Several infant behaviors spanning multiple developmental domains have been identified as promising markers of early neurodivergence, such as ADHD or ASD. Some of these early markers include social-communication differences, atypical attention, and motor deficits. Research involving early predictors of ADHD features in infants is scarcer than research involving early predictors of ASD. However, studies among school-age children have observed comparable profiles of language, attention, and motor skills between children with ASD and children with ADHD. Given that assessing early features of ASD and ADHD is fundamental to increasing earlier diagnoses, this study examined parent-reported social-communication, attention, and motor profiles across 12-month-old infants at elevated genetic likelihoods for ASD (EL-ASD) and ADHD (EL-ADHD), and low genetic likelihood for either disorder (LL). Parent responses on the CSBS-CG, FYI, and EMQ were compared across the three groups. Results showed EL-ASD participants as scoring lower than both LL and EL-ADHD participants on parent-reported social skills and attention constructs (Responding to and Initiating Social Attention). Although FYI constructs are meant to measure attention, the Responding to and Initiating Social Attention subscales also include aspects of social communication. Differences between EL-ADHD and LL infants on measures of social-communication, motor, and attention skills were not observed, suggesting that parent-reported differences between EL-ADHD and LL infants' behavior may not be as detectable during infancy as those associated with ASD. Future research is required to further the understanding of developmental differences of infants with features of ADHD.

Toxic metals in new-generation weapons pose health risks to civilians, and pregnant women are especially vulnerable in wars. Studies have focused on single toxins, such as white phosphorus and depleted uranium, although civilians are exposed to multiple toxic metals. Research has mainly concentrated on toxic metals impacting new-born health but has neglected older infants' development and salient dyadic factors. This study examines how maternal and new-born prenatal exposure to multiple carcinogen, neurotoxic, and teratogen metals during a war impacts infants' sensorimotor, cognitive, and socioemotional development, and the role of breastfeeding in that association. The participants were 502 Palestinian mothers, pregnant during the 2014 War on Gaza, and their new-borns, recruited at childbirth (T1) and followed up at 6 months (T2; N = 392) and 18 months (T3; N = 358). At T1, maternal and new-born hair samples were tested for 18 toxic metals. At T2, mothers reported infants' fine-gross-motor, language, and socioemotional skills, and at T3, psychologists tested their motor, cognitive-language, and socioemotional skills. Mothers reported breastfeeding practices at T2 and T3. Results showed that the timing of direct developmental impact of maternal and new-born loads of toxic metals differed, as mothers' high loads of carcinogen metals was associated with infant developmental problems at 6 months, and new-borns' high loads of carcinogen and teratogen metals predicted developmental problems at 18 months. Both maternal and new-born high toxic metal loads were associated with decreased breastfeeding intensity and duration. The impact of maternal, but not newborn's, exposure to toxic metals was mediated into infant development through decreased breastfeeding.

Rolling is an important part of infant motor development and is largely affected by experiences and surroundings. The purpose of this study was to determine how inclined mechanical environments affect infant muscle activation during previously defined coordinated rolling movements. The results demonstrate that infant muscle utilization (age: 6.5 ± 0.7 months; 23 M/15 F) differs while achieving the same rolling movements on a flat surface compared to four inclined environments representing a range of inclines to which infants are commonly exposed. Thus, rolling milestone achievement on a firm flat surface is not indictive of the same ability to roll in inclined seated environments.

Theories of perceptual development differ in the extent to which initial perceptual sensitivities and language experience influence infants' perception of speech. Extant research focuses largely on infants' ability to distinguish native and non-native speech sound categories. In two experiments, we investigated infants' developing perception of relationships between similar sounds, i.e., vowel harmony patterns, to inform this debate. In Experient 1, we showed that language experience is not necessary to detect vowel harmony; 4-month-olds without harmony experience can differentiate harmonic and disharmonic nonce words. We argue that this is due to a universal perceptual grouping bias, wherein similar sounds are perceived as being grouped together despite their temporal distance. Then in Experiment 2, we showed that without relevant language experience, this initial sensitivity to vowel harmony declines by 8-months as infants begin to tune into the sound patterns of their native language. We argue that our results, combined with previous findings, are best explained under perceptual attunement theories. When not reinforced by their language input, infants show a decline in their sensitivity to vowel harmony; but an initial sensitivity to relationships between similar vowels may facilitate infants' learning of vowel harmony patterns in their native language.

