The effects of economic and sociocultural stressors on the well-being of children of Latino immigrants living in poverty.

This paper explored whether preschooler's physical (body mass index and salivary cortisol levels) and psychological (internalizing/externalizing behaviors) well-being were predicted by economic hardship as has been previously documented, and further whether parental immigration-related stress and/or acculturation level moderated this relationship in low-income Latino families

The Cortisol Awakening Response (CAR) in 2-to 4-year-old Children: Effects of Acute Nighttime Sleep Restriction, Wake Time, and Daytime Napping

The cortisol awakening response (CAR) is presumed critically important for healthy adaptation. The current literature, however, is hampered by systematic measurement difficulties relative to awakening, especially with young children. While reports suggest the CAR is smaller in children than adults, well-controlled research in early childhood is scarce. We examined whether robust CARs exist in 2- to 4-year-old children and if sleep restriction, wake timing, and napping influence the CAR (n?=?7). During a 25-day in-home protocol, researchers collected four salivary cortisol samples (0, 15, 30, 45?min post-wake) following five polysomnographic sleep recordings on nonconsecutive days after 4?hr (morning nap), 7?hr (afternoon nap), 10?hr (evening nap), 13?hr (baseline night), and 16?hr (sleep restriction night) of wakefulness (20 samples/child). The CAR was robust after nighttime sleep, diminished after sleep restriction, and smaller but distinct after morning and afternoon (not evening) naps. Cortisol remained elevated 45?min after morning and afternoon naps. (c) 2011 Wiley Periodicals, Inc. Dev Psychobiol 54:412422, 2012

Parental Buffering in the Context of Poverty: Positive Parenting Behaviors Differentiate Young Children\u27s Stress Reactivity Profiles

Experiencing poverty increases vulnerability for dysregulated hypothalamic–pituitary–adrenal (HPA) axis functioning and compromises long-term health. Positive parenting buffers children from HPA axis reactivity, yet this has primarily been documented among families not experiencing poverty. We tested the theorized power of positive parenting in 124 parent–child dyads recruited from Early Head Start (Mage = 25.21 months) by examining child cortisol trajectories using five samples collected across a standardized stress paradigm. Piecewise latent growth models revealed that positive parenting buffered children\u27s stress responses when controlling for time of day, last stress task completed, and demographics. Positive parenting also interacted with income such that positive parenting was especially protective for cortisol reactivity in families experiencing greater poverty. Findings suggest that positive parenting behaviors are important for protecting children in families experiencing low income from heightened or prolonged physiologic stress reactivity to an acute stressor

The CIRCORT database: Reference ranges and seasonal changes in diurnal salivary cortisol derived from a meta-dataset comprised of 15 field studies

Diurnal salivary cortisol profiles are valuable indicators of adrenocortical functioning in epidemiological research and clinical practice. However, normative reference values derived from a large number of participants and across a wide age range are still missing. To fill this gap, data were compiled from 15 independently conducted field studies with a total of 104,623 salivary cortisol samples obtained from 18,698 unselected individuals (mean age: 48.3 years, age range: 0.5–98.5 years, 39% females). Besides providing a descriptive analysis of the complete dataset, we also performed mixed-effects growth curve modeling of diurnal salivary cortisol (i.e., 1–16 h after awakening). Cortisol decreased significantly across the day and was influenced by both, age and sex. Intriguingly, we also found a pronounced impact of sampling season with elevated diurnal cortisol in spring and decreased levels in autumn. However, the majority of variance was accounted for by between-participant and between-study variance components. Based on these analyses, reference ranges (LC/MS–MS calibrated) for cortisol concentrations in saliva were derived for different times across the day, with more specific reference ranges generated for males and females in different age categories. This integrative summary provides important reference values on salivary cortisol to aid basic scientists and clinicians in interpreting deviations from the normal diurnal cycle

Looking Back and Moving Forward: Evaluating and Advancing Translation from Animal Models to Human Studies of Early Life Stress and DNA Methylation

