Nature and origins of mathematics difficulties in very preterm children: a different etiology than developmental dyscalculia

Cognitive heterogeneity in Attention Deficit Hyperactivity Disorder: Implications for maths

This study investigated whether cognitive function better predicted maths test performance than a clinical diagnosis of attention deficit hyperactivity disorder (ADHD). Forty-four drug naïve children (Mage = 101.34 months, SD = 19.39; 30% girls) were recruited from clinical ADHD referral waiting lists. Children underwent assessment of Executive Functions (EF), lower-level cognitive processes, and maths performance. Children were grouped using a categorical approach comprising (1) children with a clinical ADHD diagnosis and (2) children without a diagnosis (i.e., subthreshold ADHD). Secondly, hierarchical cluster analysis generated subgroups of children using EF scores. Children were compared on cognition, maths, and parent-rated symptoms of ADHD and co-occurring difficulties. Children's diagnostic outcomes did not differentiate maths performance. By contrast, EF subgroups generated meaningful cognitive clusters which differentiated maths test scores. This suggests that cognitive patterns of performance, rather than children's diagnostic outcomes, are more informative for identifying meaningful groups with variable maths performance which has implications for remedial support.

Developmental Dyscalculia in Relation to Individual Differences in Mathematical Abilities

There is still much debate about the exact nature and frequency of developmental dyscalculia, and about how it should be defined. This article examines several key questions in turn: Is developmental dyscalculia a distinct disorder, or should it be seen as the lower end of a continuum-or possibly more than one continuum-of numerical ability? Do individuals with developmental dyscalculia show atypical brain structure or function? Does the study of acquired dyscalculia have anything to teach us about developmental dyscalculia? In studying dyscalculia, should we look less at arithmetical ability as a single entity, and more at separable components of arithmetical ability? How heterogeneous is developmental dyscalculia, and how important is it to study individual profiles? To what extent is developmental dyscalculia influenced by domain-specific versus domain-general abilities? The conclusion is that, though a significant amount has been discovered through existing research, and though this has some important implications for screening and diagnosis of dyscalculia, there is much more research that still needs to be conducted if we are to answer all of these questions fully. In particular, the study of developmental dyscalculia must be more integrated with the study of individual differences in mathematics in the population as a whole.

Mathematics abilities associated with adaptive functioning in preschool children born preterm

It is well known that infants born very preterm (VPT) often demonstrate deficits in mathematical abilities in early childhood which are associated with poorer academic outcomes. Mathematic skills are also critical for other areas of functioning. However, it is not known whether mathematics skills are associated with adaptive functioning in children born preterm. Infants born at ≤31 weeks gestation and full term were recruited at birth and followed over time. At the 36-month corrected age assessment, children were administered the Early Number Concepts subtest of the Differential Abilities Scale, Second Edition, and caregivers completed the Adaptive Behavior Assessment System, Third Edition. After controlling for age, sex, cognitive abilities, and caregiver education, performance on the mathematics measure was uniquely and positively associated with adaptive behavior for preschool children in the VPT group only. Exploratory analyses revealed this association to be specifically related to the Practical and Social composites. Knowledge of concepts of number and quantity were associated with better adaptive functioning, particularly for behaviors related to functioning at home and in the community and play/social functioning, for children born VPT. Although replication is warranted, it would appear that mathematical skills may be an important early intervention target for children born VPT.

Cognition and maths in children with Attention-Deficit/Hyperactivity disorder with and without co-occurring movement difficulties

BACKGROUND

Movement difficulties are common in ADHD, however, the implications of their co-occurrences on cognitive and maths performance is unknown.

AIMS

This study set out to examine whether cognitive and maths performance of children with high ADHD symptoms differs depending on the co-occurrence of movement difficulties given evidence that weaker visuospatial processing, known to be important for maths performance, differentiates ADHD and DCD. We also aimed to examine whether relationships between cognition and maths in ADHD differs depending on co-occurring movement difficulties.

METHODS

Participants were 43 drug naïve children between 6 and 12 years old (M = 101.53 months SD = 19.58). The ADHD-only group (n = 18) included children with high ADHD scores, and those in the ADHD+DCD group (n = 25) concurrently had high movement difficulty scores. All completed executive function and memory, including 2 visuo-spatial memory tasks from the CANTAB battery and Mathematics Problem Solving, Numeracy, and Maths Fluency tasks from the WIAT-III and specific factual, conceptual, and procedural maths component tasks.

RESULTS

Children in the ADHD+DCD group scored significantly lower on visuospatial working memory (WM) capacity, than those in the ADHD-only group. Both groups were comparable on all other cognitive assessments of executive functions, memory, and processing speed. The groups did not differ in their maths attainment scores, nor on more specific maths skills. Comparison of the correlations between cognitive processes and maths revealed that the association between visuospatial WM updating and procedural skill efficiency was stronger for the ADHD-only group. Moreover, associations between visuospatial WM and maths problem solving attainment were stronger in the ADHD+DCD group.

CONCLUSIONS

Despite similarities in maths performance, children with ADHD+DCD could be distinguished by lower visuospatial WM. Differential associations with some of the maths domain implicate recruitment of different cognitive processes for some aspects of maths. This distinction can be particularly useful for conceptualising cognitive characteristics of different clinical groups and understanding cognitive pathways of maths difficulties. Implications for interventions are discussed.

[Cognitive disorders in children with dyscalculia]

OBJECTIVE

This study was to study the features of cognitive disorders in children with dyscalculia.

MATERIAL AND METHODS

The main study group included 48 children aged 8 to 10 years with manifestations of dyscalculia. The control group consisted of 30 children aged 8 to 10 years without manifestations of learning disabilities and other neuropsychiatric disorders. The following research methods were used in the work: the SNAP-IY scale for assessing concomitant manifestations of attention deficit hyperactivity disorder, the L.D. Malkova, «Working memory» technique for the quantitative assessment of working memory, TOVA computer test for the quantitative assessment of attention disorders and impulsiveness.

RESULTS

The study showed that only in 4 cases (8.3%) dyscalculia was of an isolated nature, without concomitant neuropsychiatric disorders. Most often, manifestations of attention deficit hyperactivity disorder (ADHD) were recorded in children with dyscalculia - 33 (68.8%) children and manifestations of other learning disorders (dyslexia - 27 (56.3%) children, dysgraphia - 22 (45.8%) children). In 20 (41.7%) cases, children in the study group had asthenic symptoms. When comparing the results of working memory testing in the study group, the number of correct answers was significantly lower than in the control group. Indicators of the TOVA psychophysiological test in children with dyscalculia showed a statistically significant increase in the number of inattention errors both in the first and second half of the test, compared with children from the control group.

CONCLUSION

Thus, dyscalculia should be considered not only as a disorder of arithmetic skills, but also as a disorder based on multiple cognitive dysfunctions, such as working memory dysfunction, dysfunction of attention.

Math difficulties in attention deficit hyperactivity disorder do not originate from the visual number sense

There is ample evidence from literature and clinical practice indicating mathematical difficulties in individuals with ADHD, even when there is no concomitant diagnosis of developmental dyscalculia. What factors underlie these difficulties is still an open question. Research on dyscalculia and neurotypical development suggests visual perception of numerosity (the number sense) as a building block for math learning. Participants with lower numerosity estimation thresholds (higher precision) are often those with higher math capabilities. Strangely, the role of numerosity perception in math skills in ADHD has been neglected, leaving open the question whether math difficulties in ADHD also originate from a deficitary visual number sense. In the current study we psychophysically measured numerosity thresholds and accuracy in a sample of children/adolescents with ADHD, but not concomitant dyscalculia (N = 20, 8-16 years). Math abilities were also measured by tasks indexing different mathematical competences. Numerosity performance and math scores were then compared to those obtained from an age-matched control group (N = 20). Bayesian statistics indicated no difference between ADHD and controls on numerosity perception, despite many of the symbolic math tasks being impaired in participants with ADHD. Moreover, the math deficits showed by the group with ADHD remained substantial even when numerosity thresholds were statistically regressed out. Overall, these results indicate that math difficulties in ADHD are unlikely to originate from an impaired visual number sense.

