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.

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.

Preterm children are a risk group for neurodevelopmental delays, while interactions with their mothers may serve as a protective factor.

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.

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.

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.

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).

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.

Benefits of attachment security have been demonstrated in multiple realms of development, and an extensive body of research has identified some of the antecedents associated with the development of secure attachments. While previous research has indicated that infant massage may support the development of mothers' attachment to their babies, no published research exists that investigated infants' attachment security after mothers learn infant massage strokes. This study tested the impact of an infant massage intervention on mothers' massage frequency and attachment security in infants. Fifty-eight mother-infant dyads were randomly assigned to a treatment (massage, n = 28) or control (education, n = 30) group. Most mothers had preschool aged children participating in Head Start as well as an infant under 8 months of age; the remaining mothers were from the community. Mothers in the treatment group completed 4 weeks of infant massage training using standard strokes from Infant Massage USA, a chapter of the International Association of Infant Massage, headquartered in Sweden. At 12 months, mothers were guided through the standard sorting procedure of the Attachment Q-set (Waters, 1987). The treatment was effective, as 86 % of mothers in the massage group were still massaging their babies at the follow-up, an average of 10 months later, and infants whose mothers massaged them had higher attachment security scores. Surprisingly, 29 % of the mothers in the comparison group reported that they massaged their babies. A treatment X massage frequency ANOVA indicated that 12-month-old infants whose mothers in the treatment group had massaged them more than once per week were more securely attached than infants of mothers who massaged their infants less than once per week and also were more securely attached than infants in the comparison group. However mothers in the control group defined massage, it was not associated with infant attachment security at the follow-up. These results indicate that this inexpensive, easy to implement intervention effectively increased mothers' ongoing use of infant massage, which in turn predicted more attachment security in their infants.

Gestational Age (GA) at birth plays a crucial role in identifying potential vulnerabilities to long-term difficulties in cognitive and behavioral development. The present study aims to explore the influence of gestational age on the efficiency of early visual attention orienting, as a potential marker for the development of specific high-level socio-cognitive skills. We administered the Gap-Overlap task to measure the attentional orienting and disengagement performance of 16-month-olds born between the 34th and 41st weeks of gestation. Our findings indicate that GA might be a significant predictor of attentional disengagement performance, with lower GAs associated with slower orienting of visual attention in the gap condition. Additionally, we discuss a possible influence of endogenous attention control on disengagement accuracy at this age, particularly among full-term infants. Overall, the findings highlight the role of GA as a key factor in evaluating early visual attention development, acting as a marker for detecting early vulnerabilities.

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.

Young infants' remarkable ability to discriminate non-native phoneme contrasts played a critical role in shaping the tenets of the perceptual narrowing hypothesis: early on, infants are sensitive to most phoneme categories, including those not used in their native language, but lose this sensitivity as they attune to their language. However, supporting evidence was derived from limited geographical regions and languages, particularly on early sensitivity, requiring further studies to specify the extent of early sensitivity and reassess the dominant developmental pattern. This study aimed to fill this gap by examining discrimination patterns for three-way Thai stop contrasts by two other Asian language learners (Korean and Japanese) at age 4-6 months. The three stop categories in Thai are distinct along the voice onset time (VOT) dimension, encompassing both negative and positive values. Thai pre-voiced and voiceless (i.e., short lag) stops are similar to stop categories used in languages such as French, Dutch, and Spanish. Thai voiceless and voiceless aspirated (i.e., long lag) stops are similar to those in English, Chinese, and German. Therefore, Thai stop categories provide an ideal test continuum for confirming early universal sensitivities to two supposedly language-general VOT boundaries (-30 ms, +30 ms). We presented two Thai phoneme pairs (pre-voiced vs. voiceless, voiceless vs. voiceless aspirated) to Korean and Japanese infants aged 4-6 months and observed their discrimination patterns using a visual habituation paradigm. The results showed divergent discrimination between the two language learners. Korean infants showed sensitivity to the pre-voiced-voiceless pair, whereas Japanese infants did not. By contrast, only Japanese infants showed some sensitivity to the voiceless-voiceless aspirated pair with some directionality effect, whereas Korean infants did not. These results demonstrate systematic cross-linguistic differences reflecting input influence in early perceptual sensitivity and suggest the ambient language environment may influence consonant perception much earlier than has been considered by the perceptual narrowing theory, calling for further refinement of the extent of initial perceptual state in the theory.

