Cross-sectional and longitudinal assessment of cognitive development in Williams syndrome.

Williams syndrome (WS) is a rare genetic syndrome. As with all rare syndromes, obtaining adequately powered sample sizes is a challenge. Here we present legacy data from seven UK labs, enabling the characterisation of cross-sectional and longitudinal developmental trajectories of verbal and non-verbal development in the largest sample of individuals with WS to-date. In Study 1, we report cross-sectional data between N = 102 and N = 209 children and adults with WS on measures of verbal and non-verbal ability. In Study 2, we report longitudinal data from N = 17 to N = 54 children and adults with WS who had been tested on at least three timepoints on these measures. Data support the WS characteristic cognitive profile of stronger verbal than non-verbal ability, and shallow developmental progression for both domains. Both cross-sectional and longitudinal data demonstrate steeper rates of development in the child participants than the adolescent and adults in our sample. Cross-sectional data indicate steeper development in verbal than non-verbal ability, and that individual differences in the discrepancy between verbal and non-verbal ability are largely accounted for by level of intellectual functioning. A diverging developmental discrepancy between verbal and non-verbal ability, whilst marginal, is not mirrored statistically in the longitudinal data. Cross-sectional and longitudinal data are discussed with reference to validating cross-sectional developmental patterns using longitudinal data and the importance of individual differences in understanding developmental progression.

Playing hide and seek: Contextual regularity learning develops between 3 and 5 years of age.

The ability to acquire contextual regularities is fundamental in everyday life because it helps us to navigate the environment, directing our attention where relevant events are more likely to occur. Sensitivity to spatial regularities has been largely reported from infancy. Nevertheless, it is currently unclear when children can use this rapidly acquired contextual knowledge to guide their behavior. Evidence of this ability is indeed mixed in school-aged children and, to date, it has never been explored in younger children and toddlers. The current study investigated the development of contextual regularity learning in children aged 3 to 5 years. To this aim, we designed a new contextual learning paradigm in which young children were presented with recurring configurations of bushes and were asked to guess behind which bush a cartoon monkey was hiding. In a series of two experiments, we manipulated the relevance of color and visuospatial cues for the underlying task goal and tested how this affected young children's behavior. Our results bridge the gap between the infant and adult literatures, showing that sensitivity to spatial configurations persists from infancy to childhood, but it is only around the fifth year of life that children naturally start to integrate multiple cues to guide their behavior.

A holistic approach to fragile X syndrome integrated guidance for person-centred care.

BACKGROUND: The Fragile X community has expressed a desire for centralised, national guidelines in the form of integrated guidance for Fragile X Syndrome (FXS). METHODS: This article draws on existing literature reviews, primary research and clinical trials on FXS, a Fragile X Society conference workshop and first-hand experience of clinicians who have worked with those living with FXS over many years. RESULTS: The article scopes proposed integrated guidance over the life course, including appendices of symptoms, comorbidities and referral options for FXS and Fragile X Premutation Associated Conditions. CONCLUSION: Integrated guidance would provide an authoritative source for doctors, health professionals, therapists, care workers, social workers, educators, employers, families and those living with FXS, so that a holistic, person-centred approach can be taken across the United Kingdom to garner the best outcomes for those with FXS.

Visual Motion and Decision-Making in Dyslexia: Reduced Accumulation of Sensory Evidence and Related Neural Dynamics.

