What Paves the Way to Conventional Language? The Predictive Value of Babble, Pointing, and Socioeconomic Status

Rapid Increases in Children's Spontaneous and Responsive Speech Vocalizations Following Cochlear Implantation: Implications for Spoken Language Development

OBJECTIVES

Cochlear implants are the most effective means to provide access to spoken language models for children with severe to profound deafness. In typical development, spoken language emerges gradually as children vocally explore and interact with caregivers. But it is unclear how early vocal activity unfolds after children gain access to auditory signals, and thus spoken language, via cochlear implants, and how this early vocal exploration predicts children's spoken language development. This longitudinal study investigated how two formative aspects of early language-child speech productivity and caregiver-child vocal interactions-develop following cochlear implantation, and how these aspects impact children's spoken language outcomes.

DESIGN

Data were collected via small wearable recorders that measured caregiver-child communication in the home pre- and for up to 3 years post-implantation (N = 25 children, average = 167 hours/child, 4,180 total hours of observation over an average of 11 unique days/child). Spoken language outcomes were measured using the Preschool Language Scales-5. Growth trajectories were compared with a normative sample of children with typical hearing (N = 329).

RESULTS

Even before implantation, all children vocalized and vocally interacted with caregivers. Following implantation, child speech productivity (β = 9.67, p < 0.001) and caregiver-child vocal interactions (β = 12.65, p < 0.001) increased significantly faster for children with implants than younger, hearing age-matched typical hearing controls, with the fastest growth occurring in the time following implant activation. There were significant, positive effects of caregiver-child interaction on children's receptive, but not expressive, spoken language outcomes.

CONCLUSIONS

Overall, children who receive cochlear implants experience robust growth in speech production and vocal interaction-crucial components underlying spoken language-and they follow a similar, albeit faster, developmental timeline as children with typical hearing. Regular vocal interaction with caregivers in the first 1 to 2 years post-implantation reliably predicts children's comprehension of spoken language above and beyond known predictors such as age at implantation.

Joint attention and exogenous attention allocation during mother-infant interaction at 12 months associate with 24-month vocabulary composition

Introduction

Early attentional processes are inherently linked with early parent-infant interactions and play a critical role in shaping cognitive and linguistic development. This study explored how specific early attention mechanisms-namely, exogenous attention allocation and joint attention initiation-during mother-infant interactions at 12 months may influence language development at 24 months.

Methods

A sample of 46 typically developing children was observed at 12 months during mother-infant interactions obtained through remote videotaping. Quantitative measures of exogenous attention allocation to external auditory stimuli and joint attention initiation by the infant were obtained through micro-analytical coding. Language outcomes were assessed at 24 months, with a focus on vocabulary composition (i.e., percentage of predicates).

Results

Findings showed significant negative associations between early life exogenous attention allocation and later vocabulary composition (i.e., predicate percentage). This association was modulated by joint attention initiation: infants displaying lower levels of joint attention initiation showed a negative association between exogenous attention allocation and language development.

Discussion

The findings are suggestive of a complex relationship among different forms of early attention skills and language development in the first 2 years of life.

The robustness of speech-like vocalization in typically developing infants and infants with autism

BACKGROUND

Human infants produce speech-like vocalizations ("volubility") at very high rates, 4-5 per minute during waking hours across the first year, far exceeding rates of our ape relatives.

AIMS

We document volubility in 127 typically developing (TD) infants, 44 with autism (ASD), and 21 with non-autism developmental delay (DD) through longitudinal recordings and human coding.

METHODS AND PROCEDURES

Families of 302 infants (110 not yet diagnosed or with other diagnoses) supplied 8.6 all-day recordings across the first year. Trained coders analyzed 21 randomly-selected 5-minute segments per recording, counting speech-like vocalizations, cries, and laughter.

OUTCOMES AND RESULTS

Infants in all groups (including those with other diagnoses or not yet diagnosed) showed volubility of 4-5 per minute for the first year, but boys showed higher volubility than girls in the TD, ASD, and DD groups. While volubility was relatively stable across the first year for both boy and girl TD infants, volubility fell in both ASD and DD boys, while being more stable for girls.

CONCLUSIONS AND IMPLICATIONS

Strong similarities in volubility were seen across all groups, but male infants diagnosed with ASD or DD showed falling volubility across the first year, a pattern not seen in TD infants.

Frequencies and functions of vocalizations and gestures in the second year of life

Speculations on the evolution of language have invoked comparisons across human and non-human primate communication. While there is widespread support for the claim that gesture plays a central, perhaps a predominant role in early language development and that gesture played the foundational role in language evolution, much empirical information does not accord with the gestural claims. The present study follows up on our prior work that challenged the gestural theory of language development with longitudinal data showing early speech-like vocalizations occurred more than 5 times as often as gestures in the first year of life. Now we bring longitudinal data on the second year (13, 16 and 20 mo), showing again that vocalizations predominated, and especially in conventional (learned) communication; > 9 times more spoken words were observed than gestures that could be viewed as functionally equivalent to words (i.e., signs). Our observations also showed that about ¾ of gestures across these second-year data were deictics (primarily pointing and reaching), acts that while significant in supporting the establishment of referential vocabulary in both spoken and signed languages, are not signs, but have single universal deictic functions in the here and now. In contrast, words and signs, the primary semantic components of spoken and signed languages, are functionally flexible, making possible reference to abstractions that are not bound to any particular illocutionary force nor to the here and now.

Developmental Relationships Between Early Vocabulary Acquisition, Joint Attention and Parental Supportive Behaviors

In late infancy and early toddlerhood, joint attention ability is widely recognized as a crucial foundation for children's vocabulary development, though the exact nature of its contribution remains debated. This study investigates associations between joint attention and subsequent vocabulary development, as well as the possible moderating role of supportive parental behaviors. Seventy children and their families participated in this longitudinal study, which began when the children were 10 months of age. Parents completed the Swedish Communicative Development Inventory (CDI) at four age points (10, 12, 18, and 24 months) to assess receptive and expressive vocabulary growth. Children participated in lab-based assessment of joint attention abilities at 10, 12, and 18 months. Additionally, at 10 and 12 months, parent-child dyads participated in two semi-structured lab assessments to evaluate the quality of parental supportive behaviors during interactions with their child. Primary analysis showed no significant effects of joint attention on subsequent receptive and expressive vocabulary. However, a significant interaction was found between a child's ability to respond to joint attention cues and parental supportive behaviors on receptive vocabulary. These findings indicate that parental supportive behaviors play a crucial role in promoting the development of children's receptive vocabulary.

Longitudinal follow-up of hearing, speech, and language skills in 6-year-old children with congenital moderate hearing loss

OBJECTIVES

Children born with moderate hearing loss present with speech and language outcomes at both ends of the spectrum. To explore reasons for this, the objective of this study was to follow up a group of children born with moderate sensorineural hearing loss at 6 years of age (n = 7) by investigating their outcomes in hearing, speech, and language development from time point of hearing aid fitting at 6 months. Another objective was to investigate the relationship between earlier outcomes on precursing variables to the current status in auditory, speech and language development.

