Sleep and Negative Affect Across Toddlerhood in the Context of Stress.

Negative affect is associated with both high stress and poor sleep, but questions remain about the direction of these associations across time and interactions between stress and sleep, especially in early childhood. The present study examined sleep deficits, family stress, and observed negative affect in a sample of toddlers at 30, 36, and 42 months (N = 504). Negative affect was observed during a parent-child free play task. Sleep was measured via actigraphy. Stress was measured using a cumulative risk index of socioeconomic status, single parent status, household chaos, role overload, parenting hassles, social support, and stressful events. Findings showed few associations between sleep and negative affect, except for toddlers experiencing high levels of family stress. Toddlers experiencing both high stress and poor sleep demonstrated the highest levels of negative affect in the lab at 30 months. Adequate sleep may serve as a protective factor for children in high-stress families.

Heterotypic continuity of inhibitory control in early childhood: Evidence from four widely used measures.

Inhibitory control has been widely studied in association with social and academic adjustment. However, prior studies have generally overlooked the potential heterotypic continuity of inhibitory control and how this could affect assessment and understanding of its development. In the present study, we systematically considered heterotypic continuity in four well-established measures of inhibitory control, testing two competing hypotheses: (a) the manifestation of inhibitory control coheres within and across time in consistent, relatively simple ways, consistent with homotypic continuity. Alternatively, (b) with developmental growth, inhibitory control manifests in more complex ways with changes across development, consistent with heterotypic continuity. We also explored differences in inhibitory control as a function of the child's sex, language ability, and the family's socioeconomic status. Children (N = 513) were studied longitudinally at 30, 36, and 42 months of age. Changes in the patterns of associations within and among inhibitory control measures across ages suggest that the measures' meanings change with age, the construct manifests differently across development, and, therefore, that the construct shows heterotypic continuity. We argue that the heterotypic continuity of inhibitory control motivates the use of different combinations of inhibitory control indexes at different points in development in future research to improve validity. Confirmatory factors and growth curves also suggest that individual differences in inhibitory control endure, with convergence among inhibitory control measures by 36 months of age. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Sustained attention across toddlerhood: The roles of language and sleep.

The present study examined individual differences in the development of sustained attention across toddlerhood, as well as how these individual differences related to the development of language and sleep. Toddlers (N = 314; 54% male) were assessed at 30, 36, and 42 months using multiple measures of attention, a standardized language assessment, and actigraphic measures of sleep. Toddlers were 80% White. Family socioeconomic status (SES) was calculated using the Hollingshead Four Factor Index and ranged from 13 to 66 (M = 47.59, SD = 14.13). Aims were (a) to examine associations between measures of attention across situations, informants, and time; (b) to consider the independent and interactive effects of language and sleep on attention; and (c) to test potential bidirectional associations between sleep and attention. Findings showed attention measures were stable across time but were only weakly linked with each other at 42 months. Attention was consistently linked with language. More variable sleep and longer naps were associated with less growth in sustained attention across time. Nighttime sleep duration interacted with language in that sleep duration was positively associated with attention scores among toddlers with less advanced language, even when SES was controlled. The findings describe an understudied aspect of how sustained attention develops, involving the main effect of consistent sleep schedules and the interaction effect of amount of sleep and child language development. These findings are relevant to understanding early childhood risk for developing attention problems and to exploring a potential prevention target in family sleep practices. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The Family Context of Toddler Sleep: Routines, Sleep Environment, and Emotional Security Induction in the Hour before Bedtime.