Children with and without dyslexia differ in their behavioral responses to visual information, particularly when required to pool dynamic signals over space and time. Importantly, multiple processes contribute to behavioral responses. Here we investigated which processing stages are affected in children with dyslexia when performing visual motion processing tasks, by combining two methods that are sensitive to the dynamic processes leading to responses. We used a diffusion model which decomposes response time and accuracy into distinct cognitive constructs, and high-density EEG. Fifty children with dyslexia (24 male) and 50 typically developing children (28 male) 6-14 years of age judged the direction of motion as quickly and accurately as possible in two global motion tasks (motion coherence and direction integration), which varied in their requirements for noise exclusion. Following our preregistered analyses, we fitted hierarchical Bayesian diffusion models to the data, blinded to group membership. Unblinding revealed reduced evidence accumulation in children with dyslexia compared with typical children for both tasks. Additionally, we identified a response-locked EEG component which was maximal over centro-parietal electrodes which indicated a neural correlate of reduced drift rate in dyslexia in the motion coherence task, thereby linking brain and behavior. We suggest that children with dyslexia tend to be slower to extract sensory evidence from global motion displays, regardless of whether noise exclusion is required, thus furthering our understanding of atypical perceptual decision-making processes in dyslexia.SIGNIFICANCE STATEMENT Reduced sensitivity to visual information has been reported in dyslexia, with a lively debate about whether these differences causally contribute to reading difficulties. In this large preregistered study with a blind modeling approach, we combine state-of-the art methods in both computational modeling and EEG analysis to pinpoint the stages of processing that are atypical in children with dyslexia in two visual motion tasks that vary in their requirement for noise exclusion. We find reduced evidence accumulation in children with dyslexia across both tasks, and identify a neural marker, allowing us to link brain and behavior. We show that children with dyslexia exhibit general difficulties with extracting sensory evidence from global motion displays, not just in tasks that require noise exclusion.

The adolescent HIV executive function and drumming (AHEAD) study, a feasibility trial of a group drumming intervention amongst adolescents with HIV.

AHEAD feasibility trial assessed the feasibility and acceptability of an 8-session group drumming programme aiming to improve executive function, depression and anxiety symptoms, and perceived social support in adolescents living with HIV in a rural low-income South African setting. Sixty-eight 12- to 19-year-old adolescents participated. They were individually randomised. The intervention arm (n = 34) received weekly hour-long group drumming sessions. Controls (n = 34) received no intervention. Feasibility and acceptability were assessed using rates of: enrolment; retention; attendance; logistical problems; adolescent-reported acceptability. Secondary measures included: five Oxford Cognitive Screen-Executive Function (OCS-EF) tasks; two Rapid Assessment of Cognitive and Emotional Regulation (RACER) tasks; the Self-Reporting Questionnaire-20 (SRQ-20) measuring depression and anxiety symptoms; the Multidimensional Scale of Perceived Social Support (MSPSS). All feasibility criteria were within green progression limits. Enrolment, retention, and acceptability were high. There was a positive effect on adolescent depressed mood with signal for a working memory effect. There were no significant effects on executive function or socio-emotional scales. Qualitative findings suggested socio-emotional benefits including: group belonging; decreased internalised stigma; improved mood; decreased anxiety. Group drumming is a feasible and acceptable intervention amongst adolescents living with HIV in rural South Africa. A full-scale trial is recommended.

Executive functioning skills and their environmental predictors among pre-school aged children in South Africa and The Gambia.

Executive functions (EFs) in early childhood are predictors of later developmental outcomes and school readiness. Much of the research on EFs and their psychosocial correlates has been conducted in high-income, minority world countries, which represent a small and biased portion of children globally. The aim of this study is to examine EFs among children aged 3-5 years in two African countries, South Africa (SA) and The Gambia (GM), and to explore shared and distinct predictors of EFs in these settings. The SA sample (N = 243, 51.9% female) was recruited from low-income communities within the Cape Town Metropolitan area. In GM, participants (N = 171, 49.7% female) were recruited from the rural West Kiang region. EFs, working memory (WM), inhibitory control (IC) and cognitive flexibility (CF), were measured using tablet-based tasks. Associations between EF task performance and indicators of socioeconomic status (household assets, caregiver education) and family enrichment factors (enrichment activities, diversity of caregivers) were assessed. Participants in SA scored higher on all EF tasks, but children in both sites predominantly scored within the expected range for their age. There were no associations between EFs and household or familial variables in SA, except for a trend-level association between caregiver education and CF. Patterns were similar in GM, where there was a trend-level association between WM and enrichment activities but no other relationships. We challenge the postulation that children in low-income settings have poorer EFs, simply due to lower socioeconomic status, but highlight the need to identify predictors of EFs in diverse, global settings. RESEARCH HIGHLIGHTS: Assessed Executive Functioning (EF) skills and their psychosocial predictors among pre-school aged children (aged 3-5 years) in two African settings (The Gambia and South Africa). On average, children within each setting performed within the expected range for their age, although children in South Africa had higher scores across tasks. There was little evidence of any association between socioeconomic variables and EFs in either site. Enrichment activities were marginally associated with better working memory in The Gambia, and caregiver education with cognitive flexibility in South Africa, both associations were trend-level significance.