Neurodevelopmental disability (ND) poses a significant challenge to infants' socio-emotional and cognitive development, as well as to caregiving dynamics, such as parental sensitivity and mother-infant interaction. Prior research highlights the crucial role of early parenting support interventions in enhancing parental behaviors, serving as a protective developmental factor for children at risk for or diagnosed with ND. This single-cohort, multicentric study aims to evaluate the efficacy of early video-feedback intervention (VFI) in improving maternal parenting behaviors. Thirty-four mothers with their children diagnosed with ND participated in the study. Different dimensions of parenting behavior (i.e., affection, responsiveness, encouragement, teaching) were assessed during 10-minute mother-infant interactions, both before (T0) and after (T1) completing six weekly VFI sessions. Additionally, mothers completed standardized questionnaires assessing parenting stress, anxiety, and depressive symptoms. The results indicated significant improvements in maternal responsiveness, encouragement, and teaching following the intervention. Furthermore, mothers reported a state anxiety reduction at T1. Additionally, higher scores in affection and responsiveness were correlated with reduced maternal stress. These findings support the utility of VFI as a valuable tool for enhancing positive parenting skills in the context of ND, and provide insights into the dyadic processes through which parenting behaviors may promote socio-emotional and cognitive development in children with ND.

The increasing prevalence of digital media devices in families with young children has raised concerns over problematic media use. However, the link between toddlers' problematic media use, their socioemotional development, and the influence of parental factors remains unclear. The current study examined the roles of problematic media use by both mothers and toddlers in the association between maternal parenting stress and toddlers' socioemotional development. Participants comprised 215 mothers and 73 lead child care classroom teachers of toddlers aged 24-36 months enrolled in child care centers in South Korea. Mothers reported parenting stress and problematic media use by themselves and their toddlers, and child care teachers reported toddlers' socioemotional development. The results from structural equation modeling analysis revealed that maternal parenting stress was related to toddlers' socioemotional development both directly and indirectly through toddlers' problematic media use, both alone and in conjunction with mothers' problematic media use. Although maternal parenting stress was related to mothers' problematic media use, mothers' problematic media use was not directly related to toddlers' socioemotional development. These findings underscore the importance of toddlers' problematic media use in their socioemotional development and highlight the need for comprehensive approaches that address family dynamics, such as maternal parenting stress and problematic media use.

There is a need of expanding research on neonatal behaviour to encompass diverse global populations. However, few measures appropriate for use from birth in diverse cultural contexts exist. We present data from rural Gambia and the UK using the Neonatal Behavioural Assessment Scale (NBAS). In Phase 1, the scale was piloted for use in The Gambia, highlighting great utility for use in this setting. Adaptations included 1) additional explanation of some items to caregivers and 2) omission of items where the home environment necessitated to do so. In Phase 2, the NBAS was administered in both the UK and The Gambia. Item level comparisons across the sites showed fewer state changes in Gambian infants and a greater degree of examiner facilitation throughout the session. Factor analysis within the larger Gambian cohort indicated best model fits where first-order factors mapping onto each NBAS subscale were accompanied by a second-order 'Self-Organising System'-factor, mirroring prior factor analytic studies on the scale. Further, the habituation subscale had to be omitted from analyses due to large amounts missing data, highlighting potential differences across subscales when implementing the NBAS across diverse settings. We found associations between our NBAS factor scores and NBAS supplementary items. Examining known risk factors for early neonatal development, we found associations of the Social Interactive and Self-Organising System factor with pregnancy anxiety and gestational age at birth and birthweight, but not maternal anaemia. Our findings inform future studies seeking to understand the interplay between cultural contexts, perinatal factors, and early neurobehavioural development.

