Peggy S. Keller

Concurrent and Longitudinal Relations between Children's Sleep and Cognitive Functioning: The Moderating Role of Parent Education.

Relations between childrens sleep and cognitive functioning were examined over 2 years, and race and socioeconomic status were assessed as moderators of effects. Third-grade African American and European American children (N = 166; M = 8.72 years) participated at Time 1 and again 2 years later (N = 132). At both Time 1 and Time 2, sleep was examined via self-report and actigraphy. Children were administered selected tests from the Woodcock-Johnson III Tests of Cognitive Abilities, and Stanford Achievement Test scores were obtained from schools. Childrens sleep was related to intellectual ability and academic achievement. Results build substantially on an emerging literature supportive of the importance of sleep in children.

Longitudinal relations between parental drinking problems, family functioning, and child adjustment

Relations between maternal and paternal problem drinking symptoms and destructive marital conflict, parenting problems, and childrens internalizing and externalizing problems were investigated. Participants were community families with a child in kindergarten who completed questionnaire measures at baseline (N=235), 1 year later (N=227), and 2 years later (N=215). Structural equation modeling revealed that paternal problem drinking at Time 1 was associated with greater destructive marital conflict 1 year later. In turn, destructive marital conflict was related to decreased parental warmth and increased parental psychological control; these parenting problems were associated with greater child internalizing and externalizing problems at the third time point. Further analyses revealed that the indirect effects of paternal drinking on childrens adjustment were significant, and that relations remained even after including autoregressive effects. Findings are discussed in terms of family process models for relations between parental drinking and child adjustment problems.

Child emotional insecurity and academic achievement : The role of sleep disruptions

The authors examined childrens sleep as an intervening variable in the connection between emotional insecurity in the family and academic achievement. The role of ethnicity (African American and European American) and socioeconomic status (SES) in moderating the examined relations was assessed. One hundred sixty-six children (8- and 9-year-olds) reported their emotional insecurity, and the quantity and quality of childrens sleep were examined through actigraphy and self-report. Decreased amount and quality of sleep were intervening variables in the relations between insecurity in the marital relationship and childrens achievement. The effects of disrupted sleep on achievement were more pronounced for both African American children and children of lower SES. Results highlight the importance of the contemporaneous examinations of family and sleep functioning in the prediction of child outcomes.

Children's objective and subjective sleep disruptions: links with afternoon cortisol levels.

OBJECTIVE The purpose of this study was to determine possible relations between the quality and amount of childrens sleep and cortisol in healthy children. DESIGN Childrens sleep was monitored with actigraphs for 7 nights. Children came to the laboratory to provide saliva samples, which were used to assess cortisol. Children reported on their sleepiness and sleep/wake problems. Sixty-four healthy children participated (M = 8.75 years; SD = .55). MAIN OUTCOME MEASURES Self-reported sleepiness and sleep/wake problems, actigraphy-measured total sleep minutes, sleep efficiency, minutes awake after sleep onset, and sleep activity, and afternoon cortisol levels. RESULTS After controlling for demographic variables and child characteristics, higher levels of cortisol were related to increased subjective sleep problems and objective measures of shorter sleep duration and poorer sleep quality. CONCLUSION These findings are of importance for understanding critical facets of childrens health and well-being, and are noteworthy given the high prevalence of sleep disruptions in otherwise normally developing children in the United States.

Children’s sleep and adjustment: the moderating role of vagal regulation

Children’s vagal tone and vagal suppression were examined as moderators of associations between children’s sleep disruptions and adjustment problems. A relatively large sample (n = 167) of boys and girls who ranged in age between 8 and 9 years participated with their parents. Sleep was examined via actigraphy in the child’s home for seven consecutive days. Children’s vagal tone was examined during baseline conditions, and their vagal suppression was assessed in response to an inter‐adult argument. In comparison with children exhibiting higher levels of vagal tone, those with lower vagal tone were at increased risk of externalizing problems, depression symptoms and higher body mass index associated with increased sleep disruptions (i.e. lower Sleep Efficiency, increased Wake Minutes and fewer Sleep Minutes). Thus, lower vagal tone functioned as a vulnerability factor for adjustment problems in the context of sleep problems. A higher level of vagal suppression to the inter‐adult argument functioned as a protective factor against externalizing behaviors otherwise associated with increased Wake Minutes and reduced Sleep Efficiency. Findings demonstrating the moderating role of vagal functioning in the context of sleep disruptions are novel, and highlight the importance of individual differences in children’s physiological regulation for sleep and adjustment.

Children's Emotional Security and Sleep: Longitudinal Relations and Directions of Effects.

