Exploring Infant Gesture and Joint Attention as Related Constructs and as Predictors of Later Language

Parent attention-orienting behavior is associated with neural entropy in infancy

Parents use joint attention to direct infants to environmental stimuli. We hypothesized that infants whose parents provide more bids for joint attention will display a more complex neural response when viewing social scenes. Sixty-one 8-month-old infants underwent electroencephalography (EEG) while viewing videos of joint- and parallel-play and participated in a free play interaction. EEG data was analyzed using multiscale entropy, which quantifies neural variability. Free play interactions assessed parent alternating gaze, a behavioral mechanism for directing attention to environmental cues. We found a significant positive association between parent alternating gaze and neural entropy in frontal and central regions. These results suggest a relationship between parent behavior and infant neural mechanisms that regulate social attention, underlying the importance of parental cues in forming neural networks.

Parent attention-orienting behavior is associated with neural entropy in infancy

Parents play a significant role in directing infant's attention to environmental stimuli via joint attention. We hypothesized that infants whose parents provide more bids for joint attention will display a more complex neural response when viewing social scenes. Sixty-one 8-month-old infants underwent electroencephalography (EEG) while viewing videos of joint- and parallel-play and participated in a parent-infant free play interaction. EEG data was analyzed using multiscale entropy, which quantifies moment-to-moment neural variability. Free play interactions were coded for parent alternating gaze, a behavioral mechanism for directing attention to environmental cues. We found a significant positive association between parent alternating gaze and neural entropy in frontal and central brain regions. These results suggest a relationship between parent behavior and infant neural mechanisms that regulate social attention, underlying the importance of parent cues in the formation of neural networks in infancy.

Infants' pointing at nine months is associated with maternal sensitivity but not vocabulary

Infants often start pointing toward the end of their first year of life. Pointing shows a strong link to language, perhaps because parents label what infants point to. In the present study, we tested whether 9-month-olds' pointing was related to parental sensitivity and concurrent and subsequent vocabulary scores. Observations were made of 88 9-month-old infants in free-play situations with their mothers. Less than half the infants produced at least one index-finger point. The mothers' reactions to their infants' behaviour were coded for sensitivity. The mothers of the infants who pointed were less directing and responded more contingently than the mothers of the infants who did not point. However, there was no difference in vocabulary scores of pointers and non-pointers, either concurrently or at 12 and 18 months of age. These results could mean that parents' reactions play an important role in shaping pointing to be communicative.

Interacting with autistic virtual characters: intrapersonal synchrony of nonverbal behavior affects participants' perception

Temporal coordination of communicative behavior is not only located between but also within interaction partners (e.g., gaze and gestures). This intrapersonal synchrony (IaPS) is assumed to constitute interpersonal alignment. Studies show systematic variations in IaPS in individuals with autism, which may affect the degree of interpersonal temporal coordination. In the current study, we reversed the approach and mapped the measured nonverbal behavior of interactants with and without ASD from a previous study onto virtual characters to study the effects of the differential IaPS on observers (N = 68), both with and without ASD (crossed design). During a communication task with both characters, who indicated targets with gaze and delayed pointing gestures, we measured response times, gaze behavior, and post hoc impression formation. Results show that character behavior indicative of ASD resulted in overall enlarged decoding times in observers and this effect was even pronounced in observers with ASD. A classification of observer's gaze types indicated differentiated decoding strategies. Whereas non-autistic observers presented with a rather consistent eyes-focused strategy associated with efficient and fast responses, observers with ASD presented with highly variable decoding strategies. In contrast to communication efficiency, impression formation was not influenced by IaPS. The results underline the importance of timing differences in both production and perception processes during multimodal nonverbal communication in interactants with and without ASD. In essence, the current findings locate the manifestation of reduced reciprocity in autism not merely in the person, but in the interactional dynamics of dyads.

Effect of online parent training in promoting language development of children with language delay in Hubei province, China

BACKGROUND

Training parents to implement language and communication intervention strategies is an effective approach to promote language development for children with language delay.

AIMS

This study introduces an online parent training program conducted in Hubei province, China, which was designed to help parents of language-delayed children with a diagnosis of autism spectrum disorder (ASD), developmental language disorder (DLD) or global developmental delay (GDD) apply language intervention strategies into daily interactions and promote their children's language development at home.

