Early Lexical Development Research Articles

Language Development of Japanese Children Raised in Institutional Care.

Nurturing environments have a critical influence on children's language development. It is unclear to what extent nurturing environments in institutions influence children's language development. The present study investigated the early lexical development in Japanese children raised in institutional care (IC) (N = 86; 10-33 months; 37 boys) and compared their lexical skills to a large sample of age peers being raised in biological family care (BFC) (N = 1897; 937 boys) using vocabulary checklists. Our results present three main findings: (1) Japanese IC children did not exhibit a delay in productive vocabulary compared with BFC children, although their comprehensive vocabulary was delayed; (2) IC children who experienced maltreatment showed poorer vocabulary scores than non-maltreated IC children; (3) both the duration at the institution and the number of books read to them significantly predicted children's vocabulary scores. Our study suggests that the Japanese institutions included in the present study did not show a negative impact, at least on productive vocabulary, and may competently foster children's language development. We discussed the relationship between institutional environments and children's language development.

Little evidence for a noun bias in Tseltal spontaneous speech

This study examines whether children acquiring Tseltal (Mayan) demonstrate a noun bias – an overrepresentation of nouns in their early vocabularies. Nouns, specifically concrete and animate nouns, are argued to universally predominate in children’s early vocabularies because their referents are naturally available as bounded concepts to which linguistic labels can be mapped. This early advantage for noun learning has been documented using multiple methods and across a diverse collection of language populations. However, past evidence bearing on a noun bias in Tseltal learners has been mixed. Tseltal grammatical features and child–caregiver interactional patterns dampen the salience of nouns and heighten the salience of verbs, leading to the prediction of a diminished noun bias and perhaps even an early predominance of verbs. We here analyze the use of noun and verb stems in children’s spontaneous speech from egocentric daylong recordings of 29 Tseltal learners between 0;9 and 4;4. We find weak to no evidence for a noun bias using two separate analytical approaches on the same data; one analysis yields a preliminary suggestion of a flipped outcome (i.e. a verb bias). We discuss the implications of these findings for broader theories of learning bias in early lexical development.

Early Lexical Development by English–Chinese Bilinguals

This study investigated the lexical development of English–Chinese bilingual children in a Chinese immersion program in the US. Cross-linguistic Lexical Tasks in American English and Mandarin Chinese were given to 20 English–Chinese bilingual six-year-olds. They did better in English than in Chinese, even with Chinese-speaking parents. Their proficiency in Chinese is comparable to that of two- or three-year-old native speakers after one year of Chinese exposure. Lexical development correlates with both the learner’s Age of Acquisition and the estimated age of acquisition of the target words. The results of this study will enhance our understanding of bilingual lexical development and give us insight into providing support to foster bilingual lexical development.

The Effect of Combined Intervention on Improvement of Early Lexical Development in Minimally Verbal Children with Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder defined by severe communication deficits and limited and repetitive behavioral tendencies. There are several treatment approaches and methods for minimally verbal children with ASD; nonetheless, there is inconclusive evidence about how early lexical development could be improved. The present study aimed to investigate the effect of combined intervention derived from the principles of different theories-including contemporary behaviorism, schemas, sociocultural, and event representation theories-to improve early lexical development in minimally verbal children with ASD. In this single-group pretest-posttest study, 10 children with ASD (mean age, 47.9 ± 8.3 months), including 7 boys and 3 girls, participated. Participants received 16 intervention sessions in 8 weeks. The combined intervention consisted of various methods derived from contemporary behaviorism, schemas, sociocultural, and event representation approaches. The MacArthur-Bates Communicative Development Inventory 1 (Infant form) assessed early lexical development before and after intervention and after a 2-month follow-up. The Friedman test was used to analyze the data, and pairwise comparisons were performed with the Will-Coxon test. Cohen's d was used to investigate the effect sizes. Significant increases in expressive vocabulary (P < 0.001) and receptive language (P < 0.001) were seen after the end of the intervention and at the follow-up (P = 0.005). Large effect sizes were found for expressive vocabulary (d = 3.7) and receptive vocabulary (d = 2.17). This study suggests that the combination of intervention based contemporary behaviorism, schemas, sociocultural, and event representation approaches improved receptive and expressive vocabulary in minimally verbal children with ASD.