The study aimed to explore the developmental trajectory of infants' vocal responses and the temporal characteristics of vocal interactions between infants and caregivers in natural home environments, focusing specifically on Korean infants aged 3, 6, 9, and 12 months.

Parental nurturing touch plays a crucial role in early infant development by activating C-Tactile afferents, which trigger neurobiological pathways essential for parent-infant bonding and the building of attachment. This process is said to regulate the infant's parasympathetic nervous system, fostering emotional and physiological connection with the caregiver. Research has consistently shown that CT-mediated touch enhances infant parasympathetic tone, yet no clear patterns of mutual co-regulation between parent and infant have been reported. Here, we replicated our previous study design to test the impact of three minutes of maternal stroking touch on mother-infant cardiorespiratory regulation, using no-touch pre- and post-stroking baselines. To control for potential confounds, we standardised the infant's holding position, used active baselines (i.e., active group) instead of resting baselines (i.e., resting group) to account for maternal metabolic activity, and compared stroking with and without massaging oil in the active group. Electrocardiogram (ECG) and respiration were measured in 30 mother-infant dyads (active group) and 24 mother-infant dyads (resting group) (infants aged 5-14 weeks) to calculate RRI-intervals (RRI), respiration frequency (fR), and Respiratory Sinus Arrhythmia (RSA). Surprisingly, no significant changes in mother and infant cardiorespiratory measures were observed in the active contrary to the resting group and the use of massaging oil had no notable impact in the active group. We suggest that these lack of changes show that subtle experimental manipulations have an influence on maternal-infant co-regulation, emphasising the importance of using research designs that respect the individualised ecological environment of parent-infant interactions and the role of micro-processes and multisensory integration in shaping regulatory attachment dynamics.

Language interventions may yield greater benefits for younger children than their older counterparts, making it critical to evaluate children's language skills as early as possible. Yet, assessing young children's language presents many challenges, such as limited attention spans, low expressive language, and hesitancy to speak with an unfamiliar examiner. To address these challenges, the Quick Interactive Language Screener for Toddlers (QUILS:TOD; for children 24- to 36-months of age) was developed as a quick, tablet-based language screener capable of assessing children's vocabulary, syntax, and word learning skills. We explored how children's performance on the QUILS:TOD and the MacArthur-Bates Communicative Development Inventory, another language screener, at two years of age relates to their performance one year later on the Quick Interactive Language Screener (QUILS), a validated and normed screener for children between three and six years of age. Results revealed that performance on the QUILS:TOD was predictive of QUILS performance, highlighting the utility of the QUILS:TOD for identifying which children at age two would continue to lag behind their peers at age three. Lastly, although all QUILS:TOD areas (vocabulary, syntax, and word learning) were predictive of QUILS performance, the most robust predictor of children's performance on the same receptive language dimensions at 3 years was their syntax, emphasizing the necessity of evaluating language beyond vocabulary.

This randomized controlled study was conducted to evaluate the effects of telephone-assisted breastfeeding monitoring on physiological jaundice, exclusive breastfeeding in the first six months, colic, breastfeeding success, and breastfeeding self-efficacy. Breastfeeding and infant care training were given to pregnant women by video calls (N = 54). Video call counseling was provided to the mothers in the intervention group (n = 27) every day for the first week after discharge and weekly until the 24th week, and the control group (n = 27) was only telephone called in follow-up weeks. The primary variables were exclusive breastfeeding and breastfeeding success, while secondary variables were physiological jaundice, colic, and breastfeeding self-efficacy. The LATCH Breastfeeding Assessment Tool, the Breastfeeding Self-Efficacy Scale, and the Infantile Colic Scale were used. The mean scores of the intervention and control groups were compared using the Mann-Whitney U test and multivariate analysis of variance in repeated measurements. The telephone-assisted breastfeeding monitoring increased exclusive breastfeeding in the first six months. Physiological jaundice was experienced less in infants in the intervention group. There was no difference in terms of infantile colic, breastfeeding success, and breastfeeding self-efficacy between group and group*time interaction, a difference was found in terms of time. The telephone-assisted breastfeeding monitoring can be used to increase exclusive breastfeeding and prevent physiological jaundice (ClinicalTrials.gov Identifier: NCTXXX).

