Vocabulary size and speed of word recognition in very young French-English bilinguals: A longitudinal study

The role of translation equivalents in bilingual word learning

Bilingual environments present an important context for word learning. One feature of bilingual environments is the existence of translation equivalents (TEs)-words in different languages that share similar meanings. Documenting TE learning over development may give us insight into the mechanisms underlying word learning in young bilingual children. Prior studies of TE learning have often been confounded by the fact that increases in overall vocabulary size with age lead to greater opportunities for learning TEs. To address this confound, we employed an item-level analysis, which controls for the age trajectory of each item independently. We used Communicative Development Inventory data from four bilingual datasets (two English-Spanish and two English-French; total N = 419) for modeling. Results indicated that knowing a word's TE increased the likelihood of knowing that word for younger children and for TEs that are more similar phonologically. These effects were consistent across datasets, but varied across lexical categories. Thus, TEs may allow bilingual children to bootstrap their early word learning in one language using their knowledge of the other language. RESEARCH HIGHLIGHTS: Bilingual children must learn words that share a common meaning across both languages, that is, translation equivalents, like dog in English and perro in Spanish. Item-level models explored how translation equivalents affect word learning, in addition to child-level (e.g., exposure) and item-level (e.g., phonological similarity) factors. Knowing a word increased the probability of knowing its corresponding translation equivalent, particularly for younger children and for more phonologically-similar translation equivalents. These findings suggest that young bilingual children use their word knowledge in one language to bootstrap their learning of words in the other language.

Child-level factors associated with Spanish-English bilingual toddlers' productive vocabulary growth

This longitudinal study-conducted in the Midwestern United States-examines the child-level factors that promote Spanish-English bilingual toddlers' (n = 47; Mage = 18.80 months; SDage = 0.57) productive vocabulary skills from 18 to 30 months of age. At 6-month intervals, caregivers reported on toddlers' Spanish and English words produced as well as their language exposure at home. Video recordings at child age 18 months yielded estimates of toddlers' speech output (word tokens per minute). In addition, at child age 18 months, caregivers reported on toddlers' linguistic skills (comprehension), demographic background (gender, household income), and nonverbal behaviors (gesture production). Results showed that toddlers were exposed to both English and Spanish and received more Spanish than English from primary caregivers; there were no significant primary caregiver input differences across time. Growth modeling revealed linear growth rates for Spanish and conceptual (Spanish, English combined) vocabulary and a curvilinear trajectory for English vocabulary. Furthermore, toddlers' Spanish and conceptual vocabularies were positively associated with their higher frequencies of token use, greater production of gesture, and greater comprehension skills, even after controlling for input. Moreover, Spanish and conceptual growth rates were positively associated with higher token use. In terms of English, toddlers' vocabulary at child age 18 months was positively associated with their comprehension skills. Toddlers' use of more gestures and tokens as well as gender (boys) influenced their English acceleration rates over time. Findings indicate that unique trajectories exist for each of a bilingual's languages and these trajectories are differentially influenced by child-level factors, including their speech output, not only exposure to language. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Touching while listening: Does infants' haptic word processing speed predict vocabulary development?

The present study examined the links between haptic word processing speed, vocabulary, and inhibitory control among bilingual children. Three main hypotheses were tested: faster haptic processing speed, measured by the Computerized Comprehension Task at age 1;11, would be associated with larger concurrent vocabulary and greater longitudinal vocabulary growth. Second, early vocabulary size would be associated with greater vocabulary growth at 3;0 and 5;0. Finally, faster haptic processing speed would be associated with greater concurrent inhibitory control, as measured by the Shape Stroop Task. The results revealed that haptic processing speed was associated with concurrent vocabulary, but not predictive of later language skills. Also, early decontextualized vocabulary was predictive of vocabulary at 3;0. Finally, haptic processing speed measured in the non-dominant language was associated with inhibitory control. These results provide insight on the mechanisms of lexical retrieval in young bilinguals and expand previous research on haptic word processing and vocabulary development.

