Comparing Executive Functions in Children and Adolescents with Autism and ADHD-A Systematic Review and Meta-Analysis.

Two neurodevelopmental conditions, autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), have been associated with executive function (EF) impairments but the specificity of their impairments is still controversial. The present meta-analysis aimed to identify the differences in EF profiles of ASD, ADHD, and ASD+ADHD in relation to a control group of individuals with typical development (TD) and to understand whether the EF performance could change depending upon the type of measure used to assess EF (performance tests vs. questionnaires). Results from 36 eligible studies revealed that ADHD and ASD showed more difficulties than the TD group in tests and, particularly, in questionnaires. No significant differences in the EF profile emerged between ASD and ADHD when assessed through neuropsychological tests (d = 0.02), while significant differences emerged when assessed through questionnaires, with ADHD having higher ratings than ASD (d = -0.34). EF questionnaires and neuropsychological tests may catch two different constructs of EF, with the former being more predictive of everyday life EF impairments. The comparison between the double diagnosis group (ADHD+ASD) and the clinical groups pointed out that the former has a more similar EF profile to the ADHD-alone one and that it shows more difficulties than ASD-alone.

Dyslexia and dyscalculia: which neuropsychological processes distinguish the two developmental disorders?

This study analyses the specific neuropsychological profiles of children with dyslexia and/or dyscalculia, in particular concerning phonological awareness, lexical access, working memory and numerical processing. Four groups were selected, through a screening process that used strict criteria, from 1568 7-10-year-old children: 90 with typical development, 61 with dyslexia, 13 with dyscalculia, and 14 with dyslexia + dyscalculia. Children with dyslexia show a deficit in phonological processing, lexical access, and verbal working memory, especially with alphabetic stimuli. Children with developmental dyscalculia show a deficit of phonological processing, verbal working memory with digits and visual-spatial working memory. They also show an impairment in spatial representation of numbers and in the automatic access to numerical semantics to a greater extent than those with double disturbance. Children with dyslexia + dyscalculia show a profile generally characterized by the summation of the deficits of the two disorders, although they have a lower deficit in access to numerical semantics and mental representation of numbers.

Teachers' report of sense of time in kindergarten predicts children's time-processing skills in first grade.

The main aim of this longitudinal study was to evaluate if a questionnaire measuring the sense of time, filled in by teachers and parents in the last year of kindergarten, was able to predict children's time-processing skills at the end of 1st grade. The sample included 131 children (initial mean age = 4.77 ± 0.29 years) tested three times in a 2-year period with tasks of time reproduction, time discrimination, and comparison of durations. One of their parents and teachers filled in a questionnaire about children's sense of time both in kindergarten and 1st grade. The teacher version of the questionnaire administered in kindergarten was able to predict most of the time-processing tasks at the end of 1st grade. The parent version of the questionnaire was not able to predict children's performance in these tasks. Different developmental trajectories of time reproduction and time discrimination were observed. This study supports the role of preschool teachers as skilled evaluators of children's time-processing skills.

Executive functions in children with specific learning disorders: Shedding light on a complex profile through teleassessment.

Executive Functions (EFs) are high-order cognitive processes relevant to learning and adaptation and frequently impaired in children with specific learning disorders (SLDs). This study aimed to investigate EFs in children with SLD and explore the role of specific EF-related subprocesses, such as stimuli processing and processing speed. Fifty-seven SLD and 114 typically developing (TD) children, matched for gender and age, completed four tasks measuring response inhibition, interference control, shifting, and updating on a web-based teleassessment platform. The results show that SLD children performed lower in all EF tasks than TD children, regardless of stimulus type and condition. Mediation analyses suggested that differences between the SLD and TD groups are mediated by EF-related subprocesses, offering an interpretative model of EF deficits in children with SLD.

The Relationship between Narrative Skills and Executive Functions across Childhood: A Systematic Review and Meta-Analysis.

