have adequate knowledge and experience on the meaning, effects, root causes of dyscalculia, and the intervention strategies for dyscalculic children.

The impact of anxiety and life quality on the mathematical performance of dyscalculic middle school children

Dyscalculia is a specific difficulty in learning mathematics that strongly influences activities of daily living that require skills such as counting and simple mathematical operations. The aim of this study is to investigate the effect of negative emotions on mathematical performance in children with and without developmental dyscalculia using psychosocial tests, a quality of life test, an anxiety test and the Zareki-R mathematical performance test. This pilot study was realized on a sample of 20 children in the first year of secondary school (a group of 10 dyscalculic children and another group of 10 control children with an average age of 12.65 years). Descriptive statistics showed that dyscalculic children had low scores on all Zareki-R subtests. The Mann Whitney analysis revealed a significant difference between dyscalculic children and typically developing children on the Zareki-R subtests and the quality of life test, but no significance was found for the anxiety test. Analysis of the ANOVA by gender revealed no significant differences for the three tests, and the opposite for the ANOVA by age (F = 3.86, dll = 2, p ˂ 0.05). Using multiple linear regression, the subtests of physical quality of life, emotional quality of life and academic quality of life were significantly different for the two groups. In conclusion, the psychosocial quality of life and the high level of anxiety in dyscalculic children strongly influence their performance in mathematics.

Transcranial direct current stimulation to enhance mathematical performance in school going developmental dyscalculic children: A single group pretest-posttest, quasi experimental study

INTRODUCTION: Developmental dyscalculia (DD) deals with impaired mathematical performance and affects the educational and day-to-day activities of children. There is evidence that transcranial direct current stimulation (tDCS) applied to the posterior parietal cortex facilitates the hypoactive neuronal structure and improves mathematical performance in individuals with DD. OBJECTIVE: The objective of this study is to investigate whether tDCS adjuvant with conventional numeracy training (CNT) would enhance the mathematical abilities of school-going children affected with DD. MATERIALS AND METHODS: Thirteen school-going children affected with DD received tDCS and CNT three sessions per week for up to 2 consecutive weeks. Left anodal and right cathodal stimulation at P3/P4 region with 2mA intensity combined with CNT for 30 minutes in a day was given. Learning disability diagnostic inventory (LDDI) was used as an outcome measure and collected at baseline and the end of the 2-week intervention. RESULTS: There was a significant improvement in the mathematical performance of school-going children. The results show statistically as well as a clinically significant improvement after the 2 weeks of intervention. CONCLUSIONS: tDCS combined with CNT is effective for improving the mathematical abilities of school-going children affected with DD. The findings of this study provide a new perspective for the rehabilitation of school-going DD children.

The Causes, Prevalence and Interventions for Dyscalculia in Malaysia

Children with Dyscalculia show deficits in the basic understanding of quantities and numbers, which cause difficulties in math skills acquisition despite adequate schooling. This study summarizes the current knowledge regarding causes, diagnosis and treatment of Dyscalculia in Malyasia from a clinician’s perspective. The findings reveal that Dyscalculia is a brain based specific learning disability, which often co-exist with other neurological disorders such as Dyslexia and attention-deficit hyperactive disorder (ADHD). Symptoms of Dyscalculia include difficulty in reading, writing, counting, arithmetic calculation, direction co-ordination, finger counting agnosia and time management. A computer-based Diagnosis of Dyscalculia should measure all the possible difficulties that are faced by Dyscalculic patient along with other disorders that might co-exist with Dyscalculia and IQ. Care can be provided to Dyscalculia children using one-on-one intervention and the implementation of a standard policy based on health professionals, teachers, parents for diagnosis and treatment. The study also shows the need for more research into the current situation, diagnosis and intervention of dyscalculic cases in Malaysia to help meet the needs of these dyscalculic children.