METHOD

Earlier data from a project with the same participants of auditory variables, speech, and language development were compared to the current study outcomes at 6 years of age. Children in this study performed standardized tests of phonology (SVANTE), expressive vocabulary (BNT), and speech-in-noise test (Hagerman's sentences). Parents reported on their child's functional auditory performance in everyday life (PEACH), and demographics and general development (questionnaire). Etiology and frequency of speech and language-directed intervention from time point of diagnosis to 6 years of age were collected through medical journals.

RESULTS

Hearing levels were stable over time in all children but one, who had received bilateral cochlear implants. Performance on speech-in-noise testing varied in aided condition (-0.8 to 8, mean 2.65, SD 3.09) and unaided condition (7.2 dB-21.2 dB, mean 12.06, SD 4.82). Scores on the PEACH indicated further review in four of the seven children. Mean group score on consonant proficiency had increased from 3 to 6 years of age and were within age norms. Vocabulary scores were below the norms of children with typical hearing. Outcomes on vocabulary measures at 2.5 years showed strong correlations that were significant to scores on the BNT at 6 years of age (r = 0.87, p = 0.05). Correlations between hours of hearing aid use and vocabulary was not significant at 6 years of age. The frequency of intervention sessions in the first 6 years varied between participants (4-55, mean 19.1, SD 17.1).

CONCLUSION

Despite homogeneous hearing and other background variables in the participants from birth, large individual variations in speech and language outcomes at 6 years of age were found. Considering the many factors involved that impact the development of children with moderate hearing loss, the results suggest that monitoring early precursors in auditory, speech and language development may be helpful in setting commensurate goals for each child. Detecting additional conditions that may pose challenges in future speech and language as early as possible is important. There is ample room for improvement in terms of increasing the frequency of intervention for children with moderate hearing loss and their families.

Living the first years in a pandemic: children's linguistic development and related factors in and out of the COVID-19 lockdowns

This retrospective study provides insights on linguistic development in exceptional circumstances assessing 378 children (between 2;6 and 3;6) who lived their first years during the COVID-19 pandemic and comparing it with normative data collected before this period (CDI-III-PT; Cadime et al., 2021). It investigates the extent to which linguistic development was modulated by a complex set of factors, including sex, maternal education, book reading, language-promoting practices, COVID-19 infection, parental stress and sleeping problems, considering three periods (during lockdowns, out of lockdowns and at present). The results show a substantial negative effect of the pandemic on both lexical and syntactic development. Considering individual variation, structural equation modelling unveiled a complex scenario in which age, sex, book reading, language-promoting practices, sleeping problems and COVID-19 infection showed a direct effect on linguistic development. Maternal education and parental stress had an indirect effect on children's language, mediated by book reading and sleeping problems, respectively.

Supporting Early Language by Supporting Systemic Solutions

A large body of research shows connections between infants' and toddlers' home language input and a wide range of receptive and expressive early language skills. Some facets of caretaker input and early language skills are associated with socioeconomic status (SES), though not all. Given the complexity of language learning, language use, and its many pathways of connection to SES, testing causal links between these dimensions is difficult at best. Interventions aimed at changing parent language use have seen mixed success, in part because "language infusions" generally fail to target underlying challenges facing underresourced families, and perhaps because parent language is the wrong target. System-level interventions such as paid parental leave and expansion and enrichment of childcare and early education options hold greater promise for improving families' lives, with positive repercussions for a broad range of family and child outcomes, including linguistic ones.

Socioeconomic Deprivation Detrimentally Influences Language Outcomes in Toddlers With Cleft Palate

PURPOSE

The purpose of this study was to examine the influence of socioeconomic deprivation on language and developmental outcomes in toddlers with cleft palate with or without cleft lip (CP ± L). Other factors known to influence language outcomes were also considered, including home language history, history of hearing problems, syndromic diagnoses, and sex.

METHOD

A multicenter, cross-sectional study design was conducted. Data for 566 16-month-old toddlers with CP ± L were collected from 17 outpatient cleft palate clinics located throughout the United States. Outcome measures included the MacArthur-Bates Communicative Development Inventories, LENA Developmental Snapshot, age at first word as reported by the caregiver, and the Ages and Stages Questionnaires-Third Edition (ASQ-3). Multivariable linear or logistic regression was used to determine the influence of socioeconomic deprivation, as measured by the Area Deprivation Index, on language and developmental outcomes.

RESULTS

Greater socioeconomic deprivation significantly predicted poorer language outcomes in toddlers with CP ± L, including receptive vocabulary words (p = .02), expressive vocabulary words (p = .02), and late-developing gestures (p = .02). Additionally, toddlers from less affluent neighborhoods produced their first words significantly later than their counterparts living in more affluent areas (p < .01). Lower maternal education levels predicted significantly increased risk for problem solving delays (p < .01), and patients with subsidized insurance were at significantly increased risk for personal-social delays on the ASQ-3 (p < .01).

CONCLUSIONS

Children with CP ± L are susceptible to developmental delays associated with socioeconomic deprivation. These findings have implications for identifying a child's individual risk factors for developmental language disorders when conducting speech-language assessments. Future study should examine how inequities in care can be mitigated and addressed.

The Language ENvironment Analysis system (LENA): A validation study with Italian-learning children

This study is a validation of the LENA system for the Italian language. In Study 1, to test LENA's accuracy, seventy-two 10-minute samples extracted from daylong LENA recordings were manually transcribed for 12 children longitudinally observed at 1;0 and 2;0. We found strong correlations between LENA and human estimates in the number of Adult Word Count (AWC) and Child Vocalisations Count (CVC) and a weak correlation between LENA and human estimates in Conversational Turns Count (CTC). In Study 2, to test the concurrent validity, direct and indirect language measures were considered on a sample of 54 recordings (19 children). Correlational analyses showed that LENA's CVC and CTC were significantly related to the children's vocal production, a parent report measure of prelexical vocalizations and the vocal reactivity scores. These results confirm that the automatic analyses performed by the LENA device are reliable and powerful for studying language development in Italian-speaking infants.

How does social contingency facilitate vocabulary development?

Previous research shows that infants of parents who are more likely to engage in socially contingent interactions with them tend to have larger vocabularies. An open question is how social contingency facilitates vocabulary growth. One possibility is that parents who speak in response to their infants more often produce larger amount of language input, which accelerates vocabulary growth. Another possibility is that the simplicity of contingent language input is especially suitable to support early word learning. A third possibility is that more evidence of the communicative nature of language, achieved through frequent contingent responses, helps infants build a link between their own words or vocalizations and others' behaviors. This link may lead to a better understanding of the communicative nature of language and further language advances, including vocabulary growth. To distinguish between these hypotheses, we analyzed the relations between parent-infant interactions when infants were 9 months and their vocabulary size at 12 months, using a naturalistic corpus. Our findings show that the frequency of parents' verbal contingent responses predicts receptive vocabulary size at 12 months and this predictive relation is unlikely to be due to the amount of language input or the simplicity of language within socially contingent interactions. RESEARCH HIGHLIGHTS: Infants of parents who respond to their vocalizations more often during the first year of life tend to have larger vocabularies in the second year. It is an open question what drives the predictive relation between parents' responsiveness and infants' vocabulary; we tested three hypotheses that offer competing explanations. More responsive parents might provide (1) more language input, (2) simpler language input, (3) more evidence of the communicative nature of language (via frequent responses). We find support for the third hypothesis; the frequency of parents' responses predicts infants' vocabularies above and beyond the amount and simplicity of language input.