Advances in epigenetic methodologies have deepened theoretical explanations of mechanisms linking early life stress (ELS) and disease outcomes and suggest promising targets for intervention. To date, however, human studies have not capitalized on the richness of diverse animal models to derive and systematically evaluate specific and testable hypotheses. To promote cross‐species dialog and scientific advance, here we provide a classification scheme to systematically evaluate the match between characteristics of human and animal studies of ELS and DNA methylation. Three preclinical models were selected that are highly cited, and that differ in the nature and severity of the ELS manipulation as well as in the affected epigenetic loci (the licking and grooming, maternal separation, and caregiver maltreatment models). We evaluated the degree to which human studies matched these preclinical models with respect to the timing of ELS and of DNA methylation assessment, as well as the type of ELS, whether sex differences were explicitly examined, the tissue sampled, and the targeted loci. Results revealed \u3c50% match (range of 8–83%) between preclinical models and human work on these variables. Immediate and longer‐term suggestions to improve translational specificity are offered, with the goal of accelerating scientific advance

The dynamics of attention during free looking.

Simple methods to study attention dynamics in challenging research and practical applications are limited. We explored the utility of examining attention dynamics during free looking with steady-state visual evoked potentials (SSVEPs), which reflect the effects of attention on early sensory processing. This method can be used with participants who cannot follow verbal instructions and patients without voluntary motor control. In our healthy participants, there were robust fluctuations in the strength of SSVEPs driven by the fixated and non-fixated stimuli (rapidly changing pictures of faces) in the seconds leading up to the moment they chose to shift their gaze to the next stimulus sequence. Furthermore, the amplitude of SSVEPs driven by the fixated stimuli predicted subsequent recognition of individual stimuli. The results illustrate how information about the temporal course of attention during free looking can be obtained with simple methods based on the attentional modulation of SSVEPs

Beyond Income: Expanding our Empirical Toolkit to Better Predict Caregiver Well-Being

Objectives Despite growing concern that income alone does not capture how low-income families are managing financially, it continues to be one of the most commonly used indicators of socioeconomic status and is routinely used as a qualifying factor for government assistance programs. Income can be difficult to measure accurately and alone may not be the best predictor of caregiver well-being, in particular among ethnically diverse families. A more nuanced understanding may be critical for identifying families in need of services and supporting success after enrollment in need-based programming. Thus, the current study investigated the relationship between traditional (low income, low education, unemployment), and less traditional (economic pressure, economic hardship, perceived social status, crowding) socioeconomic indicators and caregiver well-being (caregiver depressive symptoms, anxiety, dysfunction in the parent-child relationship) using data from a multisite study. Methods Participants were 978 racially/ethnically diverse caregivers (97% female) of young children enrolled in Early Head Start programming from six sites across the United States. Results Exploratory factor analyses resulted in a three-factor model, capturing demographic risk, resource strain, and perceived social status. The Resource Strain factor was most strongly associated with greater caregiver depressive and anxiety symptoms, and dysfunction in the parent-child relationship. Further, hierarchical regression models revealed up to a four-fold increase in variance explained when adding economic strain along with traditional variables to models predicting caregiver well-being. Conclusions Results support the need to supplement traditional economic measurement when supporting families experiencing low income and for measuring poverty among ethnically diverse families

The Cortisol Awakening Response (CAR) in Toddlers: Nap-dependent Effects on the Diurnal Secretory Pattern