Executive functions (EFs) and narrative competence (NC) are two important predictors of many outcomes in human development. To date, however, it is unclear whether these skills develop synergistically-supporting or opposing each other-or whether they are independent of each other. The purpose of this meta-analysis is to understand if these skills are related to over development and if the magnitude of their association changes over time; differs in typical and atypical development; and changes with EF (inhibition, working memory, flexibility, planning) and NC (oral, written; micro and macrostructural level). For this purpose, 30 studies containing 285 effect sizes were selected and combined. The results show that EFs and NC are weakly associated with each other (r = 0.236, p < 0.001) and that this association decreases with age (b(267) = -0.0144, p = 0.001). They are more associated in preschool and early elementary school grades, becoming more independent after seven years old. Between 3 and 7 years of age, the association seems stronger in atypically developing children and for macrostructural NC. Additionally, before 7 years old, the various EF domains seem to associate indistinctly with NC, and only later specific links between EFs and NC would be observed.

Preschool Executive Functioning and Child Behavior: Association with Learning Prerequisites?

Preschool age is a golden period for the emergence of executive functions (EFs) that, in turn, predict learning and adaptive behavior throughout all life. The study was aimed to identify which EFs measures significantly explained the learning prerequisites and the mediation role of self-regulatory and executive behavior recorded in structured or free settings. One hundred and twenty-seven preschoolers were remotely assessed by standardized tests of response inhibition, working memory, control of interference, and cognitive flexibility. Teachers provided a global measure of learning prerequisites by an observational questionnaire. Self-regulatory behavior during the assessment was evaluated by a rating scale filled by the examiners. Executive function behavior in daily life was measured by a questionnaire filled by parents. Accuracy in tasks of response inhibition and working memory explained about 48% of the variability in learning prerequisites while response speed and accuracy in the control of interference and in cognitive flexibility were not significant. EFs also had indirect effects, mediated by the child's self-regulatory behavior evaluated during the assessment but not in daily life. The results are interpreted with respect to the contribution of the main EF components to school readiness and the mediation of the child behavior as measured in structure contexts.

A multimethod approach to assessing motor skills in boys and girls with autism spectrum disorder.

LAY ABSTRACT: Motor peculiarities are often reported in children with autism spectrum disorder and may predict subsequent adaptive functioning and quality of life. Although the sex bias in the prevalence of the disorder is well documented, little is known about differences in motor profile in males and females with autism spectrum disorder. Our goal was to study differences in motor functioning of boys and girls with autism spectrum disorder aged 3-11 years compared with typically developing children. Their motor performances were evaluated using a multimethod approach, including standardized motor tests, caregiver reports, and a detailed motion capture analysis of a simple reach-to-drop movement. We found that, irrespective of sex, children with autism spectrum disorder had worse scores than typically developing children on standardized tests and on caregiver reports. Interestingly, girls with autism spectrum disorder, but not boys, presented altered motor anticipation in reach-to-drop. Our findings emphasize the need for more sex-specific assessment of motor function in autism spectrum disorder.

Symbolic versus non-symbolic training for improving early numeracy in preschoolers at risk of developing difficulties in mathematics.

BACKGROUND: Children's understanding of symbolic (e.g., Arabic digits) and non-symbolic (e.g., sets of dots) magnitudes plays a key role in their mathematics achievement, but only a few studies directly compared the effects of symbolic and non-symbolic interventions on mathematical abilities. AIMS: This longitudinal study compared the impact of symbolic and non-symbolic trainings in a group of preschoolers at risk of developing difficulties in mathematics (RM), analyzing their post-intervention performance both in early math skills (last preschool year) and in mathematics achievement in 1st grade. METHODS: Eighty-nine RM children and 66 typically developing controls were selected from among 604 preschoolers. RM children were assigned to three intervention conditions: no intervention, symbolic or non-symbolic intervention. RESULTS: Results showed specific effects on tasks related to the training (e.g., effects of symbolic training on symbolic tasks) and some effects of generalization (e.g., effects of symbolic training on non-symbolic tasks). In 1st grade, children attending the symbolic intervention showed a mathematics achievement profile similar to that of typically developing peers. CONCLUSIONS: These results suggest the importance of training the symbolic processing of numbers at preschool age, allowing at risk children to catch up with their peers before entering formal schooling.