Family processes during the pre-bedtime period likely have a crucial influence on toddler sleep, but relatively little previous research has focused on family process in this context. The current study examined several aspects of family process during the pre-bedtime period, including the use of bedtime routines, the qualities of the child's home sleep environment, and the promotion of child emotional security, in families of 30-month-old toddlers (N= 546; 265 female) who were part of a multi-site longitudinal study of toddler development. These characteristics were quantified using a combination of parent- and observer-reports and examined in association with child sleep using correlation and multiple regression. Child sleep was assessed using actigraphy to measure sleep duration, timing, variability, activity, and latency. Bedtime routines were examined using parents' daily records. Home sleep environment and emotional security induction were quantified based on observer ratings and in-home observation notes, respectively. All three measures of pre-bedtime context (i.e., bedtime routine inconsistency, poor quality sleep environments, and emotional security induction) were correlated with various aspects of child sleep (significant correlations:.11-.22). The most robust associations occurred between the pre-bedtime context measures and sleep timing (i.e., the timing of the child's sleep schedule) and variability (i.e., night to night variability in sleep timing and duration). Pre-bedtime variables, including bedtime routine consistency, home sleep environment quality, and positive emotional security induction, also mediated the association between family socioeconomic status and child sleep. Our findings underscore the value of considering family context when examining individual differences in child sleep.

Sleep across early childhood: implications for internalizing and externalizing problems, socioemotional skills, and cognitive and academic abilities in preschool.

BACKGROUND: Sleep is thought to be important for behavioral and cognitive development. However, much of the prior research on sleep's role in behavioral/cognitive development has relied upon self-report measures and cross-sectional designs. METHODS: The current study examined how early childhood sleep, measured actigraphically, was developmentally associated with child functioning at 54 months. Emphasis was on functioning at preschool, a crucial setting for the emergence of psychopathology. Participants included 119 children assessed longitudinally at 30, 36, 42, and 54 months. We examined correlations between child sleep and adjustment across three domains: behavioral adjustment (i.e., internalizing and externalizing problems), socioemotional skills, and academic/cognitive abilities. We further probed consistent associations with growth curve modeling. RESULTS: Internalizing problems were associated with sleep variability, and cognitive and academic abilities were associated with sleep timing. Growth curve analysis suggested that children with more variable sleep at 30 months had higher teacher-reported internalizing problems in preschool and that children with later sleep timing at 30 months had poorer cognitive and academic skills at 54 months. However, changes in sleep from 30 to 54 months were not associated with any of the domains of adjustment. CONCLUSIONS: Findings indicate that objectively measured sleep variability and late sleep timing in toddlerhood are associated with higher levels of internalizing problems and poorer academic/cognitive abilities in preschool.

Examining the Associations Between Performance Based and Ratings of Focused Attention in Toddlers: Are We Measuring the Same Constructs?

The study examines the concurrent and longitudinal associations between ratings-based measures (parents, secondary caregivers, observers) and performance-based measures of focused attention in toddlers aged 30- (n = 147), 36- (n =127), and 42-months (n =107). Parents and secondary caregivers rated focused attention behaviors using the Children's Behavior Questionnaire (Rothbart et al., 2001), and observers rated toddlers' focused attention during a series of laboratory tasks using the Leiter-R Examiner Rating Scale (Roid & Miller, 1997). Toddlers' behaviors on three structured tasks (Token Sort, Toy Play, Lock Box) were used to assess their performance based focused attention in a laboratory setting. Correlations show that parent ratings are not related to observer and teacher ratings, or to the performance-based measures at all ages tested. Second, based on confirmatory factor analyses, a single factor explains the common variance between indicators when the parent ratings are not included in the models. The single factor shows measurement invariance between ages 36 and 42 months based on factor structure, relations of indicators to the factor, and factor scale over time. Third, indicators of focused attention at age 30 months do not seem to measure a common, coherent factor. Interpretations of similarities and differences between ratings and performance-based indicators of focused attention and the presence of a focused attention construct are discussed.

Child Sleep and Socioeconomic Context in the Development of Cognitive Abilities in Early Childhood.

Despite a robust literature examining the association between sleep problems and cognitive abilities in childhood, little is known about this association in toddlerhood, a period of rapid cognitive development. The present study examined the association between various sleep problems, using actigraphy, and performance on a standardized test of cognitive abilities, longitudinally across three ages (30, 36, and 42 months) in a large sample of toddlers (N = 493). Results revealed a between-subject effect in which the children who had more delayed sleep schedules on average also showed poorer cognitive abilities on average but did not support a within-subjects effect. Results also showed that delayed sleep explains part of the association between family socioeconomic context and child cognitive abilities.

