Cortical Thickness Is Related to Variability in Heritage Bilingual Language Proficiency

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.

Translational Approaches to Bilingualism and Multilingualism Research

Bilingualism and multilingualism provide a unique lens for exploring how human experiences influence language and cognition. This editorial presents a collection of studies on the relationship between bilingualism/multilingualism and cognition in typically developing and neurodiverse populations. The articles assembled in this issue synthesize findings from diverse linguistic populations (e.g., second-language learners, heritage speakers, different-script bilinguals, etc.) and techniques (e.g., behavioral, magnetic resonance imaging, electroencephalography, eye-tracking, etc.) to provide compelling evidence that knowing more than one language can benefit learning, health, and social outcomes. Translational research on bilingualism and multilingualism is necessary for informing policy and can serve as a guide to researchers, practitioners, and educators who work with linguistically diverse populations, as well as individuals and parents who speak multiple languages. We conclude that multilingualism shapes cells, selves, and societies.