METHODS & PROCEDURES

The Bethel Hearing and Speaking Training Center Family Training for Early Communication & Language Development (Bethel Family Training Program, BFT) (Bethel HSTC, 2020) was designed to improve the language and communication skills for children with language delay in a naturalistic way. The caregivers (including parents, grandparents and other main caregivers) participated in an 8-h online program, including lectures on milestones in child language development, common misunderstandings of child language development, and three basic family language intervention strategies ('Looking together, playing together, and talking together') incorporating active learning through video analysis and discussion. Tongji Hospital in Hubei then continued with 3 months of online home intervention monitoring to all the caregivers via weekly online Q&As led by BFT certified speech therapists' team. The Gesell Developmental Schedules (GDS) was carried out before the online parent training program and after the 3-month online home intervention monitoring.

OUTCOMES & RESULTS

146 families whose children aged 12-68 months with language delay participated in the online training program. The results of the GDS assessments conducted before and after the program showed that not only did the developmental quotient (DQ) of language improve, but so did the DQ of social behaviour and adaptive behaviour (p < 0.001). There is no between-group difference in the application of three strategies between the ASD group and the DLD or GDD group (p > 0.05). Furthermore, both caregivers' ability to apply 'looking together, playing together, talking together' strategies and the effective interaction time played important roles in improving the child's language abilities.

CONCLUSION & IMPLICATIONS

The online parent training focusing on improving daily interaction with children through speech-language stimulation strategies promoted the development of language skills. It is an economic and practical approach for children with language delay who have limited access to local language intervention programs.

WHAT THIS PAPER ADDS

What is already known on the subject Parent-implemented language intervention is an effective approach at improving children's language development. Telepractice is an appropriate model of service delivery for audiologists and speech-language therapists and may be the primary mode of service delivery or may supplement in-person services. What this paper adds to the existing knowledge This paper explores the effectiveness of an online parent training program and provides new evidence that online training on language support strategies (looking together, playing together, talking together) followed by home intervention monitoring works for Mandarin-speaking children and it is equally effective for children with ASD and non-ASD diagnosis. What are the potential or actual clinical implications of this work? Developmental behavioural paediatricians and speech-language therapists in countries and areas that lack sufficient training resource for every child will have the option to deliver parent training and home intervention monitoring online, which will save time and cost considerably while offering convenience.

Preliminary feasibility and effectiveness of a novel community language intervention for preschool children in the United Kingdom

BACKGROUND

Very young children from lower socioeconomic status (SES) backgrounds often show poorer language development. Whilst there have been attempts to provide early intervention programmes, these sometimes miss the most disadvantaged groups.

AIMS

This report presents preliminary feasibility and effectiveness data for a novel language intervention designed for parents of toddlers in the United Kingdom.

METHODS AND PROCEDURES

In total, 43 UK families of 2-4-year-olds were recruited to the study, half of whom completed an 8-week course (Tots Talking) focussed on parent interaction, and half of whom acted as wait-list controls.

RESULTS AND OUTCOMES

Results suggest that such programmes are feasible for families with 86% staying in the intervention. In addition, greater changes in underlying communication skills such as joint attention and gesture were evident compared to wait-list controls.

CONCLUSIONS AND IMPLICATIONS

We conclude that pre-verbal skills may be more important to measure as initial outcomes than language or vocabulary change in this population.

WHAT THIS PAPER ADDS

What is already known on the subject Children from lower socioeconomic status (SES) backgrounds are at higher risk of communication difficulties and there is a need for community intervention programmes for very young children. What this study adds This study suggests that such programmes can be feasible and effective, but that very early/basic communicative skills (such as joint attention) may be boosted first rather than language or vocabulary. What are the clinical implications of this work? Children's centres and other community services could feasibly run short parent facing courses emphasising contingent communication in low SES families and other diverse groups. These may be more successful run with younger preschoolers. Joint attention may be a better focus of intervention before expecting vocabulary or language change. Community health professionals may find this information useful in referring and supporting families in need.