Night-to-Night Variability in the Bedtime Routine Predicts Sleep in Toddlers.

The present study examined relations between nightly bedtime routines and sleep outcome measures in a sample of 185 toddlers aged 30 months. Parents reported on their toddler's sleep duration and the length and activities included in the bedtime routine each night for approximately 2 weeks. Toddlers wore actigraphs to track their sleep during the same time period. Correlation, mean difference, and regression analyses indicated that toddlers experienced different bedtime routines and exhibited differences in parent reported sleep duration between weeknights and weekends. Multi-level models revealed that variability in the bedtime routine on an individual night most consistently affected parent reported sleep duration on that night. Differences in the bedtime routines between weeknights and weekends also affected actigraph recorded sleep duration and sleep efficiency. Results suggest that keeping consistent bedtime routines between weeknights and weekends is important for optimal sleep outcomes.

Relations Between Toddler Sleep Characteristics, Sleep Problems, and Temperament.

Two sources of information (parent-reported sleep diaries and actigraph records) were used to investigate how toddler sleep characteristics (bed time/sleep onset, wake time/sleep offset, total nighttime sleep, and total sleep time) are related to sleep problems and temperament. There were 64 toddler participants in the study. Consistent with studies of older children, parent reports differed from actigraph-based records. The findings that parent-reported and actigraph-recorded sleep characteristics varied as a function of parent report of toddler sleep problems and temperament add needed information on toddler sleep. Such information may contribute to improving parents' awareness of their child's sleep characteristics and correlates of problem sleep.

Estimating child sleep from parent report of time in bed: development and evaluation of adjustment approaches.

OBJECTIVE: To develop and evaluate adjustment factors to convert parent-reported time in bed to an estimate of child sleep time consistent with objective measurement. METHODS: A community sample of 217 children aged 4-9 years (mean age = 6.6 years) wore actigraph wristwatches to objectively measure sleep for 7 days while parents completed reports of child sleep each night. After examining the moderators of the discrepancy between parent reports and actigraphy, 3 adjustment factors were evaluated. RESULTS: Parent report of child sleep overestimated nightly sleep duration by ∼24 min per night relative to actigraphy. Child age, gender, and sleep quality all had small or nonsignificant associations with correspondence between parent report and actigraph. Empirically derived adjustment factors significantly reduced the discrepancy between parent report and objective measurement. CONCLUSIONS: Simple adjustment factors can enhance the correspondence and utility of parent reports of child sleep duration for clinical and research purposes.

A one-hour sleep restriction impacts brain processing in young children across tasks: evidence from event-related potentials.

The effect of mild sleep restriction on cognitive functioning in young children is unclear, yet sleep loss may impact children's abilities to attend to tasks with high processing demands. In a preliminary investigation, six children (6.6-8.3 years of age) with normal sleep patterns performed three tasks: attention ("Oddball"), speech perception (consonant-vowel syllables), and executive function (Directional Stroop). Event-related potentials (ERPs) responses were recorded before (Control) and following 1 week of 1-hour per day of sleep restriction. Brain activity across all tasks following Sleep Restriction differed from activity during Control Sleep, indicating that minor sleep restriction impacts children's neurocognitive functioning.

Executive Function Skills of 6 to 8 Year Olds: Brain and Behavioral Evidence and Implications for School Achievement.

Academic and social success in school has been linked to children's self-regulation. This study investigated the assessment of the executive function (EF) component of self-regulation using a low-cost, easily administered measure to determine whether scores obtained from the behavioral task would agree with those obtained using a laboratory-based neuropsychological measure of EF skills. The sample included 74 children (37 females; M = 86.2 months) who participated in two assessments of working memory and inhibitory control: Knock-Tap (NEPSY: Korkman, Kirk, and Kemp, 1998), and participation in event-related potential (ERP) testing that included the Directional Stroop Test (Davidson, Cruess, Diamond, O'Craven, & Savoy, 1999). Three main findings emerged. First, children grouped as high versus low performing on the NEPSY Knock-Tap Task were found to performed differently on the more difficult conditions of the DST (the Incongruent and Mixed Conditions), suggesting that the Knock-Tap Task as a low-cost and easy to administer assessment of EF skills may be one way for teachers to identify students with poor inhibitory control skills. Second, children's performance on the DST was strongly related to their ERP responses, adding to evidence that differences in behavioral performance on the DST as a measure of EF skills reflect corresponding differences in brain processing. Finally, differences in brain processing on the DST task also were found when the children were grouped based on Knock-Tap performance. Simple screening procedures can enable teachers to identify children whose distractibility, inattentiveness, or poor attention spans may interfere with classroom learning.

