Background

While numerous studies have examined the developmental trajectory of task-based neural oscillations during childhood and adolescence, far less is known about the evolution of spontaneous cortical activity during this time period. Likewise, many studies have shown robust sex differences in task-based oscillations during this developmental period, but whether such sex differences extend to spontaneous activity is not understood.

Methods

Herein, we examined spontaneous cortical activity in 111 typically-developing youth (ages 9–15 years; 55 male). Participants completed a resting state magnetoencephalographic (MEG) recording and a structural MRI. MEG data were source imaged and the power within five canonical frequency bands (delta, theta, alpha, beta, gamma) was computed. The resulting power spectral density maps were analyzed via vertex-wise ANCOVAs to identify spatially-specific effects of age, sex, and their interaction.

Results

We found robust increases in power with age in all frequencies except delta, which decreased over time, with findings largely confined to frontal cortices. Sex effects were distributed across frontal and temporal regions; females tended to have greater delta and beta power, whereas males had greater alpha. Importantly, there was a significant age-by-sex interaction in theta power, such that males exhibited decreasing power with age while females showed increasing power with age in the bilateral superior temporal cortices.

Discussion

These data suggest that the strength of spontaneous activity undergoes robust change during the transition from childhood to adolescence (i.e., puberty onset), with intriguing sex differences in some cortical areas. Future developmental studies should probe task-related oscillations and spontaneous activity in parallel.

中文翻译：

---

在向青春期过渡期间，自发皮质 MEG 活性经历了独特的与年龄和性别相关的变化

 背景

虽然大量研究已经研究了童年和青春期基于任务的神经振荡的发展轨迹，但人们对这一时期自发皮质活动的演变知之甚少。同样，许多研究表明，在这个发育时期，基于任务的振荡存在巨大的性别差异，但这种性别差异是否延伸到自发活动尚不清楚。

 方法

在此，我们检查了 111 名发育正常的青少年（9-15 岁；55 名男性）的自发皮质活动。参与者完成了静息态脑磁图 (MEG) 记录和结构 MRI。 MEG 数据进行源成像，并计算五个标准频段（δ、θ、α、β、γ）内的功率。通过逐点ANCOVA分析所得的功率谱密度图，以识别年龄、性别及其相互作用的空间特定影响。

 结果

我们发现，除了 delta 之外，所有频率的功率都随着年龄的增长而强劲增加，而 delta 则随着时间的推移而下降，研究结果主要局限于额叶皮层。性别效应分布在额叶和颞区；女性往往具有更大的δ和β功率，而男性则具有更大的α功率。重要的是，不同性别的θ功率存在显着的相互作用，男性的双侧上颞叶皮层的θ功率随着年龄的增长而降低，而女性的θ功率则随着年龄的增长而增加。

 讨论

这些数据表明，在从童年到青春期（即青春期开始）的过渡过程中，自发活动的强度经历了剧烈的变化，并且某些皮质区域存在有趣的性别差异。未来的发展研究应该同时探讨与任务相关的振荡和自发活动。