Data_Sheet_1_Spontaneous Alpha and Theta Oscillations Are Related to Complementary Aspects of Cognitive Control in Younger and Older Adults.DOCX

The resting-state human electroencephalogram (EEG) power spectrum is dominated by alpha (8–12 Hz) and theta (4–8 Hz) oscillations, and also includes non-oscillatory broadband activity inversely related to frequency (1/f activity). Gratton proposed that alpha and theta oscillations are both related to cognitive control function, though in a complementary manner. Alpha activity is hypothesized to facilitate the maintenance of representations, such as task sets in preparation for expected task conditions. In contrast, theta activity would facilitate changes in representations, such as the updating of task sets in response to unpredicted task demands. Therefore, theta should be related to reactive control (which may prompt changes in task representations), while alpha may be more relevant to proactive control (which implies the maintenance of current task representations). Less is known about the possible relationship between 1/f activity and cognitive control, which was analyzed here in an exploratory fashion. To investigate these hypothesized relationships, we recorded eyes-open and eyes-closed resting-state EEG from younger and older adults and subsequently tested their performance on a cued flanker task, expected to elicit both proactive and reactive control processes. Results showed that alpha power and 1/f offset were smaller in older than younger adults, whereas theta power did not show age-related reductions. Resting alpha power and 1/f offset were associated with proactive control processes, whereas theta power was related to reactive control as measured by the cued flanker task. All associations were present over and above the effect of age, suggesting that these resting-state EEG correlates could be indicative of trait-like individual differences in cognitive control performance, which may be already evident in younger adults, and are still similarly present in healthy older adults.

静息态人类脑电图（EEG）的功率谱主要由阿尔法（8-12赫兹）和theta（4-8赫兹）振荡组成，并包含与频率成反比的非振荡宽带活动（1/f活动）。Gratton提出，阿尔法和theta振荡均与认知控制功能相关，但以互补的方式存在。阿尔法活动被假定为促进表征的维持，例如为预期任务条件准备的任务集。相比之下，theta活动则有助于表征的变化，如响应不可预测任务需求的任务集更新。因此，theta应与反应性控制（可能导致任务表征的变化）相关，而alpha可能更与前瞻性控制（暗示当前任务表征的维持）相关。关于1/f活动与认知控制之间可能存在的关系所知甚少，本文对此进行了探索性分析。为了探究这些假设关系，我们记录了年轻和老年成人的睁眼和闭眼静息态EEG，随后测试了他们在提示边缘任务上的表现，该任务预计会激发前瞻性和反应性控制过程。结果显示，与年轻人相比，老年人的alpha功率和1/f偏移较小，而theta功率没有显示出与年龄相关的减少。静息态alpha功率和1/f偏移与前瞻性控制过程相关，而theta功率与通过提示边缘任务测量的反应性控制相关。所有这些关联均超越了年龄效应，表明这些静息态EEG相关指标可能预示着认知控制表现上的特质性个体差异，这些差异可能在年轻成人中就已显现，并在健康老年成人中仍然存在。