The neural correlates of inhibitory control in 10-month-old infants: A functional near-infrared spectroscopy study.

Inhibitory control, a core executive function, emerges in infancy and develops rapidly across childhood. Methodological limitations have meant that studies investigating the neural correlates underlying inhibitory control in infancy are rare. Employing functional near-infrared spectroscopy alongside a novel touchscreen task that measures response inhibition, this study aimed to uncover the neural underpinnings of inhibitory control in 10-month-old infants (N = 135). We found that when inhibition was required, the right prefrontal and parietal cortices were more activated than when there was no inhibitory demand. This demonstrates that inhibitory control in infants as young as 10 months of age is supported by similar brain areas as in older children and adults. With this study we have lowered the age-boundary for localising the neural substrates of response inhibition to the first year of life.

The influence of attentional biases on multiple working memory precision parameters for children and adults.

Working memory (WM) improves dramatically during childhood but what drives this improvement is not well understood. One influential account thus far has proposed a simple increase in storage capacity. However, recent findings have shown that multiple factors, such as differences in the ability to use attention to enhance the maintenance of internal representations, as well as changes in WM precision, also interact in influencing age-related differences in WM capacity. We aimed to examine whether and how the developing ability to orient attention retrospectively to internal representations influences WM precision. To do so, we employed a paradigm that combined the continuous-recall WM task with the partial-cueing report task. Specifically, 7-year-olds and young adults were asked to reproduce the colour of a probe item in a colour wheel. The initial memory array, which included the probe item, could be followed by a spatial cue that directed participants' attention to a location in the memory array (a 'retro-cue'). Results showed that attentional biases engendered by retro-cues facilitated overall precision compared to uncued baseline performance, for both age groups, although to a smaller degree in 7-year-olds compared to adults. Importantly, investigation of modelling parameters suggested that children demonstrate lower representational quality of items in WM but that spatial attentional cues improve overall precision by increasing the probability of target storage, maintenance and recall, and by reducing misbinding errors as well as random guessing, not by changing representational quality. These results add significantly to our knowledge on the relation between retrospective attention and WM development.

Correlates of health-related quality of life in primary caregivers of perinatally HIV infected and HIV exposed uninfected adolescents at the Kenyan Coast.

BACKGROUND: Mothers and other primary caregivers play a crucial role in looking after perinatally HIV infected, and HIV exposed uninfected adolescents in sub-Saharan Africa. Day- to-day caregiving in the context of limited instrumental support and added biomedical risk (HIV seropositivity) may expose these caregivers to adverse states of health. Unfortunately, very few studies have examined their health-related quality of life (HRQoL). Our study documents the HRQoL profile, and associated factors in primary caregivers of perinatally HIV infected, perinatally HIV exposed but uninfected and HIV unexposed/uninfected adolescents aged 12-17 years at the Kenyan Coast. METHODS: This was a cross-sectional analysis of 485 primary caregivers: 195 of perinatally HIV infected adolescents, 128 of perinatally HIV exposed but uninfected adolescents and 162 of HIV unexposed/uninfected adolescents. All caregivers completed a self-report measure of HRQoL (having 8 subscales), depressive symptoms, and parenting stress. They also provided their sociodemographic information and that of the care recipients. We used one-way analysis of variance to assess statistical differences among the groups. Linear regression analyses were used to identify correlates of HRQoL. RESULTS: Overall, caregivers of HIV unexposed/uninfected adolescents reported significantly higher mean HRQoL scores than the other caregivers in the overall HRQoL domain and majority of the subscales. There were no statistical differences in the overall HRQoL scores and most subscales between caregivers of HIV exposed adolescents. Linear regression analyses across the sample indicated that depressive symptoms, increasing age of caregiver, and caring for an adolescent perinatally exposed to HIV were significantly associated with reduced HRQoL at both the overall and sub-scale level. Having a professional job relative to subsistence farming was the only factor associated with improved overall HRQoL. At subscale level, higher socioeconomic status correlated positively with HRQoL while being a grandparent, level of education, parenting stress were negatively associated with HRQoL. CONCLUSIONS: Caregivers in this sample, especially those who are ageing, at risk of mental ill-health, and taking care of adolescents perinatally exposed to HIV, appear to be vulnerable to poor quality of life. Inclusive and multi-component interventions tailored to the caregivers' psychosocial and mental needs will potentially enhance their quality of life.