Language proficiency predictors of code-switching behavior in dual-language-learning children

Code-switching, switching between different languages within the same conversation, is a prominent feature in bilingual communication. This study aimed to elucidate to what extent the linguistic abilities and age of dual-language-learning preschoolers influence the frequency and purposes of code-switching (compensatory, to bridge linguistic gaps; preferential, to express content as fluently as possible; pragmatic, to phrase something appropriately for the situation). Parental code-switching ratings of 101 German/French-Turkish/Italian dual-language learners aged 32-78 months were analyzed. Generalized linear mixed models revealed positive but no negative effects of societal- and heritage-language skills on children's code-switching frequencies independent of switching purposes and with no evidence of age effects. Hence, code-switching across the preschool age mainly reflects high linguistic competences. Models with linguistically and psychometrically parallelized language scores indicated a strong switching tendency toward the societal language when proficiency in both languages is high and away from the societal language when language proficiencies are low.

Coping with dialects from birth: Role of variability on infants' early language development. Insights from Norwegian dialects

Previous research suggests that exposure to accent variability can affect toddlers' familiar word recognition and word comprehension. The current preregistered study addressed the gap in knowledge on early language development in infants exposed to two dialects from birth and assessed the role of dialect similarity in infants' word recognition and comprehension. A 12-month-old Norwegian-learning infants, exposed to native Norwegian parents speaking the same or two Norwegian dialects, took part in two eye-tracking tasks, assessing familiar word form recognition and word comprehension. Their parents' speech was assessed for similarity by native Norwegian speakers. First, in contrast to previous research, our results revealed no listening preference for words over nonwords in both monodialectal and bidialectal infants, suggesting potential language-specific differences in the onset of word recognition. Second, the results showed evidence for word comprehension in monodialectal infants, but not in bidialectal infants, suggesting that exposure to dialectal variability impacts early word acquisition. Third, perceptual similarity between parental dialects tendentially facilitated bidialectal infants' word recognition and comprehension. Forth, the results revealed a strong correlation between the raters and parents' assessment of similarity between dialects, indicating that parental estimations can be reliably used to assess infants' speech variability at home. Finally, our results revealed a strong relationship between word recognition and comprehension in monodialectal infants and the absence of such a relationship in bidialectal infants, suggesting that either these two skills do not necessarily align in infants exposed to more variable input, or that the alignment might occur at a later stage.

Drivers of Lexical Processing and Implications for Early Learning

Understanding words in unfolding speech requires the coordination of many skills to support successful and rapid comprehension of word meanings. This multifaceted ability emerges before our first birthday, matures over a protracted period of development, varies widely between individuals, forecasts future learning outcomes, and is influenced by immediate context, prior knowledge, and lifetime experience. This article highlights drivers of early lexical processing abilities while exploring questions regarding how learners begin to acquire, represent, and activate meaning in language. The review additionally explores how lexical processing and representation are connected while reflecting on how network science approaches can support richly detailed insights into this connection in young learners. Future research avenues are considered that focus on addressing how language processing and other cognitive skills are connected.

Language-Fair Fast Mapping and Mutual Exclusivity Tasks for Mono- and Bilingual Preschoolers

PURPOSE

Both monolingual and bilingual children use learning constraints and heuristics to acquire new words from their environment. Overall, fast mapping abilities seem to be similar in both populations, but monolinguals rely more than bilinguals on the mutual exclusivity strategy. Our study probes the robustness of these results in a large group of children learning different language combinations, with a newly devised language-fair task that relies as little as possible on previous linguistic knowledge, in order to avoid disadvantaging bilingual children.

METHOD

We tested 138 3- to 5-year-old mono- and bilingual children in their dominant language (German, French, Italian, or Turkish) in a computerized task starting with a fast mapping phase, followed by a mutual exclusivity phase, using only invented nonobjects and nonwords.

