Mathematical skill in individuals with Williams syndrome: evidence from a standardized mathematics battery

Williams syndrome (WS) is a developmental disorder associated with relatively spared verbal skills and severe visuospatial deficits. It has also been reported that individuals with WS are impaired at mathematics. We examined mathematical skills in persons with WS using the second edition of the Test of Early Mathematical Ability (TEMA-2), which measures a wide range of skills. We administered the TEMA-2 to 14 individuals with WS and 14 children matched individually for mental-age on the matrices subtest of the Kaufman Brief Intelligence Test. There were no differences between groups on the overall scores on the TEMA-2. However, an item-by-item analysis revealed group differences. Participants with WS performed more poorly than controls when reporting which of two numbers was closest to a target number, a task thought to utilize a mental number line subserved by the parietal lobe, consistent with previous evidence showing parietal abnormalities in people with WS. In contrast, people with WS performed better than the control group at reading numbers, suggesting that verbal math skills may be comparatively strong in WS. These findings add to evidence that components of mathematical knowledge may be differentially damaged in developmental disorders.     

Pathways to adulthood and their precursors and outcomes

Norway has an extensive welfare system which may provide adolescents with many options and high levels of flexibility in terms of pathways to adulthood. This study aimed to describe Norwegian developmental pathways to adulthood, including changes in role statuses (such as living situations, education, work, marriage/cohabitation and parenthood) from 16 to 30 years of age, and their precursors and outcomes. Repeated measures latent class analysis of longitudinal data from 998 Norwegian individuals indicated three main pathways to adulthood among women and men. In both sexes, most individuals undertook a long period of education and postponed family formation. However, some individuals started working early, a group of women established families with partners and children early, and a group of men remained primarily single between 16 and 30 years of age. Furthermore, the results show that pathways to adulthood in Norway are surprisingly similar to pathways in other countries such as the US, UK and Finland. The results indicate that pathways to adulthood are influenced by social reproduction factors in a country with high levels of welfare benefits as well. In addition, the results suggest that pathways involving living with a partner and either higher education or work are associated with high life satisfaction at age 30.     

Externalising behaviour from infancy to mid-adolescence: Latent profiles and early predictors

The overall aim of the current study was to identify typical trajectory classes of externalising behaviour, and to identify predictors present already in infancy that discriminate the trajectory classes. 921 children from a community sample were followed over 13 years from the age of 18 months. In a simultaneously estimated model, latent class analyses and multinomial logit regression analyses suggested a five-class solution for developmental patterns of externalising problem behaviours: High stable (18% of the children), High childhood limited (5%), Medium childhood limited (31%), Adolescent onset (30%), and Low stable (16%). Six risk factors measured at 18 months significantly discriminated among the classes. Family stress and maternal age discriminated the High stable class from all the other classes. The results suggest that focusing on enduring problems in the relationship with the partner and partners' health may be important in preventive and early intervention efforts.     

Brief report: Response inhibition and processing speed in children with motor difficulties and developmental coordination disorder

A previous study reported that children with poor motor skills, classified as having motor difficulties (MD) or Developmental Coordination Disorder (DCD), produced more errors in a motor response inhibition task compared to typically developing (TD) children but did not differ in verbal inhibition errors. The present study investigated whether these groups differed in the length of time they took to respond in order to achieve these levels of accuracy, and whether any differences in response speed could be explained by generally slow information processing in children with poor motor skills. Timing data from the Verbal Inhibition Motor Inhibition test were analyzed to identify differences in performance between the groups on verbal and motor inhibition, as well as on processing speed measures from standardized batteries. Although children with MD and DCD produced more errors in the motor inhibition task than TD children, the current analyses found that they did not take longer to complete the task. Children with DCD were slower at inhibiting verbal responses than TD children, while the MD group seemed to perform at an intermediate level between the other groups in terms of verbal inhibition speed. Slow processing speed did not account for these group differences. Results extended previous research into response inhibition in children with poor motor skills by explicitly comparing motor and verbal responses, and suggesting that slow performance, even when accurate, may be attributable to an inefficient way of inhibiting responses, rather than slow information processing speed per se.     

Developmental neuropsychological assessment of 4- to 5-year-old children born following Preimplantation Genetic Diagnosis (PGD): A pilot study

