Unpredictable maternal signals and developmental profiles of child executive function from infancy to early childhood.

Maternal substance use and unpredictable maternal sensory signals may affect child development, but no studies have examined them together. We explored the unpredictability, frequency and duration of maternal sensory signals in 52 Caucasian mother–child dyads, 27 with and 25 without maternal substance use. We also examined the association between unpredictable maternal signals and children's cognitive development. Maternal sensory signals were evaluated with video‐recorded dyadic free‐play interactions at child age of 24 months. Children's cognitive development was evaluated with Bayley‐III at 24 months and with WPPSI‐III at 48 months. We found similar unpredictability, frequency and duration of sensory signals between substance‐using and non‐using mothers. Higher unpredictability of maternal sensory signals was robustly linked with poorer child cognitive development at 24 months. The link persisted, although weakened to 48 months. Unpredictability of maternal sensory signals may be a vital parenting aspect shaping children's development, but more research is needed in high‐risk groups.Highlights We examined unpredictability, frequency and duration of maternal sensory signals among substance‐using and non‐using mothers, and the associations between unpredictability and children's cognitive development. We assessed sensory signals with dyadic free‐play interaction and children's cognitive development with standardized tests. Groups showed similar sensory signal unpredictability, frequency and duration. Unpredictable sensory signals were linked with poorer child cognitive development at 24 and 48 months. Unpredictability of maternal sensory signals is a potentially vital aspect of parental care in shaping children's development. More research is needed especially including high‐risk mothers.

Pronounced improvements in executive functions (EF) during preschool years have been documented in cross-sectional studies. However, longitudinal evidence on EF development during the transition to school and predictive associations between early EF and later school achievement are still scarce. This study examined developmental changes in EF across three time-points, the predictive value of EF for mathematical, reading and spelling skills and explored children’s specific academic attainment as a function of early EF. Participants were 323 children following regular education; 160 children were enrolled in prekindergarten (younger cohort: 69 months) and 163 children in kindergarten (older cohort: 78.4 months) at the first assessment. Various tasks of EF were administered three times with an interval of one year each. Mathematical, reading and spelling skills were measured at the last assessment. Individual background characteristics such as vocabulary, non-verbal intelligence and socioeconomic status were included as control variables. In both cohorts, changes in EF were substantial; improvements in EF, however, were larger in preschoolers than school-aged children. EF assessed in preschool accounted for substantial variability in mathematical, reading and spelling achievement two years later, with low EF being especially associated with significant academic disadvantages in early school years. Given that EF continue to develop from preschool into primary school years and that starting with low EF is associated with lower school achievement, EF may be considered as a marker or risk for academic disabilities.

This longitudinal study examined the developmental relations between first-order Theory of Mind (ToM), advanced ToM, and executive function (EF) from ages 4 to 7.5. Two-hundred-three German children were assessed at ages 4, 5.5, and 7.5 on measures of ToM, EF (working memory, inhibition, cognitive flexibility), general cognition, and language. Using regression, structural equation modeling (SEM), and latent class analysis, we investigated whether early ToM and EF predict advanced ToM performance and how the developmental pathways unfold. We found significant concurrent relations between ToM and EF at all time points, as well as a predictive relation from EF at age 4 to advanced ToM at age 7.5. ToM at age 4 also significantly predicted ToM at age 7.5, suggesting early ToM lays a foundation for later conceptual growth. Cross-lagged SEM revealed that EF at age 4-but not at 5.5-predicted advanced ToM, indicating EF may support ToM development at key transition points. Latent class analysis identified four ToM profiles: consistently high performers, late bloomers, partial achievers, and inconsistent performers. Early language skills and later inhibition differentiated these groups; general cognition played a lesser role. These findings support a hybrid account of ToM development: early conceptual understanding is foundational for later competence, but qualitative shifts are required to master more complex ToM forms. EF and language appear as critical supports for ToM development, especially during periods of conceptual change. This study contributes to a more nuanced view of how domain-general and domain-specific processes interact in the development of complex social cognition. SUMMARY: Longitudinal study of Theory of Mind (ToM), advanced ToM, and executive function (EF) from ages 4 to 7.5. ToM and early EF at age 4 significantly predicted advanced ToM performance at age 7.5, independent of general cognitive ability. Latent class analysis identified four distinct developmental ToM pathways, including partial achievers and inconsistent performers. Findings support a hybrid view: early conceptual continuity lays a foundation, but later conceptual change is needed for advanced mental state reasoning.