Experience with pointing gestures facilitates infant vocabulary growth through enhancement of sensorimotor brain activity

Exposure to communicative gestures, through their parents' use of gestures, is associated with infants' language development. However, the mechanisms supporting this link are not fully understood. In adults, sensorimotor brain activity occurs while processing communicative stimuli, including both spoken language and gestures. Using electroencephalogram (EEG) mu rhythm desynchronization (mu ERD), a marker of sensorimotor activity, we examined whether experimental manipulation of infants' exposure to gestures would affect language development, and specifically whether such an effect would be mediated by changes in sensorimotor brain activity. Mu ERD was measured in 10- to 12-month-old infants (N = 81; 42 male; 15% Hispanic, 62% White) recruited from counties surrounding a large mid-Atlantic university while they observed an experimenter gesturing toward or grasping an object. Half of the infants were randomized to receive increased gesture exposure through a parent-directed training. All 81 infants provided behavioral (infant and parent pointing and infant vocabulary) data prior to intervention and 72 provided behavioral data postintervention. Forty-two infants provided usable (post artifact removal) EEG data prior to intervention and 40 infants provided usable EEG data post-intervention. Twenty-nine infants provided usable EEG data at both sessions. Increased parent gesture due to the intervention was associated with increased infant right lateralized mu ERD at follow-up, but only while observing the experimenter gesturing not grasping. Increased mu ERD, again only while observing the experimenter gesture, was associated with increased infant receptive vocabulary. This is the first evidence suggesting that increasing exposure to gestures may impact infants' language development through an effect on sensorimotor brain activity. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Early Identification of Children at Risk of Communication Disorders: Introducing a Novel Battery of Dynamic Assessments for Infants

PURPOSE

Many children with communication disorders (CDs) experience lengthy gaps between parental reporting of concerns and formal identification by professionals. This means that children with CDs are denied access to early interventions that may help support the development of communication skills and prevent possible negative sequelae associated with long-term outcomes. This may be due, in part, to the lack of assessment instruments available for children younger than 3 years of age. This study therefore reports on promising preliminary data from a novel set of valid dynamic assessment (DA) measures designed for infants.

METHOD

We recruited 53 low-risk children and two groups of children considered to be at high risk for CDs (n = 17, social high risk, and n = 22, language high risk) due to family members with language and social communication difficulties. The children were between 1 and 2 years of age and were assessed using a battery of five DA tasks related to receptive vocabulary, motor imitation, response to joint attention, turn taking, and social requesting. A set of standardized measures were also used.

RESULTS

The DA tasks showed high levels of interrater reliability and relationships with age across a cross-sectional sample of children from the low-risk group. Three tasks showed moderate to strong correlations with standardized measures taken at the same age, with particularly strong correlations between the DA of receptive vocabulary and other receptive language measures. The DA of receptive vocabulary was also the only task to discriminate between the three risk groups, with the social high risk group scoring lower.

CONCLUSIONS

These results provide preliminary information about early DA tasks, forming the basis for further research into their utility. DA tasks might eventually facilitate the development of new methods for detecting CDs in very young children, allowing earlier intervention and support.

A concert for babies: Attentional, affective, and motor responses in an infant audience

Many of our most powerful musical experiences are shared with others, and researchers have increasingly investigated responses to music in group contexts. Though musical performances for infants are growing in popularity, most research on infants' responses to live music has focused on solitary caregiver-infant pairs. Here, we report infants' attentional, affective, and motor responses to live music as audience members. Two groups of caregiver-infant (6-18 months) pairs (50 total) watched a short musical performance with two song styles - lullaby and playsong. Caregivers were instructed to watch passively or interactively. The playsong captured more infant attention and, especially in the interactive condition, elicited more infant smiles. Notably, infant attention was more coordinated with their own caregiver than a random caregiver, and infants with no experience attending group musical events in the past were especially attentive to the performance. Infants were more likely to generate movements when parents remained still. Overall, infants' responses to live musical performance in an audience were influenced by song style, caregiver behavior, and their own musical histories. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=q61qnDMW8dU. RESEARCH HIGHLIGHTS: Infants' responses to live musical performances are shaped by the music, by their caregivers, and by their own musical histories During a concert for babies, a playsong more effectively elicited infant attention and smiles than a lullaby, especially when caregivers were interactive Infant attention was more coordinated with their own caregiver than with other caregivers watching the same show.

Parent-child interaction and developmental outcomes in children with typical and elevated likelihood of autism

BACKGROUND

Early parent-child interactions have a critical impact on the developmental outcomes of the child. It has been reported that infants with a family history of autism and their parents may engage in different patterns of behaviours during interaction compared to those without a family history of autism. This study investigated the association of parent-child interactions with child developmental outcomes of those with typical and elevated likelihood of autism.

