Subcortical and cerebellar volume differences in bilingual and monolingual children: An ABCD study.

Research suggests that bilingual children experience an extension or delay in the closing of the sensitive/critical period of language development due to multiple language exposure. Moreover, bilingual experience may impact the development of subcortical regions, although these conclusions are drawn from research with adults, as there is a scarcity of research during late childhood and early adolescence. The current study included 1215 bilingual and 5894 monolingual children from the ABCD Study to examine the relationship between subcortical volume and English vocabulary in heritage Spanish bilingual and English monolingual children, as well as volumetric differences between the language groups. We also examined the unique effects of language usage in bilingual children's subcortical volumes. In general, bilingual children had less cerebellar volume and greater volume in the putamen, thalamus, and globus pallidus than monolingual children. English vocabulary was positively related to volume in the cerebellum, thalamus, caudate, putamen, nucleus accumbens, and right pallidum in all children. Moreover, the positive relationship between vocabulary and volume in the nucleus accumbens was stronger for monolingual adolescents than bilingual adolescents. The results are somewhat in line with existing literature on the dynamic volume adaptation of subcortical brain regions due to bilingual development and experience. Future research is needed to further explore these regions longitudinally across development to examine structural changes in bilingual brains.

Cortical Thickness Is Related to Variability in Heritage Bilingual Language Proficiency.

Research suggests that bilingual experience is associated with gray matter changes, such that initial language gains are associated with expansion and language expertise is associated with renormalization. Previous studies on language proficiency development primarily focused on between-subjects, quasiexperimental comparisons of monolinguals and bilinguals. This study proposes a new paradigm to examine language expertise and cortical thickness within heritage bilinguals (n = 215), as well as between bilinguals and monolinguals (n = 145), using data combined from eight previous magnetic resonance imaging studies. In general, results highlight variability within bilinguals, finding relationships between cortical thickness and English proficiency that are relatively consistent within monolinguals, but inconsistent within bilinguals. In all participants, higher levels of proficiency in English-monolinguals' only language and bilinguals' second but stronger language-were negatively related to cortical thickness. In bilinguals, higher proficiency in the weaker, albeit first learned, language was positively related to cortical thickness. Moreover, there was an interaction between language group and English proficiency in predicting cortical thickness, such that the relationship between proficiency and thickness was stronger in monolinguals than in bilinguals. Findings also demonstrate that the regions associated with language expertise differ between bilinguals and monolinguals. Future directions for cognitive-developmental neuroscience research in bilinguals are suggested, particularly the longitudinal examination of cortical changes in relation to bilingual experiences.

Factors predicting secondary school language course enrollment and performance among U.S. heritage speakers of Spanish.

Introduction: While a growing body of research indicates that Spanish language courses can promote Spanish maintenance and lead to overall improved educational outcomes among heritage speakers, there is little empirical or longitudinal evidence of factors that shape their enrollment in Spanish language courses at the secondary level. To address this issue, the current study takes a large-scale, longitudinal approach to investigate rates of enrollment in secondary school (6th-12th grade) Spanish and other non-English language courses, as well as factors that predict heritage speakers' enrollment and performance in non-English language courses. Method: We analyzed subsample data from the Miami School Readiness Project (MSRP), a large-scale, longitudinal study consisting of 17,341 heritage speakers of Spanish (47% female, 95.4% Hispanic/Latino, 82.8% received free/reduced-price lunch, and 18.3% with a disability) who were followed from 4 years old until the end of high school. Results: In general, Heritage speakers enrolled in Spanish language courses at a higher rate than other non-English language courses (52.2 and 25.3%, respectively). Enrollment patterns varied across different type of languages and grade level. Student-level factors including disability status, poverty status, early behavioral problems, and prior academic achievement significantly predicted students' enrollment in Spanish and performance in non-English language courses. Discussion: Findings shed light on the long-term patterns of language study of this growing segment of the US school population with implications for future research and school policies that seek to improve heritage language learning and maintenance as well as equitable access to language education for language-minority students.

Early bilingualism predicts enhanced later foreign language learning in secondary school.

Foreign language learning is generally not required in the United States, despite its link to various cognitive and social benefits later in life. Students who speak a home language different from the instructional language of school may experience unique benefits when learning additional languages in school. The present study examined whether students' early language status (monolingual, dual language learner [DLL], or bilingual) in Kindergarten predicts later foreign language course enrollment and performance in middle and high school. A total of 33,247 students (48% female, 59% Latino, 34% Black, 7% White/Asian/other, 82% receiving free/reduced-price lunch) were assessed for school readiness at age 4 and prospectively followed through high school. Regression analyses predicted foreign language course enrollment and performance in middle or high school, with students' demographic, school readiness, and prior academic performance as covariates. Results show early language status significantly predicts later enrollment and performance in foreign language courses, even after controlling for student demographics, school readiness skills, and early academic achievement. Early bilinguals were more likely to take foreign language courses than DLLs, who enrolled in such courses more than monolingual students. The same pattern favoring bilinguals, then DLLs, then monolinguals was found for performance in foreign language courses. Early bilingualism is an important resource for young children that continues to offer benefits throughout schooling. Implications for heritage language maintenance, language learning, and bilingual education are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cortical Thickness in bilingual and monolingual children: Relationships to language use and language skill.

There is a growing body of evidence based on adult neuroimaging that suggests that the brain adapts to bilingual experiences to support language proficiency. The Adolescent Brain Cognitive Development (ABCD) Study is a useful source of data for evaluating this claim during childhood, as it involves data from a large sample of American children. Using the baseline ABCD Study data collected at ages nine and ten, the goal of this study was to identify differences in cortical thickness between bilinguals and monolinguals and to evaluate how variability in English vocabulary and English use within bilinguals might explain these group differences. We identified bilingual participants as children who spoke a non-English language and were exposed to the non-English language at home. We then identified a matched sample of English monolingual participants based on age, sex, pubertal status, parent education, household income, non-verbal IQ, and handedness. Bilinguals had thinner cortex than monolinguals in widespread cortical regions. Within bilinguals, more English use was associated with greater frontal and parietal cortical thickness; greater English vocabulary was associated with greater frontal and temporal cortical thickness. These findings replicate and extend previous research with bilingual children and highlight unexplained cortical thickness differences between bilinguals and monolinguals.