ABSTRACT

Recent findings suggest that electroencephalography (EEG) oscillations in the theta and alpha frequency-bands reflect synchronized interregional neuronal activity and are considered to reflect cognitive-control, and executive working memory mechanisms in humans. Above the age of 50 years, hypothesized pronounced alterations in alpha and theta-band power at resting or across different WM-functioning brain states may well be due to pre-dementia cognitive impairments, or increasing severity of age-related neurological disorders. Executive working memory (EWM) functioning was assessed in older-adult participants (54 to 83 years old) by obtaining their WM-related EEG oscillations and WM performance scores. WM performance and WM brain-state EEG were recorded during online-WM periods as well as during specific online WM events within EWM periods, and during resting offline-WM periods that preceded online-WM periods. Left-prefrontal alpha-power was enhanced during offline-WM periods versus online-WM periods and was significantly related to WM accuracy. Left-prefrontal alpha power and left prefrontal-parietal theta power anterior-posterior difference-gradient during online WM activity were related to reaction times (RT’s). Importantly, during active-storage events, WM-offset offline-periods, and preparatory pre-retrieval events, excessive left-prefrontal alpha activity was related to poor EWM performance. The potential for developing targeted noninvasive cognition-enhancing interventions and developing clinical-monitoring EEG-based biomarkers of pathological cognitive-decline in elderly people is discussed.

摘要

最近的研究结果表明，theta 和 alpha 频带中的脑电图 (EEG) 振荡反映了同步的区域间神经元活动，并被认为反映了人类的认知控制和执行工作记忆机制。在 50 岁以上，假设在休息时或在不同 WM 功能大脑状态下 α 和 θ 波段功率的显着变化很可能是由于痴呆前的认知障碍，或与年龄相关的神经系统疾病的严重程度增加。通过获得与 WM 相关的脑电图振荡和 WM 性能分数，评估老年参与者（54 至 83 岁）的执行工作记忆 (EWM) 功能。在在线 WM 期间以及在 EWM 期间的特定在线 WM 事件期间记录 WM 性能和 WM 脑状态 EEG，在线 WM周期之前的离线 WM 周期。与在线 WM 期间相比，离线 WM 期间左前额叶 α 功率增强，并且与 WM 准确性显着相关。在线 WM 活动期间的左前额 α 功率和左前额顶叶 θ 功率前后差梯度与反应时间 (RT) 相关。重要的是，在主动存储事件、WM 偏移离线期间和准备前检索事件期间，过度的左前额叶 alpha 活动与较差的 EWM 性能有关。讨论了开发有针对性的非侵入性认知增强干预措施和开发基于临床监测脑电图的老年人病理性认知衰退生物标志物的潜力。