Dynamic links between emerging cognitive skills and brain processes.

The goal of the present study was to investigate whether advanced cognitive skills in one domain impact the neural processing of unrelated skills in a different cognitive domain. This question is related to the broader issue of how cognitive-neurodevelopment proceeds as different skills are mastered. To address this goal, event-related brain potentials (ERPs) were used to assess linkages between cognitive skills of preschool children as reflected in their performance on a pre-reading screening test (Get Ready To Read) and their neural responses while engaged in a geometric shape matching task. Sixteen children (10 males) participated in this study. The children ranged from 46 to 60 months (SD = 4.36 months). ERPs were recorded using a 128-electrode high-density array while children attended to presentations of matched and mismatched shapes (triangles, circles, or squares). ERPs indicated that children with more advanced pre-reading skills discriminated between matched and mismatched shapes earlier than children with poorer pre-readings skills. The earlier discrimination effect observed in the advanced group was localized over the occipital electrode sites whereas in the Low Group such effects were present over frontal, parietal, and occipital sites. Modeled magnetic resonance images (MRIs) of the ERP component sources identified differences in neural generators between the two groups. Both sets of findings support the hypothesis that processing in a poorer-performing group is more distributed temporally and spatially across the scalp, and reflects the engagement of more distributed brain regions. These findings are seen as support for a theory of neural-cognitive development that is advanced in the present article.

Smoking during pregnancy affects speech-processing ability in newborn infants.

BACKGROUND: Tobacco smoking during pregnancy is known to adversely affect development of the central nervous system in babies of smoking mothers by restricting utero-placental blood flow and the amount of oxygen available to the fetus. Behavioral data associate maternal smoking with lower verbal scores and poorer performance on specific language/auditory tests. OBJECTIVES: In the current study we examined the effects of maternal smoking during pregnancy on newborns' speech processing ability as measured by event-related potentials (ERPs). METHOD: High-density ERPs were recorded within 48 hr of birth in healthy newborn infants of smoking (n = 8) and nonsmoking (n = 8) mothers. Participating infants were matched on sex, gestational age, birth weight, Apgar scores, mother's education, and family income. Smoking during pregnancy was determined by parental self-report and medical records. ERPs were recorded in response to six consonant-vowel syllables presented in random order with equal probability. RESULTS: Brainwaves of babies of nonsmoking mothers were characterized by typical hemisphere asymmetries, with larger amplitudes over the left hemisphere, especially over temporal regions. Further, infants of nonsmokers discriminated among a greater number of syllables whereas the newborns of smokers began the discrimination process at least 150 msec later and differentiated among fewer stimuli. CONCLUSIONS: Our findings indicate that prenatal exposure to tobacco smoke in otherwise healthy babies is linked with significant changes in brain physiology associated with basic perceptual skills that could place the infant at risk for later developmental problems.

Letter knowledge, phonological processing, and print knowledge: skill development in nonreading preschool children.

Development of reading skills was examined in 4-year-old children from low-income homes attending a prekindergarten program. Fall to spring gains in letter identification were examined and compared with skills in phonological processing, rhyme detection, and environmental print, and with performance on a screening tool (Get Ready to Read). It was anticipated that participants might show slow skill development. However, the identification of a large group of children (n = 30) who made little or no gains in letter identification compared to their classmates (n = 27), whose gains averaged 7 letters, was not anticipated. Fall to spring gains in letter identification correlated with phonological processing, rhyme detection, environmental print, and Get Ready to Read! scores. Age and general cognitive skills influenced performance on some tasks. More knowledge of the characteristics of children who show the most variations in skill development may lead to insights on using classroom curriculum to focus on skill development.