The purpose of this pilot study was to evaluate developmental neuropsychological profiles of 4- to 5-year-old children born after Preimplantation Genetic Diagnosis (PGD). Twenty-seven participants received a neurological examination and a battery of neuropsychological assessments including Wechsler Preschool & Primary Scale of Intelligence - Third Edition (WPPSI-III; cognitive development), Preschool Language Scale, Fourth Edition (PLS-4; language development), Wide Range Assessment of Visual Motor Abilities (visual motor abilities), Childhood Autism Rating Scales II (a screening test for autistic spectrum disorders), and the Miles ABC Test (ocular dominance). Parental questionnaires included the Behavior Rating Inventory of Executive Function Preschool Version (BRIEF-P; executive function), Child Behavior Checklist (CBCL) and the Carey Temperament Scales Behavioral Style Questionnaire (socioemotional development and temperament), and the Vineland Adaptive Behavior Scales, Interview Edition, Second Edition (general adaptive behavior). Subjects’ tests results were compared to each test’s norms. Children born after PGD demonstrated scores within the normal or above-normal ranges for all developmental outcomes (mean ± SD): WPPSI-III-VIQ 107.4 ± 14.4 (p = .013), PLS-4-Total 113.2 ± 12.4, p < .001), CBCL-Total 41.1 ± 8.6 (p < .001), BRIEF-P-Global Executive Composite 44.8 ± 9.5 (p = .009). Twelve (44%) of the PGD children had a significant difference between their VIQ and PIQ scores (compared to 27% in the general population). One subject was found to show possible signs of autistic spectrum disorder, although a family history of autism was noted. In conclusion, in this pilot study, children assessed at age 4–5 years and conceived after PGD displayed developmental neuropsychological outcomes within normal limits as compared to their chronologic peers. A larger study is needed to evaluate and follow the neuropsychological development of children born after PGD.     

Procedural learning,consolidation, and transfer of a new skill in Developmental Coordination Disorder

The aim of this study was to explore the differences in procedural learning abilities between children with DCD and typically developing children by investigating the steps that lead to skill automatization (i.e., the stages of fast learning, consolidation, and slow learning). Transfer of the skill to a new situation was also assessed. We tested 34 children aged 6–12 years with and without DCD on a perceptuomotor adaptation task, a form of procedural learning that is thought to involve the cerebellum and the basal ganglia (regions whose impairment has been associated with DCD) but also other brain areas including frontal regions. The results showed similar rates of learning, consolidation, and transfer in DCD and control children. However, the DCD children's performance remained slower than that of controls throughout the procedural task and they reached a lower asymptotic performance level; the difficulties observed at the outset did not diminish with practice.     

Resilience in developing systems: the promise of integrated approaches

Abstract

This article describes a contemporary systems approach to resilience in human development and its promise for integrating findings and applications across system levels. Resilience is defined as the capacity of a system for successful adaptation to disturbances that threaten system function, viability, or development. Advantages of this definition are delineated in regard to integrating sciences and disciplines across scales and levels of interaction in a bioecological systems framework. Central concepts of resilience, including pathways and cascades, are described in light of this approach, and advances that link system levels are highlighted. Given significant progress toward a more dynamic, integrated, multisystem approach, developmental resilience science stands at new frontier of possibilities that promises to inform science, practice, and policy focused on building human capacity for surviving and thriving in times of turbulence and change.     

Culture and the organization of infant sleep: A study in the Netherlands and the U.S.A.

This study investigates differences in the amount and structure of infant sleep in two cultural places with previously documented, divergent parental beliefs and practices. Eight-month-old infants (n = 24 per site) were recruited from towns in the Netherlands and the eastern U.S.A. To evaluate sleep, infants’ physical activity was recorded at home for 24 h using a miniature actigraph, while parents kept a diary of infant activities. Measures derived from actigraphy include total sleep, longest sleep episode, longest wake episode, number of sleep episodes, and percent of sleep during nighttime, as well as time in the stages of Quiet and Active Sleep. Measures based on the parental diaries include most of these aspects as well, except those related to sleep stages. Results based on the more precise actigraphy method indicate that (1) the Dutch infants averaged 13.65 h of sleep per 24 h, 1.67 h more than the U.S. infants; this difference was mostly due to daytime sleep; (2) The Dutch infants’ longest wake episode averaged less than that of the U.S. infants, while their longest sleep episode appeared slightly longer. (3) The Dutch infants, compared to the U.S. sample, spent more time in the Quiet, rather than the Active phase of sleep; (4) They began their Quiet sleep earlier in the evening than did their U.S. counterparts. Measures derived from parental diaries are largely in agreement with the actigraph findings. These results are consistent with reported and observed practices and beliefs in the two communities. The pattern of differences – less apparent maturity among the Dutch in the amount of sleep, but greater apparent maturity in the structure of sleep -- illustrates that behavioral and neurological maturity can be assessed only in the context of the developing child’s adaptation to the specific demands and affordances of the culturally structured developmental niche.     

Constrained Choice: Children's and Adults’ Attribution of Choice to a Humanoid Robot

Young children, like adults, understand that human agents can flexibly choose different actions in different contexts, and they evaluate these agents based on such choices. However, little is known about children's tendencies to attribute the capacity to choose to robots, despite increased contact with robotic agents. In this paper, we compare 5- to 7-year-old children's and adults’ attributions of free choice to a robot and to a human child by using a series of tasks measuring agency attribution, action prediction, and choice attribution. In morally neutral scenarios, children ascribed similar levels of free choice to the robot and the human, while adults were more likely to ascribe free choice to the human. For morally relevant scenarios, however, both age groups considered the robot's actions to be more constrained than the human's actions. These findings demonstrate that children and adults hold a nuanced understanding of free choice that is sensitive to both the agent type and constraints within a given scenario.