Barry Robert J, Clarke Adam R, Johnstone Stuart J, Brown Christopher R
Brain & Behaviour Research Institute and School of Psychology, University of Wollongong, Wollongong 2522, Australia.
Clin Neurophysiol. 2009 Oct;120(10):1806-11. doi: 10.1016/j.clinph.2009.08.006. Epub 2009 Sep 12.
Recent work on arousal vs. activation in adults showed that skin conductance levels (SCLs) increased, and global alpha levels decreased, from eyes-closed to eyes-open resting baseline conditions. This study explored whether similar effects occur in children.
EEG activity was recorded from 30 children aged 8-12 years during counterbalanced eyes-closed and eyes-open resting conditions; SCL was measured as an index of arousal.
SCLs were negatively correlated with mean alpha levels in the eyes-closed condition, and increased significantly from eyes-closed to eyes-open. Reductions were found in across-scalp mean absolute delta, theta, alpha, and beta from eyes-closed to eyes-open. Topographic changes were evident in all bands except alpha.
Results confirm the use of mean alpha level as a measure of resting-state arousal under eyes-closed and eyes-open conditions. Focal changes in the other bands suggest that these reflect differences in activation, rather than the simple increase in arousal shown in alpha.
This child study confirms the generality of eyes-closed vs. eyes-open non-alpha EEG measures differing in mean power levels and topography, the latter indicating brain activity related to visual processing. Such differences should be considered when evaluating EEG research, and in choosing baseline conditions for different paradigms.
近期关于成人觉醒与激活的研究表明,从闭眼静息基线状态到睁眼静息基线状态,皮肤电导水平(SCLs)升高,而全局阿尔法水平降低。本研究探讨了儿童是否会出现类似效应。
在平衡的闭眼和睁眼静息状态下,记录了30名8至12岁儿童的脑电图活动;测量SCL作为觉醒指标。
在闭眼状态下,SCL与平均阿尔法水平呈负相关,并且从闭眼到睁眼显著增加。从闭眼到睁眼,全头皮平均绝对德尔塔、西塔、阿尔法和贝塔波均有所降低。除阿尔法波外,所有频段均出现明显的地形变化。
结果证实了平均阿尔法水平可作为闭眼和睁眼条件下静息态觉醒的指标。其他频段的局灶性变化表明,这些反映的是激活差异,而非阿尔法波所显示的单纯觉醒增加。
这项儿童研究证实了闭眼与睁眼非阿尔法脑电图测量在平均功率水平和地形上存在差异具有普遍性,后者表明与视觉处理相关的大脑活动。在评估脑电图研究以及为不同范式选择基线条件时,应考虑这些差异。