Evaluation of a community health worker home visit intervention to improve child development in South Africa: A cluster-randomized controlled trial.

BACKGROUND: Effective integration of home visit interventions focused on early childhood development into existing service platforms is important for expanding access in low- and middle-income countries (LMICs). We designed and evaluated a home visit intervention integrated into community health worker (CHW) operations in South Africa. METHODS AND FINDINGS: We conducted a cluster-randomized controlled trial in Limpopo Province, South Africa. CHWs operating in ward-based outreach teams (WBOTs; clusters) and caregiver-child dyads they served were randomized to the intervention or control group. Group assignment was masked from all data collectors. Dyads were eligible if they resided within a participating CHW catchment area, the caregiver was at least 18 years old, and the child was born after December 15, 2017. Intervention CHWs were trained on a job aid that included content on child health, nutrition, developmental milestones, and encouragement to engage in developmentally appropriate play-based activities, for use during regular monthly home visits with caregivers of children under 2 years of age. Control CHWs provided the local standard of care. Household surveys were administered to the full study sample at baseline and endline. Data were collected on household demographics and assets; caregiver engagement; and child diet, anthropometry, and development scores. In a subsample of children, electroencephalography (EEG) and eye-tracking measures of neural function were assessed at a lab concurrent with endline and at 2 interim time points. Primary outcomes were as follows: height-for-age z-scores (HAZs) and stunting; child development scores measured using the Malawi Developmental Assessment Tool (MDAT); EEG absolute gamma and total power; relative EEG gamma power; and saccadic reaction time (SRT)-an eye-tracking measure of visual processing speed. In the main analysis, unadjusted and adjusted impacts were estimated using intention-to-treat analysis. Adjusted models included a set of demographic covariates measured at baseline. On September 1, 2017, we randomly assigned 51 clusters to intervention (26 clusters, 607 caregiver-child dyads) or control (25 clusters, 488 caregiver-child dyads). At endline (last assessment June 11, 2021), 432 dyads (71%) in 26 clusters remained in the intervention group, and 332 dyads (68%) in 25 clusters remained in the control group. In total, 316 dyads attended the first lab visit, 316 dyads the second lab visit, and 284 dyads the third lab visit. In adjusted models, the intervention had no significant impact on HAZ (adjusted mean difference (aMD) 0.11 [95% confidence interval (CI): -0.07, 0.30]; p = 0.220) or stunting (adjusted odds ratio (aOR) 0.63 [0.32, 1.25]; p = 0.184), nor did the intervention significantly impact gross motor skills (aMD 0.04 [-0.15, 0.24]; p = 0.656), fine motor skills (aMD -0.04 [-0.19, 0.11]; p = 0.610), language skills (aMD -0.02 [-0.18, 0.14]; p = 0.820), or social-emotional skills (aMD -0.02 [-0.20, 0.16]; p = 0.816). In the lab subsample, the intervention had a significant impact on SRT (aMD -7.13 [-12.69, -1.58]; p = 0.012), absolute EEG gamma power (aMD -0.14 [-0.24, -0.04]; p = 0.005), and total EEG power (aMD -0.15 [-0.23, -0.08]; p < 0.001), and no significant impact on relative gamma power (aMD 0.02 [-0.78, 0.83]; p = 0.959). While the effect on SRT was observed at the first 2 lab visits, it was no longer present at the third visit, which coincided with the overall endline assessment. At the end of the first year of the intervention period, 43% of CHWs adhered to monthly home visits. Due to the COVID-19 pandemic, we were not able to assess outcomes until 1 year after the end of the intervention period. CONCLUSIONS: While the home visit intervention did not significantly impact linear growth or skills, we found significant improvement in SRT. This study contributes to a growing literature documenting the positive effects of home visit interventions on child development in LMICs. This study also demonstrates the feasibility of collecting markers of neural function like EEG power and SRT in low-resource settings. TRIAL REGISTRATION: PACTR 201710002683810; https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=2683; South African Clinical Trials Registry, SANCTR 4407.

Eye tracking: empirical foundations for a minimal reporting guideline.

