Word learning and executive functions in preschool children : bridging the gap between vocabulary acquisition and domain-general cognitive processes

Language development in children depends on domain-specific language mechanisms, biases and domain-general cognitive development (i.e., executive functions [EFs]). Additionally, both language proficiency and EFs underpin new learning and predict academic success and lifelong wellbeing. However, despite the intuitive assumption that EFs are involved in the development of language, the relationship between word-learning abilities and EFs is not fully understood. Therefore, the present thesis addresses this gap by examining novel word learning under three different scenarios integrating three main EF components. The current thesis investigated 1) whether children learn and retain words differently depending on the word-learning scenario, and 2) whether EFs in the non-linguistic domain predict word learning in children. More specifically, the present study assessed the impact of three different word-learning scenarios and EF measurements on novel word learning outcomes in 4-year-old children in Greater Sydney, Australia. Participants were 47 children from diverse language backgrounds, including monolinguals (n= 28) and heterogeneous bilinguals (n=19). The present study demonstrates that 4-year-old children are successful at learning words across three word-learning scenarios: Mutual Exclusivity (ME), Cross Situational Word Learning (CSW)L and an eBook. Crucially, different word-learning scenarios foster different learning outcomes, with eBook reading and disambiguation via ME facilitating rapid and more accurate word learning, while CSWL yielded less success. We conclude that at this crucial age prior to entering formal schooling in Australia, children benefit from contextual information and referential input during the word-learning experience. Four-year-olds easily disambiguate and learn novel label-to-referent associations when presented alongside a familiar referent in virtue of the ME assumption. They also successfully activate attentional resources to detect and learn novel label-to-referent associations among abundant visual and auditory input when listening and observing a colourful eBook. These findings should be considered in early childhood education settings to support lexical acquisition in children. In addition, findings point out a bidimensional structure of EF in 4-year-old children, with one of the dimensions corresponding to a composite construct comprised of inhibition and flexibility, while the other dimension corresponds to working memory. However, our analyses did not reveal visuospatial memory, inhibition or flexibility as significant predictors for any of the word-learning scenarios. Altogether, the present thesis advances the knowledge of children’s cognitive structure and their relationship with different word-learning scenarios, providing foundations to help further bridge the research gap between word learning and cognitive processes

Understanding preschoolers’ word learning success in different scenarios: disambiguation meets statistical learning and eBook reading

Children’s ability to learn new words during their preschool years is crucial for further academic success. Previous research suggests that children rely on different learning mechanisms to acquire new words depending on the available context and linguistic information. To date, there is limited research integrating different paradigms to provide a cohesive view of the mechanisms and processes involved in preschool children’s word learning. We presented 4 year-old children (n = 47) with one of three different novel word-learning scenarios to test their ability to connect novel words to their correspondent referents without explicit instruction to do so. The scenarios were tested with three exposure conditions of different nature: (i) mutual exclusivity–target novel word-referent pair presented with a familiar referent, prompting fast-mapping via disambiguation, (ii) cross-situational–target novel word-referent pair presented next to an unfamiliar referent prompting statistically tracking the target pairs across trials, and (iii) eBook - target word-referent pairs presented within an audio-visual electronic storybook (eBook), prompting inferring meaning incidentally. Results show children succeed at learning the new words above chance in all three scenarios, with higher performance in eBook and mutual exclusivity than in cross-situational word learning. This illustrates children’s astounding ability to learn while coping with uncertainty and varying degrees of ambiguity, which are common in real-world situations. Findings extend our understanding of how preschoolers learn new words more or less successfully depending on specific word learning scenarios, which should be taken into account when working on vocabulary development for school readiness in the preschool years

Four-year-old's online versus face-to-face word learning via ebooks

Developmental research typically relies on face-to-face testing at laboratories, childcare centers, museums or playgroups. Current social distancing measures have led to a halt in research. Although face-to-face interaction is considered essential for research involving young children, current technology provides viable alternatives. This paper introduces an accessible, replicable and easy to follow method to conduct online developmental research with young children employing a word-learning task as an exemplar, including a detailed workflow and step-by-step guide to using easily accessible programs and platforms. Four-year-old children's (N = 56) performance on a word-learning task delivered online vs. face-to-face is provided as a method validation. Children's performance on the word-learning task was predominantly consistent across delivery modes, with only slight variation in performance between modes. The implications of these similar results across face-to-face and online methods are discussed alongside avenues for further research. Importantly, this paper presents an emerging methodological approach for the online administration of developmental science both within and beyond the COVID-19 pandemic, adding a new tool to current and future developmental scientist's toolkits

