Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, 200433, China.
Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence (Fudan University), Ministry of Education, Shanghai, 200433, China.
Commun Biol. 2023 Jan 25;6(1):99. doi: 10.1038/s42003-023-04446-5.
How bilingual brains accomplish the processing of more than one language has been widely investigated by neuroimaging studies. The assimilation-accommodation hypothesis holds that both the same brain neural networks supporting the native language and additional new neural networks are utilized to implement second language processing. However, whether and how this hypothesis applies at the finer-grained levels of both brain anatomical organization and linguistic functions remains unknown. To address this issue, we scanned Chinese-English bilinguals during an implicit reading task involving Chinese words, English words and Chinese pinyin. We observed broad brain cortical regions wherein interdigitated distributed neural populations supported the same cognitive components of different languages. Although spatially separate, regions including the opercular and triangular parts of the inferior frontal gyrus, temporal pole, superior and middle temporal gyrus, precentral gyrus and supplementary motor areas were found to perform the same linguistic functions across languages, indicating regional-level functional assimilation supported by voxel-wise anatomical accommodation. Taken together, the findings not only verify the functional independence of neural representations of different languages, but show co-representation organization of both languages in most language regions, revealing linguistic-feature specific accommodation and assimilation between first and second languages.
双语大脑如何完成一种以上语言的处理，这一问题已被神经影像学研究广泛探讨。同化-顺应假说认为，支持母语的相同脑神经网络和额外的新神经网络都被用来实现第二语言处理。然而，这一假说是否以及如何适用于大脑解剖组织和语言功能的更精细层次尚不清楚。为了解决这个问题，我们在一项涉及汉字、英语单词和汉语拼音的内隐阅读任务中扫描了中英双语者的大脑。我们观察到广泛的大脑皮质区域，其中交错分布的神经群体支持不同语言的相同认知成分。尽管在空间上是分开的，但包括额下回的眶部和三角部、颞极、上颞和中颞回、中央前回和辅助运动区在内的区域被发现跨越语言执行相同的语言功能，这表明基于体素的解剖顺应支持区域水平的功能同化。总之，这些发现不仅验证了不同语言的神经表现的功能独立性，而且还显示了大多数语言区域中两种语言的共同表现组织，揭示了第一语言和第二语言之间的语言特征特定的顺应和同化。