RESULTS

As hypothesized, monolingual and bilingual children showed similar results during the initial fast mapping stage, but monolinguals relied significantly more on the mutual exclusivity strategy than their bilingual peers.

CONCLUSIONS

The language-fair design of our task supports the idea that differences in mutual exclusivity strategy use between mono- and bilingual children really stem from their specific linguistic background, and not from potential familiarity differences with respect to the test words. We discuss the implications of our results for bilingual language assessment in clinical or educational contexts.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20669214.

Factors structuring lexical development in toddlers: The effects of parental education, language exposure, and age

A growing body of research suggests that individual variation in young children's word comprehension (indexed by response times and accuracy) is structured and meaningful. In this paper, we assess how children's word comprehension correlates with three factors: socio-economic status (indexed by maternal education), lingual status (based on language exposure), and age. We present results from 91 2- to 3-year-old children using a paired forced-choice task built on a child-friendly touch screen. Effects associated with maternal education and exposure to the tested language (French) were small, and they were greater for accuracy than response times. This pattern of results is compatible with an interpretation whereby the greatest effects of these two variables are on cumulative knowledge (vocabulary size) rather than on processing. Effects for age were larger and affected both accuracy and response times. Finally, response time variation did not mediate the effects of socio-economic status on accuracy or vice versa.

Lexico-semantic structure in vocabulary and its links to lexical processing in toddlerhood and language outcomes at age three

Toddlerhood is marked by advances in several lexico-semantic skills, including improvements in the size and structure of the lexicon and increased efficiency in lexical processing. This project seeks to delineate how early changes in vocabulary size and vocabulary structure support lexical processing (Experiment 1), and how these three skills together (vocabulary size, structure, and lexical processing) relate to later language outcomes at age 3 (Experiment 2). Experiment 1 explored how the size and semantic structure of toddlers' vocabulary from 18 to 24 months (N = 61) predicted performance on two lexical processing tasks (semantically related and semantically unrelated trials). Denser semantic connectivity (i.e., global level connectivity between near and far neighbors) positively associated with semantic interference during semantically related lexical processing, whereas denser category structure (i.e., lower-level connectivity between near neighbors) facilitated lexical processing in semantically unrelated trials. In Experiment 2, a subset of the same children (N = 49) returned at age 36 months and completed a comprehensive assessment of their language skills using the Clinical Evaluation of Language Fundamental, Preschool 2 (CELF-P2). Here, earlier measures of lexico-semantic connectivity and lexical processing best predicted age 3 language skill. The findings support accounts that early vocabulary structure and lexical processing skills promote continued growth in language. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Effects of language mixing on bilingual children's word learning

Language mixing is common in bilingual children's learning environments. Here, we investigated effects of language mixing on children's learning of new words. We tested two groups of 3-year-old bilinguals: French-English (Experiment 1) and Spanish-English (Experiment 2). Children were taught two novel words, one in single-language sentences ("Look! Do you see the dog on the teelo?") and one in mixed-language sentences with a mid-sentence language switch ("Look! Do you see the chien/perro on the walem?"). During the learning phase, children correctly identified novel targets when hearing both single-language and mixed-language sentences. However, at test, French-English bilinguals did not successfully recognize the word encountered in mixed-language sentences. Spanish-English bilinguals failed to recognize either word, which underscores the importance of examining multiple bilingual populations. This research suggests that language mixing may sometimes hinder children's encoding of novel words that occur downstream, but leaves open several possible underlying mechanisms.

Language acquisition in a multilingual society: English vocabulary norms and predictors in Singaporean children

In this study, infant vocabulary development was tracked in a multilingual society (Singapore) within a socioeconomically diverse sample. The sample comprised 1316 infants from 17.4 to 27.7 months (669 females, 647 males; 88% Chinese race, 4% Malay, 4% Indian, and 0.004% mixed-race [4% declined to provide race information]). Children varied in English language exposure and socioeconomic status. Analyses focused on identifying demographic predictors of English vocabulary size in multilingually exposed infants. Adaptations of the Macarthur-Bates Communicative Development Inventory for English, Mandarin, and Malay are provided as well as English vocabulary norms that account for variation in English exposure. This manuscript reports the first set of English language norms-calibrated to English exposure-for multilingual infants in a non-Western setting.