Daylong egocentric recordings in small- and large-scale language communities: A practical introduction

Daylong egocentric (i.e., participant-centered) recordings promise an unprecedented view into the experiences that drive early language learning, impacting both assumptions and theories about how learning happens. Thanks to recent advances in technology, collecting long-form audio, photo, and video recordings with child-worn devices is cheaper and more convenient than ever. These recording methods can be similarly deployed across small- and large-scale language communities around the world, opening up enormous possibilities for comparative research on early language development. However, building new high-quality naturalistic corpora is a massive investment of time and money. In this chapter, we provide a practical look into considerations relevant for developing and managing daylong egocentric recording projects: Is it possible to re-use existing data? How much time will manual annotation take? Can automated tools sufficiently tackle the questions at hand? We conclude by outlining two exciting directions for future naturalistic child language research.

Infants who develop autism show smaller inventories of deictic and symbolic gestures at 12 months of age

Gestures are an important social communication skill that infants and toddlers use to convey their thoughts, ideas, and intentions. Research suggests that early gesture use has important downstream impacts on developmental processes, such as language learning. However, autistic children are more likely to have challenges in their gestural development. The current study expands upon previous literature on the differences in gesture use between young autistic and non-autistic toddlers by collecting data using a parent-report questionnaire called the MCDI-Words and Gestures at three time points, 12, 18, and 24 months of age. Results (N = 467) showed that high-likelihood infants who later met diagnostic criteria for ASD (n = 73 HL-ASD) have attenuated gesture growth from 12 to 24 months for both deictic gestures and symbolic gestures when compared to high-likelihood infants who later did not meet criteria for ASD (n = 249 HL-Neg) and low-likelihood infants who did not meet criteria for ASD (n = 145 LL-Neg). Other social communicative skills, like play behaviors and imitation, were also found to be impacted in young autistic children when compared to their non-autistic peers. Understanding early differences in social communication growth before a formal autism diagnosis can provide important insights for early intervention.

Dimensionality of Speech-Language Pathologists' Child-Directed Talk During School-Based Therapy With Primary-Grade Students

PURPOSE

The purpose of this study was to examine the measurement structure of the linguistic features of speech-language pathologists' (SLPs) talk during business-as-usual therapy sessions in the public schools and to test the longitudinal stability of a theorized dimensional structure consisting of quantity, grammatical complexity, and lexical complexity.

METHOD

Seventy-five SLPs' talk during therapy sessions with primary-grade students was automatically transcribed and coded for linguistic features from a corpus of 579 videotaped therapy session videos collected at the beginning, middle, and end of one school year with an approximately 12-week interval. We explored video characteristics and conducted descriptive statistics on eight linguistic indices of SLP talk to examine the variability in SLP talk between therapy sessions. Confirmatory factor analyses were used to explore the dimensional structure of SLP talk at each time point separately for the theorized three dimensions, and we conducted longitudinal measurement invariance analyses to test the stability of the three-factor structural model across the academic year.

RESULTS

There were considerable variabilities among SLPs in the characteristics of SLP talk during therapy sessions. The proposed three-factor structure of SLP talk consisting of quantity, grammatical complexity, and lexical complexity had good model fit at all three time points. The linguistic measurement properties representing the three factors were invariant over time.

CONCLUSIONS

Results provided robust evidence of between-SLP variability in their child-directed talk, established a three-dimensional structure of the linguistic features in SLP talk, and identified that the linguistic features in SLP talk stably measured the same constructs across one school year, based on measurement invariance. The dimensions of SLP talk during therapy with students may represent important, malleable features of therapy that influence child language gains.

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.

Babbling in extremely premature infants at 12 months corrected age

Babbling is an important precursor to speech in infancy, and deviations from the typical babbling development can predict later difficulties in speech, language, and communication. This cross-sectional study aimed to investigate babbling and early speech in Swedish extremely premature infants. Samples of babbling were collected from 20 extremely premature infants (EPT group) at the corrected age of 12 months. Data collection was home-based and consisted of an audio-video recording of each infant playing with a parent. Presence of canonical babbling (CB), and three oral stop variables distinctive of typical babbling, and consonant inventory were assessed. The assessment was performed during a standardised observation of babbling. Data from the EPT group were compared to previously collected data of a reference group of 20 10-month-old infants without known medical diagnoses. The results showed that the EPT group had a lower proportion of infants producing CB, and that they used a significantly smaller consonant inventory compared to the reference group. Although not statistically significant, oral stops were less frequently found in the EPT group. The findings of a restricted consonant inventory and low proportion of CB in the EPT group are not surprising considering that the group has been found to be at risk of speech and language delay in toddlerhood. Still, further research is needed to explore whether babbling at 12 months can predict speech and language skills at an older age in extremely premature infants.

The timeline of non-vocal and vocal communicative skills in infants with hearing loss

Objective

The study investigates what is the link between early verbal and non-vocal abilities, when does predominantly verbal communicative style occur after the intervention with cochlear implants (CI) or hearing aids (HA), and how predictive it is of later linguistic development in deaf and hard of hearing (DHH) infants and children.

Methods

Cohort: children with moderate-to-profound hearing impairment (N = 49, 20 girls, mean age at HA or CI intervention = 15 months, range: 4-35 months).

Measures

Receptive and productive vocabulary at 24 and 36 months and video analysis at 12 months post-intervention. Analysis: Predictive values of total and verbal responses to communicative turns for later vocabulary development were assessed, as well as the relative time course of the development of vocal/verbal communication in DHH children.

Results

Vocabulary at 24 months is predicted by auditory responses at 12 months, as well as by overall responsiveness before intervention. Non-vocal responses decline and overall verbal responses increase significantly between 6 and 12 months after intervention. The trend is delayed in children with delayed (>12 months of age) treatment with CI or HA.

Conclusions

Age of intervention affects the development of vocal/verbal communicative style. Language development, in particular, vocabulary growth, can be further stimulated by the enhancement of preverbal (both vocal and non-vocal) communicative skills.

Socio-economic status and other potential risk factors for language development in the first year of life

A wide variety of language skills has been shown to be compromised in children from low socioeconomic status (SES). However, few studies have investigated the effect of SES on language development in infants. The aim of this study is two-fold: to investigate when the first SES-effects on language can be observed and to explore the effects of three variables often claimed to be linked to SES - gestational duration, stress and parent-child interaction - on language development. Parents/caregivers of 539 Dutch-acquiring infants aged 8-13 months from mid to high SES backgrounds completed a questionnaire including the LENA Developmental Snapshot (Gilkerson et al., 2017a) and the Brigance Parent-Child Interaction Scale (Glascoe & Brigance, 2002). No association was found between SES and language development. However, the results suggest that corrected age and parent-child interaction positively influence language development at this early age.