Be there on time: Spatial-temporal regularities guide young children's attention in dynamic environments.

Children's ability to benefit from spatiotemporal regularities to detect goal-relevant targets was tested in a dynamic, extended context. Young adults and children (from a low-deprivation area school in the United Kingdom; N = 80; 5-6 years; 39 female; ethics approval did not permit individual-level race/ethnicity surveying) completed a dynamic visual-search task. Targets and distractors faded in and out of a display over seconds. Half of the targets appeared at predictable times and locations. Search performance in children was poorer overall. Nevertheless, they benefitted equivalently from spatiotemporal regularities, detecting more predictable than unpredictable targets. Children's benefits from predictions correlated positively with their attention. The study brings ecological validity to the study of attentional guidance in children, revealing striking behavioral benefits of dynamic experience-based predictions.

Maternal depressive symptoms and early childhood temperament before and during the COVID-19 pandemic in the United Kingdom.

The COVID-19 pandemic is an unexpected and major global event, with the potential to have many and varied impacts on child development. However, the implications of the pandemic for maternal depressive symptoms, early childhood temperament dimensions, and their associations, remain largely unknown. To investigate this, questionnaires were completed by mothers (N = 175) before and during the pandemic when their child was 10- and 16-months old (Study 1), and by an extended group of mothers with young children (6-48 months; 66 additional mothers) during the first and second national lockdowns in the United Kingdom in 2020 (Study 2). Results indicated that while maternal pandemic-related stress decreased over the first 6 months of the pandemic, there was an increase in mothers who reported feeling some level of pandemic-specific depression. Despite this, we did not observe an increase in the severity of global maternal depressive symptoms, or any negative impact of the pandemic on the development of temperament in infancy and early childhood.

Executive function in HIV-affected children and adolescents: a systematic review and meta-analyses.

This review aimed to determine: whether EF is affected in children and adolescents (2-24-years-old) with perinatal HIV infection, perinatal HIV exposure without infection, and behaviourally acquired HIV. A systematic review (PROSPERO number: CRD42017067813) was conducted using 11 electronic databases (01.01.1981-09.07.2019) and 8 conference websites. Primary quantitative studies with EF scores on cognitive tasks and/or behavioural report measures were included. Meta-analyses were performed by EF subtype and subpopulations compared. 1789 records were found. Sixty-one studies were included in the narrative synthesis; 32 (N = 7884 participants) were included in meta-analyses. There was a distinct pattern of reduced EF in those with perinatal HIV infection on antiretroviral therapy compared to controls: pooled effect sizes were largest for verbal and visuospatial working memory, with smaller effects on planning, inhibitory control and set-shifting. Data were limited for other HIV-affected subpopulations. Perinatal HIV infection is associated with reduced EF with varying effect sizes for the different EF subtypes.

The relationship between executive function, risky behaviour and HIV in young women from the HPTN 068 study in rural South Africa.