Neuropsychological abilities underpinning academic attainment in children born extremely preterm

Children born extremely preterm (EP) have poorer academic attainment than their term-born peers. There is a need to identify the specific cognitive mechanisms that are associated with poor academic attainment in preterm populations to inform the development of intervention strategies. A parallel mediation analysis was conducted with cross-sectional data from 152 EP children (< 27 weeks of gestation) and 120 term-born controls who were assessed at age 11. Mathematics and reading attainment was assessed using the Wechsler Individual Achievement Test 2nd Edition. Controlling for sex and socio-economic status we evaluated the following mediators: verbal working memory, visuospatial working memory, verbal processing speed, attention, and visuospatial processing. These were assessed using subtests from the standardized NEPSY-II test and Wechsler Intelligence Scale for Children-5th Edition. Verbal working memory, visuospatial working memory, visuospatial processing and verbal processing speed, but not attention, were significant independent mediators between EP birth and attainment in reading. No direct relationship between EP birth and reading attainment remained in the mediated model. All five neuropsychological variables mediated the relationship between EP birth and attainment in mathematics, but a direct effect of EP birth on mathematics remained in the mediated model. Together, all five neuropsychological abilities indirectly explained 44% of the variance in reading and 52% of the variance in mathematics. Visuospatial processing was the strongest mediator of both mathematics and reading. Components of executive function, especially visuospatial processing, are important predictors of academic attainment. Interventions to improve visuospatial skills could be trialed in EP populations.

Discerning Developmental Dyscalculia and Neurodevelopmental Models of Numerical Cognition in a Disadvantaged Educational Context

Developmental Dyscalculia (DD) signifies a failure in representing quantities, which impairs the performance of basic math operations and schooling achievement during childhood. The lack of specificity in assessment measures and respective cut-offs are the most challenging factors to identify children with DD, particularly in disadvantaged educational contexts. This research is focused on a numerical cognition battery for children, designed to diagnose DD through 12 subtests. The aims of the present study were twofold: to examine the prevalence of DD in a country with generally low educational attainment, by comparing z-scores and percentiles, and to test three neurodevelopmental models of numerical cognition based on performance in this battery. Participants were 304 Brazilian school children aged 7–12 years of both sexes (143 girls), assessed by the Zareki-R. Performances on subtests and the total score increase with age without gender differences. The prevalence of DD was 4.6% using the fifth percentile and increased to 7.4% via z-score (in total 22 out of 304 children were diagnosed with DD). We suggest that a minus 1.5 standard deviation in the total score of the Zareki-R is a useful criterion in the clinical or educational context. Nevertheless, a percentile ≤ 5 seems more suitable for research purposes, especially in developing countries because the socioeconomic environment or/and educational background are strong confounder factors to diagnosis. The four-factor structure, based on von Aster and Shalev’s model of numerical cognition (Number Sense, Number Comprehension, Number Production and Calculation), was the best model, with significant correlations ranging from 0.89 to 0.97 at the 0.001 level.

Visuospatial working memory of children and adults born very preterm and/or very low birth weight

BACKGROUND

This paper examines the visuospatial working memory (WM) performance of children and adults born very preterm (VPT) and/or very low birth weight (VLBW) relative to their full-term (FT)-born peers. Of interest was the nature and severity of observed impairments, as well associations with educational/occupational functioning at each age point.

METHODS

Participants were drawn from two prospective cohort studies: (1) a regional cohort of 110 VPT (<32 weeks' gestation and <1500 g) and 113 FT born children assessed at age 12 years; (2) a national cohort of 229 VLBW (<1500 g) and 100 FT born adults assessed at age 28 years. Visuospatial WM was assessed using a four-span/difficulty-level computerized task.

RESULTS

Both children and adults born VPT/VLBW had poorer visuospatial WM than FT controls, with their performance less accurate, slower (correct trials), and less efficient with increasing task difficulty (Cohen's d = 0.27-0.51; p < 0.05). Adults had better visuospatial WM than children, but between-group differences were highly similar across ages, before and after adjustment for confounding social background and individual factors. Poorer WM was associated with lower levels of educational and occupational/socioeconomic achievement.

CONCLUSIONS

Visuospatial WM difficulties persist into adulthood raising concerns for the longer-term cognitive and adaptive functioning of VPT survivors.

IMPACT

Both children and adults born very preterm have poorer visuospatial working memory than their term-born peers. They are less accurate, take longer to respond correctly and are less efficient, with test performance declining with increasing cognitive demand. Similar differences in visuospatial working memory are observed between VPT/VLBW and full-term individuals during both childhood and adulthood, with these differences remaining even after covariate adjustment. Individuals with poorer visuospatial working memory have lower levels of educational achievement and occupational/socioeconomic success. Visuospatial working memory difficulties persist into adulthood and appear to continue to impact everyday functioning and life-course opportunities.

Mathematical performance in childhood and early adult outcomes after very preterm birth: an individual participant data meta-analysis

AIM

To investigate the strength of the independent associations of mathematics performance in children born very preterm (<32wks' gestation or <1500g birthweight) with attending postsecondary education and their current employment status in young adulthood.

METHOD

We harmonized data from six very preterm birth cohorts from five different countries and carried out one-stage individual participant data meta-analyses (n=954, 52% female) using mixed effects logistic regression models. Mathematics scores at 8 to 11 years of age were z-standardized using contemporary cohort-specific controls. Outcomes included any postsecondary education, and employment/education status in young adulthood. All models were adjusted for year of birth, gestational age, sex, maternal education, and IQ in childhood.

RESULTS

Higher mathematics performance in childhood was independently associated with having attended any postsecondary education (odds ratio [OR] per SD increase in mathematics z-score: 1.36 [95% confidence interval {CI}: 1.03, 1.79]) but not with current employment/education status (OR 1.14 per SD increase [95% CI: 0.87, 1.48]).

INTERPRETATION

Among populations born very preterm, childhood mathematics performance is important for adult educational attainment, but not for employment status.

Mathematical skills of 11-year-old children born very preterm and full-term

Preterm birth affects the academic development of children, especially in mathematics. Remarkably, only a few studies have measured specific effects of preterm birth on mathematical skills in primary school. The aim of this study was to compare 11-year-old children, with an IQ above 70, born very preterm (N = 64) and full-term (N = 72) on a variety of 5th grade mathematical skills and cognitive abilities important for mathematical learning. The measures were spontaneous focusing on numerosity (SFON), spontaneous focusing on quantitative relations (SFOR), arithmetic fluency, mathematics achievement, number line estimation, rational number magnitude knowledge, mathematics motivation, reading skills, visuospatial processing, executive functions, and naming speed. The children born very preterm and full-term differed in arithmetic fluency, SFON and SFOR. Domain general cognitive abilities did not fully explain the group differences in SFON and SFOR. Retrospective comparisons of the samples at the age of five years showed large group differences in early mathematical skills and cognitive abilities. Despite lower early mathematical skills, the children born very preterm reached peer equivalent performance in many mathematical skills by the age of 11 years. Nevertheless, they appear less likely to focus on implicit mathematical features in their everyday life.