Introduction Cortisol levels in adults show a sharp decrease from mid-morning to mid-afternoon. Most toddlers take afternoon naps, which is associated with a less mature diurnal pattern characterized by a midday plateau in cortisol secretion. Napping in preschoolers produces a robust cortisol awakening response (CAR), which may account for such maturational differences. This experimental study extends prior work by examining whether the presence and timing of the nap-dependent CAR influences the diurnal cortisol pattern in toddlers. Methods Toddlers (n = 28; 13 females; 30–36 months) followed a strict biphasic sleep schedule (≥12.5 h time in bed; ≥90 min nap) for ≥3 days before each of four randomly ordered, in-home cortisol assessments. For each assessment, saliva samples were obtained at morning awakening, ∼09:30, pre-nap, 0, 15, 30, 45, 90, and 135 min post-nap awakening (verified with actigraphy), and ∼19:30. On one day, children napped at their scheduled time, and parents collected saliva samples. On another day, children missed their nap, and parents collected saliva samples at matched times. On two other days, children napped 4 h (morning) and 7 h (afternoon) after awakening in the morning, during which time researchers collected pre- and post-nap saliva samples. Saliva was assayed for cortisol (μg/dl). Results Three-level multilevel models were used to estimate the CAR and diurnal cortisol patterns in all four conditions. Compared to the no-nap condition (no observed CAR; b = −0.78, p = 0.65), we found a pronounced cortisol rise following the morning nap (b = 11.00, p \u3c 0.001) and both afternoon naps whether samples were collected by parents (b = 5.19, p \u3c 0.01) or experimenters (b = 4.97, p \u3c 0.01). Napping in the morning resulted in the most robust post-nap cortisol rise (b = 10.21, p \u3c 0.001). Diurnal patterns were analyzed using piecewise growth modeling that estimated linear coefficients for five separate periods throughout the day (corresponding to morning decline, noon decline, post-nap rise, post-nap decline, and evening decline). We observed a significant post-nap rise in cortisol values on the parent-collected afternoon nap (b = 3.41, p \u3c 0.01) and the experimenter-collected morning nap (b = 7.50, p \u3c 0.01) days as compared to the no-nap day (b = −0.17, p = 0.82). No other differences in diurnal profiles were observed between the parent-collected nap and no-nap conditions; however, toddlers had a steeper evening decline on the day of the morning nap compared to the parent-collected afternoon nap (b = 0.30, p \u3c 0.05) and no-nap conditions (b = 0.27, p \u3c 0.05). Discussion These well-controlled findings suggest that the presence and timing of daytime naps influence the pattern of diurnal cortisol secretion in toddlers. They also provide support for the hypothesis that napping is the primary state driving the immature midday plateau in cortisol secretion, which becomes more adult-like across childhood. Prior studies of the diurnal cortisol pattern have employed a cubic model, and therefore, have not detected all possible variations due to napping. Our experimental data have important methodological implications for researchers examining associations between the slope of the diurnal cortisol pattern and developmental outcomes, as well as those utilizing afternoon cortisol reactivity protocols in napping children

SSVEP amplitude preceding un-cued gaze shifts.

<p>Mean amplitude (µV) of SSVEPs elicited by the fixated (F, red curve) and non-fixated (NF, black curve) stimulus sequences in a 250 ms moving window during the 4 s preceding un-cued gaze shifts in the first (A), second (B), and third (C) shift sets. Standard errors for each moving window have been omitted to reduce visual clutter. The mean (± SEM) SSVEP amplitude for each shift set is plotted to the right of the corresponding time series. The decreased difference between SSVEP amplitude driven by the fixated and non-fixated stimulus sequences after the first shift set (fixated 2.71±.15 vs. non-fixated 2.13±0.13 for shift set 1, 2.61±.14 vs. 2.26±0.16 for shift set 2, 2.61±.12 vs. 2.28±0.15 for shift set 3; mean ± SEM µV), indicated by a Stimulus×Shift Set interaction (<i>p</i> = .003) in the analysis of variance, is evident. The dependence of this trend on the time before the next shift, indicated by a Stimulus×Shift Set×Time interaction (<i>p</i> = .008), is also evident. The thick portions of the curves indicate times during which SSVEP amplitude exceeded 1 SD above the mean for more than 2 consecutive windows. Asterisks (*) mark the local maxima within those intervals for which SSVEP amplitude predicted subsequent recognition of fixated stimuli as measured by <i>d′</i> (Pearson correlation, <i>p</i><.0005). Details of the analyses are in the text.</p

Amplitude spectrum of EEG.

<p>Example of EEG (inset) recorded at TO1 from one participant during the 4 s before an un-cued gaze shift from the stimulus sequence on the left to the stimulus sequence on the right (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056428#pone-0056428-g001" target="_blank">Figure 1</a>). Peaks in the amplitude spectrum are evident at the flicker frequencies of the fixated (8 Hz) and non-fixated (12 Hz) stimulus sequences.</p