Co-occurring risk and protective factors and regulatory behavior of infants living in low-income homes

Early self-regulation is a foundation for lifelong wellness and can be shaped by the interplay among several vital exposures. In this study, we examined the emergence of reliable profiles based upon exposure to risk and protective factors in infancy, determined if sociodemographic resources predict profile membership, and determined if these profiles predict early regulatory behaviors in a sample of infants reared in low-income homes. Data were collected from a sample of primarily Black or White mother-infant dyads living in low-income homes in the Midwest (n = 222) during the infants’ first year of life (mean maternal age at enrollment: 26.29 years; range 18−43 years). Exposures included mother-infant interactions; father support; maternal depression, stress, and self-efficacy; home environment; food security; and breastfeeding duration. Sociodemographic resources included poverty status; economic hardship; maternal education, employment, and age; parental marital status; and infant race and sex. Infant regulatory behaviors were measured with the Infant Behavior Questionnaire-Revised Very Short Form effortful control subscale (mean age 11 months; range 8.5−14.3 months). Latent profile analysis was used to profile infants by risk and protective exposures. Regression was used to differentiate profiles by sociodemographic resources and to predict infant regulatory behavior from profiles. Three profiles emerged: low father support, good maternal mental health, and poor maternal mental health. A married mother, less economic hardship, and working mothers predicted infant exposure to good maternal mental health. Infant regulatory behavior was best when the infant was exposed to the good maternal mental health profile. Implications for future research are discussed.     

Hair sampling for cortisol analysis with mother-toddler dyads living in low-income homes

BackgroundA first step to advance stress science research in young children is understanding the relationship between chronic stress in a mother and chronic stress in her child. One non-invasive measure of chronic stress is hair cortisol. However, little is known about strategies for hair sampling in mother-toddler dyads living in low-income homes in the U.S. To address prior limitations, the purpose of this study was to understand the feasibility of sampling hair for cortisol analysis in mother-toddler dyads living in low-income homes in the U.S. We examined feasibility related to participation, eligibility, and gathering an adequate hair sample weight.MethodsWe approached 142 low-income, racially diverse, urban-dwelling mothers who were participating in an ongoing longitudinal birth cohort study for informed consent to cut approximately 150 hairs from the posterior vertex of their scalp and their toddlers’ (20–24 months) scalp. We demonstrated the process of sampling hair with a hairstyling doll during home visits to the mother and toddler using rounded-end thinning shears.ResultsOverall, 94 of 142 mother-toddler dyads (66 %) participated in hair sampling. The most common reason for participation refusal was related to hairstyle. All but three hair samples were of adequate weight for cortisol extraction.DiscussionThe findings from this study can help researchers address sampling feasibility concerns in hair for cortisol analysis research in mother-toddler dyads living in low-income homes in the U.S.     

Temperament and its Relationship to Autistic Symptoms in a High-Risk Infant Sib Cohort

The present study prospectively investigated early temperamental profiles and their associations with autistic symptoms in high-risk infants (N = 138) with an older sibling with autistic spectrum disorder (ASD) and low-risk infants (N = 73) with no family history of ASD. Children who were diagnosed with ASD at 36 months were distinguished from non-ASD sibs and controls by a temperament profile marked by lower positive affect, higher negative affect and difficulty controlling attention and behavior, which we labeled Effortful Emotion Regulation. This profile also distinguished the non-ASD sib group from the control group. Children with ASD were distinguished from both of the other two groups by a temperament profile of low Behavioral Approach (lower sensitivity to “social” reward cues). Low levels of Behavioral Approach were associated with a higher number of ASD symptoms, even after taking into account IQ, sex and group membership. Finally, a cluster analysis revealed two ASD subgroups distinguished by number of ASD symptoms, IQ, age of diagnosis and scores on the Behavioral Approach profile. These findings suggest that temperament may be a useful framework for understanding the emergence of ASD early in life.     

Nighttime sleep and physical activity in 6-7 month-old infants

This study examined associations between objectively-measured nighttime sleep duration and physical activity in a sample of 6–7 month-old infants (N=93). The study also investigated relationships between infant sleep and demographic and environmental characteristics. Cross-sectional relationships were assessed using linear regression analyses. Nighttime sleep duration was positively associated with physical activity levels. Nighttime sleep duration was greater when infants had a consistent bedtime, slept in a separate room, were male, and had mothers who reported having a college education or greater. These findings can inform the development of interventions that aim to improve infant sleep.     

