Pinal Diego, Zurrón Montserrat, Díaz Fernando, Sauseng Paul
Department of Clinical Psychology and Psychobiology, Universidade de Santiago de Compostela, Santiago de Compostela, Galiza, Spain; Department of Psychology, University of Surrey, Guildford, United Kingdom.
Department of Clinical Psychology and Psychobiology, Universidade de Santiago de Compostela, Santiago de Compostela, Galiza, Spain.
Neurobiol Aging. 2015 Apr;36(4):1611-1618. doi: 10.1016/j.neurobiolaging.2015.01.009. Epub 2015 Jan 16.
Aging-related decline in short-term memory capacity seems to be caused by deficient balancing of task-related and resting state brain networks activity; however, the exact neural mechanism underlying this deficit remains elusive. Here, we studied brain oscillatory activity in healthy young and old adults during visual information maintenance in a delayed match-to-sample task. Particular emphasis was on long range phase:amplitude coupling of frontal alpha (8-12 Hz) and posterior fast oscillatory activity (>30 Hz). It is argued that through posterior fast oscillatory activity nesting into the excitatory or the inhibitory phase of frontal alpha wave, long-range networks can be efficiently coupled or decoupled, respectively. On the basis of this mechanism, we show that healthy, elderly participants exhibit a lack of synchronization in task-relevant networks while maintaining synchronized regions of the resting state network. Lacking disconnection of this resting state network is predictive of aging-related short-term memory decline. These results support the idea of inefficient orchestration of competing brain networks in the aging human brain and identify the neural mechanism responsible for this control breakdown.
与衰老相关的短期记忆能力下降似乎是由任务相关脑网络和静息态脑网络活动的平衡不足所致；然而，这种缺陷背后的确切神经机制仍不清楚。在此，我们研究了健康年轻人和老年人在延迟样本匹配任务中视觉信息维持期间的脑振荡活动。特别关注的是额叶α波（8 - 12赫兹）与后部快速振荡活动（>30赫兹）的长程相位：振幅耦合。有人认为，通过后部快速振荡活动嵌套到额叶α波的兴奋或抑制相位中，长程网络可分别有效地耦合或解耦。基于这一机制，我们发现健康的老年参与者在维持静息态网络同步区域的同时，任务相关网络缺乏同步。这种静息态网络缺乏断开与衰老相关的短期记忆衰退具有预测性。这些结果支持了衰老人类大脑中竞争性脑网络协调效率低下的观点，并确定了导致这种控制失灵的神经机制。