Exploring communicative competence in autistic children who are minimally verbal: The Low Verbal Investigatory Survey for Autism (LVIS)

LAY ABSTRACT

Approximately one in three autistic children is unable to communicate with language; this state is often described as minimally verbal. Despite the tremendous clinical implications, we cannot predict whether a minimally verbal child is simply delayed (but will eventually develop spoken language) or will continue to struggle with verbal language, and might therefore benefit from learning an alternative form of communication. This is important for clinicians to know, to be able to choose the most helpful interventions, such as alternative forms of communication. In addition, the field lacks a standard definition of "minimally verbal." Even when we do agree on what the term means (e.g. fewer than 20 words), describing a child based on their lack of words does not tell us whether that child is communicating in other ways or how they are using those 20 words. To address these concerns, we developed the Low Verbal Investigatory Survey (LVIS), a one-page parent-report measure designed to help us characterize how minimally verbal autistic children are communicating. Parents of 147 children (aged 1-8 years) completed the LVIS. Here, we ask (1) whether the survey measures what it was designed to measure, that is, communicative ability in children without much spoken language, and (2) how the LVIS relates to cognitive and language ability, and symptoms of autism. Results suggest that this survey, which takes only 5 min to complete, is a good estimate of the child's communication skills. Furthermore, LVIS survey scores are correlated with other measures of language and cognitive abilities as well as autism symptomatology. The LVIS has the potential to save time and money in both clinical and research efforts to assess communication skills in minimally verbal autistic children.

Early diagnostic indicators of childhood apraxia of speech in young children with 7q11.23 duplication syndrome: preliminary findings

Limited evidence for early indicators of childhood apraxia of speech (CAS) precludes reliable diagnosis before 36 months, although a few prior studies have identified several potential early indicators. We examined these possible early indicators in 10 toddlers aged 14-24 months at risk for CAS due to a genetic condition: 7q11.23 duplication syndrome (Dup7). Phon Vocalisation analyses were conducted on phonetic transcriptions of each child's vocalisations during an audio-video recorded 30-minute play session with a caregiver and/or a trained research assistant. The resulting data were compared to data previously collected by Overby from similar-aged toddlers developing typically (TD), later diagnosed with CAS (LCAS), or later diagnosed with another speech sound disorder (LSSD). The Dup7 group did not differ significantly from the LCAS group on any measure. In contrast, the Dup7 group evidenced significant delays relative to the LSSD group on canonical babble frequency, volubility, consonant place diversity, and consonant manner diversity and relative to the TD group not only on these measures but also on canonical babble ratio, consonant diversity, and vocalisation structure diversity. Toddlers with Dup7 also demonstrated expressive vocabulary delay as measured by both number of word types orally produced during the play sessions and primary caregivers' responses on a standardised parent-report measure of early expressive vocabulary. Examining babble, phonetic, and phonotactic characteristics from the productions of young children may allow for earlier identification of CAS and a better understanding of the nature of CAS.

Relations between Positive Parenting Behavior during Play and Child Language Development at Early Ages

Parental behavior in interactions with children has been related to child language development. Our study contributes to the literature about relations between the characteristics of parent–child interactions during play and a child’s language development in typically developing children at early ages, with data from mothers and fathers from the same families in Spain. Our aim was to analyze the relation between positive parenting behaviors assessed with the Spanish version of the Parenting Interactions with Children: Checklist of Observations Linked to Outcomes (PICCOLO) and child language development assessed with the Bayley-III scales. We controlled for some sociodemographic variables. The participants were 90 children aged 15–31 months and their mothers and fathers. Bivariate analysis showed significant positive relations between mothers’ responsive, encouraging and teaching behaviors and a child’s language scores. Relations were found between fathers’ encouraging and teaching behaviors and a child’s language. Regression models indicate that maternal and paternal encouraging behaviors predicted 18% of the variability in the child’s receptive language, and maternal responsive and teaching behaviors predicted 16% of the variability in the child’s expressive language and total language scores. The study provides new data that support the relevance of positive parental behaviors to improve a child’s linguistic development.

Language Experience during Infancy Predicts White Matter Myelination at Age 2 Years

Parental input is considered a key predictor of language achievement during the first years of life, yet relatively few studies have assessed the effects of parental language input and parent-infant interactions on early brain development. We examined the relationship between measures of parent and child language, obtained from naturalistic home recordings at child ages 6, 10, 14, 18, and 24 months, and estimates of white matter myelination, derived from quantitative MRI at age 2 years (mean = 26.30 months, SD = 1.62, N = 22). Analysis of the white matter focused on dorsal pathways associated with expressive language development and long-term language ability, namely, the left arcuate fasciculus (AF) and superior longitudinal fasciculus (SLF). Frequency of parent-infant conversational turns (CT) uniquely predicted myelin density estimates in both the AF and SLF. Moreover, the effect of CT remained significant while controlling for total adult speech and child speech-related utterances, suggesting a specific role for interactive language experience, rather than simply speech exposure or production. An exploratory analysis of 18 additional tracts, including the right AF and SLF, indicated a high degree of anatomic specificity. Longitudinal analyses of parent and child language variables indicated an effect of CT as early as 6 months of age, as well as an ongoing effect over infancy. Together, these results link parent-infant conversational turns to white matter myelination at age 2 years, and suggest that early, interactive experiences with language uniquely contribute to the development of white matter associated with long-term language ability.SIGNIFICANCE STATEMENT Children's earliest experiences with language are thought to have profound and lasting developmental effects. Recent studies suggest that intervention can increase the quality of parental language input and improve children's learning outcomes. However, important questions remain about the optimal timing of intervention, and the relationship between specific aspects of language experience and brain development. We report that parent-infant turn-taking during home language interactions correlates with myelination of language related white matter pathways through age 2 years. Effects were independent of total speech exposure and infant vocalizations and evident starting at 6 months of age, suggesting that structured language interactions throughout infancy may uniquely support the ongoing development of brain systems critical to long-term language ability.

Towards a Characterization of Late Talkers: The Developmental Profile of Children with Late Language Emergence through a Web-Based Communicative-Language Assessment

Children acquire language naturally, but there is variation in language acquisition patterns. Indeed, different internal and external variables play a role in acquiring language. However, there are open research questions about the contribution of different variables to language development. Moreover, with societal changes and due to the pandemic situation, there has been a growing interest in testing digitalization related to indirect language acquisition assessment. In this study, a web-based assessment survey was developed to (1) describe the relation between expressive vocabulary, Socio-Conversational Skills (SCS), gender, parental education, executive functions (EFs), and pretend play; (2) determine whether the survey can detect differences between late talkers (LTs) and children with typical language development; (3) identify children with "overall high" and "overall low" communicative-language scores to test the validity of expressive vocabulary as a main indicator to detect LTs. The parents of 108 Italian children (51 males) aged 24-36 months participated in the study. The results showed that expressive vocabulary correlates with measures of SCS (assertiveness and responsiveness) and is reliable in identifying LTs (d = 2.73). Furthermore, SCS and EFs contribute to better characterizing the developmental profile of children aged 24-36 months.