A comparison of simultaneous and sequential visuo-spatial memory in children born very preterm

Research suggests that children born very preterm (≤32 weeks' gestation) are at greater risk of impairments in information processing (particularly when information is presented simultaneously rather than sequentially) and visuo-spatial short-term and working memory relative to children born at term. This study compared the performance of children born very preterm with their term-born peers to elucidate the nature of group differences in these areas. 113 children (65 very preterm; 48 term-born) aged 8-to-11 years completed four visuo-spatial recall tasks. Tasks varied by presentation type (simultaneous or sequential) and memory type (short-term or working memory). Both groups recalled more locations in simultaneous than sequential tasks, and in short-term than working memory tasks. In short-term memory tasks, children born at term recalled more locations than children born very preterm for the sequential task, but groups did not differ on the simultaneous task. The opposite pattern was observed in the working memory tasks, with no group differences on the sequential task, but better performance on the simultaneous task for children born at term. Our findings indicate that simultaneous processing may not be impaired in children born very preterm per se, with poorer performance observed only under high cognitive demand. This interaction suggests very preterm birth may affect the level of cognitive resources available during feature integration, the consequences of which become apparent when resources are already stretched. The impact of interactions with cognitive demand in this population should be an important consideration for educational support strategies, and for assessment in research and clinic.

Development of brain white matter and math computation ability in children born very preterm and full-term

Children born very preterm (VPT; <32 weeks' gestation) have alterations in brain white matter and poorer math ability than full-term (FT) peers. Diffusion-weighted magnetic resonance imaging studies suggest a link between white matter microstructure and math in VPT and FT children, although longitudinal studies using advanced modelling are lacking. In a prospective longitudinal cohort of VPT and FT children we used Fixel-Based Analysis to investigate associations between maturation of white matter fibre density (FD), fibre-bundle cross-section (FC), and combined fibre density and cross-section (FDC) and math computation ability at 7 (n = 136 VPT; n = 32 FT) and 13 (n = 130 VPT; n = 44 FT) years, as well as between change in white matter and math computation ability from 7 to 13 years (n = 103 VPT; n = 21 FT). In both VPT and FT children, higher FD, FC and FDC in visual, sensorimotor and cortico-thalamic/thalamo-cortical white matter tracts were associated with better math computation ability at 7 and 13 years. Longitudinally, accelerated maturation of the posterior body of the corpus callosum (FDC) was associated with greater math computation development. White matter-math associations were similar for VPT and FT children. In conclusion, white matter maturation is associated with math computation ability across late childhood, irrespective of birth group.

Etiology of persistent mathematics difficulties from childhood to adolescence following very preterm birth

Children born very preterm (VP; <32 weeks' gestation) have poorer mathematics achievement than term-born peers. This study aimed to determine whether VP children's mathematics difficulties persist from primary to secondary school and to explore the nature of mathematics difficulties in adolescence. For this study, 127 VP and 95 term-born adolescents were assessed at age 11-15 years. Mathematics achievement was assessed using the Wechsler Individual Achievement Test-II. Specific mathematics skills and general cognitive skills were assessed using standardized and experimental tests. VP adolescents had poorer mathematics achievement than term-born adolescents (-10.95 points; 95% CI -16.18, -5.73) and poorer number fact knowledge, understanding of arithmetic concepts, written arithmetic, counting, reading and writing large numbers, and algebra. Between-group differences in mathematics skills were no longer significant when working memory and visuospatial skills were controlled for (p's >0.05), with the exception of writing large numbers and conceptual understanding of arithmetic. In a previous study, 83 of the VP adolescents and 49 of the term-born adolescents were assessed at age 8-10 years using measures of the same skills. Amongst these, the between-group difference in mathematics achievement remained stable over time. This study extends findings of a persistent deficit in mathematics achievement among VP children over the primary and secondary school years, and provides evidence of a deficit in factual, procedural and conceptual mathematics skills and in higher order mathematical operations among VP adolescents. We provide further evidence that VP children's mathematics difficulties are driven by deficits in domain-general rather than domain-specific cognitive skills.

Typical Crossmodal Numerosity Perception in Preterm Newborns

Premature birth is associated with a high risk of damage in the parietal cortex, a key area for numerical and non-numerical magnitude perception and mathematical reasoning. Children born preterm have higher rates of learning difficulties for school mathematics. In this study, we investigated how preterm newborns (born at 28-34 weeks of gestation age) and full-term newborns respond to visual numerosity after habituation to auditory stimuli of different numerosities. The results show that the two groups have a similar preferential looking response to visual numerosity, both preferring the incongruent set after crossmodal habituation. These results suggest that the numerosity system is resistant to prematurity.

Multi-domain cognitive impairments at school age in very preterm-born children compared to term-born peers

Background

Preterm infants are at risk for functional impairments in motor, cognitive, and behavioral development that may persist into childhood. The aim of this study was to determine the co-occurrence of cognitive impairments in multiple cognitive domains at school age in very preterm born children compared to term-born children.

Methods

Comparative study including 60 very preterm-born children (gestational age ≤ 32 weeks) and 120 term-born controls. At school age, we assessed intelligence with the WISC-III, and visuomotor integration with the NEPSY-II, verbal memory with the AVLT, attention with the TEA-ch, and executive functioning with the BRIEF. We investigated co-occurrence of various abnormal (<5th percentile) and suspect-abnormal (<15th percentile, including both suspect and abnormal) cognitive functions.

Results

At mean age 8.8 years, 15% of preterm children had abnormal outcomes in multiple cognitive functions (≥2), versus 3% of the controls (odds ratio, OR 4.65, 95%-confidence interval, CI 1.33–16.35). For multiple suspect-abnormal cognitive outcomes, rates were 55% versus 25% (OR 3.02, 95%-CI 1.49–6.12). We found no pattern of co-occurrence of cognitive impairments among preterm children that deviated from term-born controls. However, low performance IQ was more frequently accompanied by additional cognitive impairments in preterms than in controls (OR 5.43, 95%-CI 1.75–16.81).

Conclusions

A majority of preterm children showed co-occurrence of impairments in multiple cognitive domains, but with no specific pattern of impairments. The occurrence of multi-domain cognitive impairments is higher in preterms but this seems to reflect a general increase, not one with a pattern specific for preterm-born children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02641-z.

Perceptual reasoning skills mediate the relationship between attention and math proficiency in individuals with a neurodevelopmental condition

BACKGROUND

An important component of academic success in typically developing students is the development of math skills, which is associated with attention and perceptual reasoning (PR) skills. For children with a neurodevelopmental condition (NDC), the relationship is confounded by diagnostic-specific cognitive characteristics. Specifically, enhanced PR is specific to individuals with Autism Spectrum Disorder (ASD).

AIMS

The purpose of this study was to test: (i) a mediation model where PR skills would mediate the relationship between attention and math proficiency for students with an NCD, and (ii) whether this mediation model is moderated by a diagnostic profile.

METHODS AND PROCEDURES

One hundred and thirty-seven students with an NDC participated in a school-based study examining the effectiveness of using a standardized measure of attention in predicting math capabilities.

OUTCOMES AND RESULTS

PR mediated the relationship between attention and math proficiency for students diagnosed with an NDC. However, the model was not moderated by diagnostic profile.

