Neuper Christa, Grabner Roland H, Fink Andreas, Neubauer Aljoscha C
Institute of Psychology, University of Graz, Universitaetsplatz 2/III, A-8010 Graz, Austria.
Clin Neurophysiol. 2005 Jul;116(7):1681-94. doi: 10.1016/j.clinph.2005.03.013.
We examined whether task-related band power changes (event-related desynchronization/synchronization; ERD/ERS) that have been linked to individual differences in cognitive ability demonstrate satisfying temporal stability and cross-situational consistency.
Multi-channel EEG recordings from 29 adults, assessed at three different occasions over 2 years were examined. Between-session correlations and consistency coefficients (Cronbach's alpha) across the three experiments were evaluated for both, spectral power features of the resting EEG and ERD/ERS estimates while the participants performed some cognitive task (i.e. different elementary cognitive tasks that put comparable demands on the participants).
ERD/ERS values, while subjects performed a cognitive task, demonstrated satisfactory stability and consistency (i.e. >0.7), whereby the degree of consistency varied as a function of frequency band and brain region. Highest consistency was found for the 8-10 Hz ERD in parieto-occipital recording sites (i.e. >0.9). In resting EEG, mean alpha (gravity) frequency was the most stable EEG feature.
The present data suggest that ERD/ERS phenomena in different narrow frequency bands are rather stable over time and across different situations. The relatively high reproducibility of ERD/ERS promotes the usefulness of this measure in assessing individual differences of physiological activation patterns accompanying cognitive performance.
This study addresses the issue of reproducibility of EEG in general and ERD/ERS experiments in particular, which is a prerequisite for both basic research and clinical studies.
我们研究了与认知能力个体差异相关的任务相关频段功率变化（事件相关去同步化/同步化；ERD/ERS）是否表现出令人满意的时间稳定性和跨情境一致性。
对29名成年人在2年中的三个不同时间点进行的多通道脑电图记录进行了检查。评估了三个实验之间的会话间相关性和一致性系数（克朗巴哈系数），包括静息脑电图的频谱功率特征以及参与者执行某些认知任务（即对参与者提出类似要求的不同基本认知任务）时的ERD/ERS估计值。
当受试者执行认知任务时，ERD/ERS值表现出令人满意的稳定性和一致性（即>0.7），一致性程度随频段和脑区而变化。在顶枕记录部位，8-10Hz的ERD一致性最高（即>0.9）。在静息脑电图中，平均阿尔法（重心）频率是最稳定的脑电图特征。
目前的数据表明，不同窄频段的ERD/ERS现象在时间上和不同情境下相当稳定。ERD/ERS相对较高的可重复性促进了该测量方法在评估伴随认知表现的生理激活模式个体差异方面的实用性。
本研究探讨了脑电图一般情况下以及特别是ERD/ERS实验的可重复性问题，这是基础研究和临床研究的先决条件。