Early predictors of language outcomes in Down syndrome: A mini-review

As children with Down syndrome (DS) typically manifest significant delays in language development, the research has pointed out the predictors of later language skills for this clinical population. The purpose of this study was to systematically explore the evidence for early predictors of language outcomes in infants and toddlers with DS from studies published between 2012 and 2022. After the search, nine studies met the inclusion criteria. The results indicated that maternal educational level, adaptive level of functioning, cognitive function, attention skills, communicative intent of the child, early vocalizations, gestures, baby signs, parents' translation of their children's gestures into words, and vocabulary level are significant predictors of language outcomes in children with DS. These findings provide a timely and warranted summary of published work that contributes to current understanding of the development of language and communication in DS. They are therefore useful to researchers, clinicians, and families.

Describing (pre)linguistic oral productions in 3- to 5-year-old autistic children: A cluster analysis

LAY ABSTRACT

For most autistic children, spoken language emergence and development happen after the age of 3. Once they start developing and using spoken language, some eventually manage to reach typical levels of language abilities, while others remain minimally speaking into adulthood. It is therefore difficult to consider young autistic preschoolers as a homogeneous group in terms of spoken language levels. In our study, we breakdown a representative and inclusive group of children on the spectrum aged from 3 to 5 into five subgroups that correspond to different linguistic profiles. To do so, we qualitatively described children's (pre)verbal productions elicited during interactions with a parent and with an experimenter. We then used a type of statistical analysis called cluster analysis to group together the children that had a similar expressive (pre)linguistic behavior. Using this analysis, we were able to delineate five linguistic profiles with qualitatively different patterns of vocal production. Two of these profiles are composed of speaking children; the three others are composed of non- or minimally speaking children. Our findings show that traditional binary division of speaking versus nonspeaking autistic children is not precise enough to describe the heterogeneity of early spoken language in young autistic children. They also support the use of qualitative descriptions of vocal productions and speech to accurately document children's level of language, which could, in turn, help design very finely tailored language intervention specific to each child.

[Early detection of primary developmental language disorders-increasing relevance due to changes in diagnostic criteria?]

Language development disorders (in German: Sprachentwicklungsstörungen, SES) are the most common developmental disorders in childhood. In contrast to "secondary SES," "primary SES" (prevalence about 7%) are not (co-)caused by other developmental disorders or diseases. In the German modification of the International Statistical Classification of Diseases and Related Health Problems (ICD-10-GM-22), primary SES are referred to as "circumscribed developmental disorders of speech and language" (in German: USES; international previously known as Specific Language Impairment SLI), with an intelligence quotient (IQ) < 85 as an exclusion criterion, among other criteria. In ICD-11, primary SES are listed as "developmental language disorders" (DLD).German-speaking speech and language therapists would now like to replace the term "USES" with "DLD" using the diagnostic criteria proposed by the international CATALISE consortium (Criteria and Terminology Applied to Language Impairments Synthesizing the Evidence), in an effort to redefine the disorder. However, according to this conceptualization, only children with an intellectual disability (IQ < 70) would be excluded from the diagnosis. This change in the diagnostic criteria would most likely result in an increase in prevalence of DLDs. This makes the issue of early detection more important than ever. This discussion paper explains that the public health relevance of primary SES is growing and that systematic early detection examinations will play an even more important role. With early diagnosis and treatment, risks in the areas of mental health, behaviour and skill development can be mitigated.Currently, diagnosis (and therapy) are usually carried out relatively late. The way out could lie in the application of neurobiological parameters. However, this requires further studies that examine child cohorts for early indicators in a prospective longitudinal design. The formation of an early detection index from several indicators should also be considered.

Infants later diagnosed with autism have lower canonical babbling ratios in the first year of life

BACKGROUND

Canonical babbling-producing syllables with a mature consonant, full vowel, and smooth transition-is an important developmental milestone that typically occurs in the first year of life. Some studies indicate delayed or reduced canonical babbling in infants at high familial likelihood for autism spectrum disorder (ASD) or who later receive an ASD diagnosis, but evidence is mixed. More refined characterization of babbling in the first year of life in infants with high likelihood for ASD is needed.

METHODS

Vocalizations produced at 6 and 12 months by infants (n = 267) taking part in a longitudinal study were coded for canonical and non-canonical syllables. Infants were categorized as low familial likelihood (LL), high familial likelihood diagnosed with ASD at 24 months (HL-ASD) or not diagnosed (HL-Neg). Language delay was assessed based on 24-month expressive and receptive language scores. Canonical babble ratio (CBR) was calculated by dividing the number of canonical syllables by the number of total syllables. Generalized linear (mixed) models were used to assess the relationship between group membership and CBR, controlling for site, sex, and maternal education. Logistic regression was used to assess whether canonical babbling ratios at 6 and 12 months predict 24-month diagnostic outcome.

RESULTS

No diagnostic group differences in CBR were detected at 6 months, but HL-ASD infants produced significantly lower CBR than both the HL-Neg and LL groups at 12 months. HL-Neg infants with language delay also showed reduced CBR at 12 months. Neither 6- nor 12-month CBR was significant predictors of 24-month diagnostic outcome (ASD versus no ASD) in logistic regression.

LIMITATIONS

Small numbers of vocalizations produced by infants at 6 months may limit the reliability of CBR estimates. It is not known if results generalize to infants who are not at high familial likelihood, or infants from more diverse racial and socioeconomic backgrounds.

CONCLUSIONS

Lower canonical babbling ratios are apparent by the end of the first year of life in ASD regardless of later language delay, but are also observed for infants with later language delay without ASD. Canonical babbling may lack specificity as an early marker when used on its own.

Speech Development Across Subgroups of Autistic Children: A Longitudinal Study

Subgroups of children with different speech profiles have been described however, little is known about the trajectories of speech development or stability of subgroups over time. This longitudinal study described both speech trajectories and subgroup stability of 22 autistic children, aged 2;0-6;11 years, over 12 months. Independent and relational speech analyses, vocabulary size and nonverbal communication were used in clustering. Results suggest varied speech trajectories, particularly for children with 'low language and low speech' at Time 1. Receptive vocabulary and consonant inventory at Time 1 may predict speech outcomes after 12 months. A small subgroup of children (n = 3) present with low expressive vocabulary and speech but higher receptive vocabulary and use of gestures. This unique profile remained stable.