Below-average, average, and above-average readers engage different and similar brain regions while reading.

Event-related potentials (ERPs) were recorded from 27 children (14 girls, 13 boys) who varied in their reading skill levels. Both behavior performance measures recorded during the ERP word classification task and the ERP responses themselves discriminated between children with above-average, average, and below-average reading skills. ERP amplitudes and peak latencies decreased as reading skills increased. Furthermore, hemisphere differences increased with higher reading skill levels. Sex differences were also related to ERP amplitude variations across the scalp. However, ERPs recorded from boys and girls did not differ as a function of differences in the children's reading levels.

Alphabetic skills in preschool: a preliminary study of letter naming and letter writing.

Development of letter naming and writing (skills in writing first name, dictated and copied letters, and dictated and copied numbers) was examined in 79 preschool children (M age = 56 months). Skills were assessed in the fall to determine the status of these procedural skills that are components of alphabetic knowledge at the start of the school year. Children with high letter-naming scores also had high scores on letter writing, including dictated or copied letters and writing some or all of the letters of their names. Letter-naming skills were related to number-writing skills whether the numbers were dictated or copied. The highest writing scores were found for first name writing compared to writing or copying letters and numbers. A focus on the development of procedural knowledge in the preschool period may yield the hopep for impacts on later reading skills that has not been found in curricula emphasizing conceptual knowledge (e.g., knowledge of print concepts, book conventions).

Development of auditory event-related potentials in young children and relations to word-level reading abilities at age 8 years.

A relationship between brain responses at birth and later emerging language and reading skills have been shown, but questions remains whether changes in brain responses after birth continue to predict the mastery of language-related skills such as reading development. To determine whether developmental changes in the brain-based perceptual skills are systematically related to differences in word-level reading proficiency at age 8 years, brain event-related potentials (ERPs) to speech and non-speech stimuli were recorded annually at the ages of 1 through 8 years in a sample of 109 typically developing children. Two measures of word-level reading (one that requires decoding of real words and one of pseudowords) were administered at age 8 years. Growth curve analysis, using the hierarchical linear models, related reading performance (average versus low) to the longitudinal maturation in the ERP waveform peak and latencies. Maturational changes (e.g. slope, acceleration and cubic growth) in N1 amplitude from ages 1 to 4 were related to proficiency in decoding pseudoword stimuli only, with children who were less proficient in decoding pseudowords evidencing more steeply negative declines in amplitude with age, particularly at the frontal and parietal recording sites in response to both speech and non-speech stimuli. In contrast, proficient in decoding real words was related to developmental changes in N2 amplitudes from ages 4 to 8 only at the parietal recording site and only in response to non-speech stimuli. The early development of biologically-based differences in the perception and processing of auditory information contributes to later group differences in reading proficiencies at school age.

Snoring in preschoolers: associations with sleepiness, ethnicity, and learning.

Sleep-disordered breathing (SDB) in children is associated with poor school performance, with minority children being at increased risk for both conditions. The latter have been attributable to low socio-economic status (SES). To further study these relationships, the contribution of SES to SDB and learning was examined in 1,010 validated questionnaires collected from parents of both white and African-American low-SES preschoolers. Twenty-two percent of disadvantaged preschoolers were reported to be at risk for SDB. These children were more likely to be African American, and had a higher incidence of daytime sleepiness, lower academic performance, and hyperactivity. Maternal education level did not account for these differences.

Influence of environment on speech-sound discrimination: findings from a longitudinal study.

Event-related potentials (ERPs) from 134 children were obtained at 3 and 8 years of age and recorded to a series of consonant-vowel speech syllables and their nonspeech analogues. The HOME inventory was administered to these same children at 3 and 8 years of age and the sample was divided into 2 groups (low vs. high) based on their HOME scores. Discriminant functions analyses using ERP responses to speech and non-speech analogues successfully classified HOME scores obtained at 3 and 8 years of age and discriminated between children who received low vs. high levels of stimulation for language and reading.