The dimensionality of early executive functions in young preschoolers: Comparing unidimensional versus bidimensional models and their ecological validity.

The study analyses the dimensionality of executive functions (EF) and its relationship with behavior in typically developing 3- and 4-year-old children. In study 1, confirmatory factor analysis (CFA) was used to investigate the validity of a one-factor model in 117 preschoolers. Since this model was not confirmed, a two-factor model was identified through exploratory factor analysis. In study 2, the validity of the new two-factor versus one-factor model was tested on a new sample of 128 children through a series of CFAs. The relationship between the models and specific behavioral aspects of the children was investigated. The results suggest that a bidimensional structure showed a better fit to the data and more ecological validity than a unitary structure.

Second-language learning difficulties in Italian children with reading difficulties.

BACKGROUND: Children with dyslexia often show second-language reading and writing difficulties, but the cognitive mechanisms connected to this impairment need to be clarified. AIMS: The present study examined the neuropsychological mechanisms underlying learning English as a foreign language in 4th- to the 8th-grade Italian students showing reading difficulties (RD) or typical development (TD). For this purpose, screening involving 901 students was carried out to select children with RD. SAMPLE: Ninety students with RD were compared with 90 typically developing (TD) children matched for non-verbal IQ, grade, and gender. METHODS: The two groups were compared on different measures to understand the relationships between reading skills in their mother tongue and in English as a second-language (L2). Subsequently, their phonological and memory skills were investigated to understand the potential role of these variables in learning L2 English. RESULTS: Students with RD obtained worse results than TD students for phonological awareness and working memory, which are both crucial to L2 learning. CONCLUSIONS: The results suggest that memory mainly influences accuracy in English writing and, together with phonological skills, plays an important role in reading accuracy. Socio-economic status also plays an important role in L2 learning.

Fundamental Motor Skills Intervention for Children with Autism Spectrum Disorder: A 10-Year Narrative Review.

In the past decade, converging evidence has suggested that motor impairment is one of the most consistent markers, alongside sociocommunicative difficulties, for autism spectrum disorder (ASD). Indeed, widespread anomalies of movement have been described in the ASD context. These motor abnormalities could have critical implications for subsequent cognitive and social development. Nevertheless, this area of development is particularly underexamined in the autism-related context, and early intervention programs commonly focus on the core symptoms of the condition. In the present work, we review and discuss the findings from recent studies that investigated the effect of interventions regarding fundamental motor skills in autistic children. Although the limited nature of the literature prevents researchers from drawing definitive conclusions, the results from the studies discussed here demonstrated potentially significant improvements in the motor abilities of autistic children after the interventions. Only a subset of the reviewed studies explored possible changes in the sociocommunicative domain after the motor skills improvements, and they had not concordant, although promising, conclusions. Overall, in consideration of the well-documented motor impairment people with the condition, the present findings highlight the importance of including motor skills training within the rehabilitation programs designed for autistic children. Furthermore, this narrative review encourages future interventional trials to consider motor skills as a possible target for reducing activity limitations and participation restrictions of autistic children.

Corrigendum: Is Cognitive Training Effective for Improving Executive Functions in Preschoolers? A Systematic Review and Meta-Analysis.

[This corrects the article DOI: 10.3389/fpsyg.2019.02812.].

Teachers, not parents, are able to predict time processing skills in preschoolers.

