Some controls control too much

Post-stroke cognitive deficits rarely come alone: Handling co-morbidity in lesion-behaviour mapping

Post‐stroke behavioural symptoms often correlate and systematically co‐occur with each other, either because they share cognitive processes, or because their neural correlates are often damaged together. Thus, neuropsychological symptoms often share variance. Many previous lesion‐behaviour mapping studies aimed to methodologically consider this shared variance between neuropsychological variables. A first group of studies controlled the behavioural target variable for the variance explained by one or multiple other variables to obtain a more precise mapping of the target variable. A second group of studies focused on the shared variance of multiple variables itself with the aim to map neural correlates of cognitive processes that are shared between the original variables. In the present study, we tested the validity of these methods by using real lesion data and both real and simulated data sets. We show that the variance that is shared between post‐stroke behavioural variables is ambiguous, and that mapping procedures that consider this variance are prone to biases and artefacts. We discuss under which conditions such procedures could still be used and what alternative approaches exist.

A Model-Based Cluster Analysis of Maternal Emotion Regulation and Relations to Parenting Behavior

In a diverse community sample of mothers (N = 108) and their preschool-aged children (M_age  = 3.50 years), this study conducted person-oriented analyses of maternal emotion regulation (ER) based on a multimethod assessment incorporating physiological, observational, and self-report indicators. A model-based cluster analysis was applied to five indicators of maternal ER: maternal self-report, observed negative affect in a parent-child interaction, baseline respiratory sinus arrhythmia (RSA), and RSA suppression across two laboratory tasks. Model-based cluster analyses revealed four maternal ER profiles, including a group of mothers with average ER functioning, characterized by socioeconomic advantage and more positive parenting behavior. A dysregulated cluster demonstrated the greatest challenges with parenting and dyadic interactions. Two clusters of intermediate dysregulation were also identified. Implications for assessment and applications to parenting interventions are discussed.

Child effects and child care: Implications for risk and adjustment

Evocative effects of child characteristics on the quality and quantity of child care were assessed in two studies using longitudinal data from the NICHD Study of Early Child Care. We focus on the influence of child characteristics on two important aspects of the child care experience: language stimulation provided by caregivers and quantity of care. In Study 1, associations between the developmental status of children aged 15 to 54 months and the language stimulation provided by their caregivers were examined using path models, and longitudinal child effects were detected across the earliest time points of the study. In Study 2, the associations among child behavior, temperament, development, and time in care were examined. Little evidence was found for such child effects on time in care. The results are discussed in terms of the effects of child care on child development and implications for developmental processes, particularly for children at greatest risk for developmental delay or psychopathology.

Contributions of executive function and spatial skills to preschool mathematics achievement

Early mathematics achievement is highly predictive of later mathematics performance. Here we investigated the influence of executive function (EF) and spatial skills, two generalizable skills often overlooked in mathematics curricula, on mathematics performance in preschoolers. Children (N=44) of varying socioeconomic status (SES) levels were assessed at 3 years of age on a new assessment of spatial skill (Test of Spatial Assembly, TOSA) and a vocabulary measure (Peabody Picture Vocabulary Test, PPVT). The same children were tested at 4 years of age on the Beery Test of Visual-Motor Integration (VMI) as well as on measures of EF and mathematics. The TOSA was created specifically as an assessment for 3-year-olds, allowing the investigation of links among spatial, EF, and mathematical skills earlier than previously possible. Results of a hierarchical regression indicate that EF and spatial skills predict 70% of the variance in mathematics performance without an explicit math test, EF is an important predictor of math performance as prior research suggested, and spatial skills uniquely predict 27% of the variance in mathematics skills. Additional research is needed to understand whether EF is truly malleable and whether EF and spatial skills may be leveraged to support early mathematics skills, especially for lower SES children who are already falling behind in these skill areas by 3 and 4 years of age. These findings indicate that both skills are part of an important foundation for mathematics performance and may represent pathways for improving school readiness for mathematics.

Cutting-edge statistical methods for a life-course approach

Advances in research methods, data collection and record keeping, and statistical software have substantially increased our ability to conduct rigorous research across the lifespan. In this article, we review a set of cutting-edge statistical methods that life-course researchers can use to rigorously address their research questions. For each technique, we describe the method, highlight the benefits and unique attributes of the strategy, offer a step-by-step guide on how to conduct the analysis, and illustrate the technique using data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development. In addition, we recommend a set of technical and empirical readings for each technique. Our goal was not to address a substantive question of interest but instead to provide life-course researchers with a useful reference guide to cutting-edge statistical methods.