The more they hear the more they learn? Using data from bilinguals to test models of early lexical development

Children have an early ability to learn and comprehend words, a skill that develops as they age. A critical question remains regarding what drives this development. Maturation-based theories emphasise cognitive maturity as a driver of comprehension, while accumulator theories emphasise children's accumulation of language experience over time. In this study we used archival looking-while-listening data from 155 children aged 14–48 months with a range of exposure to the target languages (from 10% to 100%) to evaluate the relative contributions of maturation and experience. We compared four statistical models of noun learning: maturation-only, experience-only, additive (maturation plus experience), and accumulator (maturation times experience). The best-fitting model was the additive model in which both maturation (age) and experience were independent contributors to noun comprehension: older children as well as children who had more experience with the target language were more accurate and looked faster to the target in the looking-while-listening task. A 25% change in relative language exposure was equivalent to a 4 month change in age, and age effects were stronger at younger than at older ages. Whereas accumulator models predict that the lexical development of children with less exposure to a language (as is typical in bilinguals) should fall further and further behind children with more exposure to a language (such as monolinguals), our results indicate that bilinguals are buffered against effects of reduced exposure in each language. This study shows that continuous-level measures from individual children's looking-while-listening data, gathered from children with a range of language experience, provide a powerful window into lexical development.

Two pathways in vocabulary development: Large-scale differences in noun and verb semantic structure

In adults, nouns and verbs have varied and multilevel semantic interrelationships. In children, evidence suggests that nouns and verbs also have semantic interrelationships, though the timing of the emergence of these relationships and their precise impact on later noun and verb learning are not clear. In this work, we ask whether noun and verb semantic knowledge in 16–30-month-old children tend to be semantically isolated from one another or semantically interacting from the onset of vocabulary development. Early word learning patterns were quantified using network science. We measured the semantic network structure for nouns and verbs in 3,804 16–30-month-old children at several levels of granularity using a large, open dataset of vocabulary checklist data. In a cross-sectional approach in Experiment 1, early nouns and verbs exhibited stronger network relationships with other nouns and verbs than expected across multiple network levels. Using a longitudinal approach in Experiment 2, we examined patterns of normative vocabulary development over time. Initial noun and verb learning was supported by strong semantic connections to other nouns, whereas later-learned words exhibited strong connections to verbs. Overall, these two experiments suggest that nouns and verbs demonstrate early semantic interactions and that these interactions impact later word learning. Early verb and noun learning is affected by the emergence of noun and verb semantic networks during early lexical development.

Developing early lexical composition in Mandarin-speaking children: A longitudinal study.

This study investigated the developmental pattern of early lexical production and composition in Mandarin-speaking children. Forty Mandarin-speaking children and their parents participated in this one-and-a-half-year longitudinal study, and naturalistic samples of parent-to-child speech in toy play were collected when the children were 1;8, 2;2, and 3;0. The results showed that children's lexical production increased significantly between ages 1;8 and 3;0. The proportion of closed-class words increased significantly with age, whereas the proportion of common nouns showed the inverse pattern, indicating the role of grammatical words increased as the children grew. Furthermore, nouns and verbs were predominant in Mandarin-speaking children between ages 1;8 and 3;0, and Mandarin-speaking children used more verbs than nouns at 2;2 and 3;0 in the toy play context. The longitudinal study clarifies early lexical development in Mandarin-speaking children, which provides a valuable contrast for different language systems.

Systematic Review of the Effects of Sleep on Memory and Word Learning in Infancy

AbstractThis systematic review surveyed research on the associations between sleep and the memory processes involved in word learning in infancy. We found only 16 studies that addressed this topic directly, identifying associations between infant sleep and the memory processes, the identification of word forms in running speech, and the stabilization and generalization of new word form–meaning associations. Some studies investigated changes in brain responses after word learning and in sleep parameters during postlearning sleep. Others investigated the long‐term effects of sleeping patterns on later vocabulary development. All but one of these studies identified positive associations between sleep and word learning in early childhood, extending similar findings from studies on adults and school‐aged children. However, there remain several gaps in the current research on early lexical development and sleep. Future investigations should address these gaps for researchers to better understand lexical development and to create links between memory and language acquisition research.

Comparativa entre procedimientos para el análisis del primer desarrollo lingüístico en niños y niñas con L1 vasco y español