Time processing difficulties are associated with developmental disorders. Questionnaires for assessing children's sense of time are available from primary school, but we lack valid proxy-report tools for younger children, who are not able to complete self-reports. This study aimed to assess the criterion validity of a questionnaire investigating preschoolers' sense of time from the points of view of their parents and teachers. One hundred seventy preschoolers were included in the sample. Their parents and teachers completed the Sense of Time Questionnaire, and the children were administered time reproduction and time discrimination tasks, both concurrently and 7 months later. The assessment of preschoolers' sense of time reported by teachers, but not by parents, predicted the children's time processing skills both concurrently and longitudinally. The teacher version of the Sense of Time Questionnaire constitutes a valid instrument for assessing and predicting preschoolers' time processing skills and can be used for clinical and research purposes STATEMENT OF CONTRIBUTION: What is already known on this subject? Time processing difficulties are associated with developmental disorders such as ADHD and dyscalculia. Early assessment of time processing skills is important for clinical (e.g., screening) and research purposes. We do not have valid questionnaires for assessing sense of time in young children. What the present study adds? The sense of time ability reported by teachers predicts preschoolers' time processing skills. The sense of time ability reported by parents does not predicts preschoolers' time processing skills. The Sense of Time Questionnaire is a valid instrument for investigating time processing skills of 4-6 aged children.

Is Cognitive Training Effective for Improving Executive Functions in Preschoolers? A Systematic Review and Meta-Analysis.

In the present meta-analysis, we examined the effect of cognitive training on the Executive Functions (EFs) of preschool children (age range: 3­6 years). We selected a final set of 32 studies from 27 papers with a total sample of 123 effect sizes. We found an overall effect of cognitive training for improving EF (g = 0.352; k = 123; p < 0.001), without significant difference between near and far transfer effects on executive domains. No significant additional outcome effects were found for behavioral- and learning-related outcomes. Cognitive training programs for preschoolers are significantly more effective for developmentally at-risk children (ADHD or low socio-economic status) than for children with typical development and without risks. Other significant moderators were: individual vs. group sessions and length of training. The number of sessions and computerized vs. non-computerized training were not significant moderators. This is the first demonstration of cognitive training for transfer effects among different executive processes. We discuss this result in relationship to the lower level of modularization of EFs in younger children.

Gait Pattern and Motor Performance During Discrete Gait Perturbation in Children With Autism Spectrum Disorders.

Quantitative evaluation of gait has been considered a useful tool with which to identify subtle signs of motor system peculiarities in autism spectrum disorder (ASD). However, there is a paucity of studies reporting gait data in ASD as well as investigating learning processes of locomotor activity. Novel advanced technologies that couple treadmills with virtual reality environments and motion capture systems allows the evaluation of gait patterns on multiple steps and the effects of induced gait perturbations, as well as the ability to manipulate visual and proprioceptive feedbacks. This study aims at describing the gait pattern and motor performance during discrete gait perturbation of drug-naïve, school-aged children with ASD compared to typically developing (TD) peers matched by gender and age. Gait analysis was carried out in an immersive virtual environment using a 3-D motion analysis system with a dual-belt, instrumented treadmill. After 6 min of walking, 20 steps were recorded as baseline. Then, each participant was exposed to 20 trials with a discrete gait perturbation applying a split-belt acceleration to the dominant side at toe-off. Single steps around perturbations were inspected. Finally, 20 steps were recorded during a post-perturbation session. At baseline, children with ASD had reduced ankle flexion moment, greater hip flexion at the initial contact, and greater pelvic anteversion. After the discrete gait perturbation, variations of peak of knee extension significantly differed between groups and correlated with the severity of autistic core symptoms. Throughout perturbation trials, more than 60% of parameters showed reliable adaptation with a decay rate comparable between groups. Overall, these findings depicted gait peculiarities in children with ASD, including both kinetic and kinematic features; a motor adaptation comparable to their TD peers, even though with an atypical pattern; and a motor adaptation rate comparable to TD children but involving different aspects of locomotion. The platform showed its usability with children with ASD and its reliability in the definition of paradigms for the study of motor learning while doing complex tasks, such as gait. The additional possibility to accurately manipulate visual and proprioceptive feedback will allow researchers to systematically investigate motor system features in people with ASD.

The Strengths and Difficulties Questionnaire-Parents for Italian School-Aged Children: Psychometric Properties and Norms.