Establishing equivalence: methodological progress in group-matching design and analysis

This methodological review draws attention to the challenges faced by intellectual and developmental disabilities researchers in the appropriate design and analysis of group comparison studies. We provide a brief overview of matching methodologies in the field, emphasizing group-matching designs used in behavioral research on cognition and language in neurodevelopmental disorders, including autism spectrum disorder, Fragile X syndrome, Down syndrome, and Williams syndrome. The limitations of relying on p values to establish group equivalence are discussed in the context of other existing methods: equivalence tests, propensity scores, and regression-based analyses. Our primary recommendation for advancing research on intellectual and developmental disabilities is the use of descriptive indices of adequate group matching: effect sizes (i.e., standardized mean differences) and variance ratios.

A tale of two methods: comparing regression and instrumental variables estimates of the effects of preschool child care type on the subsequent externalizing behavior of children in low-income families

We apply instrumental variables (IV) techniques to a pooled data set of employment-focused experiments to examine the relation between type of preschool childcare and subsequent externalizing problem behavior for a large sample of low-income children. To assess the potential usefulness of this approach for addressing biases that can confound causal inferences in child care research, we compare instrumental variables results with those obtained using ordinary least squares (OLS) regression. We find that our OLS estimates concur with prior studies showing small positive associations between center-based care and later externalizing behavior. By contrast, our IV estimates indicate that preschool-aged children with center care experience are rated by mothers and teachers as having fewer externalizing problems on entering elementary school than their peers who were not in child care as preschoolers. Findings are discussed in relation to the literature on associations between different types of community-based child care and children's social behavior, particularly within low-income populations. Moreover, we use this study to highlight the relative strengths and weaknesses of each analytic method for addressing causal questions in developmental research.

First-Year Maternal Employment and Child Development in the First Seven Years

Using data from the first 2 phases of the NICHD Study of Early Child Care, we examine the links between maternal employment in the first 12 months of life and cognitive, social, and emotional outcomes for children at age 3, age 4½, and first grade. Drawing on theory and prior research from developmental psychology as well as economics and sociology, we address three main questions. First, what associations exist between first-year maternal employment and cognitive, social, and emotional outcomes for children over the first seven years of life? Second, to what extent do any such associations vary by the child's gender and temperament, or the mother's occupation? Third, to what extent do mother's earnings, the home environment (maternal depressive symptoms, sensitivity, and HOME scores), and the type and quality of child care mediate or offset any associations between first-year employment and child outcomes, and what is the net effect of first-year maternal employment once these factors are taken into account? We compare families in which mothers worked full time (55%), part time (23%), or did not work (22%) in the first year for non-Hispanic white children (N=900) and for African-American children (N=113). Comparisons are also made taking into account the timing of mothers' employment within the first year. A rich set of control variables are included. OLS and SEM analyses are constructed. With regard to cognitive outcomes, first, we find that full-time maternal employment in the first 12 months of life (but not part-time employment) is associated with significantly lower scores on some, but not all, measures of cognitive development at age 3, 4 ½, and first grade for non-Hispanic white children, but with no significant associations for the small sample of African-American children Part-time employment in the first year is associated with higher scores than full-time employment for some measures. Employment in the second and third year of life is not associated with the cognitive outcomes. Second, we examine the role of the child's gender and temperament and the mother's occupation in moderating the associations between first-year maternal employment and cognitive outcomes, but find few significant interactions for either child characteristics or mother's occupation. Third, we examine the role of an extensive set of potential mediators - the mother's earnings, the home environment, and the type and quality of child care. We find that mothers who worked full time have higher income in the first year of life and thereafter, that mothers who worked part time have higher HOME and maternal sensitivity scores than mothers who did not work or worked full time, and that mothers who worked either full time or part time were more likely to place their children in high-quality child care by age 3 and 4 ½ and their children spent more time in center-based care by age 4 ½ than in families where mothers did not work in the first year of life. However, we also find some links between first-year maternal employment and elevated levels of maternal depressive symptoms thereafter. Turning to results from structural equation modeling, we find that the overall effects of first-year maternal employment on the cognitive outcomes are neutral. This occurs because significantly negative direct effects of full-time first-year employment are offset by significantly positive indirect effects working through more use of center-based care and greater maternal sensitivity by age 4 ½. Regarding social and emotional outcomes, several findings, again limited to non-Hispanic white children, stand out. First, we find no significant associations between first-year maternal employment and later social and emotional outcomes (including attachment security) when comparing children whose mothers worked full-time or part-time in the first year with the reference group of children whose mothers did not work in the first year, although in models that take the timing of employment within the first year into account, we find some significant associations between full-time maternal employment in the first year and higher levels of caregiver- or teacher-reported externalizing problems at age 4 ½ and first grade. Second, part-time maternal employment by 12 months tends to be associated with fewer externalizing problems at age 4 ½ and first grade than full time maternal employment by 12 months. These results are unchanged when we allow for the possibility of moderation by child characteristics or maternal occupation. Third, the results from SEM models indicate that, while neither full-time nor part-time first-year employment has significant total effects on children's externalizing behavior problems at age 4 ½ or first grade, part-time first-year employment has indirect positive effects, working primarily through differences in the home environment and maternal sensitivity. Another important finding from the SEM models is that center-based care, which is often associated with maternal employment, is not significantly associated with elevated levels of child behavior problems. Taken together, our findings provide new insight as to the net effects of first-year maternal employment as well as the potential pathways through which associations between first-year maternal employment and later child outcomes, where present, come about. Our SEM results indicate that, on average, the associations between first-year maternal employment and later cognitive, social, and emotional outcomes are neutral, because negative effects, where present, are offset by positive effects. These results confirm that maternal employment in the first year of life may confer both advantages and disadvantages and that for the average non-Hispanic white child, those effects balance each other.

