Abstract A growing body of research shows that the brain adapts functionally and structurally to specific bilingual experiences. These brain adaptations seem related to modulations in cognitive processes (specifically the executive functions). However, the trajectory of these adaptations is varied and seems at least partially dependent on different aspects of language exposure and use. Here we provide a review of the existing theoretical models covering bilingualism-induced neuroplasticity. Moreover, we propose a unifying framework (Unifying the Bilingual Experience Trajectories, UBET) to more comprehensively map the relationship between the various neurocognitive adaptations and different aspects of bilingual experience trajectories, focusing on intensity and diversity of language use, language switching, relative proficiency, and duration of bilingual experience. Crucially, we also outline predictions regarding both relationships between different bilingual experience factors and relationships between the measurable neurocognitive adaptations. Our framework offers a theoretical backdrop and clear testable predictions for future large-scale empirical studies on individual differences in bilingual trajectories and their effects on neurocognitive adaptations.

中文翻译：

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了解双语大脑功能和结构变化？你打赌！统一的双语体验轨迹模型

摘要 越来越多的研究表明，大脑会在功能和结构上适应特定的双语体验。这些大脑适应似乎与认知过程（特别是执行功能）的调节有关。然而，这些适应的轨迹各不相同，似乎至少部分取决于语言接触和使用的不同方面。在这里，我们对涵盖双语诱导的神经可塑性的现有理论模型进行了回顾。此外，我们提出了一个统一框架（Unifying the Bilingual Experience Trajectories，UBET）来更全面地映射各种神经认知适应和双语体验轨迹不同方面之间的关系，重点关注语言使用的强度和多样性、语言转换、相对熟练程度、和双语经验的持续时间。至关重要的是，我们还概述了关于不同双语体验因素之间的关系以及可测量的神经认知适应之间的关系的预测。我们的框架为未来关于双语轨迹的个体差异及其对神经认知适应的影响的大规模实证研究提供了理论背景和明确的可测试预测。