Age-related changes in tissue signal properties within cortical areas important for word understanding in 12- to 19-month-old infants.
Age-related changes in tissue signal properties within cortical areas important for word understanding in 12- to 19-month-old infants.
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皮质区域组织信号特性与年龄相关的变化对于 12 至 19 个月大婴儿的单词理解很重要。
DOI：
10.1093/cercor/bht052
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Halgren,Eric
中科院分区：
文献类型：
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作者：
Travis,KatherineE;Curran,MeganM;Torres,Christina;Leonard,MatthewK;Brown,TimothyT;Dale,AndersM;Elman,JeffreyL;Halgren,Eric
最近，我们的实验室已经表明，成年人编码词汇语义信息的神经机制在12-18个月大时在左额颞叶皮质内功能性地运作（Travis等人，2011. 12- 18个月婴儿词汇理解的时空神经动力学。大脑皮层8：1832-1839）。然而，对这些和其他对语言发展很重要的皮质区域内发生的结构变化知之甚少。为了确定在婴儿发育的这一重要时期发生的区域结构变化，我们检查了灰质（GM）和白色物质（WM）强度和对比度的组织信号特性的年龄相关变化。在双侧下外侧和前腹颞区、背内侧额叶和上级顶叶皮质内，观察到GM和WM强度和对比度的显著年龄效应。感兴趣区域（ROI）分析显示，GM和WM的强度和对比度显着增加，随着年龄的增长，在相同的左侧颞叶区域内，在婴儿和成人产生词汇语义活动。这些发现表明，支持语言和认知行为的神经生理过程可能在联合皮层内的细胞和结构成熟之前发展。这些结果对于理解脑结构与功能发育的神经生物学机制具有重要意义。
Recently, our laboratory has shown that the neural mechanisms for encoding lexico-semantic information in adults operate functionally by 12–18 months of age within left frontotemporal cortices (Travis et al., 2011. Spatiotemporal neural dynamics of word understanding in 12- to 18-month-old-infants. Cereb Cortex. 8:1832–1839). However, there is minimal knowledge of the structural changes that occur within these and other cortical regions important for language development. To identify regional structural changes taking place during this important period in infant development, we examined age-related changes in tissue signal properties of gray matter (GM) and white matter (WM) intensity and contrast.T1-weighted surface-based measures were acquired from 12- to 19-month-old infants and analyzed using a general linear model. Significant age effects were observed for GM and WM intensity and contrast within bilateral inferior lateral and anterovental temporal regions, dorsomedial frontal, and superior parietal cortices. Region of interest (ROI) analyses revealed that GM and WM intensity and contrast significantly increased with age within the same left lateral temporal regions shown to generate lexico-semantic activity in infants and adults. These findings suggest that neurophysiological processes supporting linguistic and cognitive behaviors may develop before cellular and structural maturation is complete within associative cortices. These results have important implications for understanding the neurobiological mechanisms relating structural to functional brain development.