Validity and reliability of the Arabic dyscalculia test in diagnosing Egyptian dyscalculic school-age children

BackgroundMathematical skills have an important role in progress of the educational level of nations. Unfortunately, there are still some pupils in school with normal intellectual function, but they have different degrees of mathematical disabilities that really can fall apart their whole life.Dyscalculia is called number blindness. It is the name given to the condition that affects our ability to acquire arithmetical skills. In the Arabic language, there is a deficiency in tools for diagnosis of dyscalculia, so we conducted this study to formulate a test suitable for diagnosis of dyscalculia in Egyptian children via translation and modification of an American test (TOMA 3 test).ResultsThe modified test was highly significant in discriminating dyscalculic from non-dyscalculic Egyptian pupils regarding all items of the test.ConclusionThe Arabic version of TOMA-3 is valid and reliable for diagnosis of dyscalculia in Egyptian school-age children.

Persistent Differences in Brain Structure in Developmental Dyscalculia: A Longitudinal Morphometry Study.

Developmental dyscalculia (DD) is a learning disability affecting the acquisition of numerical-arithmetical skills. Affected people show persistent deficits in number processing, which are associated with aberrant brain activation and structure. Reduced gray matter has been reported in DD for the parietal cortex including the intraparietal sulcus (IPS), but also the frontal and occipito-temporal cortex. Furthermore, dyscalculics show white matter differences for instance in the inferior (ILF) and superior longitudinal fasciculus (SLF). However, the longitudinal development of these structural differences is unknown. Therefore, our goal was to investigate the developmental trajectory of gray and white matter in children with and without DD. In this longitudinal study, neuropsychological measures and T1-weighted structural images were collected twice with an interval of 4 years from 13 children with DD (8.2–10.4 years) and 10 typically developing (TD) children (8.0–10.4 years). Voxel-wise estimation of gray and white matter volumes was assessed using voxel-based morphometry for longitudinal data. The present findings reveal for the first time that DD children show persistently reduced gray and white matter volumes over development. Reduced gray matter was found in the bilateral inferior parietal lobes including the IPS, supramarginal gyri, left precuneus, cuneus, right superior occipital gyrus, bilateral inferior and middle temporal gyri, and insula. White matter volumes were reduced in the bilateral ILF and SLF, inferior fronto-occipital fasciculus (IFOF), corticospinal tracts, and right anterior thalamic radiation (ATR). Behaviorally, children with DD performed significantly worse in various numerical tasks at baseline and follow-up, corroborating persistent deficits in number processing. The present results are in line with the literature showing that children with DD have reduced gray and white matter volumes in the numerical network. Our study further sheds light on the trajectory of brain development, revealing that these known structural differences in the long association fibers and the adjacent regions of the temporal- and frontoparietal cortex persist in dyscalculic children from childhood into adolescence. In conclusion, our results underscore that DD is a persistent learning disorder accompanied by deficits in number processing and reduced gray and white matter volumes in number related brain areas.

Effectiveness of working memory training among children with dyscalculia: evidence for transfer effects on mathematical achievement-a pilot study.

We examined whether the working memory (WM) capacity of developmentally dyscalculic children can be improved by a WM training program and whether outcomes relate to mathematical performance. The experimental design comprised two groups with developmental dyscalculia with grade 4 schooling: an experimental group (n=14; mean age=115.29months) and a control group (n=14; mean age=116.07months). All participants were assessed on measures of WM, mathematic attainment, and nonverbal mental ability (Raven test) before and after training. The WM training program focused on manipulating and maintaining arithmetic information. The results show that both WM and mathematical performances improved significantly after intervention, indicating a strong relationship between these two constructs. The control group improved slightly in Raven's progressive matrices and a reading number task. These findings are discussed in terms of near and far transfer toward trained and untrained skills and stress the positive impact of WM training on learning mathematics in children with dyscalculia.