Understanding preschoolers' word learning success in different scenarios : disambiguation meets statistical learning and ebook reading

Children’s ability to learn new words during their preschool years is crucial for further academic success. Previous research suggests that children rely on different learning mechanisms to acquire new words depending on the available context and linguistic information. To date, there is limited research integrating different paradigms to provide a cohesive view of the mechanisms and processes involved in preschool children’s word learning. We presented 4 year-old children (n = 47) with one of three different novel word-learning scenarios to test their ability to connect novel words to their correspondent referents without explicit instruction to do so. The scenarios were tested with three exposure conditions of different nature: (i) mutual exclusivity–target novel word-referent pair presented with a familiar referent, prompting fast-mapping via disambiguation, (ii) cross-situational–target novel word-referent pair presented next to an unfamiliar referent prompting statistically tracking the target pairs across trials, and (iii) eBook - target word-referent pairs presented within an audio-visual electronic storybook (eBook), prompting inferring meaning incidentally. Results show children succeed at learning the new words above chance in all three scenarios, with higher performance in eBook and mutual exclusivity than in cross-situational word learning. This illustrates children’s astounding ability to learn while coping with uncertainty and varying degrees of ambiguity, which are common in real-world situations. Findings extend our understanding of how preschoolers learn new words more or less successfully depending on specific word learning scenarios, which should be taken into account when working on vocabulary development for school readiness in the preschool years

Do bilingual and monolingual children differ? : measuring and comparing attentional control skills in the verbal and non-verbal domains

The aim of the current master’s thesis was to investigate 1) whether bilingual and monolingual children display differences in behavioural measures of attentional control in the verbal and non-verbal domains and 2) whether attentional control performance in children correlates across domains. The present study therefore explored the impact of being bilingual from birth on the cognitive skills (specifically attentional control) and lexical retrieval proficiency of early-school-aged children in Greater Sydney, Australia. Participants included monolingual (N=17) and bilingual (N=17) Australian born children who were matched in age, sex and parental education. Bilingual participants were exposed to two languages from birth and were highly proficient in both their languages. Chapter 1 introduces the thesis, including the literature review and general design of the study. Chapter 2 presents the study of the verbal domain in terms of children’s lexical performance. In this Chapter, performance in the letter and category verbal fluency task (VFT) (partially in Pino Escobar et al., 2016) are analysed and compared between language groups. Chapter 3 investigates the cognitive non-verbal domain under the Dimensional Card Change Sort (DCCS) and the Day-Night Stroop task (Day-Night). Afterwards, Chapter 4 investigates the relations between verbal and non-verbal tasks of attentional control in bilingual and monolingual children. Finally, Chapter 5 concludes the thesis with a General discussion. Results indicated better bilingual performance on the letter and category VFT but comparable performance between monolingual and bilingual groups on the DCCS and the Day-Night task. It was also found that performance in the letter VFT correlated with the DCCS while no relation between category VFT and the Day-Night task was found. Regression analyses, however, showed that while DCCS performance predicted only letter VFT; vocabulary proficiency (as measured by the Peabody Picture Vocabulary Test (PPVT)) predicted performance of both letter and category VFT. Results were explained in light of the characteristics of the participant samples. Firstly, bilingual and monolingual groups were strictly matched in age and gender, both groups exhibited similar parental education backgrounds and similar English receptive vocabulary proficiency. And secondly and more importantly, bilingual participants were highly proficient and productive in an additional language. It was therefore proposed that this last characteristic conferred bilinguals with additional attentional control to efficiently sort and retrieve words under different conditions. These results suggest that during complex lexical retrieval (i.e., letter VFT) seven to eight-year-old bilingual and monolingual children can recruit high order attentional control. In sum, our findings show that both vocabulary proficiency and general attentional control skills account for monolingual and bilingual children’s performance on complex verbal fluency tasks. Additionally, controlling for vocabulary proficiency has a determining factor when comparing monolingual and bilingual performance: high vocabulary proficiency in both languages likely underlies the unprecedented bilingual advantage shown in the present study

Vocabulary matters! : the relationship between verbal fluency and measures of inhibitory control in monolingual and bilingual children