Moderating Effects of Early Pointing on Developmental Trajectories of Word Comprehension and Production

The present study investigated the moderating role of early communicative pointing on the developmental trends of word comprehension and production over the second year of life. Seventy-seven infants were involved in an experimental pointing task (T-POINT) in sessions at 9 and 12 months, and the MB-CDI questionnaire was filled in by their parents at 15, 18 and 24 months. Based on the age at which the infants were seen to use pointing, they were classified into three groups: the ‘Early’ pointers, who first pointed during the 9-month session; the ‘Typical’ pointers, who first pointed in the 12-month session; and the ‘Late’ pointers, who never pointed in either of the sessions. Using multilevel modelling, we traced the developmental trajectories and individual differences for the two lexical domains of word comprehension and production according to the three pointing groups. The main results showed that compared to the Typical pointers: (i) the Early pointers were faster for word comprehension development, and were similar for word production; (ii) the Late pointers showed lexical delay before 18 months for word comprehension, and between 18 and 24 months for word production. These data are discussed in light of the different roles of early pointing on receptive compared to expressive vocabulary development.

Language Development in the Second Year of Life: The Case of Children with Sex Chromosome Trisomies Diagnosed before Birth

Many individual factors, such as early communicative skills, could play a role in explaining later linguistic outcomes. The detection of predictive variables is fundamental to identifying early the children who need intervention. The present study focuses on children with sex chromosome trisomies (SCTs), genetic conditions with an increased risk of developing language delays or impairments. The aims are to analyse their communicative skills at 18 months of age, and identify significant predictors of their later vocabulary size. Participants were 76 18-month-old children (38 with SCTs, and 38 typically-developing (TD) children). Their communicative skills were assessed during a parent–child play session, and parents filled in a report on their vocabulary development at 18 and 24 months. Children with SCTs showed significantly poorer linguistic skills at 18 months in both preverbal (babbling and gestures) and verbal abilities. A high percentage (nearly 70%) of toddlers with SCTs were late-talking children at 24 months, and those toddlers showed a lower frequency of babbling utterances at 18 months. Early lexical skills, children’s developmental quotient, and being part of the group of toddlers with SCTs were significant predictors of children’s vocabulary size six months later. These variables should be considered when assessing the linguistic competence of a child with SCTs to detect possible early risk factors of future language impairment.

Clinical utilisation of the Infant Monitor of vocal Production (IMP) for early identification of communication impairment in young infants at-risk of cerebral palsy: a prospective cohort study

AIM

To report prospective longitudinal data of early vocaliszations of infants identified "at-risk" of cerebral palsy (CP) for early identification of communication impairment.

METHOD

This case-control longitudinal prospective cohort study reports on the assessment of 36 infants, 18 identified as at-risk of CP at the time of enrolment and 18 typically developing (TD) children, at three time points: 6 months, 9 months and 12 months of age, Data were obtained through criterion and norm referenced assessments of vocaliszation behaviors.

RESULTS

Early vocal behaviors of infants identified as at-risk of CP did not differ from their age matched peers at 6 months of age, however, significant group differences emerged at 9 and 12 months when pre-canonical and canonical babble typically emerge. Generalized linear mixed models analysis showed that the rate of development of early language ability and more complex speech-related vocal behaviors was slower for infants at risk of CP when compared to TD infants, with over 75% of infants with CP showing below normal vocal production and impaired language by 12 months of age.

INTERPRETATION

Our data suggest characteristics of infant vocalizations associated with pre-canonical and canonical babbling provide a strong evidence base for predicting communication outcomes in infants at risk of CP.

Personal Pronoun Errors in Form versus Meaning Produced by Children with and without Autism Spectrum Disorder

The current study investigates whether the types of pronominal errors children with autism spectrum disorder (ASD) make are different from those of their TD peers at similar stages of language development. A recent review about language acquisition in ASD argues that these children show relative deficits in assigning/extending lexical meaning alongside relative strengths in morpho-syntax (Naigles & Tek, 2017). Pronouns provide an ideal test case for this argument because they are marked both for grammatical features (case) and features that reflect qualities of the referent itself (gender and number) or the referent's role in conversation (person). The form-meaning hypothesis predicts that children with ASD should struggle more with these latter features. The current study tests this hypothesis with data from a caregiver report, completed by caregivers of 151 children with and without ASD. Reported pronominal errors were categorized as meaning or form and compared across groups. In accordance with the form-meaning hypothesis, a higher proportion of children with ASD make meaning errors than they do form errors, and significantly more of them make meaning errors than TD children do.

Canonical babbling ratio - Concurrent and predictive evaluation of the 0.15 criterion

INTRODUCTION

Canonical babbling ratio (CBR) is a commonly used measure to quantify canonical babbling (CB), and 0.15 is the commonly accepted criterion for the canonical babbling stage. However, this has not been thoroughly investigated. The aim of this study was to evaluate the validity of this criterion using concurrent and predictive comparisons.

METHODS

Longitudinal data from 50 children recruited in different clinical projects were used. At 10 months of age, CBR was calculated based on counted utterances from audio-video recorded parent-child interactions. The videos were also assessed by CB observation, where an observer made an overall judgement on whether the child was in the canonical babbling stage or not. For the concurrent evaluation, CBR was compared to CB observation as a reference test, using area under the curve (AUC). The criterion resulting in the best combination of sensitivity and specificity was identified using positive likelihood ratios. In the predictive comparisons CBR was analyzed as a predictor of speech/language difficulties at 30-36 months. Participants presenting with difficulties in consonant production and/or parent-reported vocabulary were considered to have speech/language difficulties. Sensitivity and specificity were compared for CBR using the 0.15 criterion and the new criterion identified in this study.

RESULTS

An AUC of 0.87 indicated that CBR is a valid measure of canonical babbling in 10-month-old children. The best combination of sensitivity and specificity was found at a criterion of 0.14 (sensitivity 0.96, specificity 0.70). In the predictive comparison, CBR with a 0.14 or 0.15 criterion revealed the same sensitivity (0.71) but 0.14 showed a slightly better specificity (0.52 versus 0.42).

CONCLUSIONS

CBR is a valid measure of CB (at 10 months). However, when using CBR to classify children's babbling as canonical or non-canonical, researchers need to carefully consider the implications of the chosen criterion.

The origin of language and relative roles of voice and gesture in early communication development

Both vocalization and gesture are universal modes of communication and fundamental features of language development. The gestural origins theory proposes that language evolved out of early gestural use. However, evidence reported here suggests vocalization is much more prominent in early human communication than gesture is. To our knowledge no prior research has investigated the rates of emergence of both gesture and vocalization across the first year in human infants. We evaluated the rates of gestures and speech-like vocalizations (protophones) in 10 infants at 4, 7, and 11 months of age using parent-infant laboratory recordings. We found that infant protophones outnumbered gestures substantially at all three ages, ranging from >35 times more protophones than gestures at 3 months, to >2.5 times more protophones than gestures at 11 months. The results suggest vocalization, not gesture, is the predominant mode of communication in human infants in the first year.