The establishment of early bedtime routine is essential for children's emotion and behavioral outcomes. Less is known, however, about the longitudinal effects and mechanisms predicting behavioral outcomes through early bedtime routine and emotion regulation in school-age children from low-income families. Thus, the present study examined emotion regulation at age three as a potential mediator in the longitudinal links between early bedtime routine and behavioral outcomes among racially diverse school age children from low-income families. Participants include a subsample of families (n = 2977) participating in the Early Head Start Research and Evaluation Project (EHSRE). Structural equation modeling with bootstrapping techniques was used to examine the models. The early bedtime routine index was created from parents' reports at 14, 24, and 36 months. Children's emotion regulation was drawn from interviewer assessments at 36 months and problem behaviors were reported by mothers when the child was approximately at age 10. Results indicated that children with consistent early bedtime routine were better able to regulate their emotions at age three. Also, emotion regulation at age three mediated the associations between early bedtime routine at 14-36 months and internalizing and externalizing behaviors among fifth-grade children. Findings indicated that consistent early bedtime routine helps children to regulate their emerging emotions which in turn has long-term benefits on their emotional and behavioral outcomes. These findings have important implications for pediatricians, nurse practitioners, nurses, and early childhood educators who can provide education and resources to support families in establishing consistent bedtime routine for their young children.

Early intervention is effective for reducing ADHD symptoms and related impairments, yet methods of identifying young children in need of services are lacking. Most early predictors of ADHD previously identified are of limited clinical utility. This study examines several theoretically relevant predictors of ADHD in infancy and toddlerhood and whether assessment at multiple time points improves prediction. We also examine whether links between early risk factors and middle childhood ADHD are driven by shared genetic and/or environmental mechanisms to identify potential early intervention targets.

The study examined the saccadic behavior of 4- to 10-month-old infants when tracking a two-dimensional linear motion of a circle that occasionally bounced off a barrier constituted by the screen edges. It was investigated whether infants could anticipate the angle of the circle's direction after the bounce and the circle's displacement from the location of bounce. Seven bounce types were presented which differed in the angle of incidence. Three of the seven bounce types showed physically implausible bounces. Saccades that started before the infant could perceive the bounce and ended after the bounce were analyzed. Infants' saccades matched the circle's displacement with sufficient accuracy to conclude that they made predictive saccades. Only results from two bounce types where the circle's speed was less than 12.5°/s allowed for the possibility that infants made reactive saccades. The infants' anticipated angle was close to the angle of the circle's direction after the bounce. When the circle was moving at 40°/s, the difference between the two aforementioned angles was less than 15°, but it increased as the circle became slower. The effect of age on the saccade targets and other object-tracking measures was small and mostly masked by a large estimation error. Estimates of the saccade amplitude, saccade frequency, and the gaze-circle displacement were similar to those observed for saccades made when no bounce occurred and they were also similar to those reported in previous studies of infant object tracking with similar trajectories but without a barrier.

Parent-child interactions are important for children's emotional and behavioral development. In autism research, parent-child interactions are typically observed during free play. Yet, studies outside the autism field underscored the importance of observing parent-child interactions during other contexts, as parents' behaviors may depend on the context, and different contexts may reveal different relationships between parents' and children's behaviors. Therefore, we observed interactions between 102 mothers and their 24-month-old children at elevated likelihood of autism during two scenarios: free play and goal-directed play. Participating children had an older autistic sibling (n = 68) or were born very preterm (born before 30 weeks; n = 34). We found that mothers adapt their behaviors to contextual cues, which supports and expands on previous findings regarding older autistic children, and children without autism. Furthermore, as expected, the relationship between mothers' and children's outings of negative affect only became apparent during the goal-directed play scenario. A relationship between mothers' and children's outings of positive affect was found in both scenarios, thus regardless of the context. Parent-reported emotional and behavioral difficulties of children were not related to maternal behaviors during either context, nor to fluctuations in maternal behaviors across contexts. This contrasts with studies with older children, which did find such relationships. Therefore, our findings suggest that predictable patterns might not yet be visible when children's emotional and behavioral difficulties first become apparent.