Media exposure and language for toddlers from low-income homes

In the current study, we examined whether the quantity of toddlers’ exposure to media was related to language skills and whether meeting the American Association of Pediatrics (AAP) recommendations of limiting media exposure to one hour or less per day was related to language skills. We examined these associations in a sample of toddlers (N = 157) living in low-income homes. Toddlers were about two years of age (M = 28.44 months, SD = 1.48 months) during the first visit when parents reported on toddlers’ exposure to media in the home. Toddlers were about three years of age (M = 33.61 months, SD = 1.06 months) during the second visit when direct measures of toddlers’ expressive and receptive language and receptive vocabulary skills were completed. Controls were child gender, race, mothers’ education, marital status, work status, and center-based child care. Results indicated that more frequent exposure to media was related to lower expressive language, but not receptive language or receptive vocabulary. The predictor of AAP recommendation was not significantly related to any child language outcomes. These results suggest that media exposure may be related to the displacement of language-enhancing activities during a critical time for toddlers’ language development. However, the AAP media recommendation of one hour may not be related to language development.     

Mothers’ physical interventions in toddler play in a low-income,African American sample

This mixed method study examined 28 low-income African American mothers’ physical interventions in their 14-month-old toddlers’ play. Inductive methods were used to identify six physical intervention behaviors, the affect accompanying physical interventions, and apparent reasons for intervening. Nonparametric statistical analyses determined that toddlers experienced physical intervention largely in the context of positive maternal affect. Mothers of boys expressed highly positive affect while physically intervening more than mothers of girls. Most physically intervening acts seemed to be motivated by maternal intent to show or tell children how to play or to correct play deemed incorrect. Neutral affect was the most common toddler affect type following physical intervention, but boys were more likely than girls to be upset immediately after physical interventions. Physical interventions intended to protect health and safety seemed the least likely to elicit toddler upset.     

Predicting Growth Curves of Early Childhood Externalizing Problems: Differential Susceptibility of Children with Difficult Temperament

Using an accelerated longitudinal design, the development of externalizing problems from age 2 to 5 years was investigated in relation to maternal psychopathology, maternal parenting, gender, child temperament, and the presence of siblings. The sample consisted of 150 children selected at age 2–3 years for having high levels of externalizing problems. Parenting was measured using observational methods, and maternal reports were used for the other variables. Overall, mean levels of externalizing problems decreased over time, and higher initial levels (intercept) were related to a stronger decrease (negative slope) in externalizing problems. Results showed that higher levels of maternal psychopathology were related to less decrease in early childhood externalizing problems. Parental sensitive behavior predicted a stronger decrease in externalizing problems, but only for children with difficult temperaments. A stronger decrease of externalizing problems in children with older siblings also pertained only to children with difficult temperaments. Thus, temperamentally difficult children appear to be more susceptible to environmental influences on the development of externalizing behaviors. Our results indicate that the role of siblings in early childhood externalizing problems deserves more research attention, and that intervention efforts need to take into account temperamental differences in children’s susceptibility to environmental influences.     

Vowel categorization during word recognition in bilingual toddlers

Toddlers’ and preschoolers’ knowledge of the phonological forms of words was tested in Spanish-learning, Catalan-learning, and bilingual children. These populations are of particular interest because of differences in the Spanish and Catalan vowel systems: Catalan has two vowels in a phonetic region where Spanish has only one. The proximity of the Spanish vowel to the Catalan ones might pose special learning problems. Children were shown picture pairs; the target picture’s name was spoken correctly, or a vowel in the target word was altered. Altered vowels either contrasted with the usual vowel in Spanish and Catalan, or only in Catalan. Children’s looking to the target picture was used as a measure of word recognition. Monolinguals’ word recognition was hindered by within-language, but not non-native, vowel changes. Surprisingly, bilingual toddlers did not show sensitivity to changes in vowels contrastive only in Catalan. Among preschoolers, Catalan-dominant bilinguals but not Spanish-dominant bilinguals revealed mispronunciation sensitivity for the Catalan-only contrast. These studies reveal monolingual children’s robust knowledge of native-language vowel categories in words, and show that bilingual children whose two languages contain phonetically overlapping vowel categories may not treat those categories as separate in language comprehension.     

