Number transcoding (e.g., writing 29 when hearing "twenty-nine") is one of the most basic numerical abilities required in daily life and is paramount for mathematics achievement. The aim of this study is to investigate psychometric properties of an Arabic number-writing task and its capacity to identify children with mathematics difficulties. We assessed 786 children (55% girls) from first to fourth grades, who were classified as children with mathematics difficulties (n = 103) or controls (n = 683). Although error rates were low, the task presented adequate internal consistency (0.91). Analyses revealed effective diagnostic accuracy in first and second school grades (specificity equals to 0.67 and 0.76 respectively, and sensitivity equals to 0.70 and 0.88 respectively). Moreover, items tapping the understanding of place-value syntax were the most sensitive to mathematics achievement. Overall, we propose that number transcoding is a useful tool for the assessment of mathematics abilities in early elementary school.

Introduction: Reading disability (RD) and Attention Deficit Hyperactivity Disorder (ADHD) symptoms often co-occur in school-age children. Methods: The present study evaluated the performance of 216 Brazilian children from 3 rd and 4 th grades on "cool" executive function (EF) abilities and phonological processing. The children were divided into three groups: those with ADHD symptoms only, those with RD only, and controls. Results: MANOVA analyses, controlling for age and nonverbal intelligence, showed worse performance for the RD group, compared to the ADHD symptoms group, on measures of phonological processing (phonemic awareness, phonological short-term memory, and lexical access) and "cool" EF components (orthographic verbal fluency and processing speed). The ADHD symptoms group did not differ from the control group on the majority of the "cool" EF tasks. Compared to the control group, the ADHD symptoms group and the RD group both showed significantly more errors in rapid automatized naming of figures, which evaluates the inhibition component of EF; performance on this task was similar for these groups. Conclusion: We conclude that children with RD have greater impairment in phonological processing and "cool" EF compared to those with ADHD symptoms. Furthermore, deficits in inhibitory control may be shared among children with both conditions. ? RESUMO. Introdução: Dificuldades de leitura (DL) e sintomas do Transtorno de Déficit de Atenção e Hiperatividade (TDAH) frequentemente coocorrem em crianças escolares. Métodos: O presente estudo comparou o desempenho em FE "frias" e processamento fonológico de 216 crianças brasileiras de 3ª e 4ª anos, que foram divididas em três grupos: apenas com sintomas de TDAH, apenas em DL e controles. Resultados: As análises de MANOVA, controlando para idade e inteligência não-verbal, indicaram que o grupo com DL apresentou desempenho significativamente inferior ao grupo com sintomas de TDAH nas medidas de processamento fonológico (consciência fonológica, memória verbal de curto prazo e acesso lexical) e em componentes das FE "frias" (fluência verbal ortográfica e velocidade de processamento). O grupo com sintomas de TDAH não se diferiram do grupo controle na maior parte das tarefas de FE "frias". Ambos os grupos com sintomas de TDAH e DL apresentaram desempenhos significativamente menores (mais erros) em comparação às crianças de desenvolvimento típico na tarefa de Nomeação Seriada Rápida de figuras que avalia o componente de controle inibitório, e o desempenho foi semelhante entre os

ABSTRACT. Expansive mutations in familial mental retardation 1 (FMR1) gene have been associated with different phenotypes. Full mutations are associated with intellectual disability and autism spectrum disorder; premutations are associated with math learning difficulties and working memory impairments. In gray zone, neuropsychological development has not yet been described. Objectives: This study aimed to describe the frequency of FMR1 premutation and gray zone alleles in a school population sample representing a broad spectrum of variation in math achievement and detail school achievement and cognitive performance in the children identified with FMR1 premutation or gray zone alleles. Methods: We described a two-phase study. In the first phase, 2,195 school-age children were screened for math achievement. In the second phase, 378 children with normal intelligence were neuropsychologically assessed and genotyped for FMR1. Of these, 121 children (61 girls) performed below percentile 25 in mathematics (MD group) and 257 children (146 girls) performed above percentile 25 (control group). Results: Four pupils presented expanded alleles, one premutation and three gray zone alleles. The girl with the premutation and one boy with a gray zone allele presented impairments in working memory and arithmetic performance below percentile 6, compatible with the diagnosis of developmental dyscalculia. These children’s difficulties were not associated with inaccuracy of nonsymbolic number representations or literacy impairments. Dyscalculia in these children seems to be associated mainly with working memory impairments. Conclusions: FMR1 expansions in the gray zone may contribute to dyscalculia in otherwise healthy and normally intelligent children.