In this paper, we present a review of how the various aspects of any study using an eye tracker (such as the instrument, methodology, environment, participant, etc.) affect the quality of the recorded eye-tracking data and the obtained eye-movement and gaze measures. We take this review to represent the empirical foundation for reporting guidelines of any study involving an eye tracker. We compare this empirical foundation to five existing reporting guidelines and to a database of 207 published eye-tracking studies. We find that reporting guidelines vary substantially and do not match with actual reporting practices. We end by deriving a minimal, flexible reporting guideline based on empirical research (Section "An empirically based minimal reporting guideline").

Converging neural and behavioral evidence for a rapid, generalized response to threat-related facial expressions in 3-year-old children.

Electrophysiological studies on adults suggest that humans are efficient at detecting threat from facial information and tend to grant these signals a priority in access to attention, awareness, and action. The developmental origins of this bias are poorly understood, partly because few studies have examined the emergence of a generalized neural and behavioral response to distinct categories of threat in early childhood. We used event-related potential (ERP) and eye-tracking measures to examine children's early visual responses and overt attentional biases towards multiple exemplars of angry and fearful vs. other (e.g., happy and neutral) faces. A large group of children was assessed longitudinally in infancy (5, 7, or 12 months) and at 3 years of age. The final ERP dataset included 148 infants and 132 3-year-old children; and the final eye-tracking dataset included 272 infants and 334 3-year-olds. We demonstrate that 1) neural and behavioral responses to facial expressions converge on an enhanced response to fearful and angry faces at 3 years of age, with no differentiation between or bias towards one or the other of these expressions, and 2) a support vector machine learning model using data on the early-stage neural responses to threat reliably predicts the duration of overt attentional dwell time for threat-related faces at 3 years. However, we found little within-subject correlation between threat-bias attention in infancy and at 3 years of age. These results provide unique evidence for the early development of a rapid, unified response to two distinct categories of facial expressions with different physical characteristics, but shared threat-related meaning.

Pupillary and Attentional Responses to Infant Facial Expressions in Mothers Across Socioeconomic Variations.

Maternal responses to infant facial expressions were examined in two socioeconomically diverse samples of South African mothers (Study I, N = 111; and Study II, N = 214; age: 17-44 years) using pupil and gaze tracking. Study I showed increased pupil response to infant distress expressions in groups recruited from private as compared to public maternity clinics, possibly reflecting underlying differences in socioeconomic status (SES) across the groups. Study II, sampling uniformly low-SES neighborhoods, found increased pupil dilation and faster orientation to expressions of infant distress, but only in the highest income group. These results are consistent with maternal physiological and attentional sensitivity to infant distress cues but challenge the universality of this sensitivity across socioeconomic diversity.

Maternal Depressive Symptoms During the Pre- and Postnatal Periods and Infant Attention to Emotional Faces.

We examined how infants' attentional disengagement from happy, fearful, neutral, and phase-scrambled faces at 8 months, as assessed by eye tracking, is associated with trajectories of maternal depressive symptoms from early pregnancy to 6 months postpartum (decreasing n = 48, increasing n = 34, and consistently low symptom levels n = 280). The sample (mother-infant dyads belonging to a larger FinnBrain Birth Cohort Study) was collected between 5/2013-6/2016. The overall disengagement probability from faces to distractors was not related to maternal depressive symptoms, but fear bias was heightened in infants whose mothers reported decreasing or increasing depressive symptoms. Exacerbated attention to fearful faces in infants of mothers with depressive symptoms may be independent of the timing of the symptoms in the pre- and postnatal stages.

Early development of visual attention in infants in rural Malawi.

Eye tracking research has shown that infants develop a repertoire of attentional capacities during the first year. The majority of studies examining the early development of attention comes from Western, high-resource countries. We examined visual attention in a heterogeneous sample of infants in rural Malawi (N = 312-376, depending on analysis). Infants were assessed with eye-tracking-based tests that targeted visual orienting, anticipatory looking, and attention to faces at 7 and 9 months. Consistent with prior research, infants exhibited active visual search for salient visual targets, anticipatory saccades to predictable events, and a robust attentional bias for happy and fearful faces. Individual variations in these processes had low to moderate odd-even split-half and test-retest reliability. There were no consistent associations between attention measures and gestational age, nutritional status, or characteristics of the rearing environment (i.e., maternal cognition, psychosocial well-being, socioeconomic status, and care practices). The results replicate infants' early attentional biases in a large, unique sample, and suggest that some of these biases (e.g., bias for faces) are pronounced in low-resource settings. The results provided no evidence that the initial manifestation of infants' attentional capacities is associated with risk factors that are common in low-resource environments.

