Department of Psychology, Stanford University, Stanford, CA, USA.
Department of Psychology, Stanford University, Stanford, CA, USA.
Dev Cogn Neurosci. 2018 Apr;30:41-50. doi: 10.1016/j.dcn.2017.12.005. Epub 2017 Dec 18.
Children from lower-SES families exhibit smaller hippocampal volume than do their higher-SES peers. Few studies, however, have compared hippocampal developmental trajectories as a function of SES. Thus, it is unclear whether initial rank-order stability is preserved, or whether volumes diverge/converge over the course of adolescence. In a sample of 101 girls ages 10-24 years, we examined the longitudinal association between family income and parental education, proxies for SES, and changes in hippocampal volume. Hippocampal volume was obtained using MRI; using mixed modeling, we examined the effects of income and education on hippocampal volume across age. As expected, changes in volume were non-linear across development. Further, trajectories diverged in mid-adolescence, with lower-income girls exhibiting reductions in hippocampal volume. Maximal income-related differences were observed at 18 years, and trajectories converged thereafter. This interaction remained significant when accounting for maternal hippocampal volume, suggesting a unique contribution of environment over potential heritable differences. In contrast, the association between parental education and offspring hippocampal volume appeared to be stable across adolescence, with higher levels of parental education predicting consistently larger hippocampal volume. These findings constitute preliminary evidence that girls from lower-income homes exhibit unique trajectories of hippocampal growth, with differences most evident in late adolescence.
来自社会经济地位较低家庭的儿童的海马体体积比社会经济地位较高家庭的儿童小。然而，很少有研究将海马体发育轨迹作为社会经济地位的函数进行比较。因此，目前尚不清楚初始等级是否保持稳定，或者在青春期过程中体积是否会发散/收敛。在 101 名年龄在 10 至 24 岁的女孩中，我们研究了家庭收入和父母教育，即社会经济地位的代表，与海马体体积变化之间的纵向关联。使用 MRI 获得海马体体积；使用混合建模，我们研究了收入和教育对整个年龄过程中海马体体积的影响。正如预期的那样，体积变化在整个发育过程中是非线性的。此外，在青春期中期轨迹出现分歧，低收入女孩的海马体体积减少。在 18 岁时观察到最大的与收入相关的差异，此后轨迹趋同。当考虑到母亲的海马体体积时，这种相互作用仍然具有统计学意义，这表明环境对潜在遗传差异有独特的贡献。相比之下，父母教育与后代海马体体积之间的关联似乎在整个青春期都保持稳定，较高的父母教育水平预测了更大的海马体体积。这些发现初步证明，来自低收入家庭的女孩表现出独特的海马体生长轨迹，差异在青春期后期最为明显。