Lexical-Semantic Development in Bilingual Toddlers at 18 and 24 Months

An important question in early bilingual first language acquisition concerns the development of lexical-semantic associations within and across two languages. The present study investigates the earliest emergence of lexical-semantic priming at 18 and 24 months in Spanish-English bilinguals (N = 32) and its relation to vocabulary knowledge within and across languages. Results indicate a remarkably similar pattern of development between monolingual and bilingual children, such that lexical-semantic development begins at 18 months and strengthens by 24 months. Further, measures of cross-language lexical knowledge are stronger predictors of children's lexical-semantic processing skill than measures that capture single-language knowledge only. This suggests that children make use of both languages when processing semantic information. Together these findings inform the understanding of the relation between lexical-semantic breadth and organization in the context of dual language learners in early development.

Visual and haptic responses as measures of word comprehension and speed of processing in toddlers: Relative predictive utility

Early vocabulary knowledge and speed of word processing are important foundational skills for the development of preschool and school-age language and cognition. However, the variance in outcomes accounted for by parent-reported receptive or expressive vocabulary is generally modest. Recent research suggests that directly assessed, decontextualized vocabulary predicts developmental outcomes, including general language ability and kindergarten readiness, accounting for additional variance above and beyond parent-reported vocabulary. The current research extends this finding by exploring prediction from both decontextualized vocabulary and speed of word processing at 2 years of age to vocabulary during the preschool period. At age 2, children completed a two-alternative forced-choice task that yielded a measure of decontextualized vocabulary (number of correct touch responses) and two measures of speed of processing: latency to fixate the target (visual response latency) and latency to touch (haptic response latency). Results reveal that age 2 vocabulary and visual response latency, but not haptic response latency, independently predict vocabulary at ages 3 and 4. Furthermore, only decontextualized vocabulary remains a significant predictor when controlling for speed of processing, but not vice versa. This suggests that the number of early, stable word-referent associations and the efficiency with which these are processed are important to vocabulary outcomes. However, it also suggests that decontextualized vocabulary may be a more robust unique predictor of downstream outcomes.

BiLex: A computational approach to the effects of age of acquisition and language exposure on bilingual lexical access

Lexical access in bilinguals can be modulated by multiple factors in their individual language learning history. We developed the BiLex computational model to examine the effects of L2 age of acquisition, language use and exposure on lexical retrieval in bilingual speakers. Twenty-eight Spanish-English bilinguals and five monolinguals recruited to test and validate the model were evaluated in their picture naming skills in each language and filled out a language use questionnaire. We examined whether BiLex can (i) simulate their naming performance in each language while taking into account their L2 age of acquisition, use and exposure to each language, and (ii) predict naming performance in other participants not used in model training. Our findings showed that BiLex could accurately simulate naming performance in bilinguals, suggesting that differences in L2 age of acquisition, language use and exposure can account for individual differences in bilingual lexical access.

The impact of cross-language phonological overlap on bilingual and monolingual toddlers' word recognition

We examined how L2 exposure early in life modulates toddler word recognition by comparing German-English bilingual and German monolingual toddlers' recognition of words that overlapped to differing degrees, measured by number of phonological features changed, between English and German (e.g., identical, 1-feature change, 2-feature change, 3-feature change, no overlap). Recognition in English was modulated by language background (bilinguals vs. monolinguals) and by the amount of phonological overlap that English words shared with their L1 German translations. L1 word recognition remained unchanged across conditions between monolingual and bilingual toddlers, showing no effect of learning an L2 on L1 word recognition in bilingual toddlers. Furthermore, bilingual toddlers who had a later age of L2 acquisition had better recognition of words in English than those toddlers who acquired English at an earlier age. The results suggest an important role for L1 phonological experience on L2 word recognition in early bilingual word recognition.