The Strengths and Difficulties Questionnaire [SDQ; (1)] is a multi-informant instrument for screening developmental psychopathology. This study contributes to the validation of the Italian SDQ-Parent version (SDQ-P), analyzing its factorial structure, providing norms and investigating cross-informant agreement (parents-teachers). The SDQ-P and the SDQ-Teacher version (SDQ-T) were completed for 1917 primary and middle school students. Confirmatory factor analyses were performed to compare two factorial structures: the original five-factor model and the structure obtained in a past Italian study (2). The original model showed the best fit. Significant differences by gender and school grade were found; norms were provided separately for males and females attending 1st-2nd, 3rd-5th and 6th-8th grades. Finally, the analysis of parent-teacher agreement showed correlations ranging from small (prosocial behavior) to large (hyperactivity-inattention). This study offers some reflections on the best way to use this instrument in a community sample.

Time processing impairments in preschoolers at risk of developing difficulties in mathematics.

The occurrence of time processing problems in individuals with Development Dyscalculia (DD) has favored the view of a general magnitude system devoted to both numerical and temporal information. Yet, this scenario has been partially challenged by studies indicating that time difficulties can be attributed to poor calculation or counting skills, which can support reasoning on time in school-aged children and adults. Here, we tackle this debate by exploring the performance of young children before they fully develop the symbolic number system. Preschoolers at risk of developing DD were compared with typically developing children in a series of tasks investigating time processing and in their 'sense of time', evaluated by parents and teachers. Results yielded a poorer performance in time reproduction of 5-second intervals and in time discrimination, as well as a weaker 'sense of time', in children at risk of DD. These findings provide evidence of a common magnitude system that would be responsible for deficits in both numerical and temporal domains, already at early stages of life.

Early Literacy and Numeracy Skills in Bilingual Minority Children: Toward a Relative Independence of Linguistic and Numerical Processing.

Many studies have suggested that the concept of "number" is relatively independent from linguistic skills, although an increasing number of studies suggest that language abilities may play a pivotal role in the development of arithmetic skills. The condition of bilingualism can offer a unique perspective into the role of linguistic competence in numerical development. The present study was aimed at evaluating the relationship between language skills and early numeracy through a multilevel investigation in monolingual and bilingual minority children attending preschool. The sample included 156 preschool children. Of these, 77 were bilingual minority children (mean age = 58.27 ± 5.90), and 79 were monolinguals (mean age = 58.45 ± 6.03). The study focused on three levels of analysis: group differences in language and number skills, concurrent linguistic predictors of early numeracy and, finally, profile analysis of linguistic skills in children with impaired vs. adequate numeracy skills. The results showed that, apart from the expected differences in linguistic measures, bilinguals differed from monolinguals in numerical skills with a verbal component, such as semantic knowledge of digits, but they did not differ in a pure non-verbal component such as quantity comparison. The multigroup structural equation model indicated that letter knowledge was a significant predictor of the verbal component of numeracy for both groups. Phonological awareness was a significant predictor of numeracy skills only in the monolingual group. Profile analysis showed that children with a selective weakness in the non-verbal component of numeracy had fully adequate verbal skills. Results from the present study suggest that only some specific components of language competence predict numerical processing, although linguistic proficiency may not be a prerequisite for developing adequate early numeracy skills.

Numerical Magnitude Representation in Children With Mathematical Difficulties With or Without Reading Difficulties.

This study aimed to explore the spatial numerical association of response codes (SNARC), the flanker, and the numerical distance effects in children with mathematical difficulties. From a sample of 720 third, fourth, and fifth graders, 60 children were selected and divided into the following three groups: typically developing children (TD; n = 29), children with mathematical difficulties only (MD only; n = 21), and children with mathematical and reading difficulties (MD+RD; n = 10). Children were tested with a numerical Eriksen task that was built to assess SNARC, numerical distance, and flanker (first and second order congruency) effects. Children with MD only showed stronger SNARC and second order congruency effects than did TD children, whereas the numerical distance effects were similar across the three groups. Finally, the first order congruency effect was associated with reading difficulties. These results showed that children with mathematical difficulties with or without reading difficulties were globally more impaired when spatial incompatibilities were presented.