Screen exposure is linked with attention difficulties in childhood. Yet, little is known about how different forms of screen exposure relate to specific attentional processes, namely, endogenous and exogenous attention, during infancy, a period characterized by rapid attentional development and increased sensitivity to environmental experiences. The present study addressed this gap by examining the association between screen time, background television exposure, and early attention. A total of 110 typically developing infants aged 9–16 months participated in the study. Infants completed an anti-saccade task and a distractibility task to measure exogenous and endogenous attention. Mothers reported infants’ daily screen time and background television exposure at home. Linear mixed-effects models showed that greater screen time and background television exposure predicted faster orienting to salient stimuli (i.e., heightened exogenous attention) and prolonged distraction (i.e., reduced endogenous attention). When modeled simultaneously, background television exposure remained significantly associated with faster orienting, while increased screen time remained significantly associated with prolonged distraction. These findings suggest that infants’ screen media environments may be differentially associated with specific attentional processes. Overall, the findings highlight the importance of considering both direct and background screen exposure when examining early attention development.
Previous research has examined temperament and sleep separately with respect to their relationship to young children’s physiological stress response; however, little research has jointly investigated these two constructs in relation to children’s physiological stress response. Previous research also has not considered the potential contributions of individual components of children’s negative emotionality to their stress response. In the present study, mothers reported on children’s negative emotionality and sleep problems when children were 18 and 24 months old respectively. When children were 30 months old, saliva samples were collected prior to and after the stranger approach task to assess physiological stress response as measured by total cortisol secretion (AUCg) and cortisol reactivity (AUCi). Results showed that frustration was positively associated with AUCg. Frustration and sleep problems were also both positively associated with AUCi, and shyness was negatively associated with AUCi. No other dimensions of negative emotionality were related to AUCg or AUCi. These results highlight the unique contributions of toddlers’ temperament and sleep difficulties to their stress physiology. Furthermore, these results highlight the importance of parsing out the individual components of negative emotionality when conducting temperament research on children’s stress response.
Sleep is integral to early neurodevelopment and health, yet most normative data derive from high-income, global North populations. Context-specific data from sub-Saharan Africa, and South Africa in particular, remain scarce. This study describes sleep patterns across the first three years of life in a South African sample and examines caregiver and child characteristics associated with variation in sleep outcomes. A cross-sectional online survey was completed by 340 South African caregivers of children aged 0–36 months. Sleep was assessed using items from the Brief Infant Sleep Questionnaire-Revised. Several sleep outcomes were examined across six age bands. One-way ANOVAs examined age-related differences, and multiple linear regression analyses identified caregiver and child correlates of sleep. Significant age-related differences were observed for total sleep duration, nighttime consolidation, and daytime sleep, with large effect sizes for daytime sleep. Bedtime, bedtime consistency, and sleep onset latency remained similar across the six age groups (0–3–25–36 months). Child age was the most consistent predictor of sleep outcomes. Caregiver unemployment was associated with shorter and less consolidated nighttime sleep. Second-born or later children showed more frequent night wakings and greater daytime napping. Intermediate temperament was associated with longer sleep onset latency. Age-related differences in sleep patterns during the first three years are broadly consistent with international findings, though aspects of sleep timing appear more contextually shaped. Findings provide preliminary data for South Africa and highlight the need for age-stratified, culturally sensitive sleep guidance and interventions.
Early caregiver-infant interactions play a crucial role in the development of facial expression understanding, but little is known about how early experience shapes the neural representation of facial expression information. In the adult brain, facial expressions are represented componentially, with neural activity encoding constituent facial muscle configurations, or action units (AUs), independently of global emotion categories. This may provide important functional advantages, but the developmental emergence of such a representational format is unclear. We examined whether neural representations of facial expressions become increasingly organised around AU structure across early development, and whether caregiver mirroring predicts this process. Electroencephalography (EEG) data were analysed from samples of nine-month-olds and 30-month-olds, who viewed short video clips of dynamic facial expressions. Nine-month-olds had also been observed during mother-infant interactions at two months of age. Time-resolved representational similarity analysis was used to characterise the dynamic geometry of neural representations. At 30 months, neural activity reliably encoded AU structure, whereas group-level AU encoding was not observed at nine months. However, individual differences in AU encoding at nine months were predicted by maternal mirroring of infant facial expressions at two months. This relationship was specific to direct mirroring responses, and was not explained by more general maternal responding. These findings suggest that neural representations of facial expressions become increasingly organised around constituent facial movements across early development, and that caregiver mirroring is associated with the emergence of componential facial representations. More generally, they provide initial evidence linking early embodied social interaction to the development of facial representational organisation.
Early communicative exchanges are typically examined in dyadic contexts, yet infants develop within family systems that involve multiple caregivers. This study, involving 30 monolingual Italian mother–father–infant families, investigated how vocal contingency unfolds in dyadic and triadic interactions between mothers, fathers, and their 4-month-old infants. Thirty families were observed during structured face-to-face interactions including a mother–infant dyad, a father–infant dyad, and a triadic condition involving all three partners. Vocal data were coded frame-by-frame to compute bidirectional contingency measures between each partner pair. Linear mixed-effects models tested how vocal contingency varied across contexts. When contingency was calculated relative to infants’ vocalisations (Partner-based contingency, PBC), both mothers and fathers showed lower response rates in triadic than dyadic interactions. In contrast, when calculated relative to each parent’s own vocal activity (Self-based contingency SBC), contingency was higher in triadic settings, reflecting parents’ reduced overall speech and a more selective alignment with infants’ cues. Infants, in turn, showed higher contingency toward both parents in triadic interactions, suggesting heightened temporal organisation of infant vocal responses in multi-partner contexts. These findings suggest that, within the present structured laboratory context, temporal patterns of vocal contingency may differ between dyadic and triadic interactions, with infants and parents showing context-sensitive changes in the distribution of temporally contingent vocal exchanges. Triadic contexts may offer a useful setting for observing how infants and caregivers distribute vocal responsiveness across multiple partners.