The Early Social Cognition Inventory (ESCI): An examination of its psychometric properties from birth to 47 months

Social cognition refers to a broad range of cognitive processes and skills that allow individuals to interact with and understand others, including a variety of skills from infancy through preschool and beyond, e.g., joint attention, imitation, and belief understanding. However, no measures examine socio-cognitive development from birth through preschool. Current test batteries and parent-report measures focus either on infancy, or toddlerhood through preschool (and beyond). We report six studies in which we developed and tested a new 21-item parent-report measure of social cognition targeting 0–47 months: the Early Social Cognition Inventory (ESCI). Study 1 (N = 295) revealed the ESCI has excellent internal reliability, and a two-factor structure capturing social cognition and age. Study 2 (N = 605) also showed excellent internal reliability and confirmed the two-factor structure. Study 3 (N = 84) found a medium correlation between the ESCI and a researcher-administered social cognition task battery. Study 4 (N = 46) found strong 1-month test–retest reliability. Study 5 found longitudinal stability (6 months: N = 140; 12 months: N = 39), and inter-observer reliability between parents (N = 36) was good, and children’s scores increased significantly over 6 and 12 months. Study 6 showed the ESCI was internally reliable within countries (Australia, Canada, United Kingdom, United States, Trinidad and Tobago); parent ethnicity; parent education; and age groups from 4–39 months. ESCI scores positively correlated with household income (UK); children with siblings had higher scores; and Australian parents reported lower scores than American, British, and Canadian parents.

Vocal development in a large-scale crosslinguistic corpus

This study evaluates whether early vocalizations develop in similar ways in children across diverse cultural contexts. We analyze data from daylong audio recordings of 49 children (1-36 months) from five different language/cultural backgrounds. Citizen scientists annotated these recordings to determine if child vocalizations contained canonical transitions or not (e.g., "ba" vs. "ee"). Results revealed that the proportion of clips reported to contain canonical transitions increased with age. Furthermore, this proportion exceeded 0.15 by around 7 months, replicating and extending previous findings on canonical vocalization development but using data from the natural environments of a culturally and linguistically diverse sample. This work explores how crowdsourcing can be used to annotate corpora, helping establish developmental milestones relevant to multiple languages and cultures. Lower inter-annotator reliability on the crowdsourcing platform, relative to more traditional in-lab expert annotators, means that a larger number of unique annotators and/or annotations are required, and that crowdsourcing may not be a suitable method for more fine-grained annotation decisions. Audio clips used for this project are compiled into a large-scale infant vocalization corpus that is available for other researchers to use in future work.

Show, give, and point gestures across infancy differentially predict language development

It is well established that deictic gestures, especially pointing, play an important role in children's language development. However, recent evidence suggests that other types of deictic gestures, specifically show and give gestures, emerge before pointing and are associated with later pointing. In the present study, we examined the development of show, give, and point gestures in a sample of 47 infants followed longitudinally from 10 to 16 months of age and asked whether there are certain ages during which different gestures are more or less predictive of language skills at 18 months. We also explored whether parents' responses vary as a function of child gesture types. Child gestures and parent responses were reliably coded from videotaped sessions of parent-child interactions. Language skills were measured at 18 months using standardized (Mullen Scales of Early Learning) and parent report (MacArthur-Bates Communicative Development Inventory) measures. We found that at 10 months, show+give gestures were a better predictor of 18-month language skills than pointing gestures were, yet at 14 months, pointing gestures were a better predictor of 18-month language skills than show+give gestures. By 16 months, children's use of speech in the interaction, not gesture, best predicted 18-month language skills. Parents responded to a higher proportion of shows+gives than to points at 10 months. These results demonstrate that different types of deictic gestures provide a window into language development at different points across infancy. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Speech and Language in 5-year-olds with Different Neurological Disabilities and the Association between Early and Later Consonant Production

The primary aim was to describe speech and language abilities in a clinical group of verbal 5-year-old children diagnosed with neurological disability (ND) in infancy, and the secondary aim was to trace precursors to consonant production at age 5 years (T2) in data from 12 to 22 months (T1). The participants (n = 11, with Down syndrome (DS), cerebral palsy, and chromosomal deletion syndromes) were tested with a battery of speech and language tests. Consonant production at T2 was compared to data on consonant use at T1. At T2, two participants had age appropriate speech and language and another three had age-appropriate speech, but low results on language tests. The remaining six participants had severe speech and language difficulties. Participants with DS had significantly lower results on consonant production measures. An association between consonant production at T1 and T2 for participants with DS indicates that number of different true consonants might be a predictive measure when evaluating young children with DS.

Organizational power embodied in hand and finger touchlines

Purpose

The purpose of this paper is to develop a nuanced interpretative frame that can help global managers with recommendations to avoid misapplied power with group and organizational situations.

Design/methodology/approach

Embodied metaphor is applied in analysis of the theory-praxis nexus to reconceive the bases, processes and resources associated with group and organizational power. Identified are patterns of relations in organizational bases and circuits of power, as expressed through literal and symbolic aspects of human hands and fingers. The paper does not revolve around gesticulations; instead focusing upon a novel, meta-cultural development of touchlines of the human hand, revealing conceptual relationships with the implementation of influence.

Findings

A differentiated understanding of the touchline powers of technology, information, self-awareness, relation to others and access to money can respectively improve decisions and actions. Insights are provided in the areas of controlling people to achieve objectives, demeaning others, managing change and resistance for personal gain, negotiating contracts, advancing personal interests and coordinating reward or punishment.

Research limitations/implications

Choosing one metaphor may contribute to the exclusion of other perspectives, however, the embodied nature of the hand and touchlines tends to cross cultures and may assist further research to address the embedded nature of abuses of organizational power.

Originality/value

The contribution is in the theory-praxis nexus to assist global managers in addressing the risk of potential misuse of power and influence in organizations and to respond to calls for ancient indigenous epistemological systems to assume a role in contemporary management studies.

Early language experience in a Papuan community

The rate at which young children are directly spoken to varies due to many factors, including (a) caregiver ideas about children as conversational partners and (b) the organization of everyday life. Prior work suggests cross-cultural variation in rates of child-directed speech is due to the former factor, but has been fraught with confounds in comparing postindustrial and subsistence farming communities. We investigate the daylong language environments of children (0;0-3;0) on Rossel Island, Papua New Guinea, a small-scale traditional community where prior ethnographic study demonstrated contingency-seeking child interaction styles. In fact, children were infrequently directly addressed and linguistic input rate was primarily affected by situational factors, though children's vocalization maturity showed no developmental delay. We compare the input characteristics between this community and a Tseltal Mayan one in which near-parallel methods produced comparable results, then briefly discuss the models and mechanisms for learning best supported by our findings.

Infants' vocalizations at 6 months predict their productive vocabulary at one year

Long before their first words, children communicate by using speech-like vocalizations. These protophones might be indicative of infants' later language development. We here examined infants' (n = 56) early vocalizations at 6 months (vocal reactivity scale of the IBQ-R) as a predictor of their expressive and receptive language at 12 months (German version of the CDI). Regression analyses revealed vocalizations to significantly predict expressive, but not receptive language. Our findings in German-learning 6-month-olds extend previous predictive evidence of early vocalizations reported for older infants. Together these findings are informative in light of early assessments monitoring typical and atypical language development.