Detecting temporal synchrony in audiovisual speech in infancy is fundamental for socio-communicative development, especially for language acquisition. Autism is an early-onset and highly heritable neurodevelopmental condition often associated with language difficulties that usually extend to infants with an elevated likelihood of autism. Early susceptibilities in still unclear basic mechanisms may underlie these difficulties. Here, we discuss why sensitivity to temporal synchrony in audiovisual speech should be investigated in infants with an elevated likelihood of autism as a candidate mechanism underlying language difficulties. We then review direct and indirect eye-tracking evidence. Although scarce, some studies suggest that detection of temporal synchrony in audiovisual speech may be reduced in infant siblings (but evidence is mixed); however, this does not seem to account for language difficulties. Instead, a lack of relationship between selective attention to the articulating mouth and language development may be a plausible candidate mechanism. However, longitudinal studies tracking both sensitivity to temporal synchrony and selective attention to talking faces in the first year are needed for further clarification. Our discussion highlights gaps in the literature, future research directions and implications for domain-general approaches to the emergence of autism.

Adverse childhood experiences (ACEs) can influence parenting behaviours and have lasting effects on child development. This study investigated how maternal ACEs affect mind-mindedness during interactions between 69 Brazilian mothers and their six-month-old infants, and the role of stress in this relationship. Maternal vocalisations were coded for appropriate and non-attuned mind-related comments according to the Mind-Mindedness Coding Manual. The number of maternal ACEs was assessed using the CDC-Kaiser ACE Study Questionnaire. Current stress, postnatal depression, depression, anxiety, adverse life events, and resilience were assessed using the Perceived Stress Scale, Edinburgh Postnatal Depression Scale, Depression Scale Patient Health Questionnaire, Generalized Anxiety Disorder, the Inventory of Major Life Events, and the Resilience Scale, respectively. General Linear Models analysed associations between variables. The results showed no direct link between ACEs and mind-mindedness. However, stress moderated the relationship between maternal ACEs and appropriate mind-related comments. These findings suggest that maternal exposure to ACEs affects how mothers interpret their infants' mental states, particularly under stress. Understanding these relationships can guide interventions to support maternal mental health and foster positive parent-infant interactions, potentially preventing the intergenerational transmission of trauma.

Infants spend a significant portion of their day engaging in play and accumulate immense amounts of object interactions. As infants develop, they perform increasingly complex bimanual actions, such as role differentiated bimanual manipulation (RDBM), where each hand serves a distinct role. RDBM has been well documented in structured lab settings, but these studies restrict the types of toys and postures in which infants can engage. Therefore, previous studies are limited in that they do not simulate everyday infant object interactions. Infants (39 13- and 39 24-month-olds) engaged in a 20-minute lab-based free play task designed to mimic everyday object interactions in order to assess the prevalence of RDBM and to understand the influence of posture, toy size, and toy weight on RDBM. Although both age groups frequently engaged in object interaction, RDBM did not occur as often in the lab-based free play task as found previously in structured settings. Whereas infants engaged in RDBM with toys of various sizes and weights, they favored lightweight toys and preferred to sit while engaging in RDBM. The 13-month-old infants preferred small toys while the 24-month-olds more often incorporated medium and large toys in their interactions. Examining RDBM using a lab-based free play task furthers our understanding of how complex bimanual behaviors emerge in a naturalistic setting where infants can adopt a wide range of postures and interact with a variety of toys.

Pulling-to-stand (PTS) is an important transitional posture which may facilitate the shift to walking, but infants still frequently PTS even after learning to walk. Using a group of 13 infants who had learned to PTS about three weeks prior, we aimed to track how gains in PTS, standing, and walking experience contributed to infants' selection of more skilled PTS strategies and reorganized how infants used PTS to facilitate free play. We tracked spontaneous PTS over 10 biweekly laboratory sessions and video-coded functional measures of PTS skill, including hand-, knee-, and foot-use (e.g., lateral sides, hand- and foot-steps), and how infants used PTS during play, including behaviors immediately following PTS. Results showed infants frequently adopted skilled half-kneel strategies en route to PTS even though they were slower than symmetric PTS strategies. Most PTS involved asymmetrical and diagonal activation of the hands and legs, offering a stable center of gravity, and lateralized foot preferences were strong and stable. Other functional measures of PTS skill revealed increased efficiency over time, as infants PTS using fewer alternating hand-steps. Initially, infants PTS using stationary objects and then interacted with objects and mothers, but over time, infants increasingly PTS using the stairs and stair rails and engaged in more locomotor exploration following PTS. Even months after its initial onset, infants continued to refine PTS strategies and efficiency and used PTS differently for object interactions and locomotor exploration during play, which highlights the importance of tracking patterns of interlimb coordination during PTS and goal-directed behavior in context.

