The past decade marked the beginning of the use of resting-state functional connectivity (RSFC) imaging in bilingualism studies. This paper intends to review the latest evidence of changes in RSFC in language and cognitive control networks in bilinguals during adulthood, aging, and early Alzheimer's disease, which can add to our understanding of brain functional reshaping in the context of second language (L2) acquisition. Because of high variability in bilingual experience, recent studies mostly focus on the role of the main aspects of bilingual experience (age of acquisition (AoA), language proficiency, and language usage) on intrinsic functional connectivity (FC). Existing evidence accounts for stronger FC in simultaneous rather than sequential bilinguals in language and control networks, and the modulation of the AoA impact by language proficiency and usage. Studies on older bilingual adults show stronger FC in language and frontoparietal networks and preserved FC in posterior brain regions, which can protect the brain against cognitive decline and neurodegenerative processes. Altered RSFC in language and control networks subsequent to L2 training programs also is associated with improved global cognition in older adults. This review ends with a brief discussion of potential confounding factors in bilingualism research and conclusions and suggestions for future research.

中文翻译：

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成人、老龄化和阿尔茨海默病的双语体验和内在功能连接

过去十年标志着在双语研究中使用静息状态功能连接 (RSFC) 成像的开始。本文旨在回顾 RSFC 在成年、衰老和早期阿尔茨海默病期间双语者语言和认知控制网络变化的最新证据，这可以增加我们对第二语言 (L2) 习得背景下大脑功能重塑的理解. 由于双语体验的高度可变性，最近的研究主要集中在双语体验的主要方面（习得年龄（AoA）、语言能力和语言使用）对内在功能连接（FC）的作用。现有的证据说明在语言和控制网络中同时而非顺序双语的 FC 更强，以及语言熟练程度和使用对 AoA 影响的调节。对双语老年人的研究表明，语言和额顶叶网络中的 FC 更强，大脑后部区域的 FC 保留，这可以保护大脑免受认知衰退和神经退行性过程的影响。L2 培训计划后语言和控制网络中的 RSFC 改变也与老年人的全球认知改善有关。本综述最后简要讨论了双语研究中潜在的混杂因素以及对未来研究的结论和建议。L2 培训计划后语言和控制网络中的 RSFC 改变也与老年人的全球认知改善有关。本综述最后简要讨论了双语研究中潜在的混杂因素以及对未来研究的结论和建议。L2 培训计划后语言和控制网络中的 RSFC 改变也与老年人的全球认知改善有关。本综述最后简要讨论了双语研究中潜在的混杂因素以及对未来研究的结论和建议。