Infants' attention bias to faces as an early marker of social development.

Infants have a strong tendency to look at faces. We examined individual variations in this attentional bias in 7-month-old infants by using a face-distractor competition paradigm and tested in a longitudinal sample whether these variations were associated with outcomes reflecting social behavior at 24 and 48 months of age (i.e., spontaneous helping, emotion understanding, mentalizing, and callous-unemotional traits; N = 100-138). The results showed a robust and distinct attention bias to faces at 7 months, particularly when faces were displaying a fearful expression. This bias declined between 7 and 24 months and there were no significant correlations in attention dwell times between 7 and 24 months of age. Variations in attention to faces at 7 months were not associated with emotion understanding or mentalizing abilities at 48 months of age, but increased attention to faces at 7 months (regardless of facial expression) was related to more frequent helping responses at 24 months and reduced callous-unemotional traits at 48 months of age. Thus, while the results fail to associate infants' face bias with later-emerging emotion understanding and mentalizing capacities, they are consistent with a model whereby increased attention to faces in infancy is linked with the development of affective empathy and responsivity to others' needs.

Mothers' pupillary responses to infant facial expressions.

BACKGROUND: Human parental care relies heavily on the ability to monitor and respond to a child's affective states. The current study examined pupil diameter as a potential physiological index of mothers' affective response to infant facial expressions. METHODS: Pupillary time-series were measured from 86 mothers of young infants in response to an array of photographic infant faces falling into four emotive categories based on valence (positive vs. negative) and arousal (mild vs. strong). RESULTS: Pupil dilation was highly sensitive to the valence of facial expressions, being larger for negative vs. positive facial expressions. A separate control experiment with luminance-matched non-face stimuli indicated that the valence effect was specific to facial expressions and cannot be explained by luminance confounds. Pupil response was not sensitive to the arousal level of facial expressions. CONCLUSIONS: The results show the feasibility of using pupil diameter as a marker of mothers' affective responses to ecologically valid infant stimuli and point to a particularly prompt maternal response to infant distress cues.

Evidence for spared attention to faces in 7-month-old infants after prenatal exposure to antiepileptic drugs.

INTRODUCTION: Prenatal antiepileptic drug (AED) exposure is associated with an increased risk of cognitive impairment and autism spectrum disorders detected mainly at the age of two to six years. We examined whether the developmental aberrations associated with prenatal AED exposure could be detected already in infancy and whether effects on visual attention can be observed at this early age. MATERIAL AND METHODS: We compared a prospective cohort of infants with in utero exposure to AED (n=56) with infants without drug exposures (n=62). The assessments performed at the age of seven months included standardized neurodevelopmental scores (Griffiths Mental Developmental Scale and Hammersmith Infant Neurological Examination) as well as a novel eye-tracking-based test for visual attention and orienting to faces. Background information included prospective collection of AED exposure data, pregnancy outcome, neuropsychological evaluation of the mothers, and information on maternal epilepsy type. RESULTS: Carbamazepine, oxcarbazepine, and valproate, but not lamotrigine or levetiracetam, were associated with impaired early language abilities at the age of seven months. The general speed of visuospatial orienting or attentional bias for faces measured by eye-tracker-based tests did not differ between AED-exposed and control infants. DISCUSSION: Our findings support the idea that prenatal AED exposure may impair verbal abilities, and this effect may be detected already in infancy. In contrast, the early development of attention to faces was spared after in utero AED exposure.

Attention to Faces Expressing Negative Emotion at 7 Months Predicts Attachment Security at 14 Months.

To investigate potential infant-related antecedents characterizing later attachment security, this study tested whether attention to facial expressions, assessed with an eye-tracking paradigm at 7 months of age (N = 73), predicted infant-mother attachment in the Strange Situation Procedure at 14 months. Attention to fearful faces at 7 months predicted attachment security, with a smaller attentional bias to fearful expressions associated with insecure attachment. Attachment disorganization in particular was linked to an absence of the age-typical attentional bias to fear. These data provide the first evidence linking infants' attentional bias to negative facial expressions with attachment formation and suggest reduced sensitivity to facial expressions of negative emotion as a testable trait that could link attachment disorganization with later behavioral outcomes.