CONCLUSIONS AND IMPLICATIONS

The results of this study provide a better understanding of the roles of higher-level cognitive ability specific to students with NDCs. Additionally, the superior PR skills demonstrated by the ASD sample further supports the research suggesting this population possesses cognitive strengths in this domain.

No Excess of Mathematics Anxiety in Adolescents Born Very Preterm

OBJECTIVE

To assess whether adolescents born very preterm (VP; <32 weeks' gestation) have an excess of mathematics anxiety compared with their classmates born at term.

METHODS

This cohort study included 127 adolescents born VP (51% male, mean age 13.9 years, SD 0.7) and 95 term-born classmates (56% male, mean age 13.7 years, SD 0.7) who completed the Wechsler Individual Achievement Test Second UK Edition and the Mathematics Anxiety Scale-UK at the age of 11 to 15 years. Self-reported trait anxiety was assessed using a composite of 3 items from the Strengths and Difficulties Questionnaire.

RESULTS

Adolescents born VP had significantly poorer mathematics attainment than adolescents born at term (difference in means: -0.64 SD; 95% confidence interval -0.95 to -0.34). However, there were no between-group differences in self-reported mathematics anxiety or trait anxiety. There were significant moderate associations between mathematics anxiety and mathematics attainment for adolescents born VP (rho: -0.45) and at term (rho: -0.54), after controlling for trait anxiety.

CONCLUSION

Adolescents born VP do not have heightened mathematics anxiety compared with their term-born classmates, despite poorer attainment in mathematics. Improving domain-general cognitive skills and scaffolding learning in the classroom may be more promising avenues for intervention than attempting to reduce mathematics anxiety.

Preterm children's long-term academic performance after adaptive computerized training: an efficacy and process analysis of a randomized controlled trial

BACKGROUND

Adaptive computerized interventions may help improve preterm children's academic success, but randomized trials are rare. We tested whether a math training (XtraMath®) versus an active control condition (Cogmed®; working memory) improved school performance. Training feasibility was also evaluated.

METHODS

Preterm born first graders, N = 65 (28-35 + 6 weeks gestation) were recruited into a prospective randomized controlled multicenter trial and received one of two computerized trainings at home for 5 weeks. Teachers rated academic performance in math, reading/writing, and attention compared to classmates before (baseline), directly after (post), and 12 months after the intervention (follow-up). Total academic performance growth was calculated as change from baseline (hierarchically ordered-post test first, follow-up second).

RESULTS

Bootstrapped linear regressions showed that academic growth to post test was significantly higher in the math intervention group (B = 0.25 [95% confidence interval: 0.04-0.50], p = 0.039), but this difference was not sustained at the 12-month follow-up (B = 0.00 [-0.31 to 0.34], p = 0.996). Parents in the XtraMath group reported higher acceptance compared with the Cogmed group (mean difference: -0.49, [-0.90 to -0.08], p = 0.037).

CONCLUSIONS

Our findings do not show a sustained difference in efficacy between both trainings. Studies of math intervention effectiveness for preterm school-aged children are warranted.

IMPACT

Adaptive computerized math training may help improve preterm children's short-term school performance. Computerized math training provides a novel avenue towards intervention after preterm birth. Well-powered randomized controlled studies of math intervention effectiveness for preterm school-aged children are warranted.

Eight-year-old very and extremely preterm children showed more difficulties in performance intelligence than verbal intelligence

Aim

This study determined possible discrepancies between verbal IQ and performance IQ in 8‐year‐old very preterm (VPT) and extremely preterm (EPT) children, and examined associations between verbal IQ and performance IQ, and sociodemographic factors, perinatal factors, early cognitive outcomes and also with school achievement scores.

Methods

This prospective cohort study included 120 eight‐year‐old VPT/EPT children. Cognitive development was assessed at the ages of 2, 5 and 8 years. Eight years’ school achievement results in arithmetic, reading and spelling were collected. Multiple regression analyses were performed to determine predictors of verbal IQ and performance IQ at the age of 8 years and to determine associations with school achievement scores.

Results

Mean performance IQ (89.8) was significantly lower than mean verbal IQ (99.4; Cohen's d = 0.59) at the age of 8 years. Gestational age (GA), small for GA status, and cognitive scores at the ages of 2 and 5 years significantly predicted verbal IQ and performance IQ at the age of 8 years. Performance IQ at age 8 years was an important predictor for arithmetic scores (β = 0.42).

Conclusion

Performance IQ was more strongly affected than verbal IQ in 8‐year‐old VPT/EPT children and was strongly related to mathematical difficulties.

Academic Outcomes of School-Aged Children Born Preterm: A Systematic Review and Meta-analysis

IMPORTANCE

Children born preterm are at an elevated risk of academic underachievement. However, the extent to which performance across domain-specific subskills in reading and mathematics is associated with preterm birth remains unclear.

OBJECTIVE

To conduct a systematic review and meta-analysis of academic outcomes of school-aged children born preterm, compared with children born at term, appraising evidence for higher- and lower-order subskills in reading and mathematics.

DATA SOURCES

PubMed/MEDLINE, PsycINFO, and the Cumulative Index of Nursing and Allied Health Literature electronic databases from January 1, 1980, to July 30, 2018, were searched for population, exposure, and outcome terms such as child (population), preterm birth (exposure), and education* (outcome).

STUDY SELECTION

Peer-reviewed English-language publications that included preterm-born children and a comparison group of term-born children aged 5 to 18 years and born during or after 1980 and that reported outcomes on standardized assessments from cohort or cross-sectional studies were screened. Of the 9833 articles screened, 33 unique studies met the inclusion criteria.

DATA EXTRACTION AND SYNTHESIS

Data were analyzed from August 1 to September 29, 2018. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. Two reviewers independently screened the databases and extracted sample characteristics and outcomes scores. Pooled mean differences (MDs) were analyzed using random-effects models.

MAIN OUTCOMES AND MEASURES

Performance on standardized assessment of higher-order subskills of reading comprehension and applied mathematics problems; lower-order reading subskills of decoding, pseudoword decoding, and word identification; and lower-order mathematics subskills of knowledge, calculation, and fluency.

RESULTS

Outcomes data were extracted for 4006 preterm and 3317 term-born children, totaling 7323 participants from 33 unique studies. Relative to children born at term, children born preterm scored significantly lower in reading comprehension (mean difference [MD], -7.96; 95% CI, -12.15 to -3.76; I2 = 81%) and applied mathematical problems (MD, -11.41; 95% CI, -17.57 to -5.26; I2 = 91%) assessments. Across the assessments of lower-order skills, children born preterm scored significantly lower than their term-born peers in calculation (MD, -10.57; 95% CI, -15.62 to -5.52; I2 = 92%), decoding (MD, -10.18; 95% CI, -16.83 to -3.53; I2 = 71%), mathematical knowledge (MD, -9.88; 95% CI, -11.68 to -8.08; I2 = 62%), word identification (MD, -7.44; 95% CI, -9.08 to -5.80; I2 = 69%), and mathematical fluency (MD, -6.89; 95% CI, -13.54 to -0.23; I2 = 72%). The associations remained unchanged after sensitivity analyses for reducing heterogeneity.

CONCLUSIONS AND RELEVANCE

These findings provide evidence that preterm birth is associated with academic underperformance in aggregate measures of reading and mathematics, as well as a variety of related subskills.