METHOD

This longitudinal study investigated the relationship between global attributes of parent-child interaction and the developmental outcomes of infant siblings with elevated likelihood (EL: n = 29) or typical likelihood (TL: n = 39) of developing autism. Parent-child interactions were recorded during a session of free-play when the infants were six months of age. Developmental assessments were carried out when the children were 12 and 24 months of age.

RESULTS

The intensity of mutuality was significantly higher in the TL group than in the EL group, and developmental outcomes were poorer in the EL group when compared to the TL group. Positive associations between parent-child interaction scores at six months and developmental outcomes at 12 months were observed only in the TL group. However, in the EL group, higher levels of infant positive affect and attentiveness paid to the caregiver is associated with lower autism symptoms. Due to the sample size and design of the study, the findings must be viewed as indicative.

CONCLUSION

This preliminary investigation demonstrated differences in the association between parent-child interaction quality and developmental outcomes for children with typical and elevated likelihood for autism. Future studies should combine micro-analytic and macro-analytic approaches to parent-child interaction to further examine the nature of this relationship.

When do toddlers point during mealtime?: Pointing in the second year of life in everyday situations

The present study aimed to gain insight into the development of the infant's awareness of others' attention that takes place in everyday contexts. We examined the relation between the toddler's pointing, the toddler's visual attention to the caregiver, and the context of the action of the caregiver in the same child-caregiver dyads at two time points (13 and 17 months of age) during lunchtime at a Japanese daycare center, in which toddlers ate lunch with the help of caregivers. Specifically, we focused on the question of whether the timing of the toddler's pointing reflected the ongoing context of the action of the caregiver, based on the analysis of what the caregiver was doing when a toddler exhibited pointing behavior. Our analysis revealed several interrelated results. First, the toddler's pointing behavior was related to the visual exploration of the face of the caregiver at 17 months of age, which was not obvious at 13 months of age. Second, toddlers were more likely to point when the caregivers were just looking at them without being engaged in other salient goal-directed activities. Third, toddlers were less likely to exhibit pointing behavior when the caregivers were manipulating objects or feeding the toddlers. Taken together, the results suggested that toddlers were increasingly aware of the dynamic context of social partner's engagement, differentiating the right time to modulate the attention of others by pointing in everyday situations. The present study supplemented the existing knowledge about pointing and the development of shared intentionality based on controlled experiments by providing a description of the context in which toddlers tend to point in the naturalistic situation of lunchtime within a specific cultural setting during the second year of life.

Joint Attention and Its Relationship with Autism Risk Markers at 18 Months of Age

(1) Joint attention is the ability to coordinate attention to share a point of reference with another person. It has an early onset and is a clear indicator of understanding the representations of others, and it is essential in the development of symbolic thought and the acquisition of language. Deficiencies in this prelinguistic early communication skill are strong markers of the risk of autism spectrum disorder (ASD); (2) this longitudinal study aimed to evaluate joint attention skills in a group of 32 infants at two developmental moments (8 and 12 months) in order to explore whether their performance on this skill was related to the presence of early signs of ASD at 18 months. Logistic multiple regressions were carried out for the data analysis; (3) results of the analysis showed that the variables of initiating joint attention at 8 months and responding to joint attention at 12 months were linked to the risk of ASD at 18 months of age; (4) in conclusion, early joint attention skills had a pivotal role in defining early manifestations of ASD.

You may point, but do not touch: Impact of gesture-types and cognition on language in typical and atypical development

BACKGROUND

Evidence shows that the relation with the referent (object manipulation, contact/no contact pointing) and the different hand features (index finger/open palm) when pointing indicate different levels of cognitive and linguistic attainment in typical development (TD). This evidences the close link between pointing, cognition and language in TD, but this relation is understudied in autism. Moreover, the longitudinal pathway these abilities follow remains unexplored and it is unclear what specific role (predictor or mediator) pointing and cognition have in both typical and atypical language development.

AIMS

The first aim was to investigate whether pointing hand features (index finger/open palm) and relation with the referent (manipulation, contact and no contact pointing) similarly predict language in children with and without autism. The second aim was to explore whether cognition mediates the longitudinal relationship between pointing and language development.