Age attenuates noise and increases symmetry of head movements during sleep resting-state fMRI in healthy neonates,infants, and toddlers

Newborns produce spontaneous movements during sleep that are functionally important for their future development. This nuance has been previously studied using animal models and more recently using movement data from sleep resting-state fMRI (rs-fMRI) scans. Age-related trajectory of statistical features of spontaneous movements of the head is under-examined. This study quantitatively mapped a developmental trajectory of spontaneous head movements during an rs-fMRI scan acquired during natural sleep in 91 datasets from healthy children from ∼birth to 3 years old, using the Open Science Infancy Research upcycling protocol. The youngest participants studied, 2–3 week-old neonates, showed increased noise-to-signal levels as well as lower symmetry features of their movements; noise-to-signal levels were attenuated and symmetry was increased in the older infants and toddlers (all Spearman's rank-order correlations, P < 0.05). Thus, statistical features of spontaneous head movements become more symmetrical and less noisy from birth to ∼3 years in children. Because spontaneous movements during sleep in early life may trigger new neuronal activity in the cortex, the key outstanding question for in vivo, non-invasive neuroimaging studies in young children is not “How can we correct head movement better?” but rather: How can we represent all important sources of neuronal activity that shape functional connections in the still-developing human central nervous system?     

The stability of mastery motivation and its relationship with home environment in infants and toddlers

Mastery motivation (intrinsic drives to explore and master one's environment) is a key developmental element. The aims of this study were to investigate (1) the stability of mastery motivation between 2 and 3 years of age for two genders; and (2) the associations between early home environment and toddlers’ mastery motivation in children with typical development.

Methods

Data of 102 children developing typically from a birth cohort study at Northern Taiwan were analyzed in two parts: (1) stability part: mastery motivation of children were measured at 2 and 3 years of age; (2) environment part: child-parent dyads were assessed from birth, 4 months, 6 months, and 2-3 years of age. Outcomes variables were measured at ages 2 and 3 years by the Dimension of Mastery Questionnaire-17th version. Main predictive variables were measured by Home Observation for Measuring Environment Inventory (HOME) to collect data of the qualities of home environment at 6 months and 2 years; by the Revised Infant Temperament Questionnaire to obtain 4-month activity levels; and by the Comprehensive Developmental Inventory for Infants and Toddlers to obtain 2-year developmental quotient (DQ).

Results

There was moderate stability of mastery motivation from 2 to 3 years, and girls’ stability was higher than boys’. 6-Month HOME rather than 2-year HOME measures were positively and significantly correlated with instrumental mastery motivation even when controlling for gender, activity level, and DQ.

Conclusion

Mastery motivation had moderate stability during the toddler period. The quality of home environment in infancy appeared to have a significant impact on toddler's mastery motivation. To promote mastery motivation, caregivers should provide better quality of home environment for infants/toddlers during the very early years.     

The BDNFval66met polymorphism and individual differences in temperament in 4-month-old infants: A pilot study

Individual differences in infants’ temperament are under genetic control. We investigated the association between brain-derived-neurotrophic-factor (BDNF_val66met) polymorphism and temperament in 63 full-term infants. Met-carriers (N = 25) had lower Regulatory capacities compared to val-homozygotes (N = 38). These findings suggest that the BDNF polymorphism affects early temperament individual differences.     

The longitudinal associations between temperament and sleep during the first year of life

Temperament and sleep in infants are related but also distinct concepts. The longitudinal effects of temperament on sleep in infancy remain unclear, although this information is potentially important for the prevention and treatment of early sleep problems. We examined how various temperament features influence sleep development during the first year of life in a large birth cohort. This study comprised mother-infant dyads with complete longitudinal data on sleep, temperament and sociodemographic measurements at six and 12 months (N = 1436). We observed that higher infant Negative Affectivity was related to several sleep problems, and that many subscales of Negative Affectivity and Orienting/Regulation predicted worse sleep and deterioration in sleep problems from six to 12 months. Few associations between Surgency and sleep were found. Our findings highlight especially Negative Affectivity as a risk factor for persistent and increasing sleep problems, and also the specific importance of the fine-grained aspects of temperament in predicting infant sleep development.     