Across species, unpredictable patterns of maternal behavior are emerging as novel predictors of aberrant cognitive and emotional outcomes later in life. In animal models, exposure to unpredictable patterns of maternal behavior alters brain circuit maturation and cognitive and emotional outcomes. However, whether exposure to such signals in humans alters the development of brain pathways is unknown. In mother-child dyads, we tested the hypothesis that exposure to more unpredictable maternal signals in infancy is associated with aberrant maturation of corticolimbic pathways. We focused on the uncinate fasciculus, the primary fiber bundle connecting the amygdala to the orbitofrontal cortex and a key component of the medial temporal lobe-prefrontal cortex circuit. Infant exposure to unpredictable maternal sensory signals was assessed at 6 and 12 months. Using high angular resolution diffusion imaging, we quantified the integrity of the uncinate fasciculus using generalized fractional anisotropy (GFA). Higher maternal unpredictability during infancy presaged greater uncinate fasciculus GFA in children 9-11 years of age (n = 69, 29 female). In contrast to the uncinate, GFA of a second corticolimbic projection, the hippocampal cingulum, was not associated with maternal unpredictability. Addressing the overall functional significance of the uncinate and cingulum relationships, we found that the resulting imbalance of medial temporal lobe-prefrontal cortex connectivity partially mediated the association between unpredictable maternal sensory signals and impaired episodic memory function. These results suggest that unbalanced maturation of corticolimbic circuits is a mechanism by which early unpredictable sensory signals may impact cognition later in life.SIGNIFICANCE STATEMENT Our prior work across species demonstrated that unpredictable patterns of maternal care are associated with compromised memory function. However, the neurobiological mechanisms by which this occurs in humans remain unknown. Here, we identify an association of exposure to unpredictable patterns of maternal sensory signals with the integrity of corticolimbic circuits involved in emotion and cognition using state-of-the-art diffusion imaging techniques and analyses. We find that exposure to early unpredictability is associated with higher integrity of the uncinate fasciculus with no effect on a second corticolimbic pathway, the cingulum. The resulting imbalance of corticolimbic circuit development is a novel mediator of the association between unpredictable patterns of maternal care and poorer episodic memory.

Previous work has shown that individual differences in executive function (EF) are predictive of academic skills in preschoolers, kindergartners, and older children. Across studies, EF is a stronger predictor of emergent mathematics than literacy. However, research on EF in children below age three is scarce, and it is currently unknown whether EF, as assessed in toddlerhood, predicts emergent academic skills a few years later. This longitudinal study investigates whether early EF, assessed at two years, predicts (emergent) academic skills, at five years. It examines, furthermore, whether early EF is a significantly stronger predictor of emergent mathematics than of emergent literacy, as has been found in previous work on older children. A sample of 552 children was assessed on various EF and EF-precursor tasks at two years. At age five, these children performed several emergent mathematics and literacy tasks. Structural Equation Modeling was used to investigate the relationships between early EF and academic skills, modeled as latent factors. Results showed that early EF at age two was a significant and relatively strong predictor of both emergent mathematics and literacy at age five, after controlling for receptive vocabulary, parental education, and home language. Predictive relations were significantly stronger for mathematics than literacy, but only when a verbal short-term memory measure was left out as an indicator to the latent early EF construct. These findings show that individual differences in emergent academic skills just prior to entry into the formal education system can be traced back to individual differences in early EF in toddlerhood. In addition, these results highlight the importance of task selection when assessing early EF as a predictor of later outcomes, and call for further studies to elucidate the mechanisms through which individual differences in early EF and precursors to EF come about.