METHODS & PROCEDURES

Sixteen children with autism, 13 children at high risk (HR) for autism and 18 TD children participated in an interactive gesture-elicitation task and were tested on standardised cognitive and expressive language batteries in a longitudinal design. A two-step analysis consisted of a stepwise linear regression and mediation analyses. First, the linear regression identified which hand features and types of relation with the referent predicted expressive language in all groups. Second, three mediation analyses (one per group) assessed the predictor/mediator role of the variables that met significance in the regression analysis.

OUTCOMES & RESULTS

Both cognition and index finger pointing were direct longitudinal predictors of further expressive language skills in the autism group. In TD and HR groups this relation was mediated by age.

CONCLUSIONS & IMPLICATIONS

Findings highlight the role of age in communicative development, but suggest a key role of cognition and index finger use in the longitudinal relationship between pointing gestures and expressive language development in children with autism. This has important clinical implications and supports the view that index finger pointing production might be a useful tool in the intervention for communicative and language abilities in autism.

WHAT THIS PAPER ADDS

What is already known on the subject There is evidence that no contact pointing is associated with complex socio-cognitive abilities that underpin communication in TD. Similarly, studies in TD show that index finger pointing is closely linked with language acquisition. However, it is unclear whether these associations are present in autism. In addition, the mediating (or predictive) role of cognition in the pointing-language relation has not yet been explored neither in typical nor in atypical development. What this paper adds to existing knowledge This paper shows that index finger pointing and cognition are direct longitudinal predictors of expressive language in the autism group. In the other groups this relation is mediated by age. This suggests that there is a window of opportunity for pointing to predict expressive language whereas the predictive value of cognition expands in development. Based on this, children with autism would share the same language predictors as TD children, but with delays. What are the potential or actual clinical implications of this work? This study reveals that index finger, age and cognition reliably predict spoken language in autism, which may indicate that early prelinguistic intervention based on pointing production and the improvement of cognitive skills might have a positive impact on spoken language in this population.

Connecting primate gesture to the evolutionary roots of language: A systematic review

Comparative psychology provides important contributions to our understanding of the origins of human language. The presence of common features in human and nonhuman primate communication can be used to suggest the evolutionary trajectories of potential precursors to language. However, to do so effectively, our findings must be comparable across diverse species. This systematic review describes the current landscape of data available from studies of gestural communication in human and nonhuman primates that make an explicit connection to language evolution. We found a similar number of studies on human and nonhuman primates, but that very few studies included data from more than one species. As a result, evolutionary inferences remain restricted to comparison across studies. We identify areas of focus, bias, and apparent gaps within the field. Different domains have been studied in human and nonhuman primates, with relatively few nonhuman primate studies of ontogeny and relatively few human studies of gesture form. Diversity in focus, methods, and socio-ecological context fill important gaps and provide nuanced understanding, but only where the source of any difference between studies is transparent. Many studies provide some definition for their use of gesture; but definitions of gesture, and in particular, criteria for intentional use, are absent in the majority of human studies. We find systematic differences between human and nonhuman primate studies in the research scope, incorporation of other modalities, research setting, and study design. We highlight eight particular areas in a call to action through which we can strengthen our ability to investigate gestural communication's contribution within the evolutionary roots of human language.

Sharing Experiences in Infancy: From Primary Intersubjectivity to Shared Intentionality

We contrast two theses that make different assumptions about the developmental onset of human-unique sociality. The primary intersubjectivity thesis (PIT) argues that humans relate to each other in distinct ways from the beginning of life, as is shown by newborns' participation in face-to-face encounters or "primary intersubjectivity." According to this thesis, humans' innate relational capacity is the seedbed from which all subsequent social-emotional and social-cognitive developments continuously emerge. The shared intentionality thesis (SIT) states that human-unique forms of interaction develop at 9-12 months of age, when infants put their heads together with others in acts of object-focused joint attention and simple collaborative activities. According to this thesis, human-unique cognition emerges rapidly with the advent of mind-reading capacities that evolved specifically for the purpose of coordination. In this paper, we first contrast the two theses and then sketch the outlines of an account that unifies their strengths. This unified account endorses the PIT's recognition of the fundamental importance of primary intersubjectivity. Any act of sharing experiences is founded on the communicative capacity that is already displayed by young infants in primary intersubjectivity. At the same time, we question the PIT's interpretation that dyadic encounters have the triadic structure of joint attention. Lastly, we draw on empirical work on the development of joint attention, imitation, and social referencing that serves as evidence that primary intersubjectivity continuously unfolds into the capacity for triadic joint attention.