Temperament and early stuttering intervention: Two perspectives

PurposeTo discuss clinical applications of research findings about temperament and early stuttering.MethodA “1000-bytes” format (Onslow & Millard, 2012) was used to provide readers with contemporaneous observation of a “conversation” between the authors. The conversation is proceeded by a prologue and followed by concluding statements from each author.ResultsOne author contended that comprehensive, multidimensional assessment of temperament domains is essential during clinical management of early stuttering, and the results of that assessment are best incorporated into a multifactorial treatment approach. The other author contested that view, arguing that such an approach is not empirically justifiable at present.ConclusionsThe authors agree about the salience of research on temperament and early stuttering but have different perspectives about the topic when applied to providing health care for early stuttering.     

Night waking in 6-month-old infants and maternal depressive symptoms

Relations between night waking in infants and depressive symptoms in their mothers at 6 months postpartum were examined using the data from the National Institute for Child Health and Human Development Study of Early Child Care. Although more depressive symptoms were only weakly correlated with a higher frequency of infant waking, longer wake times, and more total time awake, the rate of clinically significant depression scores was about double in mothers of chronically waking infants in comparison with mothers whose infants did not awaken during the night. The value of comparing subgroups to elucidate relations identified through correlations is discussed.     

Reactive and Regulative Temperament in Youths: Psychometric Evaluation of the Early Adolescent Temperament Questionnaire-Revised

The present study examined the psychometric properties of the self-report version of the Early Adolescent Temperament Questionnaire-Revised (EATQ-R), which is a scale for measuring reactive and regulative temperament traits, in a large sample of children and adolescents (N = 1,055). The results indicated that the internal consistency was acceptable for most EATQ-R temperament scales. Further, principal components analysis of the instrument yielded a structure with nine components, which generally reflected the temperament scales of the EATQ-R. The test–retest stability of the scale was moderate to good, whereas the parent–child agreement was rather low. Finally, the scale correlated in a theoretically meaningful way with children’s self-reports of personality and psychopathology. It can be concluded that the EATQ-R is a useful scale for measuring aspects of reactive and regulative temperament in children and adolescents, although there is certainly room for improving the instrument.

Neuroimaging the sleeping brain: Insight on memory functioning in infants and toddlers

Episodic memory, or the ability to remember past events with specific detail, is central to the human experience and is related to learning and adaptive functioning in a variety of domains. In typically developing children, episodic memory emerges during infancy and improves during early childhood and beyond. Developmental processes within the hippocampus are hypothesized to be primarily responsible for both the early emergence and persistence of episodic memory in late infancy and early childhood. However, these hypotheses are based on non-human models. In-vivo investigations in early human development of hippocampal processes have been significantly limited by methodological challenges in acquiring neuroimaging data, particularly task-related functional neuroimaging data, from infants and toddlers. Recent studies in adults have shown neural activity in the brain regions supporting episodic memory during slow-wave sleep using functional magnetic resonance imaging (fMRI), and fMRI has been increasingly utilized in infancy and early childhood to address other research questions. We review initial evidence and present preliminary data showing the promise of this approach for examining hippocampal contribution to how infants and toddlers remember individual events, and their association with information about the context in which the event occurred. Overall, our review, integrated with the presentation of some preliminary data provides insight on leveraging sleep to gain new perspectives on early memory functioning.     

Temperament and Vulnerability to Psychopathology: Introduction to the Special Section

Several authors have highlighted associations with temperament as promising avenues for understanding vulnerability to psychopathology (e.g., Muris and Ollendick, Clinical Child and Family Psychology Review, 8, 271–289, 2005; Nigg, Journal of Child Psychology and Psychiatry, and Allied Disciplines, 47, 395–422, 2006). The successful integration of models of temperament and models of psychopathology will undoubtedly increase our understanding of both. The current special section intends to present important new ideas and evidence in this field and tries to formulate answers to a couple of emerging questions. To set the stage for the papers, we provide a brief state of the art of research on temperament—psychopathology associations. After that, we discuss emerging questions in the field, some of which are addressed in the papers of this special section. To conclude, we point out a couple of future research perspectives.