A-163 APOE ε4 Alters Self-Awareness of Executive Function in Cognitively Intact Middle Aged and Older Adults

Early literacy and executive function profiles in Spanish-English emergent bilinguals

Emerging evidence suggests that exposure to unpredictable patterns of maternal sensory signals during infancy is associated with child neurodevelopment, including poorer effortful control. However, longitudinal effects on child development and possible sex differences are understudied. The aims of the present study were to explore whether exposure to unpredictable maternal sensory signals during infancy is related to child effortful control at 5 years of age and whether child sex moderates these associations. In addition, we examined how exposure to very high vs. low/moderate unpredictability using categorical cut-offs is related to child effortful control. Participants (133 mother-child pairs, all Caucasian) were drawn from the FinnBrain Birth Cohort Study in Finland. Maternal sensory signals (auditory, visual, tactile) were coded from the 10-min free-play episode on a moment-on-moment basis using Observer XT 11 (Noldus), and the unpredictability of maternal sensory signals was characterized as the entropy rate when the infant was 8 months of age. Child effortful control was assessed via mother reports using the Child Behavior Questionnaire very short form (CBQ-VSF) when the child was 5 years old. Correlational analyses showed that higher unpredictability of maternal sensory signals had a modest association with children's poorer effortful control at 5 years of age. Notably, the linear regression model showed that child sex moderated these associations, as higher exposure to unpredictable maternal sensory signals was related to poorer effortful control among males, but not among females. Moreover, the general linear model showed that exposure to very high unpredictability was associated with poorer child effortful control at 5 years of age and remained significant when adjusted for possible confounding factors. These results are in line with previous findings and suggest that the unpredictability of maternal sensory signals is potentially an important aspect of early caregiving behavior associated with the development of child effortful control.

Childhood socioeconomic status (SES) is related to disparities in the development of both language and executive functioning (EF) skills. Emerging evidence suggests that language development may precede and provide necessary scaffolding for EF development in early childhood. The present preregistered study investigates how these skills co-develop longitudinally in early childhood and whether language development explains the relationship between SES and EF development. A socioeconomically diverse sample of 305 children completed repeated assessments of language (sentence comprehension) and EF (cognitive flexibility, behavioral inhibition, and cognitive inhibition) at four waves spaced 9 months apart from ages 3 to 5 years. Bivariate latent curve models with structured residuals were estimated to disaggregate between-person and within-person components of stability and change. Results revealed bidirectional relationships between language and EF across all waves. However, at 3 years, language comprehension more strongly predicted EF than the reverse; yet by 5 years, the bidirectional effects across domains did not significantly differ. Children from higher-SES backgrounds exhibited higher initial language and EF skills than children from lower-SES families, though SES was not associated with either rate of growth. Finally, early language-mediated the association between SES and early EF skills, and this model outperformed a reverse direction mediation. Together, results suggest that EF development is driven by early language development, and that SES disparities in EF are explained, at least in part, by early differences in language comprehension. These findings have implications for early interventions to support children's language skills as a potential pathway to improving early EF development.

It has been proposed that executive functions develop in a hierarchical fashion, such that early, simple abilities seen already during the first year of life become increasingly coordinated with development, thereby enabling the emergence of more complex abilities. Although this hierarchical model has received support from empirical studies comparing executive function task performance across age groups, necessary support from longitudinal studies taking an individual differences perspective on development is missing. In addition, the model stresses the importance of attention in executive function development, but we do not know in what way attention contributes to the continued development once the earliest forms of simple functions have emerged. Using a longitudinal design, the present study investigated the relations between individual differences in simpler forms of executive functions as well as sustained attention at age 12 months and more complex executive functions at 24 and 36 months. The results indicated partial support for the hierarchical model, with infant inhibition being predictive of working memory in toddlerhood. In addition, at 12 months, sustained attention contributed to the development of toddler executive functions via the simple executive functions. This suggests that by this age, sustained attention has become an integrated part of early, simple executive functions. Copyright © 2015 John Wiley & Sons, Ltd.

Early executive function (EF) skills reliably predict school readiness and future academic success. While children’s skills undergo rapid development during the transition to formal schooling, it remains unclear the extent to which schooling exerts a unique influence on the accelerated development of EF and academic skills during the early years of schooling. In the present study, a quasi-experimental technique known as the school cutoff design was used to examine whether same-aged children who made vs. missed the age cutoff for school entry significantly differed on EF, reading, and math outcomes. Data from 166 pre-k, kindergarten, and first grade children (Range = 3.75–7.58 years, 92 girls) from a longitudinal study of literacy development were analyzed. Children were assessed on EF, reading, and math skills in fall and spring. Results revealed unique effects of kindergarten, but not first grade, on growth in EF and reading over and above the effect of age. Schooling was unrelated to growth in math. Because kindergarten represents the first year of elementary school and children’s first exposure to a formal schooling environment, kindergarten schooling may be uniquely positioned to produce greater gains in academic and behavioral outcomes compared to other grades.