Diagnosing Developmental Dyscalculia on the Basis of Reliable Single Case FMRI Methods: Promises and Limitations

FMRI-studies are mostly based on a group study approach, either analyzing one group or comparing multiple groups, or on approaches that correlate brain activation with clinically relevant criteria or behavioral measures. In this study we investigate the potential of fMRI-techniques focusing on individual differences in brain activation within a test-retest reliability context. We employ a single-case analysis approach, which contrasts dyscalculic children with a control group of typically developing children. In a second step, a support-vector machine analysis and cluster analysis techniques served to investigate similarities in multivariate brain activation patterns. Children were confronted with a non-symbolic number comparison and a non-symbolic exact calculation task during fMRI acquisition. Conventional second level group comparison analysis only showed small differences around the angular gyrus bilaterally and the left parieto-occipital sulcus. Analyses based on single-case statistical procedures revealed that developmental dyscalculia is characterized by individual differences predominantly in visual processing areas. Dyscalculic children seemed to compensate for relative under-activation in the primary visual cortex through an upregulation in higher visual areas. However, overlap in deviant activation was low for the dyscalculic children, indicating that developmental dyscalculia is a disorder characterized by heterogeneous brain activation differences. Using support vector machine analysis and cluster analysis, we tried to group dyscalculic and typically developing children according to brain activation. Fronto-parietal systems seem to qualify for a distinction between the two groups. However, this was only effective when reliable brain activations of both tasks were employed simultaneously. Results suggest that deficits in number representation in the visual-parietal cortex get compensated for through finger related aspects of number representation in fronto-parietal cortex. We conclude that dyscalculic children show large individual differences in brain activation patterns. Nonetheless, the majority of dyscalculic children can be differentiated from controls employing brain activation patterns when appropriate methods are used.

Accommodation for Dyscalculic Children in an E-Learning Environment

Dyscalculia is a specific learning disability involving innate difficulty in learning or comprehending simple arithmetic. The purpose of this paper is to identify various problems faced by dyscalculic children and provide various accommodations to cater the needs of these children in an elearning environment. General Terms E-Learning, Human Computer Interaction, Disabilities

Veränderungen psychischer Belastung durch die Förderung von rechenschwachen Kindern und Jugendlichen

The present study examined the effects of the Waterglass Intervention Program on children with mathematical learning disabilities compared to dyscalculic children who received private tutoring. In a pre-post-control group design, N = 46 children (age 7-12) and their parents were questioned about changes in test anxiety, school reluctance, anxiety disorder, and internal and external abnormality. Children who attended the Waterglass Intervention Program reported a higher reduction of test anxiety, school reluctance, and attention problems. A trend toward a higher reduction of the CBCL-score was also found. These changes were mediated by the changes in math school grades. Furthermore, results showed that more children showed internal disorders than would be expected. An intervention specific for children with mathematical learning disabilities has positive effects on the psychological stress level of these children. Further research is required to investigate the mechanisms related to these changes and the effects on mathematical achievement.

Non-Symbolic Numerical Distance Effect in Children With and Without Developmental Dyscalculia: A Parametric fMRI Study

This study investigated areas of brain activation related to non-symbolic distance effects in children with and without developmental dyscalculia (DD). We examined 15 children with DD (11.3 years) and 15 controls (10.6 years) by means of functional magnetic resonance imaging (fMRI). Both groups displayed similar behavioral performance, but differences in brain activation were observed, particularly in the supplementary motor area and the right fusiform gyrus, where children with DD demonstrated stronger activation. These results suggest that dyscalculic children engage areas attributed to higher difficulty in response selection more than control children, possibly due to a deficient development of a spatial number representation in DD.

Subitizing and counting in typical and atypical development

Enumeration performance in standard dot counting paradigms was investigated for different age groups with typical and atypically poor development of arithmetic skills. Experiment 1 showed a high correspondence between response times and saccadic frequencies for four age groups with typical development. Age differences were more marked for the counting than the subitizing range. In Experiment 2 we found a discontinuity between subitizing and counting for dyscalculic children; however, their subitizing slopes were steeper than those of typically developing control groups, indicating a dysfunctional subitizing mechanism. Across both experiments a number of factors could be identified that affect enumeration in the subitizing and the counting range differentially. These differential patterns further support the assumption of two qualitatively different enumeration processes.

