Department of Psychology, University of Zurich, Methods of Plasticity Research, Zurich, Switzerland.
University Research Priority Program (URPP) Dynamic of Healthy Aging, Zurich, Switzerland.
Elife. 2022 Aug 25;11:e77571. doi: 10.7554/eLife.77571.
Childhood and adolescence are critical stages of the human lifespan, in which fundamental neural reorganizational processes take place. A substantial body of literature investigated accompanying neurophysiological changes, focusing on the most dominant feature of the human EEG signal: the alpha oscillation. Recent developments in EEG signal-processing show that conventional measures of alpha power are confounded by various factors and need to be decomposed into periodic and aperiodic components, which represent distinct underlying brain mechanisms. It is therefore unclear how each part of the signal changes during brain maturation. Using multivariate Bayesian generalized linear models, we examined aperiodic and periodic parameters of alpha activity in the largest openly available pediatric dataset (N=2529, age 5-22 years) and replicated these findings in a preregistered analysis of an independent validation sample (N=369, age 6-22 years). First, the welldocumented age-related decrease in total alpha power was replicated. However, when controlling for the aperiodic signal component, our findings provided strong evidence for an age-related increase in the aperiodic-adjusted alpha power. As reported in previous studies, also relative alpha power revealed a maturational increase, yet indicating an underestimation of the underlying relationship between periodic alpha power and brain maturation. The aperiodic intercept and slope decreased with increasing age and were highly correlated with total alpha power. Consequently, earlier interpretations on age-related changes of total alpha power need to be reconsidered, as elimination of active synapses rather links to decreases in the aperiodic intercept. Instead, analyses of diffusion tensor imaging data indicate that the maturational increase in aperiodic-adjusted alpha power is related to increased thalamocortical connectivity. Functionally, our results suggest that increased thalamic control of cortical alpha power is linked to improved attentional performance during brain maturation.
儿童期和青春期是人类生命周期的关键阶段，在此期间会发生基本的神经重组过程。大量文献研究了伴随而来的神经生理变化，重点关注人类脑电图信号的最主要特征：alpha 振荡。脑电图信号处理的最新发展表明，alpha 功率的传统测量方法受到各种因素的干扰，需要分解为周期性和非周期性成分，这代表了不同的潜在大脑机制。因此，不清楚信号的每个部分在大脑成熟过程中如何变化。使用多元贝叶斯广义线性模型，我们在最大的公开儿科数据集（N=2529，年龄 5-22 岁）中检查了 alpha 活动的非周期性和周期性参数，并在独立验证样本（N=369，年龄 6-22 岁）的预注册分析中复制了这些发现。首先，复制了与年龄相关的总 alpha 功率下降。然而，当控制非周期性信号成分时，我们的发现为与年龄相关的非周期性调整后的 alpha 功率增加提供了强有力的证据。如先前研究报告的那样，相对 alpha 功率也显示出成熟度的增加，但表明周期性 alpha 功率与大脑成熟之间的潜在关系被低估了。非周期性截距和斜率随年龄增加而降低，与总 alpha 功率高度相关。因此，需要重新考虑关于总 alpha 功率与年龄相关变化的早期解释，因为主动突触的消除与非周期性截距的降低有关。相反，扩散张量成像数据分析表明，非周期性调整后的 alpha 功率的成熟度增加与丘脑皮质连接增加有关。从功能上讲，我们的结果表明，丘脑对皮质 alpha 功率的控制增加与大脑成熟过程中注意力表现的提高有关。