Previous research suggests that acoustic features of infant-directed speech (IDS) might be beneficial for infants' language development. However, consonants have gained less attention than vowels and prosody. In the current study, we examined voice onset time (VOT) - a distinguishing cue for stop consonant contrasts - in IDS and adult-directed speech (ADS), and its relation to infants' speech production. We used a longitudinal sample of 48 Norwegian parent-infant dyads. Parents' IDS and ADS were recorded in-lab at three timepoints (infants' age: 6, 9, 12 months), and the VOTs of the stop consonants /b-p/, /d-t/, and /g-k/ were measured. In addition, at each timepoint, parents reported their infants' production of the same consonants, as well as their babbling. Hypotheses were preregistered, and we used full-null model comparisons to minimise type I-errors in the analyses. Our results demonstrate that, while controlling for speaking rate, in IDS, parents' VOTs were longer in voiceless stops, but shorter in voiced stops, resulting in overall less distinct consonant contrasts compared to ADS. Further, VOTs in IDS approached ADS values with infants' age. However, we found no relationship between parents' VOTs and infants' consonant production or babbling. Consonants, like vowels, appear to be less distinct in IDS than ADS, thus reinforcing the interpretation that IDS may serve an attentional and/or affective aim, rather than a didactic purpose.

Physical contact between infants and caregivers is crucial for attachment development. Previous research shows that skin-to-skin contact after birth and frequent baby wearing in the first year predict secure attachment at 12-months. This relationship is thought to be mediated by the activation of infants' parasympathetic nervous system through caregiver touch. However, little is known about everyday touch behaviors and their impact on infants' real-time parasympathetic activity. Laboratory observations may not accurately represent real-world interactions, highlighting the need for ecologically valid studies. To address this, we examined everyday dyadic touch behaviors and their real-time effects on infant parasympathetic activation. We video recorded N = 28 infants (1-10 months old) and their mothers at home for behavioral analyses. All infants wore wireless ECG sensors (1024 Hz) during video recordings, and n = 21 infants had high-quality ECG data that could be used for Respiratory Sinus Arrhythmia analyses. We used a dynamic measure of RSA (updated every 200 ms) as an index for real-time parasympathetic activation. We found that dyads touch interactions at home involve short, though highly variable bouts of physical contact, that change with infant age. Younger infants spent more time remaining stationary during contact and receiving more soothing touch compared to older infants. Only soothing touch - i.e., rocking, patting, bouncing, or stroking- led to immediate, significant increases in parasympathetic activity (RSA), and this effect was driven by younger infants. This study provides new insights into the ecological patterns of touch in early development and the biobehavioral mechanisms promoting secure attachment.

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.

The purpose of this research was to examine the role of a range of play and learning activities in the home (e.g., painting, playing games, reading, singing and letters and numbers) in the socioemotional development of young children. While many previous studies have focused on the benefits of home learning activities for language and literacy outcomes, less research has examined the role of these individual activities in other aspects of development, such as prosocial behaviour. Using a bioecological framework, a secondary analysis of data from the nationally representative Growing Up in Ireland(GUI) Study was conducted. The sample consisted of 9793 children, aged 36 months (50.7 % male and 49.3 % female). The study examined if the frequency of engagement in different play activities predicted scores on measures of internalising, externalising and prosocial behaviours using the Strengths and Difficulties Questionnaire. Findings indicated that informal play activities such as games, painting and drawing, and reading predicted socioemotional development scores, in comparison with activities such as letter or number games, even after parental and other family factors are accounted for. The results also indicated that parent-child relationship factors of warmth, hostility and closeness are particularly important for socioemotional development. Findings are discussed in the context of Bronfenbrenner's bioecological model of development.