Mental number line training in children with developmental dyscalculia

Developmental dyscalculia (DD) is a specific learning disability that affects the acquisition of mathematical skills in children with normal intelligence and age-appropriate school education (prevalence 3-6%). One essential step in the development of mathematical understanding is the formation and automated access to a spatial representation of numbers. Many children with DD show a deficient development of such a mental number line. The present study aimed to develop a computer-based training program to improve the construction and access to the mental number line. Sixteen children with DD aged 8-10 years and 16 matched control children completed the 5-week computer training. All children played the game 15 min a day for 5 days a week. The efficiency of the training was evaluated by means of neuropsychological tests and functional magnetic resonance imaging (fMRI) during a number line task. In general, children with and without DD showed a benefit from the training indicated by (a) improved spatial representation of numbers and (b) the number of correctly solved arithmetical problems. Regarding group differences in brain activation, children with DD showed less activation in bilateral parietal regions, which reflects neuronal dysfunction in pivotal regions for number processing. Both groups showed reduced recruitment of relevant brain regions for number processing after the training which can be attributed to automatization of cognitive processes necessary for mathematical reasoning. Moreover, results point to a partial remediation of deficient brain activation in dyscalculics after consolidation of acquired and refined number representation. To conclude, the present study represents the first attempt to evaluate a custom-designed training program in a group of dyscalculic children and results indicate that the training leads to an improved spatial representation of the mental number line and a modulation of neural activation, which both facilitate processing of numerical tasks.

Defective number module or access deficit – two different subtypes of dyscalculia?

Event Abstract Back to Event Defective number module or access deficit – two different subtypes of dyscalculia? Andy Kramer1* and Karin Landerl1 1 University of Tuebingen, Institute of Psychology, Germany In the defective number module account of dyscalculia it is assumed that a specific deficit of an innate capacity to understand and represent quantities results in difficulties to learn number and arithmetic. In contrast, the access deficit hypothesis states that analogue magnitude representations are intact but cannot be adequately accessed from symbolic representations (Arabic numbers or number words). Empirical support exists for both positions. Another view is that the two accounts describe different subtypes of dyscalculia. For the present study, we directly compared the performance profiles of two specifically selected groups of 8 to 10 year old children with arithmetic deficits. The access deficit group (N = 18) showed intact processing of non-symbolic magnitudes but deficient symbolic magnitude processing and the defective number module group (N = 19) showed deficits in both, symbolic as well as non-symbolic magnitude processing. These two groups were compared with a large (N = 181) group of children with typical development. Children were given various tests of arithmetic (addition, subtraction, multiplication, division), basic numerical processing (subitizing, counting, number line) reading, spelling, attention (alertness, flexibility, sustained attention), and phonological processing (phoneme deletion, rapid automatized naming). No major differences were found between the profiles of the two dyscalculia subgroups. This finding suggests, that dyscalculia is mainly characterised by deficits in accessing numerical magnitudes from symbolic representations (access deficit). Although many dyscalculic children have problems with non-symbolic magnitude processing too, these deficits do not seem to have a major impact on the manifestation of dyscalculia. Conference: EARLI SIG22 - Neuroscience and Education, Zurich, Switzerland, 3 Jun - 5 Jun, 2010. Presentation Type: Poster Presentation Topic: Number processing Citation: Kramer A and Landerl K (2010). Defective number module or access deficit – two different subtypes of dyscalculia?. Front. Neurosci. Conference Abstract: EARLI SIG22 - Neuroscience and Education. doi: 10.3389/conf.fnins.2010.11.00048 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 31 May 2010; Published Online: 31 May 2010. * Correspondence: Andy Kramer, University of Tuebingen, Institute of Psychology, Tubingen, Germany, andy.kramer@uni-tuebingen.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Andy Kramer Karin Landerl Google Andy Kramer Karin Landerl Google Scholar Andy Kramer Karin Landerl PubMed Andy Kramer Karin Landerl Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Dyslexia and dyscalculia: Two learning disorders with different cognitive profiles