Secondary Benefits to Attentional Processing Through Intervention With an Interactive Maths App

Previous research has shown that a specific interactive app, designed to support the development of early mathematical skills and delivered on hand-held tablets, is effective at raising mathematical attainment in young children in low-and high-income countries. In the countries where this app has been deployed, teachers have consistently reported improved concentration skills in children who have received intervention with this app. To investigate the legitimacy of these claims, we conducted secondary data analyses of children’s performance on core cognitive tasks to examine if additional benefits are observed in children who received intervention with the interactive maths app compared to those that did not. We drew on data from a three-arm randomized control trial conducted in a primary school in Malawi (Pitchford, 2015). In addition to assessing mathematical skills, children’s visual attention, short-term memory, and manual processing speed were examined at baseline, before the introduction of the maths app intervention, and at endline, after the intervention had been implemented for 8 weeks. A group of 318 children (73–161 months) attending Standards 1–3 of a Malawian primary school were randomized to receive either the new maths app (treatment group), a non-maths app that required similar interactions to engage with the software as with the maths app (placebo group), or standard teacher-led mathematical practice (control group). Before and after the 8-week intervention period, children were assessed on mathematics and core cognitive skills. Results showed that the maths app intervention supported significant and independent gains in mathematics and visual attention. Increases in visual attention were attributable only to interactions with the maths app. No significant benefits to attention were found from using the tablet device with non-maths software or standard class-based mathematical practice. These results suggest that high-quality interactive, educational apps can significantly improve attentional processing in addition to the scholastic skills targeted by the intervention.

The Life Course Consequences of Very Preterm Birth

Around 15 million children are born preterm (<37 weeks of gestation) every year. Of these, 15% or 2.25 million are born very preterm (VP; <32 weeks of gestation). Here, the developmental outcomes of VP babies in diverse domains from motor, cognitive, and social function to mental health and well-being throughout childhood and adolescence are reviewed. Their life course adaptation in terms of romantic relationships, employment, and quality of life into adulthood is also considered. Some adverse effects reduce as individuals age, and others remain remarkably stable from childhood into adulthood. We argue that to advance understanding of developmental mechanisms and direct resources for intervention more effectively, social factors need to be assessed more comprehensively, and genetically sensitive designs should be considered with neuroimaging integrated to test alternative developmental models. As current evidence is based almost exclusively on studies from high-income countries, research from low- and middle-income countries is urgently needed.

The profile of very preterm children on academic achievement. A cross-population comparison with children with specific learning disorders

BACKGROUND

Very preterm (VPT) children showed delays in reading, spelling and maths, but their academic achievement profile is not clearly understood.

AIMS

VPT children were compared with children with specific learning disorders (SLD) and typically developing (TD) children on academic achievement, considering cognitive and linguistic phenotypic markers. A learning profile analysis was also performed.

METHODS

We included 170 10-year old monolingual Italian-speaking children (37 VPT, 28 SLD, 105 TD) assessing cognitive, linguistic and academic skills.

RESULTS

On academic achievements VPT children fell behind TD peers in some reading (text speed, comprehension), spelling (non-word), and math (number knowledge, written calculations and problem-solving) tasks. SLD children underperformed in all academic tasks with respect to VPT and TD peers. Concerning cognitive and linguistic phenotypic markers, compared to TD peers, VPT children showed lower scores in verbal IQ and phonological fluency, SLD children in phonological processing and rapid automatized naming. VPT children showed a higher rate of at-risk performance in reading compared to TD group, but a minor percentage of impaired profiles and comorbidity among learning areas compared to SLD group.

CONCLUSIONS AND IMPLICATIONS

The academic achievement profile of VPT children shows persistent delays, but it differs to that of SLD children, since delays are less widespread and severe, and differences were found in phenotypic markers and comorbidity. Follow-up programs and effective interventions are needed for VPT children.

General cognitive but not mathematic abilities predict very preterm and healthy term born adults' wealth

Objective

Very preterm (<32 weeks gestation; VP) and/or very low birth weight (<1500g; VLBW) children often have cognitive and mathematic difficulties. It is unknown whether VP/VLBW children’s frequent mathematic problems significantly add to the burden of negative life-course consequences over and above effects of more general cognitive deficits. Our aim was to determine whether negative consequences of VP/VLBW versus healthy term birth on adult wealth are mediated by mathematic abilities in childhood, or rather explained by more general cognitive abilities.

Methods

193 VP/VLBW and 217 healthy term comparison participants were studied prospectively from birth to adulthood as part of a geographically defined study in Bavaria (South Germany). Mathematic and general cognitive abilities were assessed at 8 years with standardized tests; wealth information was assessed at 26 years with a structured interview and summarized into a comprehensive index score. All scores were z-standardized.

Results

At 8 years, VP/VLBW (n = 193, 52.3% male) had lower mathematic and general cognitive abilities than healthy term comparison children (n = 217, 47.0% male). At 26 years, VP/VLBW had accumulated significantly lower overall wealth than term born comparison adults (-0.57 (1.08) versus -0.01 (1.00), mean difference 0.56 [0.36–0.77], p < .001). Structural equation modeling confirmed that VP/VLBW birth (β = -.13, p = .022) and childhood IQ (β = .24, p < .001) both directly predicted adult wealth, but math did not (β = .05, p = .413). Analyses were controlled for small-for-gestational-age (SGA) birth, child sex, and family socioeconomic status.

Conclusion

This longitudinal study from birth to adulthood shows that VP/VLBW survivors’ general cognitive rather than specific mathematic problems explain their diminished life-course success. These findings are important in order to design effective interventions at school age that reduce the burden of prematurity for those individuals who were born at highest neonatal risk.

Visual perceptive skills account for very preterm children's mathematical difficulties in preschool

BACKGROUND

Already in preschool, very preterm (VP) children perform worse than term born-children on preschool mathematical skills tests. Strong associations have been found between preschool mathematical skills, cognition and visual-motor integration.

AIMS

To compare VP children and their term-born peers on preschool mathematical achievement at the corrected age of five years, and determine whether cognitive, visual-perceptive, visual-motor, and motor-coordination skills, account for any significant differences observed.

STUDY DESIGN

Single-center, consecutive cohort study with a term-born comparison group.

SUBJECTS

54 five-year-old VP children and 28 term-born comparison children.

OUTCOME MEASURES

Standardized test for preschool mathematical skills (Dutch pupil monitoring system), cognitive skills (Wechsler Preschool and Primary Scale for Intelligence - third edition), visual-perception, visual-motor integration, and motor-coordination (Beery Visual-Motor Integration test - sixth edition). Group differences were analyzed with ANCOVAs, adjusting for maternal education, preschool grade, and time of assessment. Sobel's mediation analyses tested for possible mediation effects.

RESULTS

Preschool mathematical skills and visual perceptive skills were significantly lower in VP children than in term-born children (Cohen's d = 0.63, p = 0.01; Cohen's d = 0.84, p < 0.01, respectively). Sobel's test indicated a significant mediating effect of visual perceptive skills on the association between VP birth and preschool mathematical skills.

CONCLUSIONS

At preschool age, VP children have poorer preschool mathematical skills compared to term-born peers; deficits that were fully accounted for by poor visual perceptive skills. Our findings indicate the relevance of screening visual perceptive skills at preschool age, enabling timely identification of children at risk for mathematical difficulties.

Influence of Gestational Age and Working Memory on Math Skills in Children Aged 8 to 9 Years

OBJECTIVE

Prematurity affects children's functioning in domains such as cognitive skills and math skills. However, there is limited research examining math skills as gestational age (GA) increases weekly. We aimed at determining, in a population-based cohort of children aged 8 to 9 years, the association between the GA spectrum and math skills and working memory's (WM's) role in this relationship.

