title: Language exposure induced neuroplasticity in the bilingual brain: a follow-up fMRI study.
abstract: Although several studies have shown that language exposure crucially influence the cerebral representation of bilinguals, the effects of short-term change of language exposure in daily life upon language control areas in bilinguals are less known. To explore this issue, we employed follow-up fMRI to investigate whether differential exposure induces neuroplastic changes in the language control network in high-proficient Cantonese (L1)-Mandarin (L2) early bilinguals. The same 10 subjects underwent twice BOLD-fMRI scans while performing a silent narration task which corresponded to two different language exposure conditions, CON-1 (L1/L2 usage percentage, 50%:50%) and CON-2 (L1/L2 usage percentage, 90%:10%). We report a strong effect of language exposure in areas related to language control for the less exposed language. Interestingly, these significant effects were present after only a 30-day period of differential language exposure. In detail, we reached the following results: (1) the interaction effect of language and language exposure condition was found significantly in the left pars opercularis (BA 44) and marginally in the left MFG (BA 9); (2) in CON-2, increases of activation values in L2 were found significantly in bilateral BA 46 and BA 9, in the left BA44, and marginally in the left caudate; and (3) in CON-2, we found a significant negative correlation between language exposure to L2 and the BOLD activation value specifically in the left ACC. These findings strongly support the hypothesis that even short periods of differential exposure to a given language may induce significant neuroplastic changes in areas responsible for language control. The language which a bilingual is less exposed to and is also less used will be in need of increased mental control as shown by the increased activity of language control areas.
authors.affiliation: College of Foreign Studies, Jinan University, Guangzhou, PR China.
authors.forename: Liu
authors.initials: L
authors.lastname: Tu
authors.affiliation: Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University, Guangzhou, PR China.
authors.forename: Junjing
authors.initials: J
authors.lastname: Wang
authors.affiliation: University San Raffaele, Milan & Scientific Institute San Raffaele, Milan, Italy.
authors.forename: Jubin
authors.initials: J
authors.lastname: Abutalebi
authors.affiliation: Department of Radiology, Huangpu Clinical Medical Center, Sun Yat Sen University First Affiliated Hospital, Guangzhou, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of Radiology, Huangpu Clinical Medical Center, Sun Yat Sen University First Affiliated Hospital, Guangzhou, PR China.
authors.forename: Ximin
authors.initials: X
authors.lastname: Pan
authors.affiliation: Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University, Guangzhou, PR China.
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.affiliation: College of Foreign Studies, Jinan University, Guangzhou, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.affiliation: College of Information Science and Technology, Jinan University, Guangzhou, PR China.
authors.forename: Yuchen
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University, Guangzhou, PR China.
authors.forename: Bishan
authors.initials: B
authors.lastname: Liang
authors.affiliation: Faculty of Foreign Languages, Ningbo University, Ningbo, PR China. Electronic address: luzhi@nbu.edu.cn.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Lu
authors.affiliation: Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University, Guangzhou, PR China. Electronic address: ruiwang.huang@gmail.com.
authors.forename: Ruiwang
authors.initials: R
authors.lastname: Huang
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D019303:Multilingualism; D009473:Neuronal Plasticity / Q000502:physiology*; D055815:Young Adult
keywords: Cantonese-Mandarin; Language control network; Language exposure condition; Silent narration