Early life stress and socioeconomic variation as determinants of language-related neurodevelopment

早期生活压力和社会经济变化是语言相关神经发育的决定因素

• 批准号: RGPIN-2021-03643
• 负责人: Pierce, Lara
• 金额: $ 2.89万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742657
• 关键词: Early; life; stress; socioeconomic; variation

Early language experience shapes neural systems that support the development of increasingly complex language abilities, allowing children to adapt to their unique environments (e.g., Werker & Hensch, 2015). Yet, how early variation (e.g., in timing, quality, and quantity of input) influences the development of these neural systems, and implications for long-term language outcomes, are not well understood (Pierce et al., 2017a,b). Systematic comparisons between groups with known differences in the early language environment (e.g., bilingual, monolingual, international adoptees; Pierce et al., 2014; 2015) have been used to test pathways between early environmental variation and language outcomes via neurodevelopmental change (Pierce et al., 2017a,b). However for many children, systematic ways that early experiences differ have not been identified. For example, while socioeconomic status (SES) predicts children's language abilities (e.g., Hoff, 2003), sources of variability within a socioeconomically diverse context, and neurodevelopmental pathways leading to disparate language outcomes, are not well understood. Evidence from mother-infant dyads suggests that maternal stress, within a low-SES context, is associated with language behaviours and caregiver-child interactions during infancy (Pierce et al., 2020). Behaviours have also been associated with electroencephalography (EEG) patterns that a) vary as a function of stress (Pierce et al., 2019), and b) predict language outcomes (Benasich et al., 2008). Results suggest how early variation in a socioeconomically diverse context could be used to test interactions between early input and neurodevelopment, yet considerable work remains. I propose a novel multidisciplinary approach, using developmental neuroscience tools and home language recordings, to: 1) characterize sources of early variation (e.g., stress) in socioeconomically diverse contexts, 2) map early variation to specific neural processes underlying language development, and 3) test whether these neural processes mediate associations between early variation and language outcomes. I will also 4) probe individual differences (e.g., sex; physiological metrics of stress) as moderators of neurodevelopmental change, and 5) explore how language development interacts with other developing systems. Here I use our strong understanding of language development, along with dimensional frameworks for defining adversity, as tools to illuminate mechanisms of neuroplasticity (e.g., how early variation exerts long-lasting experience-dependent neural change). I make clear predictions for why specific language features might be affected by early input variation, and how these impact language outcomes over time. This will broadly inform our understanding of mechanistic links between early variability and language outcomes - particularly in the critically lacking area of socioeconomic variability - and will reveal fundamental properties of brain development.

早期的语言经验塑造了支持日益复杂的语言能力发展的神经系统，使儿童能够适应他们独特的环境(例如，Werker&Hensch，2015)。然而，早期的变化(例如，输入的时间、质量和数量)如何影响这些神经系统的发展，以及对长期语言结果的影响，还没有很好地理解(皮尔斯等人，2007a，b)。已知在早期语言环境中存在差异的群体(例如，双语、单语、国际被领养人；皮尔斯等人，2014；2015)之间的系统比较被用来测试早期环境变化与语言结果之间通过神经发育变化的路径(皮尔斯等人，2007a，b)。然而，对于许多儿童来说，早期经历不同的系统方式尚未确定。例如，尽管社会经济地位(SES)可以预测儿童的语言能力(例如，Hoff，2003)，但社会经济多样化背景下的变异性来源，以及导致不同语言结果的神经发育途径，还没有被很好地理解。来自母婴二元组的证据表明，在低SES背景下，母亲的压力与婴儿期的语言行为和照顾者与孩子的互动有关(皮尔斯等人，2020年)。行为也与脑电(EEG)模式有关，这种模式a)随应激而变化(皮尔斯等人，2019年)，b)预测语言结果(Benasich等人，2008年)。结果表明，在社会经济多样化的背景下，早期变量如何被用来测试早期输入和神经发育之间的交互作用，但仍有相当多的工作要做。我提出了一种新的多学科方法，使用发展神经科学工具和家庭语言录音，以：1)表征社会经济不同背景下早期变异(例如，压力)的来源，2)将早期变异映射到语言发展的特定神经过程，以及3)测试这些神经过程是否在早期变异和语言结果之间起中介作用。我还将探索个体差异(例如，性别；压力的生理指标)作为神经发育变化的调节因素，以及5)探索语言发展如何与其他发展中的系统相互作用。在这里，我使用我们对语言发展的深刻理解，以及定义逆境的维度框架，作为解释神经可塑性机制的工具(例如，早期变化如何发挥长期的经验依赖型神经变化)。我清楚地预测了为什么特定的语言特征可能会受到早期输入变化的影响，以及随着时间的推移，这些因素将如何影响语言结果。这将广泛地让我们了解早期可变性和语言结果之间的机械联系--特别是在严重缺乏社会经济可变性的领域--并将揭示大脑发育的基本特性。