First-Year Maternal Employment and Child Development in the First Seven Years

Using data from the first 2 phases of the NICHD Study of Early Child Care, we examine the links between maternal employment in the first 12 months of life and cognitive, social, and emotional outcomes for children at age 3, age 4½, and first grade. Drawing on theory and prior research from developmental psychology as well as economics and sociology, we address three main questions. First, what associations exist between first-year maternal employment and cognitive, social, and emotional outcomes for children over the first seven years of life? Second, to what extent do any such associations vary by the child's gender and temperament, or the mother's occupation? Third, to what extent do mother's earnings, the home environment (maternal depressive symptoms, sensitivity, and HOME scores), and the type and quality of child care mediate or offset any associations between first-year employment and child outcomes, and what is the net effect of first-year maternal employment once these factors are taken into account? We compare families in which mothers worked full time (55%), part time (23%), or did not work (22%) in the first year for non-Hispanic white children (N=900) and for African-American children (N=113). Comparisons are also made taking into account the timing of mothers' employment within the first year. A rich set of control variables are included. OLS and SEM analyses are constructed. With regard to cognitive outcomes, first, we find that full-time maternal employment in the first 12 months of life (but not part-time employment) is associated with significantly lower scores on some, but not all, measures of cognitive development at age 3, 4 ½, and first grade for non-Hispanic white children, but with no significant associations for the small sample of African-American children Part-time employment in the first year is associated with higher scores than full-time employment for some measures. Employment in the second and third year of life is not associated with the cognitive outcomes. Second, we examine the role of the child's gender and temperament and the mother's occupation in moderating the associations between first-year maternal employment and cognitive outcomes, but find few significant interactions for either child characteristics or mother's occupation. Third, we examine the role of an extensive set of potential mediators - the mother's earnings, the home environment, and the type and quality of child care. We find that mothers who worked full time have higher income in the first year of life and thereafter, that mothers who worked part time have higher HOME and maternal sensitivity scores than mothers who did not work or worked full time, and that mothers who worked either full time or part time were more likely to place their children in high-quality child care by age 3 and 4 ½ and their children spent more time in center-based care by age 4 ½ than in families where mothers did not work in the first year of life. However, we also find some links between first-year maternal employment and elevated levels of maternal depressive symptoms thereafter. Turning to results from structural equation modeling, we find that the overall effects of first-year maternal employment on the cognitive outcomes are neutral. This occurs because significantly negative direct effects of full-time first-year employment are offset by significantly positive indirect effects working through more use of center-based care and greater maternal sensitivity by age 4 ½. Regarding social and emotional outcomes, several findings, again limited to non-Hispanic white children, stand out. First, we find no significant associations between first-year maternal employment and later social and emotional outcomes (including attachment security) when comparing children whose mothers worked full-time or part-time in the first year with the reference group of children whose mothers did not work in the first year, although in models that take the timing of employment within the first year into account, we find some significant associations between full-time maternal employment in the first year and higher levels of caregiver- or teacher-reported externalizing problems at age 4 ½ and first grade. Second, part-time maternal employment by 12 months tends to be associated with fewer externalizing problems at age 4 ½ and first grade than full time maternal employment by 12 months. These results are unchanged when we allow for the possibility of moderation by child characteristics or maternal occupation. Third, the results from SEM models indicate that, while neither full-time nor part-time first-year employment has significant total effects on children's externalizing behavior problems at age 4 ½ or first grade, part-time first-year employment has indirect positive effects, working primarily through differences in the home environment and maternal sensitivity. Another important finding from the SEM models is that center-based care, which is often associated with maternal employment, is not significantly associated with elevated levels of child behavior problems. Taken together, our findings provide new insight as to the net effects of first-year maternal employment as well as the potential pathways through which associations between first-year maternal employment and later child outcomes, where present, come about. Our SEM results indicate that, on average, the associations between first-year maternal employment and later cognitive, social, and emotional outcomes are neutral, because negative effects, where present, are offset by positive effects. These results confirm that maternal employment in the first year of life may confer both advantages and disadvantages and that for the average non-Hispanic white child, those effects balance each other.