This study tests the hypothesis that dyslexia and dyscalculia are associated with two largely independent cognitive deficits, namely a phonological deficit in the case of dyslexia and a deficit in the number module in the case of dyscalculia. In four groups of 8- to 10-year-olds (42 control, 21 dyslexic, 20 dyscalculic, and 26 dyslexic/dyscalculic), phonological awareness, phonological and visual-spatial short-term and working memory, naming speed, and basic number processing skills were assessed. A phonological deficit was found for both dyslexic groups, irrespective of additional arithmetic deficits, but not for the dyscalculia-only group. In contrast, deficits in processing of symbolic and nonsymbolic magnitudes were observed in both groups of dyscalculic children, irrespective of additional reading difficulties, but not in the dyslexia-only group. Cognitive deficits in the comorbid dyslexia/dyscalculia group were additive; that is, they resulted from the combination of two learning disorders. These findings suggest that dyslexia and dyscalculia have separable cognitive profiles, namely a phonological deficit in the case of dyslexia and a deficient number module in the case of dyscalculia.

Typical and atypical development of basic numerical skills in elementary school

Deficits in basic numerical processing have been identified as a central and potentially causal problem in developmental dyscalculia; however, so far not much is known about the typical and atypical development of such skills. This study assessed basic number skills cross-sectionally in 262 typically developing and 51 dyscalculic children in Grades 2, 3, and 4. Findings indicate that the efficiency of number processing improves over time and that dyscalculic children are generally less efficient than children with typical development. For children with typical arithmetic development, robust effects of numerical distance, size congruity, and compatibility of ten and unit digits in two-digit numbers could be identified as early as the end of Grade 2. Only the distance effect for comparing symbolic representations of numerosities changed developmentally. Dyscalculic children did not show a size congruity effect but showed a more marked compatibility effect for two-digit numbers. We did not find strong evidence that dyscalculic children process numbers qualitatively differently from children with typical arithmetic development.

Developmental dyscalculia: Compensatory mechanisms in left intraparietal regions in response to nonsymbolic magnitudes

BackgroundFunctional magnetic resonance imaging (fMRI) studies investigating the neural mechanisms underlying developmental dyscalculia are scarce and results are thus far inconclusive. Main aim of the present study is to investigate the neural correlates of nonsymbolic number magnitude processing in children with and without dyscalculia.Methods18 children (9 with dyscalculia) were asked to solve a non-symbolic number magnitude comparison task (finger patterns) during brain scanning. For the spatial control task identical stimuli were employed, instructions varying only (judgment of palm rotation). This design enabled us to present identical stimuli with identical visual processing requirements in the experimental and the control task. Moreover, because numerical and spatial processing relies on parietal brain regions, task-specific contrasts are expected to reveal true number-specific activations.ResultsBehavioral results during scanning reveal that despite comparable (almost at ceiling) performance levels, task-specific activations were stronger in dyscalculic children in inferior parietal cortices bilaterally (intraparietal sulcus, supramarginal gyrus, extending to left angular gyrus). Interestingly, fMRI signal strengths reflected a group × task interaction: relative to baseline, controls produced significant deactivations in (intra)parietal regions bilaterally in response to number but not spatial processing, while the opposite pattern emerged in dyscalculics. Moreover, beta weights in response to number processing differed significantly between groups in left – but not right – (intra)parietal regions (becoming even positive in dyscalculic children).ConclusionOverall, findings are suggestive of (a) less consistent neural activity in right (intra)parietal regions upon processing nonsymbolic number magnitudes; and (b) compensatory neural activity in left (intra)parietal regions in developmental dyscalculia.