Widely applicable MATLAB routines for automated analysis of saccadic reaction times.

Saccadic reaction time (SRT) is a widely used dependent variable in eye-tracking studies of human cognition and its disorders. SRTs are also frequently measured in studies with special populations, such as infants and young children, who are limited in their ability to follow verbal instructions and remain in a stable position over time. In this article, we describe a library of MATLAB routines (Mathworks, Natick, MA) that are designed to (1) enable completely automated implementation of SRT analysis for multiple data sets and (2) cope with the unique challenges of analyzing SRTs from eye-tracking data collected from poorly cooperating participants. The library includes preprocessing and SRT analysis routines. The preprocessing routines (i.e., moving median filter and interpolation) are designed to remove technical artifacts and missing samples from raw eye-tracking data. The SRTs are detected by a simple algorithm that identifies the last point of gaze in the area of interest, but, critically, the extracted SRTs are further subjected to a number of postanalysis verification checks to exclude values contaminated by artifacts. Example analyses of data from 5- to 11-month-old infants demonstrated that SRTs extracted with the proposed routines were in high agreement with SRTs obtained manually from video records, robust against potential sources of artifact, and exhibited moderate to high test-retest stability. We propose that the present library has wide utility in standardizing and automating SRT-based cognitive testing in various populations. The MATLAB routines are open source and can be downloaded from http://www.uta.fi/med/icl/methods.html .

Tuning the developing brain to social signals of emotions.

Humans in different cultures develop a similar capacity to recognize the emotional signals of diverse facial expressions. This capacity is mediated by a brain network that involves emotion-related brain circuits and higher-level visual-representation areas. Recent studies suggest that the key components of this network begin to emerge early in life. The studies also suggest that initial biases in emotion-related brain circuits and the early coupling of these circuits and cortical perceptual areas provide a foundation for a rapid acquisition of representations of those facial features that denote specific emotions.

Regulatory variant of the TPH2 gene and early life stress are associated with heightened attention to social signals of fear in infants.

BACKGROUND: Cross-species evidence suggests that genetic and experiential factors act early in development to establish individual emotional traits, but little is known about the mechanisms that emerge during this period to mediate long-term outcomes. Here, we tested the hypothesis that known genetic and environmental risk conditions may heighten infants' natural tendency to attend to threat-alerting stimuli, resulting in a cognitive bias that may contribute to emotional vulnerability. METHODS: Data from two samples of 5-7-month-old infants (N = 139) were used to examine whether established candidate variations in the serotonin-system genes, i.e., TPH2 SNP rs4570625 (-703 G/T) and HTR1A SNP rs6295 (-1019 G/C), and early rearing condition (maternal stress and depressive symptoms) are associated with alterations in infants' attention to facial expressions. Infants were tested with a paradigm that assesses the ability to disengage attention from a centrally presented stimulus (a nonface control stimulus or a neutral, happy, or fearful facial expression) toward the location of a new stimulus in the visual periphery (a geometric shape). RESULTS: TPH2 -703 T-carrier genotype (i.e., TT homozygotes and heterozygotes), presence of maternal stress and depressive symptoms, and a combination of the T-carrier genotype and maternal depressive symptoms were associated with a relatively greater difficulty disengaging attention from fearful facial expressions. No associations were found with infants' temperamental traits. CONCLUSIONS: Alterations in infants' natural attentional bias toward fearful facial expressions may emerge prior to the manifestation of emotional and social behaviors and provide a sensitive marker of early emotional development.

Facial affect recognition and exit examination performance in medical students: a prospective exploratory study.

