The human brain has been uniquely equipped with the remarkable ability to acquire more than one language, as in bilingual individuals. Previous neuroimaging studies have indicated that learning a second language (L2) induced neuroplasticity at the macrostructural level. In this study, using the quantitative MRI (qMRI) combined with functional MRI (fMRI) techniques, we quantified the microstructural properties and tested whether second language learning modulates the microstructure in the bilingual brain. We found significant microstructural variations related to age of acquisition of second language in the left inferior frontal region and the left fusiform gyrus that are crucial for resolving lexical competition of bilinguals' two languages. Early second language acquisition contributes to enhance cortical development at the microstructural level.

中文翻译：

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双语大脑的微观结构可塑性

人类的大脑具有独特的能力，能够获得不止一种语言，就像双语者一样。先前的神经影像学研究表明，学习第二语言 (L2) 会在宏观结构水平上诱导神经可塑性。在这项研究中，使用定量 MRI (qMRI) 结合功能性 MRI (fMRI) 技术，我们量化了微观结构特性，并测试了第二语言学习是否会调节双语大脑中的微观结构。我们发现与左下额叶区和左梭状回第二语言习得年龄相关的显着微观结构变化对于解决双语者两种语言的词汇竞争至关重要。