Significance: Early monolingual versus bilingual experience induces adaptations in the development of linguistic and cognitive processes, and it modulates functional activation patterns during the first months of life. Resting-state functional connectivity (RSFC) is a convenient approach to study the functional organization of the infant brain. RSFC can be measured in infants during natural sleep, and it allows to simultaneously investigate various functional systems. Adaptations have been observed in RSFC due to a lifelong bilingual experience. Investigating whether bilingualism-induced adaptations in RSFC begin to emerge early in development has important implications for our understanding of how the infant brain’s organization can be shaped by early environmental factors. Aims: We attempt to describe RSFC using functional near-infrared spectroscopy (fNIRS) and to examine whether it adapts to early monolingual versus bilingual environments. We also present an fNIRS data preprocessing and analysis pipeline that can be used to reliably characterize RSFC in development and to reduce false positives and flawed results interpretations. Methods: We measured spontaneous hemodynamic brain activity in a large cohort (N = 99) of 4-month-old monolingual and bilingual infants using fNIRS. We implemented group-level approaches based on independent component analysis to examine RSFC, while providing proper control for physiological confounds and multiple comparisons. Results: At the group level, we describe the functional organization of the 4-month-old infant brain in large-scale cortical networks. Unbiased group-level comparisons revealed no differences in RSFC between monolingual and bilingual infants at this age. Conclusions: High-quality fNIRS data provide a means to reliably describe RSFC patterns in the infant brain. The proposed group-level RSFC analyses allow to assess differences in RSFC across experimental conditions. An effect of early bilingual experience in RSFC was not observed, suggesting that adaptations might only emerge during explicit linguistic tasks, or at a later point in development.

中文翻译：

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使用 fNIRS 的组级皮质功能连接模式：评估双语对幼儿的影响

意义：早期的单语与双语体验会诱导语言和认知过程发展的适应，并在生命的最初几个月调节功能激活模式。静息状态功能连接 (RSFC) 是研究婴儿大脑功能组织的便捷方法。RSFC 可以在婴儿自然睡眠期间测量，它允许同时研究各种功能系统。由于终身双语经验，在 RSFC 中观察到了适应。研究双语诱导的 RSFC 适应性是否在发育早期开始出现，对于我们理解早期环境因素如何塑造婴儿大脑的组织具有重要意义。目标：我们尝试使用功能近红外光谱 (fNIRS) 来描述 RSFC，并检查它是否适应早期的单语与双语环境。我们还提供了一个 fNIRS 数据预处理和分析管道，可用于可靠地表征开发中的 RSFC，并减少误报和有缺陷的结果解释。方法：我们使用 fNIRS 测量了 4 个月大的单语和双语婴儿的大型队列（N = 99）的自发血流动力学脑活动。我们实施了基于独立成分分析的组级方法来检查 RSFC，同时为生理混淆和多重比较提供适当的控制。结果：在小组层面，我们描述了 4 个月大婴儿大脑在大规模皮质网络中的功能组织。无偏见的组级比较显示，在这个年龄段，单语和双语婴儿的 RSFC 没有差异。结论：高质量的 fNIRS 数据提供了一种可靠描述婴儿大脑中 RSFC 模式的方法。建议的组级 RSFC 分析允许评估不同实验条件下 RSFC 的差异。在 RSFC 中没有观察到早期双语经验的影响，这表明适应性可能只出现在明确的语言任务中，或者在发展的后期。