METHODS

Children aged 8 to 9 years in 2014 (n = 1761), from 44 primary schools in a metropolitan city, were recruited through the Memory Maestros study in 2012. GA was measured using the parent report. Math skills were measured using the Wide Range Achievement Test 4 math computation subtest (mean, 100; SD, 15), and WM was measured using 2 subtests of the Automated Working Memory Assessment. The method of analysis was multivariate linear regression, with adjustment for both WM measures and social risk indicators as potential confounders.

RESULTS

A total of 1168 children (66%) had analyzable data. Compared with children of ≤34-week gestation, there was a mean difference increase of 0.48 in math standard scores per weekly increase in GA (95% confidence interval, 0.11-0.85%; p = 0.01). This equates to a difference of 6.29 (0.42 SD) standard math scores between the ≤34- and ≥42-week group. The relationship was independent of WM.

CONCLUSION

Weekly increases in GA beyond 34 weeks are associated with higher mathematics achievement scores for children aged 8 to 9 years, independent of the child's WM. This assists with identification of individuals at risk of poorer math skills.

Understanding arithmetic concepts: The role of domain-specific and domain-general skills

A large body of research has identified cognitive skills associated with overall mathematics achievement, focusing primarily on identifying associates of procedural skills. Conceptual understanding, however, has received less attention, despite its importance for the development of mathematics proficiency. Consequently, we know little about the quantitative and domain-general skills associated with conceptual understanding. Here we investigated 8–10-year-old children’s conceptual understanding of arithmetic, as well as a wide range of basic quantitative skills, numerical representations and domain-general skills. We found that conceptual understanding was most strongly associated with performance on a number line task. This relationship was not explained by the use of particular strategies on the number line task, and may instead reflect children’s knowledge of the structure of the number system. Understanding the skills involved in conceptual learning is important to support efforts by educators to improve children’s conceptual understanding of mathematics.

Cognitive predictors of parent-rated inattention in very preterm children: The role of working memory and processing speed

Inattention is one of the most common neurobehavioral problems following very preterm birth. Attention problems can persist into adulthood and are associated with negative socio-emotional and educational outcomes. This study aimed to determine whether the cognitive processes associated with inattention differ between term-born and very preterm children. Sixty-five children born very preterm (<33+0 weeks' gestation) aged 8-11 years were recruited alongside 48 term-born controls (?37 20 +0 weeks' gestation). Both groups included children with a wide spectrum of parent-rated inattention (above average attention to severe inattention) measured as a continuous dimension using the Strengths and Weaknesses of ADHD and Normal-Behavior (SWAN) scale. The children completed tests to assess basic cognitive processes and executive function. A hierarchical multiple regression analysis was implemented to assess which neurocognitive processes explained variance in parent-rated inattention and whether these differed between preterm and term-born children. In both groups, poorer verbal and visuospatial short-term memory and poorer visuospatial working memory independently explained variance in parent-rated inattention. Slower motor processing speed explained variance in inattention among very preterm children only. The cognitive mechanisms associated with parent-rated inattention were predominantly overlapping between groups, but relationships between motor processing speed and inattention were unique to very preterm children. These associations may reflect risk factors for inattention in term and very preterm children. Future research should assess the efficacy of these cognitive processes as potential targets for intervention.

Effects of extreme prematurity and kindergarten neuropsychological skills on early academic progress

OBJECTIVE

The study was designed to investigate the effect of extreme prematurity on growth in academic achievement across the early school years and the validity of kindergarten neuropsychological skills as predictors of achievement.

METHOD

A 2001-2003 birth cohort of 145 extremely preterm/extremely low birth weight (EPT/ELBW) children from a single medical center, along with 111 normal birth weight (NBW) classmate controls, were recruited during their first year in kindergarten and followed annually across the next 2 years in school. Mixed model analysis was conducted to compare the groups on growth in achievement across years and examine kindergarten neuropsychological skills as predictors of growth.

RESULTS

The EPT/ELBW group scored significantly below NBW controls on all achievement tests across years and had higher rates of special education placement and grade repetition. Despite limited catch-up of the EPT/ELBW group to the NBW controls in spelling, group differences were generally stable. Differences in spelling and mathematics achievement remained significant when controlling for global intelligence or excluding children who had intellectual or neurosensory impairments or repeated a grade. Higher scores on kindergarten tests of multiple neuropsychological ability domains predicted higher achievement levels and steeper growth in achievement.

CONCLUSIONS

The findings document persistent academic weaknesses in EPT/ELBW children across the early school years. Results point to the need for preschool interventions to enhance academic readiness and suggest that neuropsychological skills assessed in kindergarten are useful in identifying individual differences in early learning progress. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Academic performance of children born preterm: a meta-analysis and meta-regression

BACKGROUND

Advances in neonatal healthcare have resulted in decreased mortality after preterm birth but have not led to parallel decreases in morbidity. Academic performance provides insight in the outcomes and specific difficulties and needs of preterm children.

OBJECTIVE

To study academic performance in preterm children born in the antenatal steroids and surfactant era and possible moderating effects of perinatal and demographic factors.

DESIGN

PubMed, Web of Science and PsycINFO were searched for peer-reviewed articles. Cohort studies with a full-term control group reporting standardised academic performance scores of preterm children (<37 weeks of gestation) at age 5 years or older and born in the antenatal steroids and surfactant era were included. Academic test scores and special educational needs of preterm and full-term children were analysed using random effects meta-analysis. Random effects meta-regressions were performed to explore the predictive role of perinatal and demographic factors for between-study variance in effect sizes.

RESULTS

The 17 eligible studies included 2390 preterm children and 1549 controls. Preterm children scored 0.71 SD below full-term peers on arithmetic (p<0.001), 0.44 and 0.52 SD lower on reading and spelling (p<0.001) and were 2.85 times more likely to receive special educational assistance (95% CI 2.12 to 3.84, p<0.001). Bronchopulmonarydysplasia explained 44% of the variance in academic performance (p=0.006).

CONCLUSION

Preterm children born in the antenatal steroids and surfactant era show considerable academic difficulties. Preterm children with bronchopulmonarydysplasia are at particular risk for poor academic outcome.

Cognitive outcomes in children and adolescents born very preterm: a meta-analysis

AIM

To estimate the association between very preterm birth (<32wks' gestation) and intelligence, executive functioning, and processing speed throughout childhood and adolescence, and to examine the effects of gestational age, birthweight, and age at assessment.

METHOD

Studies were included if children were born at earlier than 32 weeks' gestation, aged 4 to 17 years, had an age-matched term control group, and if the studies used standardized measures, were published in an English-language peer-reviewed journal, and placed no restrictions on participants based on task performance.

RESULTS

We evaluated 6163 children born very preterm and 5471 term-born controls from 60 studies. Children born very preterm scored 0.82 SDs (95% confidence interval [CI] 0.74-0.90; p<0.001) lower on intelligence tests, 0.51 SDs (95% CI 0.44-0.58; p<0.001) lower on measures of executive functioning, and 0.49 SDs (95% CI 0.39-0.60; p<0.001) lower on measures of processing speed than term-born controls. Gestational age and birthweight were associated with study effect size in intelligence and executive functioning of younger children only. Age at assessment was not associated with study effect size.

INTERPRETATION

Children born very preterm have medium to large deficits in these cognitive domains.

WHAT THIS PAPER ADDS

This meta-analysis is centred on very preterm birth and three cognitive domains. The three critical cognitive domains are intelligence, executive functioning, and processing speed.