BACKGROUND: Facial affect recognition (FAR) abilities underpin emotional intelligence (EI). The latter is suggested to predict academic success and to be important for clinician-patient interaction. It is therefore of interest to investigate the possible association between FAR and academic performance in undergraduate medical students. METHODS: We assessed the association between the ability to recognize emotions through facial expression and exit examination performance, a measure of clinical proficiency, in undergraduate medical students stratified by gender at a South African tertiary institution using a prospective descriptive design. Data on the perception of facial expressions and exit examination marks were obtained from 144 (61%) females and 93 (39%) males with a mean age of 24.1 ± 1.6 years. Facial affect recognition measures on the Hexagon and Animation tasks were individually correlated with academic performance indicators using Pearson correlation. RESULTS: The perceptual discrimination of anger was associated with improved performance in anaesthetics (r = .24; p = .004) and urology (r = .24; p = .001), while the recognition of happiness was associated with decreased performance in obstetrics (r = -.21, p = .002). Gender was an effect modifier in the relationship between perceptual discrimination of anger and urology performance (p = .03), with a strong positive relationship for males, but a non-significant relationship for females. CONCLUSION: There was no overall correlation between FAR and overall academic performance or with gender. However, subject (specialty) specific findings with recognition of specific emotions and with gender as effect modifier poses interesting questions about EI and FAR and prompts further research into FAR as a useful tool. Being an objective test and offering a more focused assessment makes FAR worthy of further application.

Affective-motivational brain responses to direct gaze in children with autism spectrum disorder.

BACKGROUND: It is unclear why children with autism spectrum disorders (ASD) tend to be inattentive to, or even avoid eye contact. The goal of this study was to investigate affective-motivational brain responses to direct gaze in children with ASD. To this end, we combined two measurements: skin conductance responses (SCR), a robust arousal measure, and asymmetry in frontal electroencephalography (EEG) activity which is associated with motivational approach and avoidance tendencies. We also explored whether degree of eye openness and face familiarity modulated these responses. METHODS: Skin conductance responses and frontal EEG activity were recorded from 14 children with ASD and 15 typically developing children whilst they looked at familiar and unfamiliar faces with eyes shut, normally open or wide-open. Stimuli were presented in such a way that they appeared to be looming towards the children. RESULTS: In typically developing children, there were no significant differences in SCRs between the different eye conditions, whereas in the ASD group the SCRs were attenuated to faces with closed eyes and increased as a function of the degree of eye openness. In both groups, familiar faces elicited marginally greater SCRs than unfamiliar faces. In typically developing children, normally open eyes elicited greater relative left-sided frontal EEG activity (associated with motivational approach) than shut eyes and wide-open eyes. In the ASD group, there were no significant differences between the gaze conditions in frontal EEG activity. CONCLUSIONS: Collectively, the results replicate previous finding in showing atypical modulation of arousal in response to direct gaze in children with ASD but do not support the assumption that this response is associated with an avoidant motivational tendency. Instead, children with ASD may lack normative approach-related motivational response to eye contact.

The stability of early developing attentional bias for faces and fear from 8 to 30 and 60 months in the FinnBrain Birth Cohort Study.

Most infants exhibit an attentional bias for faces and fearful facial expressions. These biases reduce toward the third year of life, but little is known about the development of the biases beyond early childhood. We used the same methodology longitudinally to assess attention disengagement patterns from nonface control pictures and faces (neutral, happy, and fearful expressions) in a large sample of children at 8, 30, and 60 months (N = 389/393/492, respectively; N = 72 for data in all three assessment; girls > 45.3% in each assessment). "Face bias" was measured as a difference in disengagement probability (DP) from faces (neutral/happy) versus nonface patterns. "Fear bias" was calculated as a difference in DP for fearful versus happy/neutral faces. At group level, DPs followed a nonlinear longitudinal trajectory in all face conditions, being lowest at 8 months, highest at 30 months, and intermediate at 60 months. Face bias declined between 8 and 30 months, but did not change between 30 and 60 months. Fear bias declined linearly from 8 to 60 months. Individual differences in disengagement were generally not stable across age, but weak correlations were found in face bias between 8- and 60-month, and in DPs between 30- and 60-month (rs = .22-.41). The results suggest that prioritized attention to faces-that is, a hallmark of infant cognition and a key aspect of human social behavior-follows a nonlinear trajectory in early childhood and may have only weak continuity from infancy to mid childhood. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Assessing infant cognition in field settings using eye-tracking: a pilot cohort trial in Sierra Leone.

