Published online by Cambridge University Press: 29 November 2013
Over the last decade, research on multilingualism has grown and has provided researchers with new insights into the mechanisms at work in the multilingual brain. While some studies of multilinguals have shown similar results to what has been seen in studies of bilinguals, certain unique properties of multilinguals are beginning to be noticed, particularly regarding early language representation, gray matter density, and speed of lexical retrieval. In addition, research on cognitive control, language switching, working memory, and certain consequences of multilingualism (advantages and disadvantages) are reviewed in terms of their effects on the brains of bilinguals and multilinguals. Although there is little agreement among papers concerning specific regions that are structurally different in monolinguals and multilinguals, publications do show differences. Similarly, there are studies reporting somewhat different regions called upon for processing a given language in multilinguals compared to monolinguals.
Abutalebi, J., & Green, D. W. (2008). Control mechanisms in bilingual language production: Neural evidence from language switching studies. Language and Cognitive Processes, 23, 557–582.
In this seminal article, Abutalebi and Green provided a comprehensive review of literature on the neural basis of language switching in bilinguals. They introduced research on functional neuroimaging to reinforce our understanding of language control and how cognitive control for language switching is subserved in the bilingual brain.
Bialystok, E., Craik, F. I. M., Green, D. W., & Gollan, T. H. (2009). Bilingual minds. Psychological Science in the Public Interest, 10, 89–129.
This article provides a helpful review of lexical-retrieval processes in bilingual adults and children, comparing them to monolinguals. It discusses the brain networks involved in language processing in bilinguals and the roles of executive control linked to them. As well, it covers behavioral studies of the apparent impact of bilingualism on nonverbal cognitive processing, clinical intervention studies on bilingual children and adults with brain damage, and some public and political implications to be considered with regard to bilinguals.
De Groot, A. M. B. (2011). Language and cognition in bilinguals and multilinguals. New York, NY: Psychology Press.
This text covers a wide variety of psycholinguistic and neurolinguistic studies of bilingual and multilingual speakers and includes many of the important advances in this field in recent years. Some of the topics that are covered include age of acquisition effects, lexical representation, comprehension processes, word production and accents, language control, and cognitive consequences of multilingualism.
Bloch, C., Kaiser, A., Kuenzli, E., Zappatore, D., Haller, S., Franceschini, R., . . . Nitsch, C. (2009). The age of second language acquisition determines the variability in activation elicited by narration in three languages in Broca's and Wernicke's area. Neuropsychologia, 47, 625–633.
Multilingual participants completed a silent language production task in three languages while their brains were scanned using fMRI. Participants were assigned to one of four groups based on the age of acquisition of their second language, although all were at least trilingual. Multilinguals who learned their second language after age 9 showed more variability in activated voxels among their three languages compared to multilinguals who learned both languages from birth.