Low performance on mathematical tasks in preschoolers: the importance of domain-general and domain-specific abilities

BACKGROUND

Different domain-specific and domain-general cognitive precursors play a key role in the development of mathematical abilities. The contribution of these domains to mathematical ability changes during development. Primary school-aged children who show mathematical difficulties form a heterogeneous group, but it is not clear whether this also holds for preschool low achievers (LAs) and how domain-specific and domain-general abilities contribute to mathematical difficulties at a young age. The aim of this study was to explore the cognitive characteristics of a sample of preschool LAs and identify sub-types of LAs.

METHODS

81 children were identified as LAs from 283 preschoolers aged 3 to 5 years old and were assessed on a number of domain-general and domain-specific tasks.

RESULTS

Cluster analysis revealed four subgroups of LAs in mathematics: (1) a weak processing sub-type; (2) a general mathematical LAs sub-type; (3) a mixed abilities sub-type; and (4) a visuo-spatial deficit sub-type. Whilst two of the groups showed specific domain-general difficulties, none showed only domain-specific difficulties.

CONCLUSIONS

Current findings suggest that preschool LAs constitute a heterogeneous group and stress the importance of domain-general factors for the development of mathematical abilities during the preschool years.

Neonatal systemic inflammation and the risk of low scores on measures of reading and mathematics achievement at age 10 years among children born extremely preterm

BACKGROUND

Difficulties with reading and math occur more commonly among children born extremely preterm than among children born at term. Reasons for this are unclear.

METHODS

We measured the concentrations of 27 inflammatory-related and neurotrophic/angiogenic proteins (angio-neurotrophic proteins) in multiple blood specimens collected a week apart during the first postnatal month from 660 children born before the 28th week of gestation who at age 10 years had an IQ ≥ 70 and a Wechsler Individual Achievement Test 3rd edition (WIAT-III) assessment. We identified four groups of children, those who had a Z-score ≤ -1 on the Word Reading assessment only, on the Numerical Operations assessment only, on both of these assessments, and on neither, which served as the referent group. We then modeled the risk of each learning limitation associated with a top quartile concentration of each protein, and with high and lower concentrations of multiple proteins.

RESULTS

The protein profile of low reading scores was confined to the third and fourth postnatal weeks when increased risks were associated with high concentrations of IL-8 and ICAM-1 in the presence of low concentrations of angio-neurotrophic proteins. The profile of low math scores was very similar, except it did not include ICAM-1. In contrast, the profile of low scores on both assessments was present in each of the first four postnatal weeks. The increased risks associated with high concentrations of TNF-α in the first two weeks and of IL-8 and ICAM-1 in the next two weeks were modulated down by high concentrations of angio-neurotrophic proteins.

CONCLUSIONS

High concentrations of angio-neurotrophic proteins appear to reduce/moderate the risk of each learning limitation associated with systemic inflammation. The three categories of limitations have protein profiles with some similarities, and yet some differences, too.

Mathematics ability and related skills in preschoolers born very preterm

Children born very preterm (VPT) are at risk for academic, behavioral, and/or emotional problems. Mathematics is a particular weakness and better understanding of the relationship between preterm birth and early mathematics ability is needed, particularly as early as possible to aid in early intervention. Preschoolers born VPT (n = 58) and those born full term (FT; n = 29) were administered a large battery of measures within 6 months of beginning kindergarten. A multiple-mediation model was utilized to characterize the difference in skills underlying mathematics ability between groups. Children born VPT performed significantly worse than FT-born children on a measure of mathematics ability as well as full-scale IQ, verbal skills, visual-motor integration, phonological awareness, phonological working memory, motor skills, and executive functioning. Mathematics was significantly correlated with verbal skills, visual-motor integration, phonological processing, and motor skills across both groups. When entered into the mediation model, verbal skills, visual-motor integration, and phonological awareness were significant mediators of the group differences. This analysis provides insights into the pre-academic skills that are weak in preschoolers born VPT and their relationship to mathematics. It is important to identify children who will have difficulties as early as possible, particularly for VPT children who are at higher risk for academic difficulties. Therefore, this model may be used in evaluating VPT children for emerging difficulties as well as an indicator that if other weaknesses are found, an assessment of mathematics should be conducted.

Academic Achievement Deficits and Their Neuropsychological Correlates in Children Born Extremely Preterm

OBJECTIVE

The purpose of this study was to examine the risks associated with learning disabilities (LDs) in a large sample of children born extremely preterm. We predicted higher than expected rates of LD, particularly in math, and children with LD in math, reading, or both would have lower intelligence quotients (IQs) and specific patterns of neuropsychological deficits.

METHODS

We evaluated academic achievement, rates of LD, and their neuropsychological correlates in the Extremely Low Gestational Age Newborns (ELGANs) Study cohort of 10-year-old children born at 23 to 27 weeks gestational age. Primary analyses focused on children without intellectual disability (verbal IQ > 70 and nonverbal IQ > 70; N = 668). Low achievement was defined as a standard score ≤85 on the reading or math measures.

RESULTS

The risk of low math achievement scores (27%) was 1.5 times higher than the risk of low reading achievement scores (17%). Children were classified as having LD based on low achievement criteria in reading only (RD, 6.4% of sample), math only (MD, 16.2%), both reading and math (RD/MD, 8.3%), or no reading or math disabilities (No LD, 69.1%). Although all 3 LD groups had multiple neuropsychological weaknesses compared with the No LD group, the RD and MD groups had different patterns of neuropsychological impairment.

CONCLUSION

These children from the ELGAN cohort had higher than expected rates of LD, particularly in mathematics, even after taking socioeconomic status into consideration. These results indicate specific cognitive weaknesses that differ between extremely preterm children with RD and MD.

The effects of preterm birth on visual development

Children born very preterm are at a greater risk of abnormal visual and neurological development when compared to children born at full term. Preterm birth is associated with retinopathy of prematurity (a proliferative retinal vascular disease) and can also affect the development of brain structures associated with post-retinal processing of visual information. Visual deficits common in children born preterm, such as reduced visual acuity, strabismus, abnormal stereopsis and refractive error, are likely to be detected through childhood vision screening programs, ophthalmological follow-up or optometric care. However, routine screening may not detect other vision problems, such as reduced visual fields, impaired contrast sensitivity and deficits in cortical visual processing, that may occur in children born preterm. For example, visual functions associated with the dorsal visual processing stream, such as global motion perception and visuomotor integration, may be impaired by preterm birth. These impairments can continue into adolescence and adulthood and may contribute to the difficulties in learning (particularly reading and mathematics), attention, behaviour and cognition that some children born preterm experience. Improvements in understanding the mechanisms by which preterm birth affects vision will inform future screening and interventions for children born preterm.

Deficits in Approximate Number System Acuity and Mathematical Abilities in 6.5-Year-Old Children Born Extremely Preterm

Preterm children are at increased risk for poor academic achievement, especially in math. In the present study, we examined whether preterm children differ from term-born children in their intuitive sense of number that relies on an unlearned, approximate number system (ANS) and whether there is a link between preterm children’s ANS acuity and their math abilities. To this end, 6.5-year-old extremely preterm (i.e., <27 weeks gestation, n = 82) and term-born children (n = 89) completed a non-symbolic number comparison (ANS acuity) task and a standardized math test. We found that extremely preterm children had significantly lower ANS acuity than term-born children and that these differences could not be fully explained by differences in verbal IQ, perceptual reasoning skills, working memory, or attention. Differences in ANS acuity persisted even when demands on visuo-spatial skills and attention were reduced in the ANS task. Finally, we found that ANS acuity and math ability are linked in extremely preterm children, similar to previous results from term-born children. These results suggest that deficits in the ANS may be at least partly responsible for the deficits in math abilities often observed in extremely preterm children.