Revisiting how we operationalize joint attention

Parent-child interactions support the development of a wide range of socio-cognitive abilities in young children. As infants become increasingly mobile, the nature of these interactions change from person-oriented to object-oriented, with the latter relying on children's emerging ability to engage in joint attention. Joint attention is acknowledged to be a foundational ability in early child development, broadly speaking, yet its operationalization has varied substantially over the course of several decades of developmental research devoted to its characterization. Here, we outline two broad research perspectives-social and associative accounts-on what constitutes joint attention. Differences center on the criteria for what qualifies as joint attention and regarding the hypothesized developmental mechanisms that underlie the ability. After providing a theoretical overview, we introduce a joint attention coding scheme that we have developed iteratively based on careful reading of the literature and our own data coding experiences. This coding scheme provides objective guidelines for characterizing mulitmodal parent-child interactions. The need for such guidelines is acute given the widespread use of this and other developmental measures to assess atypically developing populations. We conclude with a call for open discussion about the need for researchers to include a clear description of what qualifies as joint attention in publications pertaining to joint attention, as well as details about their coding. We provide instructions for using our coding scheme in the service of starting such a discussion.

Brief Report: Parents' Declarative Use of Deictic Gestures Predict Vocabulary Development in Infants at High and Low Risk for Autism Spectrum Disorder

We examined the communicative intentions behind parents' deictic gesture use with high-risk infants later diagnosed with autism spectrum disorder (ASD; n = 17), high-risk infants who were not diagnosed with ASD (n = 25), and low-risk infants (n = 28) at 12 months and assessed the extent to which the parental deictic gesture intentions predicted infants' later vocabulary development. We found that parents in the three groups produced similar numbers of declarative and imperative gestures during a 10-minute parent-child interaction in the lab at 12 months and that 12-month parental declarative gesture use was significantly, positively associated with children's 36-month vocabulary scores. Encouraging parental use of declarative gestures with infants could have important implications for language development.

Early word-learning skills: A missing link in understanding the vocabulary gap?

Socioeconomic status (SES) has been repeatedly linked to the developmental trajectory of vocabulary acquisition in young children. However, the nature of this relationship remains underspecified. In particular, despite an extensive literature documenting young children's reliance on a host of skills and strategies to learn new words, little attention has been paid to whether and how these skills relate to measures of SES and vocabulary acquisition. To evaluate these relationships, we conducted two studies. In Study 1, 205 2.5- to 3.5-year-old children from widely varying socioeconomic backgrounds were tested on a broad range of word-learning skills that tap their ability to resolve cases of ambiguous reference and to extend words appropriately. Children's executive functioning and phonological memory skills were also assessed. In Study 2, 77 of those children returned for a follow-up session several months later, at which time two additional measures of vocabulary were obtained. Using Structural Equation Modeling (SEM) and multivariate regression, we provide evidence of the mediating role of word-learning skills on the relationship between SES and vocabulary skill over the course of early development.

A Cross-Cultural Analysis of Early Prelinguistic Gesture Development and Its Relationship to Language Development

Many Western industrialized nations have high levels of ethnic diversity but to date there are very few studies which investigate prelinguistic and early language development in infants from ethnic minority backgrounds. This study tracked the development of infant communicative gestures from 10 to 12 months (n = 59) in three culturally distinct groups in the United Kingdom and measured their relationship, along with maternal utterance frequency and responsiveness, to vocabulary development at 12 and 18 months. No significant differences were found in infant gesture development and maternal responsiveness across the groups, but relationships were identified between gesture, maternal responsiveness, and vocabulary development.

A meta-analysis of the predictability of LENA™ automated measures for child language development

Early language environment plays a critical role in child language development. The Language ENvironment Analysis (LENA™) system allows researchers and clinicians to collect daylong recordings and obtain automated measures to characterize a child's language environment. This meta-analysis evaluates the predictability of LENA's automated measures for language skills in young children. We systematically searched reports for associations between LENA's automated measures, specifically, adult word count (AWC), conversational turn count (CTC), and child vocalization count (CVC), and language skills in children younger than 48 months. Using robust variance estimation, we calculated weighted mean effect sizes and conducted moderator analyses exploring the factors that might affect this relationship. The results revealed an overall medium effect size for the correlation between LENA's automated measures and language skills. This relationship was largely consistent regardless of child developmental status, publication status, language assessment modality and method, or the age at which the LENA recording was taken; however, the effect was weakly moderated by the gap between LENA recordings and language measures taken. Among the three measures, there were medium associations between CTC and CVC and language, whereas there was a small-to-medium association between AWC and language. These findings extend beyond validation work conducted by the LENA Research Foundation and suggest certain predictive strength of LENA's automated measures for child language. We discussed possible mechanisms underlying the observed associations, as well as the theoretical, methodological, and clinical implications of these findings.

