School of Psychology, University of East Anglia, Norwich NR4 7TJ, United Kingdom.
Department of Psychology, Concordia University, Montreal, Quebec H4B 1R6, Canada.
J Neurosci. 2023 Jun 7;43(23):4279-4290. doi: 10.1523/JNEUROSCI.1034-22.2023. Epub 2023 May 15.
The language environment to which children are exposed has an impact on later language abilities as well as on brain development; however, it is unclear how early such impacts emerge. This study investigates the effects of children's early language environment and socioeconomic status (SES) on brain structure in infancy at 6 and 30 months of age (both sexes included). We used magnetic resonance imaging to quantify concentrations of myelin in specific fiber tracts in the brain. Our central question was whether Language Environment Analysis (LENA) measures from in-home recording devices and SES measures of maternal education predicted myelin concentrations over the course of development. Results indicate that 30-month-old children exposed to larger amounts of in-home adult input showed more myelination in the white matter tracts most associated with language. Right hemisphere regions also show an association with SES, with older children from more highly educated mothers and exposed to more adult input, showing greater myelin concentrations in language-related areas. We discuss these results in relation to the current literature and implications for future research. This is the first study to look at how brain myelination is impacted by language input and socioeconomic status early in development. We find robust relationships of both factors in language-related brain areas at 30 months of age.
儿童所处的语言环境对其日后的语言能力和大脑发育都有影响；然而，目前尚不清楚这些影响会在何时出现。本研究调查了儿童早期语言环境和社会经济地位（SES）对 6 个月和 30 个月大婴儿大脑结构的影响（包括男女）。我们使用磁共振成像技术来量化大脑中特定纤维束内髓鞘的浓度。我们的核心问题是，来自家庭录音设备的语言环境分析（LENA）测量值和母亲教育程度的 SES 测量值是否可以预测髓鞘浓度在整个发育过程中的变化。结果表明，在家庭环境中接受更多成人输入的 30 个月大的儿童，其与语言最相关的白质束中的髓鞘含量更高。右半球区域也与 SES 有关，来自受教育程度较高的母亲的年长儿童，在家庭环境中接受更多的成人输入，其与语言相关区域的髓鞘浓度更高。我们结合现有文献讨论了这些结果，并对未来的研究提出了建议。这是第一项研究，旨在探讨语言输入和社会经济地位如何在儿童发育早期影响大脑髓鞘形成。我们发现，这两个因素与 30 个月大婴儿的语言相关脑区之间存在很强的相关性。
