Amplitude modulations and inter-trial phase stability of alpha-oscillations differentially reflect working memory constraints across the lifespan
Amplitude modulations and inter-trial phase stability of alpha-oscillations differentially reflect working memory constraints across the lifespan
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DOI：
10.1016/j.neuroimage.2011.06.092
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发表时间：
2012-01-02
期刊：
影响因子：
5.7
通讯作者：
Lindenberger, Ulman
中科院分区：
文献类型：
--
作者：
Sander, Myriam C.;Werkle-Bergner, Markus;Lindenberger, Ulman
工作记忆（WM）的容量在整个童年时期增加，在年轻的成年期达到顶峰，之后下降。发展和衰老理论表明，儿童和老年人的抑制控制过程不足可能是相对于年轻人表现较低的原因。最近，脑电图（EEG）的振荡α功率（7-13 Hz）已经被认为是有助于WM表现的抑制过程的神经标记（Sauseng等人，2009年）。我们研究了20名儿童（10-13岁），12名年轻人（20-26岁）和20名老年人（70-76岁）的线索变化检测范式。在行为上，我们观察到年轻人的预期寿命峰值。与儿童和年轻人相比，老年人的EEG α功率普遍降低。与以前的研究一致，在保持间隔期间，与注意力和WM过程相关的α功率的半球差异随着年轻人的负荷而增加。在儿童和老年人中，偏侧α功率从低到中等负荷条件下增加，但在高负荷条件下下降。此外，与儿童和年轻人相比，老年人在刺激开始后不久表现出更高的试验间相位稳定性。我们的研究结果表明，抑制性控制过程的索引本地α功率调制可以在儿童和老年人中观察到，但似乎打破WM负荷高时。此外，老年人更容易受到外部刺激的影响，这可能会增加后期处理过程中对抑制控制的需求。我们的结论是，在抑制控制过程和信息摄取的差异，反映在振幅调制和试验间的相位稳定性的α节律的交互式确定WM的限制在整个生命周期。(C)2011 Elsevier Inc. All rights reserved.
Working memory (WM) capacity increases across childhood, peaks in young adulthood, and declines thereafter. Developmental and aging theories suggest that deficient inhibitory control processes in children and older adults may underlie the lower performance relative to younger adults. Recently, oscillatory alpha power (7-13 Hz) of the electroencephalogram (EEG) has been suggested as a neural marker of inhibition processes contributing to WM performance (Sauseng et al., 2009). We examined 20 children (10-13 years), 12 younger adults (20-26 years), and 20 older adults (70-76 years) in a cued change-detection paradigm. Behaviorally, we observed the expected lifespan peak in younger adults. EEG alpha power was generally reduced in older adults compared to children and younger adults. In line with previous research, hemispheric differences in alpha power related to attention and WM processes during the retention interval increased with load in younger adults. In children and older adults, lateralized alpha power increased from low to medium load conditions, but decreased for high load conditions. Furthermore, older adults showed higher inter-trial phase stability shortly after stimulus onset compared to children and younger adults. Our results show that inhibitory control processes as indexed by local alpha power modulations can be observed in children and older adults but seem to break down when WM load is high. In addition, older adults are more entrained by external stimulation what may increase a need for inhibitory control during later processing. We conclude that differences in inhibitory control processes and information uptake as reflected in amplitude modulations and inter-trial phase stability of alpha rhythms interactively determine WM constraints across the lifespan. (C) 2011 Elsevier Inc. All rights reserved.