Background and objectiveThe need to carry out studies on the level of early lexical development in Basque-Spanish bilingual children is a reality reflected in the scientific literature. In this context, both the MacArthur-Bates communicative development inventories and the methods based on early observation have been an important element for the analysis of the level of linguistic development of children. Therefore, the objective of this work has been to carry out a comparison between two different instruments on the same sample: on the one hand, the MacArthur-Bates Communication Skills Development Inventory, in its adaptations in Spanish and Basque, and, on the other hand, longitudinal observation through recordings of children in different contexts of spontaneous communication. Materials and methodThe participants were 8 Basque children with different L1 (Basque or Spanish) analyzed from 17 to 30months and from a small town in the Basque Country, Bermeo. Three recordings were made through non-participatory contextualized observation in those months in which the children were 17, 25 and 30months old. In addition, the annotations and transcripts were made through professional software: ELAN and CHAT. Likewise, at the time of the third recording, the families completed the CDI-2 in its adaptation to Spanish and Basque. ResultsThe results show the usefulness of parental reports to obtain information on the development of early communication skills. In any case, the need for larger explorations is considered necessary in order not to fall into the argument of the «overvaluation» of children's broadcasts. Likewise, it is interesting to note that children with L1 Basque and children with L1 Spanish present different results, in a similar way to what was observed in bilingual children of other languages, so it can be stated that children with the same age of early acquisition of two languages (Spanish and Basque) they can develop different patterns in their bilingualism depending on the degree of exposure to the language.

Semantic maturation during the comprehension-expression gap in late and typical talkers.

This study investigates the influence of semantic maturation on early lexical development by examining the impact of contextual diversity-known to influence semantic development-on word promotion from receptive to productive vocabularies (i.e., comprehension-expression gap). Study 1 compares the vocabularies of 3685 American-English-speaking typical talkers (TTs) and late talkers (LTs; 16-30 months old; 1257 females, 1021 gender unknown; ethnicity unknown; data downloaded in 2018) and finds that LTs, with a longer preverbal phase, produced nouns with lower contextual diversity (R2 =.80), but verbs with higher contextual diversity (R2 =.13). Study 2 compares computational network growth models of semantic maturation and finds that verbs require more semantic maturation than nouns, and TTs produce words that are more semantically mature than LTs.

Eye tracking based assessment of lexical processing and early lexical development in very preterm children

BackgroundAssociations between lexical processing and lexical development during the second year of life have been little studied in preterm children. AimsTo evaluate associations between lexical processing at 18 months and lexical development between 12 and 18 months in very preterm children. Study designCorrelational study. Subjects25 Finnish-speaking children born <32 gestational weeks. Outcome measuresLexical processing (reaction time RT; correct looking time CLT) was measured with an eye tracking technology-based task at 18 months' corrected age. Lexical development was measured longitudinally at 12-, 15- and 18-months' corrected age using the following screening instruments: the short form version of the MacArthur Communicative Development Inventories and the Communication and Symbolic Behavior Scale: Infant-Toddler Checklist. ResultsThe longer the RT of the child, the weaker expressive skills the child had at 12 and 15 months (correlations coefficient values −0.45 to −0.51). The more the child looked at the target image compared to the distractor (CLT), the stronger expressive skills the child had at 18 months (r = 0.45–0.52). A linear regression model with RT and gender as independent variables explained 33 % of the variance in lexical skills at 18 months. A model with CLT explained 40 % of expressive skills at 18 months. ConclusionsLexical processing at 18 months was associated with expressive lexical development in very preterm children. The results suggest eye tracking technology based methods may have utility in the assessment of early lexical growth in preterm children, although further research is needed to assess psychometric properties and predictive value of the method.

Child-oriented word associations improve models of early word learning

How words are associated within the linguistic environment conveys semantic content; however, different contexts induce different linguistic patterns. For instance, it is well known that adults speak differently to children than to other adults. We present results from a new word association study in which adult participants were instructed to produce either unconstrained or child-oriented responses to each cue, where cues included 672 nouns, verbs, adjectives, and other word forms from the McArthur–Bates Communicative Development Inventory (CDI; Fenson et al., 2006). Child-oriented responses consisted of higher frequency words with fewer letters, earlier ages of acquisition, and higher contextual diversity. Furthermore, the correlations among the responses generated for each pair of cues differed between unconstrained (adult-oriented) and child-oriented responses, suggesting that child-oriented associations imply different semantic structure. A comparison of growth models guided by a semantic network structure revealed that child-oriented associations are more predictive of early lexical growth. Additionally, relative to a growth model based on a corpus of naturalistic child-directed speech, the child-oriented associations explain added unique variance to lexical growth. Thus, these new child-oriented word association norms provide novel insight into the semantic context of young children and early lexical development.

Contrasting lexical biases in bilingual English-Mandarin speech: Verb-biased mothers, but noun-biased toddlers.

Is noun dominance in early lexical acquisition a widespread or a language-specific phenomenon? Thirty Singaporean bilingual English-Mandarin learning toddlers and their mothers were observed in a mother-child play interaction. For both English and Mandarin, toddlers' speech and reported vocabulary contained more nouns than verbs across book reading and toy playing. In contrast, their mothers' speech contained more verbs than nouns in both English and Mandarin but differed depending on the context of the interaction. Although toddlers demonstrated a noun bias for both languages, the noun bias was more pronounced in English than in Mandarin. Together, these findings support early noun dominance as a widespread phenomenon in the lexical acquisition debate but also provide evidence that language specificity also plays a minor role in children's early lexical development.

