Cortical activation during word processing in late bilinguals: Similarities and differences as revealed by functional magnetic resonance imaging

Abstract

Functional magnetic resonance imaging was used to compare cortical organization of the first (L1, Russian) and second (L2, English) languages. Six fluent Russian-English bilinguals who acquired their second language postpuberty were tested with words and nonwords presented either auditorily or visually. Results showed that both languages activated similar cortical networks, including the inferior frontal, middle frontal, superior temporal, middle temporal, angular, and supramarginal gyri. Within the inferior frontal gyrus (IFG), L2 activated a larger cortical volume than L1 during lexical and phonological processing. For both languages, the left IFG was more active than the right IFG during lexical processing. Within the left IFG, the distance between centers of activation associated with lexical processing of translation equivalents across languages was larger than the distance between centers of activation associated with lexical processing of different words in the same language. Results of phonological processing analyses revealed different centers of activation associated with the first versus the second language in the IFG, but not in the superior temporal gyrus (STG). These findings are discussed within the context of the current literature on cortical organization in bilinguals and suggest variation in bilingual cortical activation associated with lexical, phonological, and orthographic processing.

Bilinguals Use Language-Control Brain Areas More Than Monolinguals to Perform Non-Linguistic Switching Tasks

“…Thus, all bilinguals had a perfect command of both languages at all levels and self-reported the need for making continuous changes between Spanish and Catalan depending on the interlocutor present. Noteworthy, subjective measures of self-reported language proficiency appear to provide an effective measure of bilingual ability [16] (Marian et al 2007). This is probably even more so for very homogeneous samples like the one tested in this study.…”

Semantic processing in Spanish–English bilinguals with aphasia

“…In general, these studies have found that when the degree of proficiency for both languages in bilinguals is very high, a common language system comprising the left hemisphere language network appears to be responsible for the processing of both languages (e.g., Chee et al, 2003;Hasegawa, Carpenter, & Just, 2002;Hernandez, Hofmann, & Kotz, 2007;Klein, Watkins, Zatorre, & Milner, 2006;Perani et al, 1998). In bilinguals who are more proficient in one language than the other, however, a more extended network of activations is observed for the weaker language that includes brain regions related to speech motor and cognitive functions (e.g., Golestani et al, 2006;Kovelman, Baker, & Petitto, 2008;Luke, Liu, Wai, Wan, & Tan, 2002;Marian et al, 2007;Pillai et al, 2003;Tham et al, 2005;Yokoyama et al, 2006).…”

Left middle temporal deactivation caused by insufficient second language word comprehension by Chinese–Japanese bilinguals

“…In a report on L2 lexical decision, Marian et al (2007), Marian, Spivey, and Hirschc (2003) found that proficient L2 learners activated the posterior and superior regions of the left temporal lobe. However, in the case of non-proficient L2 learners, it is still unclear whether they use the left middle temporal gyrus during L2 lexical decision, since there has been no neuroimaging study which has examined this specific issue.…”