Translation Equivalents Facilitate Lexical Access in Very Young Bilinguals

The present study investigated the impact of translation equivalents (TE) on lexical processing in a sample of 36 French-English bilingual toddlers at 22-months of age. Children were administered the Computerized Comprehension Task (CCT; Friend & Keplinger, 2003) in each language and parents completed the MacArthur Bates Communicative Development Inventory (CDI) in both English and French across two visits (one language per visit). Correct trials on the CCT were identified and classified into one of two categories: words with a known TE as reported on the CDI and words without a known TE on the CDI. Reaction times for correct trials were then averaged in each category and compared for each of the bilinguals' languages. Interestingly, children were faster to retrieve words with a known TE on the CDI than words with no known TE. The present findings suggest that the translation facilitation effects reported in adult bilinguals are also present in very young bilinguals.

A cross-language study of decontextualized vocabulary comprehension in toddlerhood and kindergarten readiness

[Correction Notice: An Erratum for this article was reported in Vol 54(7) of Developmental Psychology (see record 2018-30226-001). In the article, the reference for Legacy, Zesiger, Friend, & Poulin-Dubois (2016) should be Legacy, Zesiger, Friend, & Poulin-Dubois (2018). The correct reference for the article is listed below: Legacy, J., Zesiger, P., Friend, M., & Poulin-Dubois, D. (2018). Vocabulary size and speed of word recognition in very young French-English bilinguals: A longitudinal study. Bilingualism: Language and Cognition, 21, 137-149. https://doi.org/10.1017/S1366728916000833. All versions of this article have been corrected.] Recent studies demonstrate that emerging literacy depends on earlier language achievement. Importantly, most extant work focuses on parent-reported production prior to 30 months of age. Of interest is whether and how directly assessed vocabulary comprehension in the 2nd year of life supports vocabulary and kindergarten readiness in the 4th year. We first contrasted orthogonal indices of parent-reported production and directly assessed vocabulary comprehension and found that comprehension was a stronger predictor of child outcomes. We then assessed prediction from vocabulary comprehension controlling for maternal education, preschool attendance, and child sex. In 3 studies early, decontextualized vocabulary comprehension emerged as a significant predictor of 4th year language and kindergarten readiness accounting for unique variance above demographic control variables. Further we found that the effect of early vocabulary on 4th year kindergarten readiness was not mediated by 4th year vocabulary. This pattern of results emerged in English monolingual children (N = 48) and replicated in French monolingual (N = 58) and French-English bilingual children (N = 34). Our findings suggest that early, decontextualized vocabulary may provide a platform for the establishment of a conceptual system that supports both later vocabulary and kindergarten readiness, including the acquisition of a wide range of concepts including print and number. Differences between parent-reported and directly assessed vocabulary and the mechanisms by which decontextualized vocabulary may contribute to conceptual development are discussed. (PsycINFO Database Record

Lexical Access in the Second Year: a Study of Monolingual and Bilingual Vocabulary Development

It is well established that vocabulary size is related to efficiency in auditory processing, such that children with larger vocabularies recognize words faster than children with smaller vocabularies. The present study evaluates whether this relation is specific to the language being assessed, or related to general language or cognitive processes. Speed of word processing was measured longitudinally in Spanish- and English-learning monolinguals and bilinguals at 16 and 22 months of age. Speed of processing in bilinguals was similar to monolinguals, suggesting that the number of languages to which children are exposed does not influence word recognition. Further, cross-language associations in bilinguals suggest that the dominant language supports processing in the non-dominant language. These cross-language associations are consistent with general language and cognitive efficiency accounts in which the relation between word processing and knowledge relies on experience within a language as well as on general and cognitive properties of language learning.