Introduction: Rapid automatized naming (RAN) is the ability to name, as fast as possible, symbols such as letters, digits and figures. The present study aimed to investigate intragroup performance patterns on RAN tasks in children with attention deficit hyperactivity disorder (ADHD) symptoms alone, children with reading disability (RD) alone and controls with typical development. Methods: A total of 216 Brazilian children between 8 to 11 years old were selected from public schools located in two Brazilian capitals, namely Porto Alegre and Belo Horizonte, to participate in the study. Mixed 3 (participant group: ADHD symptoms, RD or control group) × 3 (type of stimulus: letters, numbers or figures) ANOVAs were performed using response time and number of errors as dependent variables. Only intragroup comparisons are described in this paper. Results: The groups with ADHD symptoms and RD showed similar performance results on naming speed. There were no differences between letters and numbers within each group, but we found slower responses in figure naming compared to the other tasks for both groups. Concerning accuracy, children with ADHD symptoms showed a similar number of errors in all three tasks. These patterns were distinct from the performance of the control group. Conclusion: Results suggest a shared deficit in naming speed of alphanumeric stimuli in children with ADHD symptoms and those with RD, and impairments in naming digits correctly in children with ADHD symptoms.

ABSTRACT. Brazilian students’ mathematical achievement was repeatedly observed to fall below average levels of mathematical attainment in international studies such as PISA. Objective: In this article, we argue that this general low level of mathematical attainment may interfere with the diagnosis of developmental dyscalculia when a psychometric criterion is used establishing an arbitrary cut-off (e.g., performance<percentile 10) may result in misleading diagnoses. Methods: Therefore, the present study evaluated the performance of 706 Brazilian school children from 3rd to 5th grades on basic arithmetic operations addition, subtraction, and multiplication. Results: In line with PISA results, children presented difficulties in all arithmetic operations investigated. Even after five years of formal schooling, less than half of 5th graders performed perfectly on simple addition, subtraction, or multiplication problems. Conclusions: As such, these data substantiate the argument that the sole use of a psychometric criterion might not be sensible to diagnose dyscalculia in the context of a generally low performing population, such as Brazilian children of our sample. When the majority of children perform poorly on the task at hand, it is hard to distinguish atypical from typical numerical development. As such, other diagnostic approaches, such as Response to Intervention, might be more suitable in such a context.

ABSTRACT. Monoamine oxidase A (MAOA) polymorphisms have been associated with antisocial disorders. Less attention has been paid to the cognitive functioning of individuals with different MAOA alleles. No study has described the cognitive phenotype associated with the less frequent, low enzyme activity allele, MAOA_LPR*2R. Objective: We describe the cognitive correlates of boys having MAOA_LPR*2R allele, ascertained in a sample of school children with normal intelligence, not referred for behavioral disorders. Methods: Participants were eight boys, attending from the second to fifth grades in state-run schools. They were identified among 712 children with typical general cognitive ability, genotyped for MAOA_LPR polymorphism. Participants were assessed with general intelligence, mathematics and spelling achievement, and verbal and visuospatial working memory tests. Neuropsychological performance was compared to published standards, using 1 SD below the mean as a cutoff value for low performance. Results: Intelligence of boys with MAOA_LPR*2R allele varied from above average (N=2) to low average in the other children. Five out of eight boys with the MAOA_LPR*2R allele had low mathematics achievement, and three presented additional difficulties with spelling. Four out of eight children had low short-term and working memory performance. Discussion: This is the first study describing cognitive correlates and school performance in boys having the MAOA_LPR*2R allele. Having this allele, and therefore, probably low MAO-A activity, does not necessarily imply low intelligence or low school performance. However, learning difficulties, particularly in math, and low working memory performance were observed in boys having this allele. This suggests a role of MAOA in learning difficulties.

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Brazilian students’ mathematical achievement was repeatedly observed to fall below average levels ofmathematical attainment in international comparison studies such as PISA. In this article, we argue thatthis general low level of mathematical attainment interferes with the diagnosis of developmentaldyscalculia when the psychometric criterion is used: establishing of an arbitrary cut-off (e.g., performance&lt; percentile 10) may lead to misleading diagnoses. Therefore, the present study set off to evaluate theperformance of Brazilian school children on basic arithmetic operations. Seven hundred and six childrenfrom 3rd to 5th grades completed a calculation task assessing arithmetic fluency in addition, subtraction,and multiplication. In line with PISA results, children presented difficulties in all arithmetic operationsinvestigated. Children performed better in addition than subtraction and multiplication, and 3rd and 4thgraders were outperformed by 5th graders in all three operations. However, even after five years offormal schooling, less than half of 5th graders performed perfectly on simple addition, subtraction, andmultiplication problems. Therefore, these data substantiate the argument that the sole use of apsychometric criterion might not be sensible to diagnose dyscalculia in the context of a generally lowperforming population, such as Brazilian primary school children. When the majority of children failthe task, it is hard to distinguish atypical from typical numerical development. As such, other diagnosticapproaches, such as Response to Intervention, might be more suitable in such a context.