Institute for Disorders of Impulse & Attention, Developmental Brain-Behaviour Laboratory, School of Psychology, University of Southampton, UK.
Brain Res. 2013 Aug 2;1524:34-43. doi: 10.1016/j.brainres.2013.05.043. Epub 2013 May 31.
The default mode network (DMN) is characterised by coherent very low frequency (VLF) neural oscillations in the resting brain. The attenuation of this activity has been demonstrated following the transition from rest to performance of a broad range of cognitive goal-directed tasks. Whether the activity of resting state VLF oscillations is attenuated during non-cognitive goal-directed tasks such as waiting for rewarding outcomes is not known. This study examined the VLF EEG power from resting to performance of attention demanding task and two types of goal-directed waiting tasks. The association between the attenuation of VLF EEG power and Attention-Deficit/Hyperactivity Disorder (ADHD) symptoms was examined. Direct current EEG (DC-EEG) data were collected from 32 healthy young adults (half high and half low ADHD symptom scorers) during (i) a rest state, (ii) while performing a cognitive demanding reaction time task (2CRT), and (iii) while undertaking each of two different goal-directed waiting conditions: "forced-to-wait (FW)" and "choose-to-wait (CW)" tasks. The spatial distribution of VLF EEG power across scalp was similar to that seen in previous resting VLF EEG studies. Significant rest-to-task attenuation of VLF EEG power occurred during the 2CRT and the CW task, but not during the FW task. The association between self-ratings of ADHD symptoms and waiting-induced attenuation was not significant. This study suggests VLF EEG power attenuation that occurs following rest-to-task transition is not simply determined by changes in cognitive load. The goal-directed nature of a task, its motivated nature and/or the involvement of effortful attention may also contribute. Future studies should explore the attenuation of resting state VLF oscillations during waiting and impulsive choice.
静息态默认模式网络(DMN)的特征是大脑在静息状态下呈现出相干的极低频率(VLF)神经振荡。这种活动在从静息状态过渡到执行广泛的认知目标导向任务时会被抑制。在非认知目标导向任务(如等待奖励结果)中,静息状态 VLF 振荡的活动是否会被抑制尚不清楚。本研究通过注意力需求任务和两种类型的目标导向等待任务来检测静息状态 VLF EEG 功率的变化。研究还考察了 VLF EEG 功率衰减与注意缺陷多动障碍(ADHD)症状之间的关联。本研究从 32 名健康的年轻成年人(一半为 ADHD 症状高分者,一半为 ADHD 症状低分者)中采集了直流 EEG(DC-EEG)数据,这些参与者分别在(i)静息状态、(ii)执行认知需求反应时间任务(2CRT)时、(iii)执行两种不同的目标导向等待任务时(“强制等待”(FW)和“选择等待”(CW)任务):“强制等待”(FW)和“选择等待”(CW)任务。头皮上 VLF EEG 功率的空间分布与之前的静息 VLF EEG 研究相似。在 2CRT 和 CW 任务中,静息状态到任务状态的 VLF EEG 功率显著衰减,但在 FW 任务中没有出现这种情况。自我评定的 ADHD 症状与等待引起的衰减之间的关联并不显著。本研究表明,静息状态到任务状态过渡时 VLF EEG 功率的衰减不仅仅取决于认知负荷的变化。任务的目标导向性质、其动机性质和/或努力注意力的参与也可能有贡献。未来的研究应该探索等待和冲动选择期间静息状态 VLF 振荡的衰减。