Recent research has shown that children as young as 19 months demonstrate graded sensitivity to mispronunciations in consonant onsets and vowels in word recognition tasks. This is evident in their progressively diminishing attention to relevant objects (e.g., a dog) as mispronunciations increasingly deviate from the correct word form (such as /dog/ changing to /gog/, /kog/, or /sog/). Despite these sensitivities, uncertainties remain about their broad generalizability, especially regarding the differences between word onsets and codas, and between lexical segmental (consonants and vowels) and supra-segmental (e.g., lexical stress and tones) elements. The present study aimed to fill these gaps. Using the intermodal preferential paradigm, we conducted two experiments to evaluate toddlers' responses to coda and lexical tone mispronunciations. Our results revealed a linear decline in toddlers' attention to familiar objects as mispronunciations became more severe, suggesting that by 19-20 months, infants' lexical representations encompass detailed phonetic information of both segmental and supra-segmental categories. Moreover, our results indicate that toddlers utilize these details in lexical processing. Such findings offer a more comprehensive understanding of the phonetic structures within toddlers' early lexical representations, sheding light on the mechanisms toddlers use in processing various word positions, across different acoustic dimensions, and in multiple languages.

The developmental trajectories of tone perception among tone and non-tone language learning infants have received wide attention and discussion in recent decades under the perceptual attunement framework. Nevertheless, tone perception in infants from pitch accent and bilingual language backgrounds has not been well understood. The present study examined monolingual and bilingual Norwegian-learning infants' discrimination of two Cantonese tone contrasts at 5 and 10 months, ages corresponding to the onset and offset of perceptual attunement. Results showed that while monolingual infants were sensitive to the salient contrast, bilingual infants showed sensitivity to both contrasts at 10 months. In sum, infant age and bilingual language background affected discrimination. Pitch accent language experience or contrast salience may also play a role. The finding that early bilingual experience facilitated tone perception is of particular interest. It suggests that infant perception could be enhanced by a more complex linguistic environment on a broader level. As this was observed only at 10 months, cumulative exposure may be required for infants in a complex bilingual environment. Future studies should disambiguate explanations generated from the current finding, ranging from neurocognitive plasticity to perceptual salience, and from experience-dependent to independent possibilities.

In previous research, infants' performance on speech perception tasks has been shown to predict later language outcomes, typically vocabulary size. We used Bayesian analyses to model trial-level looking time behavior of individual infants on morphological segmentation experiments. We compared the usefulness of Bayesian estimates and the raw looking time difference measures used in previous studies to predict (a) vocabulary size at 30 months and (b) outcome measures obtained from language samples elicited via a picture description task at 36 months. We found that both estimates of morphological segmentation reliably predicted expressive vocabulary at 30 months. The Bayesian estimate also credibly predicted the correct use of verb tense morphemes obtained from the language sample. We therefore conclude that the Bayesian estimate is better for indexing individual differences in segmentation tasks and more useful for predicting clinically relevant language outcomes.

The way in which a mother and her preterm baby interact, especially in moments preceding or following stressful events, is fundamental in shaping the infant's autoregulation. Patterns of mutual sequential coordination constitute stress regulation competences and provide foundation for later socio-emotional development. Maternal affective touch has been postulated as an essential regulatory factor in early social exchange. In this study we aimed to better understand the interplay between maternal affective tactile behaviors and physiological synchrony between mother and child, with possible implications for early bonding processes. Fifteen mother-premature infant dyads were video-recorded during a free interaction and directly after a skin-interrupting medical procedure (vaccination or blood sampling) in the Neonatal Intensive Care Unit. The proportion of maternal affective touch was coded both in free and post-stress interactions. Parasympathetic response was assessed simultaneously in mothers and neonates in order to observe physiological synchrony in dyads. Finally, interactional misattunement during mothers' comforting actions and infant behavior after stress was evaluated as a potential indicator of risk in early bonding processes. Results indicated a positive association between the duration of maternal affective touch and adaptive autonomic synchrony patterns in dyads. Correlations were found between maternal affective touch both before and after stress-inducing procedure and several synchrony measures from free interaction phase (Spearman ρ = -0,57 do 0,72, p < 0,05) Additionally, the study revealed a positive correlation between the level of interactional misattunement and the duration of maternal affective touch after stress (ρ = 0,47, p < 0,05). The quality of synchrony was better in free interactions than during post-stress kangaroo care phase (p < 0,05).