BackgroundThe developmental relationships between executive functions (EF) and early language skills are unclear. This study explores the longitudinal relationships between children's early EF and language skills in a sample of children with a wide range of language abilities including children at risk of dyslexia. In addition, we investigated whether these skills independently predict children's attention/behaviour skills.MethodData are presented from 243 children at four time points. Children were selected for being at risk of reading difficulties either because of a family history of dyslexia (FR; N = 90) or because of concerns regarding their language development (LI; N = 79) or as typically developing controls (TD; N = 74). The children completed tasks to assess their executive function and language skills at ages 4, 5 and 6 years. At 6 (T4) and 7 years (T5) parents and teachers rated the children's attention/behaviour skills.ResultsThere was a strong concurrent relationship between language and EF at each assessment. Longitudinal analyses indicated a considerable degree of stability in children's language and EF skills: the influence of language on later EF skills (and vice versa) was weak and not significant in the current sample. Children's EF, but not language, skills at T3 predicted attention/behaviour ratings at T4/T5.ConclusionsThere is a strong concurrent association between language and EF skills during the preschool and early school years, when children with language impairment show persistent EF deficits. Latent variables measuring language and EF show high longitudinal stability with little evidence of significant or strong reciprocal influences between these constructs. EF, but not language, skills predict later ratings of children's attention and behaviour.

Family socio-economic status is a robust predictor of individual differences in early executive function (EF) (e.g., Hughes and Ensor, 2005), but it is not known whether variation in family environment predict developmental trajectories for EF. To address this challenge, we examined data from comprehensive EF assessments and from multiple measures of family life for a socially diverse sample of 125 British children seen at ages 2 and 4. Our longitudinal results supported three distinct models of social influence. Specifically, while unrelated to observational measures of general positive parenting, EF trajectories were positively related to individual differences in: (i) deliberate maternal scaffolding; (ii) children's opportunities for incidental observational learning (assessed via a naturalistic EF task for mothers); and negatively related to (iii) indicators of disorganised and inconsistent parenting. Together, these findings indicate that families can, unintentionally, both help and hinder young children's EF development.

BackgroundAir pollution, which includes exposure to tiny particulate matter (PM2.5) and Nitrogen Dioxide (NO2) is a notable public health hazard. Exposure has adverse effects on multiple health outcomes as well as with increased risk of developing cognitive impairment and Alzheimer’s disease and related dementias. Although the primary cognitive focus in Alzheimer’s disease is memory, there is growing recognition of the importance of early executive function (EF) deficits as a risk indicator. In addition, there is some evidence of genetic susceptibility to pollution‐related cognitive decline. Few studies have strong measures of air pollution, EF, as well as APOE genotyping. We recently showed that APOE genotype was associated with significant decline in EF from middle to early old age among individuals who were cognitively unimpaired at baseline (Gustavson et al, 2022). Here we tested the hypothesis that the impact of air pollution on executive functions would be greater in APOE‐ε4+ carriers compared with APOE‐ε4‐ individuals.MethodWe examined associations between exposure in midlife and EF from midlife to early old age in ∼800 men from the Vietnam Era Twin Study of Aging. Measures included average PM2.5 and NO2 exposure in the three years prior to the time 1 (mean age 56; range 51‐61) assessment, and an executive function factor score at time 1 and time 2 (mean age 68; range 65‐72). GEE analyses adjusted for multiple health and lifestyle covariates, as well as the random effect of family.ResultCognitive performance declined over time from age 56 to age 68 (F = 439.38, p<0.0001). There were no main effects of air pollution on EF. Overall APOE‐ε4+ carriers had higher EF performance than non‐carriers (F = 5.43, p = 0.02). In addition, we found a significant PM2.5‐by‐APOE genotype interaction (F = 8.80, p = 0.003). Increased exposure to PM2.5 in midlife was related to lower executive function in APOE‐ε4 carriers, but not non‐carriers. The interaction with NO2 did not reach significance (F = 2.83, p = 0.09).ConclusionThese results indicate that midlife PM2.5 exposure in men is associated with poorer frontal‐executive function, and APOEε4 carriers are more susceptible to the deleterious effects of PM2.5.

Effects of a responsiveness–focused intervention in family child care homes on children’s executive function