Executive function (EF) may predict sexual risk-taking and HIV risk in young women in rural South Africa. We tested associations between EF and seven risky behavioural outcomes: binge drinking, illicit substance use, unprotected vaginal sex, concurrent sexual relationships, transactional sex, herpes simplex virus type 2 (HSV-2) infection, and HIV infection. We compared EF in young women with HIV to matched controls. 1080 young women underwent cognitive assessments. Better verbal short-term memory was associated with a lower risk of HSV-2 (OR 0.77; 95% CI 0.69, 0.86; p < 0.001). Uncorrected trends (p < 0.05) were better verbal working memory being associated with a lower risk of concurrency, better planning with a lower risk of illicit drug use, and better affective inhibition with a lower risk of transactional sex. 78 participants with sexually acquired HIV were matched with 153 HIV-negative controls and had poorer verbal working memory than controls (Hedge's g = -0.38; 95% CI -0.66, -0.10; p = 0.0076), but this was non-significant after adjustment. EF's contribution to young women's risky behaviour in this context does not hold when stringent statistical corrections are applied, with only verbal short term memory reaching statistical significance as predictor. Replication in other samples is recommended.

Using a multidimensional model of attention to predict low-income preschoolers' early academic skills across time.

The current study examines the organization of attention skills across the preschool year before kindergarten, and tests how distinct attention subcomponents predict early academic skills in a sample of low-income children (n = 99). Children completed well-validated attention tasks in fall at 4.5 years old and spring at 5 years old, capturing the abilities to selectively focus, sustain attention, and employ executive control. Exploratory factor analyses at both time points support a 2-factor model differentiating selective and sustained attention from attention processing speed and executive attention, suggesting that attention in low-income preschoolers may have a simpler organization than the 3-factor structure found in adulthood. Multiple regression models find children's ability to selectively focus and sustain attention serves as a robust concurrent and longitudinal predictor of academic skills. These results highlight the role of selective and sustained attention processes in supporting school readiness for economically vulnerable children.

Understanding the psycho-social context for a new early intervention for resistance to change that aims to strike a beneficial balance between structure and flexibility.

BACKGROUND: Emotional and behavioural problems linked to changes to expectations - resistance to change - are linked to disability in neurodevelopmental disorders, including autism spectrum disorder (ASD), Prader-Willi (PWS) and fragile X syndromes (FXS). Structuring routines is best practice for minimising current resistance to change. But complete structure is impractical and flexibility in early life may actually reduce later resistance by supporting cognitive development. We aimed to examine the psycho-social context of families with children at risk of developing resistance to change so as to identify design requirements for an intervention that strikes a beneficial balance between structure and flexibility. METHODS: Thirty-six caregivers of children aged 4-12 years (17 ASD, 15 PWS, and 4 FXS) took part in an interview designed collaboratively with 12 professional stakeholders. RESULTS: Children need to feel like they are in control of flexibility but they also need support in choice making, understanding plans (using individually tailored visuals) and anxiety reduction. Caregivers need an accessible approach that they have full control over, and which they can tailor for their child. Caregivers also need clear guidance, education and support around structure and flexibility. CONCLUSIONS: We propose a digital approach which addresses the needs identified. It tackles the most perplexing challenge by presenting flexibility to children in the context of a game that children can feel they have full control over, whilst caregivers can maintain control in reality. Furthermore, individualised support for children and caregivers would be enabled.

Validation of Oxford Cognitive Screen: Executive Function (OCS-EF), a tablet-based executive function assessment tool amongst adolescent females in rural South Africa.

Short, reliable, easily administered executive function (EF) assessment tools are needed to measure EF in low- and middle-income countries, particularly in sub-Saharan Africa given the prevalence of human immunodeficiency virus (HIV)-associated neurocognitive disorder. We administered Oxford Cognitive Screen-Executive Function (OCS-EF) to 932 rural South African females (mean age 19.7 years). OCS-EF includes seven tasks: two hot inhibition tasks (a modified Iowa Gambling Task, emotional go/no-go) and five cool EF tasks, two switching tasks (visuospatial rule-finding, geometric trails) and three working memory tasks (digit recall, selection and figure drawing). We performed confirmatory factor analysis testing whether a three-factor, two-factor hot-cool, two-factor working memory and inhibition/switching, or one-factor EF model fitted the data better. The three-factor (switching, inhibition and working memory) model had the best local and global fit (χ2 (11) 24.21, p = 0.012; RMSEA 0.036; CFI 0.920; CD 0.617). We demonstrated the feasibility of OCS-EF administration by trained laypeople, the tripartite structure of EF amongst adolescent females and the factorial validity of OCS-EF in this population and context. OCS-EF tablet-based cognitive assessment tool can be administered by trained laypeople and is a valid tool for assessing cognition at scale amongst adolescents in rural South Africa and similar environments.