The role of early bilingual experience in the development of skills in the general cognitive and linguistic domains remains poorly understood. This study investigated the link between these two domains by assessing inhibitory control processes in school-aged monolingual and bilingual children with similar English receptive vocabulary size. The participants, 8-year-old monolinguals and bilinguals, completed two Verbal Fluency Tasks (VFTs), letter and category, and two measures of inhibitory control. Results showed that bilinguals outperformed monolinguals on the VFTs, but performance was similar on the inhibitory control measures approaching ceiling for both monolingual and bilingual children. Importantly, it was shown that both vocabulary proficiency and general inhibitory control skills underlie monolingual and bilingual children's performance on VFTs. These results demonstrate that vocabulary proficiency plays a fundamental role in comparing monolingual and bilingual VFT performance. The bilingual advantage found in this study seems to have escaped previous studies that did not account for vocabulary size in populations of bilingual and monolingual school-aged children

The bilingual advantage in the language processing domain : evidence from the Verbal Fluency Task

Several cognitive advantages in the non-verbal domain have been associated with bilingualism. However, it remains debated whether this advantage also extends to the language processing domain in bilingual children. To assess this, monolingual and bilingual eight-year-old children performed a letter (or phonemic) and a category (or semantic) Verbal Fluency Task (VFT) in order to observe executive functioning under language processing demands. Results showed that bilinguals significantly outperformed monolinguals in both versions of the VFT, demonstrating enhanced lexical processing abilities for bilinguals. These findings will be discussed in view of the bilingual advantage controversy

[In Press] Needs and demands for heritage language support in Australia : results from a nationwide survey

This paper reports on a survey conducted in Australia among parents raising their children with a heritage language (HL). We found strong awareness of the importance of HL maintenance (95%), but only moderate levels of engagement (37–44%) with community initiatives for HL support. There were significantly more primary school-aged children reported as enrolled in community language schools than preschool aged children, but attendance at informal initiatives, such as language social groups, was higher for pre-schoolers. Less than 20% of respondents indicated that there was enough HL support available, with significantly less support reported for pre-school aged children. However, parents of children who attended HL initiatives during preschool years reported a significantly higher HL maintenance success rate. Most parents who did not bring their children to HL initiatives stated that it was because they did not know about them. Parents of school-aged children had more positive opinions about available HL support than parents of pre-schoolers and most parents said that if more initiatives were made available they would commit to attending them on a regular basis. Consequently, we suggest a formal language extension programme at the pre-school level as the solution for improving multilingual families’ experience

Data_Sheet_1_Understanding preschoolers’ word learning success in different scenarios: disambiguation meets statistical learning and eBook reading.docx

Children’s ability to learn new words during their preschool years is crucial for further academic success. Previous research suggests that children rely on different learning mechanisms to acquire new words depending on the available context and linguistic information. To date, there is limited research integrating different paradigms to provide a cohesive view of the mechanisms and processes involved in preschool children’s word learning. We presented 4 year-old children (n = 47) with one of three different novel word-learning scenarios to test their ability to connect novel words to their correspondent referents without explicit instruction to do so. The scenarios were tested with three exposure conditions of different nature: (i) mutual exclusivity–target novel word-referent pair presented with a familiar referent, prompting fast-mapping via disambiguation, (ii) cross-situational–target novel word-referent pair presented next to an unfamiliar referent prompting statistically tracking the target pairs across trials, and (iii) eBook - target word-referent pairs presented within an audio-visual electronic storybook (eBook), prompting inferring meaning incidentally. Results show children succeed at learning the new words above chance in all three scenarios, with higher performance in eBook and mutual exclusivity than in cross-situational word learning. This illustrates children’s astounding ability to learn while coping with uncertainty and varying degrees of ambiguity, which are common in real-world situations. Findings extend our understanding of how preschoolers learn new words more or less successfully depending on specific word learning scenarios, which should be taken into account when working on vocabulary development for school readiness in the preschool years.</p

Speech normalization across speaker, sex and accent variation is handled similarly by listeners of different language backgrounds

This study assessed the influence of language background in speech normalization by examining non-native vowel categorization across speaker, sex and accent variation. Mandarin-English bilinguals, Australian English bilinguals and monolinguals categorized /ɪ/ and /ɛ/ produced by a female Dutch speaker, and were then tested with the same vowels produced by speakers of the same or different sex and/or accent. Listeners categorized the vowels regardless of speaker and sex variation, but showed lower accuracy when vowels were produced by speakers of different accent or accent and sex. Findings suggest that listeners normalize speaker and sex variation automatically, while accent variation requires contextualization