From statistical associations to causation: what developmentalists can learn from instrumental variables techniques coupled with experimental data

In this article, the authors aim to make accessible the careful application of a method called instrumental variables (IV). Under the right analytic conditions, IV is one promising strategy for answering questions about the causal nature of associations and, in so doing, can advance developmental theory. The authors build on prior work combining the analytic approach of IV with the strengths of random assignment design, whether the experiment is conducted in the lab setting or in the "real world." The approach is detailed through an empirical example about the effects of maternal education on children's cognitive and school outcomes. With IV techniques, the authors address whether maternal education is causally related to children's cognitive development or whether the observed associations reflect some other characteristic related to parenting, income, or personality. The IV estimates show that maternal education has a positive effect on the cognitive test scores of children entering school. The authors conclude by discussing opportunities for applying these same techniques to address other questions of critical relevance to developmental science.

Evaluation of a class wide teaching program for developing preschool life skills

Recently, nonmaternal center-based child care has been linked to problem behavior in young children (National Institute of Child Health and Human Development, 2003). In response, a comprehensive program to promote prosocial skills was evaluated in a classroom of 16 children between the ages of 3 and 5 years. Classroom observations were conducted during evocative situations to determine the likelihood of problem behavior (noncompliance, vocal or motor disruptions, aggression) and preschool life skills. A classwide teaching program was then implemented in a staggered manner across instruction following, functional communication, delay tolerance, and friendship skills. These four categories of preschool life skills, which included two to four related skills, were selected for classwide teaching because they were either identified by educators as important for early school success, have often been taught following functional assessments of more severe problem behavior, or both. Skills were taught on a classwide basis during typically scheduled activities (circle, free play, transitions, meals) via instructions, modeling, role play, and feedback. A multiple probe design showed that the program resulted in an 74% reduction in problem behavior and a more than four-fold increase in preschool life skills. Similar beneficial effects of the program were evident in questionnaire data gathered prior to and at the close of the evaluation. Finally, the teachers who implemented the program reported overall high levels of satisfaction with the classwide teaching program, the target skills, and the results. Implications for the design of early childhood experiences for preempting the development of serious problem behavior are discussed.

Predicting individual differences in attention, memory, and planning in first graders from experiences at home, child care, and school

This study adds to the growing literature linking children's experiences in the environment to individual differences in their developing skills in attention, memory, and planning. The authors asked about the extent to which stimulating and sensitive care in the family and in the child-care or school environments would predict these cognitive outcomes. The authors also questioned the primacy of experiences in the first 3 years of life. Data from a sample of 700 first graders whose experiences in the home and in child care or school were evaluated since early infancy revealed that the cumulative quality of the child-rearing environment was related to attention and memory but not to planning and that the quality of the family environment was more strongly associated with outcomes than was the quality of child care and of school. The quality of both children's early (6 through 36 months) and later (54 months and first grade) environments predicted performance on the attention and memory tasks.

Child care research: an editorial perspective

The goals of Child Development's new From Another Perspective format are discussed, and an overview of the content of the inaugural From Another Perspective collection on child care effects is provided. The two lead articles suggest, respectively, that long hours in child care are related to children's later behavior problems and that child care may be physiologically challenging for young children. Commentaries focus on the need to examine a range of additional factors before drawing definitive conclusions about cause and effect. Among the issues discussed in the commentaries are the need to account for context, individual differences among children, and methodological challenges. The introductory editorial also overviews policy implications and directions for future research.