Integrated Communication System: Gesture and Language Acquisition in Typically Developing Children and Children With LD and DLD

Gesture and language development are strongly connected to each other. Two types of gestures in particular are analyzed regarding their role for language acquisition: pointing and iconic gestures. With the present longitudinal study, the predictive values of index-finger pointing at 12 months and the comprehension of iconic gestures at 3;0 years for later language skills in typically developing (TD) children and in children with a language delay (LD) or developmental language disorder (DLD) are examined. Forty-two monolingual German children and their primary caregivers participated in the study and were followed longitudinally from 1;0 to 6;0 years. Within a total of 14 observation sessions, the gestural and language abilities of the children were measured using standardized as well as ad hoc tests, parent questionnaires and semi-natural interactions between the child and their caregivers. At the age of 2;0 years, 10 of the 42 children were identified as having a LD. The ability to point with the extended index finger at 1;0 year is predictive for language skills at 5;0 and 6;0 years. This predictive effect is mediated by the language skills of the children at 3;0 years. The comprehension of iconic gestures at 3;0 years correlates with index-finger pointing at 1;0 year and also with earlier and later language skills. It mediates the predictive value of index-finger pointing at 1;0 year for grammar skills at 5;0 and 6;0 years. Children with LD develop the ability to understand the iconicity in gestures later than TD children and score lower in language tests until the age of 6;0 years. The language differences between these two groups of children persist partially until the age of 5;0 years even when the two children with manifested DLD within the group of children with LD are excluded from analyses. Beyond that age, no differences in the language skills between children with and without a history of LD are found when children with a manifest DLD are excluded. The findings support the assumption of an integrated speech–gesture communication system, which functions similarly in TD children and children with LD or DLD, but with a time delay.

Does intention matter? Relations between parent pointing, infant pointing, and developing language ability

Infants' pointing is associated with concurrent and later language development. The communicative intention behind the point-i.e., imperative versus declarative-can affect both the nature and strength of these associations, and is therefore a critical factor to consider. Parents' pointing is associated with both infant pointing and infant language; however, less work has examined the intent behind parents' points. We explore relations between parents' and infants' pointing at the level of communicative intention, and examine how pointing relates to concurrent and longitudinal infant language skills. In a sample of 52 mother-infant dyads, we measured mother and infant pointing at infant age 12-months, and infant expressive and receptive language at 12-, 18-, and 24-months. We found that mothers produced points with a variety of intentions, however we did not find relations between mother and infant pointing within the different communicative intentions. Replicating previous research, infant declarative pointing was related both concurrently and longitudinally to their language ability. Mothers' declarative pointing was related to their infants' concurrent language, while their imperative pointing was not. Further, there was an interaction between parent and infant declarative pointing, such that the positive relation between parents' declarative pointing and their infants' concurrent receptive language was present only for those infants who were also producing declarative points themselves. Findings suggest that parents' declarative pointing may support both their infants' early word learning and, perhaps, provides a model for their infant to begin using points as well. This study constitutes an important initial exploration of these relations.

The role of the motor system in action understanding and communication: Evidence from human infants and non-human primates

There is growing evidence that activation of the motor system during observation of actions, a phenomenon first observed in non-human primates, underlies action understanding and even communication. This review (a) examines the evidence on motor system activity as an underlying neural correlate of action understanding; (b) reviews the theoretical and empirical work linking action understanding and the development of communication, with a specific focus on the role that gestures play as an intermediary; and (c) discusses the research on and existing opportunities for understanding the link between the motor system and communication in both humans and non-human primates, through the lens of action perception. Bringing together findings and perspectives from developmental social cognition in both humans and non-human primates and applying recent neuroscientific perspectives will help to elucidate the processes underlying the ability to understand and communicate with others.