Practice and experience predict coarticulation in child speech

Much research in child speech development suggests that young children coarticulate more than adults. There are multiple, not mutually-exclusive, explanations for this pattern. For example, children may coarticulate more because they are limited by immature motor control. Or they may coarticulate more if they initially represent phonological segments in larger, more holistic units such as syllables or feet. We tested the importance of several different explanations for coarticulation in child speech by evaluating how four-year-olds' language experience, speech practice, and speech planning predicted their coarticulation between adjacent segments in real words and paired nonwords. Children with larger vocabularies coarticulated less, especially in real words, though there were no reliable coarticulatory differences between real words and nonwords after controlling for word duration. Children who vocalized more throughout a daylong audio recording also coarticulated less. Quantity of child vocalizations was more predictive of the degree of children's coarticulation than a measure of receptive language experience, adult word count. Overall, these results suggest strong roles for children's phonological representations and speech practice, as well as their immature fine motor control, for coarticulatory development.

Sociodemographic and Pre-Linguistic Factors in Early Vocabulary Acquisition

Here, we studied the beginnings of language development, jointly assessing two groups of precursors, sociodemographic and pre-linguistic, that have previously been studied separately. Thus, the general objective of this study was to explore which factors best explained the acquisition of initial expressive vocabulary. The sample consisted of 504 participants from Catalan-speaking homes with ages ranging between 10 and 18 months. The data were obtained through the MacArthur-Bates Communicative Development Inventories (MCB-CDIs). Vocabulary development shows a lexical spurt at 17 months. Regression analyses show that pre-linguistic factors have more explanatory power of than sociodemographic ones. Within the sociodemographic variables, age, birth order and birth weight explain part of the vocabulary variance. With respect to pre-linguistic variables, imitation, late gestures and phrase comprehension are predictors of the initial vocabulary acquisition. Specifically, imitation and late gestures were the pre-linguistic behaviours that made it possible to distinguish between children with higher and lower levels of vocabulary. We discussed these findings in relation to their relevance for language acquisition and for the early assessment of linguistic competence.

Do the Eyes Have It? A Systematic Review on the Role of Eye Gaze in Infant Language Development

Eye gaze is a ubiquitous cue in child–caregiver interactions, and infants are highly attentive to eye gaze from very early on. However, the question of why infants show gaze-sensitive behavior, and what role this sensitivity to gaze plays in their language development, is not yet well-understood. To gain a better understanding of the role of eye gaze in infants' language learning, we conducted a broad systematic review of the developmental literature for all studies that investigate the role of eye gaze in infants' language development. Across 77 peer-reviewed articles containing data from typically developing human infants (0–24 months) in the domain of language development, we identified two broad themes. The first tracked the effect of eye gaze on four developmental domains: (1) vocabulary development, (2) word–object mapping, (3) object processing, and (4) speech processing. Overall, there is considerable evidence that infants learn more about objects and are more likely to form word–object mappings in the presence of eye gaze cues, both of which are necessary for learning words. In addition, there is good evidence for longitudinal relationships between infants' gaze following abilities and later receptive and expressive vocabulary. However, many domains (e.g., speech processing) are understudied; further work is needed to decide whether gaze effects are specific to tasks, such as word–object mapping or whether they reflect a general learning enhancement mechanism. The second theme explored the reasons why eye gaze might be facilitative for learning, addressing the question of whether eye gaze is treated by infants as a specialized socio-cognitive cue. We concluded that the balance of evidence supports the idea that eye gaze facilitates infants' learning by enhancing their arousal, memory, and attentional capacities to a greater extent than other low-level attentional cues. However, as yet, there are too few studies that directly compare the effect of eye gaze cues and non-social, attentional cues for strong conclusions to be drawn. We also suggest that there might be a developmental effect, with eye gaze, over the course of the first 2 years of life, developing into a truly ostensive cue that enhances language learning across the board.

Prelexical phonetic and early lexical development in German-acquiring infants: canonical babbling and first spoken words

Prelexical phonetic capacities have widely been described to be a precursor for later speech and language development. However, studies so far varied greatly in the measurements used for the detection of canonical babbling onset or the description of infants' phonetic capacities at one or more set time points. The comparability of results is, therefore, questionable. Thus, the aims of this study were to investigate the associations between (1) different measurements of CBO, (2) different aspects of phonetic capacity at the age of 9 months and (3) age of CBO and phonetic capacities at 9 months. A further aim (4) was to explore whether one of the measures would be suitable to predict the age of word onset (WO) in 20 healthy German-acquiring individuals. The data were derived from monthly recorded spontaneous speech samples between 0 and 18 months. It was found that the different applied prelexical measures equally well serve as valid estimators for the detection of CBO or of infants' phonetic capacities. Further, age of CBO and phonetic capacities at 9 months were significantly associated even though the age of CBO did not reliably predict phonetic capacities. Prelexical measures and WO were not related. Reasons for no indication of a significant association are discussed.

Preverbal Production and Early Lexical Development in Children With Cochlear Implants: A Longitudinal Study Following Pre-implanted Children Until 12 Months After Cochlear Implant Activation

Studies have shown that children vary in the trajectories of their language development after cochlear implant (CI) activation. The aim of the present study is to assess the preverbal and lexical development of a group of 20 Italian-speaking children observed longitudinally before CI activation and at three, 6 and 12 months after CI surgery (mean age at the first session: 17.5 months; SD: 8.3; and range: 10–35). The group of children with CIs (G-CI) was compared with two groups of normally-hearing (NH) children, one age-matched (G-NHA; mean age at the first session: 17.4 months; SD: 8.0; and range: 10–34) and one language-matched (G-NHL; n = 20; mean age at the first session: 11.2 months; SD: 0.4; and range: 11–12). The spontaneous interactions between children and their mothers during free-play were transcribed. Preverbal babbling production and first words were considered for each child. Data analysis showed significant differences in babbling and word production between groups, with a lower production of words in children with CIs compared to the G-NHA group and a higher production of babbling compared to the G-NHL children. Word production 1 year after activation was significantly lower for the children with CIs than for language-matched children only when maternal education was controlled for. Furthermore, latent class growth analysis showed that children with CIs belonged mainly to classes that exhibited a low level of initial production but also progressive increases over time. Babbling production had a statistically significant effect on lexical growth but not on class membership, and only for groups showing slower and constant increases. Results highlight the importance of preverbal vocal patterns for later lexical development and may support families and speech therapists in the early identification of risk and protective factors for language delay in children with CIs.

From babble to words: Infants' early productions match words and objects in their environment

Infants' early babbling allows them to engage in proto-conversations with caretakers, well before clearly articulated, meaningful words are part of their productive lexicon. Moreover, the well-rehearsed sounds from babble serve as a perceptual 'filter', drawing infants' attention towards words that match the sounds they can reliably produce. Using naturalistic home recordings of 44 10-11-month-olds (an age with high variability in early speech sound production), this study tests whether infants' early consonant productions match words and objects in their environment. We find that infants' babble matches the consonants produced in their caregivers' speech. Infants with a well-established consonant repertoire also match their babble to objects in their environment. Our findings show that infants' early consonant productions are shaped by their input: by 10 months, the sounds of babble match what infants see and hear.