The attentive brain: insights from developmental cognitive neuroscience.

Visual attention functions as a filter to select environmental information for learning and memory, making it the first step in the eventual cascade of thought and action systems. Here, we review studies of typical and atypical visual attention development and explain how they offer insights into the mechanisms of adult visual attention. We detail interactions between visual processing and visual attention, as well as the contribution of visual attention to memory. Finally, we discuss genetic mechanisms underlying attention disorders and how attention may be modified by training.

Challenging socioeconomic status: A cross-cultural comparison of early executive function.

The widely and internationally replicated socioeconomic status (SES) gradient of executive function (EF) implies that intervention approaches may do well to extrapolate conditions and practices from contexts that generate better child outcomes (in this case, higher SES circumstances) and translate these to contexts with comparatively poorer outcomes (often low-SES populations). Yet, can the reverse also be true? Using data from equivalent assessments of 1,092 pre-schoolers' EFs in South Africa and Australia, we evaluated: the SES gradient of EF within each sample; and whether this SES gradient extended cross-culturally. The oft-found EF-SES gradients were replicated in both samples. However, contrary to the inferences of EF-SES associations found nationally, the most highly disadvantaged South African subsample outperformed middle- and high-SES Australian pre-schoolers on two of three EFs. This suggests the possibility of EF-protective and -promotive practices within low- and middle-income countries that may aid understandings of the nature and promotion of EFs.

Beyond Their HIV Status: the Occurrence of Multiple Health Risk Behavior Among Adolescents from a Rural Setting of Sub-Saharan Africa.

BACKGROUND: Health risk behaviors during adolescence may cluster into patterns that might be predicted by specific factors, among which HIV may have an important role. METHOD: In a cross-sectional study conducted between 2017 and 2018, clustering of HRB and its associated factors was investigated in rural Kenya among 588 adolescents (36% perinatally HIV infected; 28% perinatally HIV exposed but uninfected; and 36% HIV unexposed/uninfected). Latent class analysis of 22 behaviors followed by multinomial logistic regression were conducted. Four risk behavior classes were identified. RESULTS: No significant differences were found in behavioral class membership across the three HIV groups (p = 0.366). The risk of membership to the higher risk behavioral classes relative to class 1 (the substance and drug abstinent low risk takers) increased with older adolescent age (p = 0.047), increased among adolescent who experienced mental distress (p < 0.001), and those who felt unsafe in their neighborhood (p < 0.002). Better working memory (p = 0.0037) was found to be protective. CONCLUSION: The results highlight a need to include screening and interventions for internalizing mental health problems and deficits in executive functioning, as well as steps to involve family members and communities to address psychosocial risk factors in adolescents in Kenya.

The Functional Consequences of Social Attention for Memory-guided Attention Orienting and Anticipatory Neural Dynamics.

Social attention when viewing natural social (compared with nonsocial) images has functional consequences on contextual memory in healthy human adults. In addition to attention affecting memory performance, strong evidence suggests that memory, in turn, affects attentional orienting. Here, we ask whether the effects of social processing on memory alter subsequent memory-guided attention orienting and corresponding anticipatory dynamics of 8-12 Hz alpha-band oscillations as measured with EEG. Eighteen young adults searched for targets in scenes that contained either social or nonsocial distracters and their memory precision tested. Subsequently, RT was measured as participants oriented to targets appearing in those scenes at either valid (previously learned) locations or invalid (different) locations. Memory precision was poorer for target locations in social scenes. In addition, distractor type moderated the validity effect during memory-guided attentional orienting, with a larger cost in RT when targets appeared at invalid (different) locations within scenes with social distractors. The poorer memory performance was also marked by reduced anticipatory dynamics of spatially lateralized 8-12 Hz alpha-band oscillations for scenes with social distractors. The functional consequences of a social attention bias therefore extend from memory to memory-guided attention orienting, a bidirectional chain that may further reinforce attentional biases.