BACKGROUND We examined longitudinal relations between childrens sleep and their emotional security in the mother-child, father-child, and parental marital relationships, with the goal of explicating the direction of association over time. Gender-related effects were also examined. METHOD Sleep duration was examined through actigraphy, and sleep quality was assessed via both actigraphy and self-reports. Children were in 3rd (T1) and 5th (T2) grades. The sample was composed of 78 boys and 98 girls at T1, and 62 boys and 80 girls at T2. RESULTS Security in the child-mother, child-father, and marital relationships at T1 were predictive of sleep problems two years later even after controlling for childrens sleep at T1. CONCLUSIONS Collectively, results were more supportive of security predicting sleep parameters than the other direction of effects. Results highlight the important associations between family functioning and childrens sleep, and extend the literature through the longitudinal design.

Relations between Mucosal Immunity and Children’s Mental Health: The Role of Child Sex

This study examines relations between childrens salivary interleukin-6 (IL-6) and secretory immunoglobulin A (SIgA) and mental health. Child sex was considered as a moderator of relations. Data were from 329 normally developing children (M age=9.85years; SD=.98years); 67% of children were European American and 33% were African American. Saliva samples were obtained during the afternoon and assayed for SIgA and IL-6. Parents completed questionnaire measures of child internalizing and externalizing symptoms, and children completed self-report measures of anxiety and depression. Structural equation models were fit to the data, and indicated that greater levels of salivary IL-6 and SIgA were associated with adjustment problems more strongly for girls than for boys.

Children's Attachment to Parents and Their Academic Functioning : Sleep Disruptions as Moderators of Effects

Objective: We investigated the amount and quality of children’s sleep as a moderator of relations between attachment to parents and child academic functioning. Method: Data were from a sample of 166 third graders in the Southeastern USA. Children reported on the security of their attachments to both mothers and fathers, and standard assessments of academic achievement were obtained from schools. Children completed questionnaire measures of subjective sleep problems and their sleep was assessed objectively via actigraphs worn for seven consecutive nights. Results: Attachment insecurity was associated with lower math achievement for children with objective sleep problems (lower quantity and efficiency). Conclusion: Findings suggest that better sleep ameliorates the risk for academic performance difficulties associated with insecure attachments to parents, and functions as a protective factor in this context.

Salivary alpha-amylase as a longitudinal predictor of children's externalizing symptoms: Respiratory sinus arrhythmia as a moderator of effects

Salivary alpha-amylase (sAA) was examined as a predictor of childrens externalizing symptoms cross-sectionally when children were in the 3rd grade (T1; N=64) and again in the 5th grade (T2; N=54) and longitudinally over two years. Parasympathetic nervous system (PNS) activity, indexed by respiratory sinus arrhythmia (RSA), was examined as a moderator of the sAA and child externalizing link. Participants were healthy, typically developing children, 34% of whom were African American and the rest European American. At each time point, saliva samples were collected during afternoon laboratory visits and assayed for sAA. Childrens RSA was measured during baseline conditions and in response to an inter-adult argument and a star-tracing task. Cross-sectional associations between sAA and externalizing symptoms at T1 and T2 were moderated by PNS functioning. Longitudinally, sAA was directly associated with changes in externalizing symptoms in a non-linear fashion. Specifically, lower externalizing symptoms were predicted for children with moderate levels of sAA, but higher externalizing was predicted for children with higher or lower levels of sAA. Findings highlight the importance of the contemporaneous assessment of SNS and PNS functioning in the prediction of child psychopathology, and the need to examine curvilinear relations between ANS functioning and behavior.

Interactions between salivary cortisol and alpha-amylase as predictors of children's cognitive functioning and academic performance

We examined relations between salivary cortisol, alpha-amylase (sAA), and childrens cognitive and academic functioning. Of interest were curvilinear and interactive effects of these salivary measures on cognitive and academic performance. Data were based on a sample of 28 boys and 36 girls (ages 8 and 9) in the Southeastern U.S.A. Children provided resting afternoon saliva samples. Children completed standardized tests of Intellectual Ability and schools provided academic achievement information. Regression analyses demonstrated significant curvilinear relations and interactions between cortisol and sAA in the prediction of child functioning. Contrary to current models of interactions among biological systems, findings indicated some of the highest and lowest scores were predicted at moderate levels of physiological arousal. For example, children with moderate sAA and either higher or lower cortisol had low predicted scores for Reading Ability. Children with moderate cortisol and lower sAA had the highest predicted scores for Intellectual Ability. Findings suggest that the study of interactions between biological stress response systems should not be based on models of rectilinear interactions.