Functional hyperconnectivity vanishes in children with developmental dyscalculia after numerical intervention

Developmental dyscalculia (DD) is a developmental learning disability associated with deficits in processing numerical and mathematical information. Although behavioural training can reduce these deficits, it is unclear which neuronal resources show a functional reorganization due to training. We examined typically developing (TD) children (N = 16, mean age: 9.5 years) and age-, gender-, and handedness-matched children with DD (N = 15, mean age: 9.5 years) during the performance of a numerical order task with fMRI and functional connectivity before and after 5-weeks of number line training. Using the intraparietal sulcus (IPS) as seed region, DD showed hyperconnectivity in parietal, frontal, visual, and temporal regions before the training controlling for age and IQ. Hyperconnectivity disappeared after training, whereas math abilities improved. Multivariate classification analysis of task-related fMRI data corroborated the connectivity results as the same group of TD could be discriminated from DD before but not after number line training (86.4 vs. 38.9%, respectively). Our results indicate that abnormally high functional connectivity in DD can be normalized on the neuronal level by intensive number line training. As functional connectivity in DD was indistinguishable to TD’s connectivity after training, we conclude that training lead to a re-organization of inter-regional task engagement.

Working memory in very-low-birthweight children at the age of 11 years

The aim of this study is to investigate the working memory (WM) of very-low-birthweight (VLBW, ≤ 1500 g) children at the age of 11 years using Baddeley's WM model. A regional cohort of 95 VLBW children was assessed for the domains of the WM model (central executive [CE], visuospatial sketchpad [VS], and phonological loop [PL]) using subtests from the Working Memory Test Battery for Children (WMTB-C) and the Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV). VLBW children were categorized into three groups according to their degree of brain pathology (normal, minor, or major) in neonatal brain magnetic resonance imaging at the term age, and the WM performance was compared between groups to test norms. The structure of the WM model was studied by analyzing correlations among domains. Even VLBW children with normal cognitive development (general ability index ≥ 85) performed worse compared to the test norms (M = 100, SD = 15) on CE (M = 87.64, SD = 20.54, p < .001) and VS (M = 91.65, SD = 11.03, p < .001), but their performance on PL was above the norm (M = 110.79, SD = 13.79, p < .001). VLBW children with major brain pathology performed significantly worse on VS and PL compared to the other groups. The correlations among the WM domains of the VLBW children differ from earlier findings in normative populations. To conclude, the WM of the VLBW children in the study differ-especially in the CE and VS subtest scores-from the normative population irrespective of the degree of brain pathology and level of cognitive development.

Learning disabilities among extremely preterm children without neurosensory impairment: Comorbidity, neuropsychological profiles and scholastic outcomes

BACKGROUND

Children born extremely preterm are at high risk for intellectual disability, learning disabilities, executive dysfunction and special educational needs, but little is understood about the comorbidity of intellectual and learning disabilities in this population.

AIMS

This study explored comorbidity in intellectual disability (ID) and learning disabilities (LD) in children born extremely preterm (EP; <26⁺⁰weeks' gestation).

SUBJECTS AND STUDY DESIGN

A UK national cohort of 161 EP children and 153 term-born controls without neurosensory impairments was assessed at 11years of age (the EPICure Study).

OUTCOME MEASURES

IQ, mathematics and reading attainment, executive function, visuospatial processing and sensorimotor skills were assessed using standardised tests, and curriculum-based attainment and special educational needs (SEN) using teacher reports.

RESULTS

Overall, 75 (47%) EP children and 7 (4.6%) controls had ID or LD (RR 10.12; 95% CI 4.81, 21.27). Comorbidity in ID/LD was more common among EP children than controls (24% vs. 0%). EP children with comorbid ID/LD had significantly poorer neuropsychological abilities and curriculum-based attainment than EP children with an isolated disability or no disabilities. LD were associated with a 3 times increased risk for SEN. However, EP children with ID alone had poorer neuropsychological abilities and curriculum-based attainment than children with no disabilities, yet there was no increase in SEN provision among this group.

CONCLUSIONS

EP children are at high risk for comorbid intellectual and learning disabilities. Education professionals should be aware of the complex nature of EP children's difficulties and the need for multi-domain assessments to guide intervention.

School-Age Outcomes of Early Intervention for Preterm Infants and Their Parents: A Randomized Trial

OBJECTIVE

To examine the child and parental outcomes at school age of a randomized controlled trial of a home-based early preventative care program for infants born very preterm and their caregivers.

METHODS

At term-equivalent age, 120 infants born at a gestational age of <30 weeks were randomly allocated to intervention (n = 61) or standard care (n = 59) groups. The intervention included 9 home visits over the first year of life focusing on infant development, parental mental health, and the parent-infant relationship. At 8 years' corrected age, children's cognitive, behavioral, and motor functioning and parental mental health were assessed. Analysis was by intention to treat.

RESULTS

One hundred children, including 13 sets of twins, attended follow-up (85% follow-up of survivors). Children in the intervention group were less likely to have mathematics difficulties (odds ratio, 0.42; 95% confidence interval [CI], 0.18 to 0.98; P = .045) than children in the standard care group, but there was no evidence of an effect on other developmental outcomes. Parents in the intervention group reported fewer symptoms of depression (mean difference, -2.7; 95% CI, -4.0 to -1.4; P < .001) and had reduced odds for mild to severe depression (odds ratio, 0.14; 95% CI, 0.03 to 0.68; P = .0152) than parents in the standard care group.

CONCLUSIONS

An early preventive care program for very preterm infants and their parents had minimal long-term effects on child neurodevelopmental outcomes at the 8-year follow-up, whereas primary caregivers in the intervention group reported less depression.

Can Touch Screen Tablets be Used to Assess Cognitive and Motor Skills in Early Years Primary School Children? A Cross-Cultural Study

Assessment of cognitive and motor functions is fundamental for developmental and neuropsychological profiling. Assessments are usually conducted on an individual basis, with a trained examiner, using standardized paper and pencil tests, and can take up to an hour or more to complete, depending on the nature of the test. This makes traditional standardized assessments of child development largely unsuitable for use in low-income countries. Touch screen tablets afford the opportunity to assess cognitive functions in groups of participants, with untrained administrators, with precision recording of responses, thus automating the assessment process. In turn, this enables cognitive profiling to be conducted in contexts where access to qualified examiners and standardized assessments are rarely available. As such, touch screen assessments could provide a means of assessing child development in both low- and high-income countries, which would afford cross-cultural comparisons to be made with the same assessment tool. However, before touch screen tablet assessments can be used for cognitive profiling in low-to-high-income countries they need to be shown to provide reliable and valid measures of performance. We report the development of a new touch screen tablet assessment of basic cognitive and motor functions for use with early years primary school children in low- and high-income countries. Measures of spatial intelligence, visual attention, short-term memory, working memory, manual processing speed, and manual coordination are included as well as mathematical knowledge. To investigate if this new touch screen assessment tool can be used for cross-cultural comparisons we administered it to a sample of children (N = 283) spanning standards 1–3 in a low-income country, Malawi, and a smaller sample of children (N = 70) from first year of formal schooling from a high-income country, the UK. Split-half reliability, test-retest reliability, face validity, convergent construct validity, predictive criterion validity, and concurrent criterion validity were investigated. Results demonstrate “proof of concept” that touch screen tablet technology can provide reliable and valid psychometric measures of performance in the early years, highlighting its potential to be used in cross-cultural comparisons and research.