Synchrony in mother-infant interactions is crucial for infant development. However, mother-infant physiological synchrony in the context of maternal childbirth-related posttraumatic stress symptoms (CB-PTSS) remains unknown. This pilot study aimed to investigate physiological synchrony within the context of CB-PTSS. Additionally, it investigated the association between mother-infant physiological synchrony and reciprocity. A total of 86 French or English-speaking mothers and their term infants participated in the study. Maternal CB-PTSS was assessed using the PTSD Checklist for DSM-5 (PCL-5), modified for childbirth. Mother-infant dyads were classified into three groups based on their responses to the PCL-5. During mother-infant interactions, physiological synchrony was measured using heart rate variability (HRV), while reciprocity was observed in video recordings. Cross-lagged analysis revealed distinct patterns of HRV fluctuations between mother-infant dyads: positive (mother and infant HRV fluctuated in the same direction) or negative (mother and infant HRV fluctuated in the opposite direction). To avoid canceling out potential effects by averaging the positive and negative correlation coefficients, we analyzed them separately. In positive dyads, maternal HRV led infant HRV by approximately two seconds. Conversely, in negative dyads, there was no significant lag or lead observed in either direction. Our analysis did not reveal a significant impact of CB-PTSS group classification on the physiological synchrony between mothers and their infants. Additionally, we found no significant relation between physiological synchrony and reciprocity within the dyads. We recommend that future studies with a similar focus should control for factors such as individual physiological regulation, maternal anxiety, and maternal depression to further explain these relationships.

We examined longitudinal direct associations between mothers' and fathers' emotion socialization behaviors (ESB) at 18 and 24 months and toddlers' social competence (SC) at 24 and 30 months in a sample of ethnically diverse families (n = 128) participating in a parenting intervention study. We also investigated interaction effects between mothers' and fathers' ESBs and between each parent's ESBs and child emotionality. We coded parents' ESBs to their toddlers' positive and negative emotions during no-toy play and a clean-up task. Mothers reported on their toddlers' social competence and emotionality. Using multiple linear regression modeling, we report three findings. First, mothers' and fathers' most frequent ESBs were emotion coaching and ignoring to positive and negative emotions, respectively, but emotion coaching of positive emotions by either parent was not associated with children's SC. Second, mothers' and fathers' ESBs to negative emotions, however, were associated with children's SC, but these associations varied by child emotionality and the other parent's ESBs. Third, fathers' non-supportive ESBs to negative emotions at 18 months were directly and positively associated with greater SC at 30 months, but their emotion coaching was significantly and positively related to children's SC only when mothers did not provide any emotion coaching. The association between mothers' non-supportive ESBs to negative emotions at 24 months and 30-month SC was negative only for children high in emotionality. These findings show that both mothers' and fathers' ESBs shape their children's social competence in different ways, which needs to be considered when developing programs for children.

Neurofibromatosis 1 (NF1) and attention-deficit hyperactivity disorder (ADHD) are distinct conditions with similarities in developmental course. Research suggests that neurodivergent processes in both conditions begin in the first year, altering infant behaviour and how parents respond, over time reducing social-communicative opportunities for social brain development. This study aimed to investigate parent-infant interactions in both groups relative to typically developing infants (TD) at 10 and 14 months. We hypothesised that the infants with NF1 and infants at elevated likelihood of ADHD (EL-ADHD) would show less attentiveness to their parent and less mutual parent-infant interaction relative to TD controls, that attentiveness-to-parent would be particularly low in infants with NF1, and that liveliness and negative affect would be higher in infants with EL-ADHD. Parents and their infants with NF1, EL-ADHD and TD were videotaped during free play interactions and coded using validated rating scales. The two non-TD groups differed in their interactive patterns from the TD group and each other in ways somewhat consistent with the early behaviours that characterise each group. The NF1 group showed relatively less mutual interactions than the EL-ADHD group, and less parental sensitive responsiveness and parental directiveness than the TD group, while EL-ADHD infants were livelier and showed less negative affect relative to the other groups. Most main effects persisted over time. While longer-term follow-up in larger samples is needed, our findings highlight how children with neurodevelopmental conditions that are not primarily characterised by social communication difficulties may nonetheless come to have distinct social experiences in the first year of life.