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.

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

ABSTRACT 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.

Pitch properties of infant-directed speech specific to word-learning contexts: a cross-linguistic investigation of Mandarin Chinese and Dutch.

This study investigates the pitch properties of infant-directed speech (IDS) specific to word-learning contexts in which mothers introduce unfamiliar words to children. Using a semi-spontaneous story-book telling task, we examined (1) whether mothers made distinctions between unfamiliar and familiar words with pitch in IDS compared to adult-directed speech (ADS); (2) whether pitch properties change when mothers address children from 18 to 24 months; and (3) how Mandarin Chinese and Dutch IDS differ in their pitch properties in word-learning contexts. Results show that the mean pitch of Mandarin Chinese IDS was already ADS-like when children were 24 months, but Dutch IDS remained exaggerated in pitch at the same age. Crucially, Mandarin Chinese mothers used a higher pitch and a larger pitch range in IDS when introducing unfamiliar words, while Dutch mothers used a higher pitch specifically for familiar words. These findings contribute to the language-specificity of prosodic input in early lexical development.

Early lexical development of children raised in institutional care in Russia.

Children abandoned to institutions display a host of developmental delays, including those involving general cognition and language. The majority of published studies focus on children over 3years of age; little is known about whether these delays may be detected earlier when children undergo rapid lexical development. To investigate the early language development of children raised in institutional settings in the Russian Federation, we compared a group of children in institutional care (n=36; 8-35months) to their age-matched peers raised in biological families, who have never been institutionalized (n=72) using the Russian version of the CDI. The results suggest that institutionalization is associated with pronounced delays in children's early language development with large and robust effect sizes. Among children with a history of institutionalization, these delays are also associated with difficulties in Daily Living skills, communication, and socialization.

Dual language input and the impact of language separation on early lexical development.

We examined properties of the input and the environment that characterize bilingual exposure in 11-month-old infants with a regular exposure to French and an additional language, and their possible effects on receptive vocabulary size. Using a diary method, we found that a majority of the families roughly followed a one-parent-one-language approach. Yet, the two languages co-occurred to various extents within the same half-hour both within and across speakers. We used exploratory correlation analyses to examine potential effects of the dual input on the size of infants' vocabularies. The results revealed some evidence for an impact of language separation by speakers.

Variability and stability in early language acquisition: Comparing monolingual and bilingual infants' speech perception and word recognition

AbstractMany human infants grow up learning more than one language simultaneously but only recently has research started to study early language acquisition in this population more systematically. The paper gives an overview on findings on early language acquisition in bilingual infants during the first two years of life and compares these findings to current knowledge on early language acquisition in monolingual infants. Given the state of the research, the overview focuses on research on phonological and early lexical development in the first two years of life. We will show that the developmental trajectory of early language acquisition in these areas is very similar in mono- and bilingual infants suggesting that these early steps into language are guided by mechanisms that are rather robust against the differences in the conditions of language exposure that mono- and bilingual infants typically experience.

Early lexicon and language skills at 42 months

ABSTRACTPrevious studies have shown that early lexical development is associated with later language development. It is less clear which language domains early receptive/expressive lexicons are associated with. This study analyses these associations. The study also investigates whether children with slow/typical/fast developing early receptive/expressive lexical skills differed in their language skills at three and a half years (42 months) and the predictive value of early receptive/expressive lexical skills for later language skills.The participants of this longitudinal study were 68 healthy, monolingual Finnish-speaking children whose language development was measured using the Finnish, short-form-version of the Communicative Development Inventories at 12, 15, 18 and 24 months. At 42 months, language skills of the participants were assessed using tests measuring lexical, phonological, morphological and general receptive/expressive language skills.Early receptive lexicon was associated with later morphological skills from 15 months and onwards and with other language domains at 24 months. Early expressive lexicon was associated with later morphological skills at 15 months and onwards but with other language domains from 18 months. A trend was found that children with different early lexical growth rates differed in their language skills at 42 months. The best models for predicting later receptive/expressive language skills included variables from both early receptive and expressive lexicons. These models worked well to explain receptive/expressive language skills at 42 months (63/78% of the variance).This study provides novel information on the specific associations between receptive and expressive lexicon growth and later language skills. For clinicians, measuring both receptive and expressive lexicons provides the most representative information on children’s language development.