OBJECTIVES: To investigate the feasibility of eye-tracking-based testing of the speed of visual orienting in malnourished young children at rural clinics in Sierra Leone. DESIGN: Prospective dual cohort study nested in a cluster-randomised trial. SETTING: 8 sites participating in a cluster-randomised trial of supplementary feeding for moderate acute malnutrition (MAM). PARTICIPANTS: For the MAM cohort, all infants aged 7-11 months at the eight sites were enrolled, 138 altogether. For controls, a convenience sample of all non-malnourished infants aged 7-11 months at the same sites were eligible, 60 altogether. A sample of 30 adults at the sites also underwent eye-tracking tests as a further control. INTERVENTIONS: Infants with MAM were provided with supplementary feeding. OUTCOME MEASURES: The primary outcomes were feasibility and reliability of eye-tracking-based testing of saccadic reaction time (SRT). Feasibility was assessed by the percent of successful tests in the infants. Reliability was measured with intraclass correlation coefficients (ICCs). Secondary outcomes were mean SRT based on nutritional state as well as and changes in mean SRT after supplementary feeding of MAM children. RESULTS: Infants exhibited consistent orienting to targets on a computer screen (>95% of valid trials). Mean SRTs had moderate stability within visits (ICCs 0.60-0.69) and across the 4-week test-retest interval (0.53) in infants; the adult control group had greater SRT stability (within visit ICC=0.92). MAM infants had a trend toward higher adjusted SRT at baseline (difference=12.4 ms, 95% CI -2 to 26.9, p=0.09) and improvement in SRT 4 weeks thereafter (difference=-14 ms, 95% CI -26.2 to -1.7, p=0.025) compared with age-matched controls. CONCLUSIONS: The results demonstrate the feasibility of eye-tracking-based testing in a resource-poor field setting and suggest eye-tracking measures have utility in the detection of group level effects of supplementary feeding.

Serotonin and early cognitive development: variation in the tryptophan hydroxylase 2 gene is associated with visual attention in 7-month-old infants.

BACKGROUND: Allelic variation in the promoter region of a gene that encodes tryptophan hydroxylase isoform 2 (TPH2), a rate-limiting enzyme of serotonin synthesis in the central nervous system, has been associated with variations in cognitive function and vulnerability to affective spectrum disorders. Little is known about the effects of this gene variant on cognition during development and about possible intermediate developmental steps that lead to the adult phenotype. Here, we examined the hypothesis that the TPH2 -703 may act during early stages of development and bias the acquisition of elementary cognitive processes involved in attention and emotion regulation. METHODS: Seven-month-old infants (n = 66) were genotyped for the TPH2 -703 G/T polymorphism (rs4570625) and tested for the efficiency of attention shifts from a stimulus at fixation to a new stimulus in the visual periphery. RESULTS: Compared to TPH2 G/G homozygotes, infants with the T-carrier genotype exhibited a significantly higher number of missing attention shifts. This genotype effect tended to be particularly pronounced when infants had to disengage from an affectively salient stimulus before shifting attention to the peripheral stimulus. The results also showed that TPH2 genotype was indirectly associated, via its effect on attention disengagement, with temperamental emotion regulation (soothability). CONCLUSIONS: Together, these results implicate serotonin system genes in early cognitive development and suggest variations in the early-emerging cognitive capacities as a potential developmental precursor of individual differences in emotion regulation and vulnerability to affective disorders.

Signaled night awakening and its association with social information processing and socio-emotional development across the first two years.

STUDY OBJECTIVES: Night awakening is common in infancy, and some infants continue to have signaled night awakenings throughout early childhood. However, the influence of signaled night awakening on children's social development is less explored. In the present study, longitudinal associations between signaled night awakening, social information processing, and socio-emotional development were measured within the CHILD-SLEEP birth cohort in two groups formed based on parent-reported night awakenings. METHODS: At 8 months, there were 77 infants in the waking group (≥3 awakenings) and 69 infants in the nonwaking group (≤1 awakening). At 8 and 24 months, social information processing was measured as children's attention to neutral and emotional faces, and at 24 months, parent-reported socio-emotional behavior was measured with the Brief Infant-Toddler Social and Emotional Assessment (BITSEA) questionnaire. RESULTS: The two groups showed different patterns of attention to emotional faces. The waking group had a more pronounced attentional bias to fearful versus happy faces, whereas in the nonwaking group, attention to fearful and happy faces did not differ. In addition, at 24 months, the waking group had more dysregulation problems and lower social competence than the nonwaking group, but no clear differences in internalizing or externalizing problems were found. CONCLUSIONS: Our results contribute to the literature by showing that during the first 2 years of life, signaled night awakening is associated with social information processing and socio-emotional behavior.