Pacharra Marlene, Debener Stefan, Wascher Edmund
Leibniz Research Centre for Working Environment and Human Factors, TU Dortmund UniversityDortmund, Germany.
Neuropsychology Lab, Department of Psychology, European Medical School, University of OldenburgOldenburg, Germany.
Front Hum Neurosci. 2017 Jun 8;11:290. doi: 10.3389/fnhum.2017.00290. eCollection 2017.
In theory, miniaturized systems such as the around-the-ear electrode arrays (cEEGrids) enable mobile monitoring of the electroencephalogram (EEG) in a variety of real life situations without interfering with the natural setting. However, the research benefit of such cEEGrid recordings critically depends on their validity. To investigate whether visual and motor processing are reflected in the cEEGrid-EEG, a direct comparison of EEG that was concurrently recorded with the cEEGrids and with a high-density cap setup was conducted. Thirteen participants performed a classic Simon task in which letters were presented laterally and a lateralized choice response was executed. N1, P1 and P300 event-related potential (ERP) waveforms were extracted from cEEGrid-EEG: they were found to be strongly correlated with corresponding waveforms extracted from cap-EEG but with lower signal strength and lower signal-to-noise-ratio (SNR). Event-related lateralizations (ERLs) recorded at posterior scalp sites were well reflected in middle cEEGrid pairs. Moreover, the effect size of the Simon correspondence effect on the extracted ERLs was similar between the two systems. However, lateralizations at central cap sites were less well reflected in the cEEGrid-EEG indicating a difficulty in capturing motor response preparation and execution. These results show that well-described visual and cognitive ERPs and ERLs can be measured using the cEEGrids, while motor-related cortical potentials are not well captured. This study further demonstrates the potential and possible limitations of unobtrusive cEEGrid-EEG recordings.
理论上,诸如耳周电极阵列(cEEGrids)这样的小型化系统能够在各种现实生活场景中对脑电图(EEG)进行移动监测,且不会干扰自然环境。然而,此类cEEGrid记录的研究价值关键取决于其有效性。为了探究视觉和运动处理是否能在cEEGrid-EEG中得到体现,研究人员对同时使用cEEGrids和高密度电极帽装置记录的EEG进行了直接比较。13名参与者执行了一项经典的西蒙任务,其中字母从侧面呈现,并执行侧向选择反应。从cEEGrid-EEG中提取了N1、P1和P300事件相关电位(ERP)波形:发现它们与从电极帽-EEG中提取的相应波形高度相关,但信号强度较低且信噪比(SNR)较低。在后头皮部位记录的事件相关侧化(ERLs)在中间的cEEGrid电极对中得到了很好的体现。此外,两个系统之间提取的ERLs上西蒙对应效应的效应大小相似。然而,电极帽中央部位的侧化在cEEGrid-EEG中体现得较差,这表明在捕捉运动反应准备和执行方面存在困难。这些结果表明,使用cEEGrids可以测量描述详尽的视觉和认知ERP及ERL,而与运动相关的皮层电位则无法很好地捕捉。这项研究进一步证明了不引人注意的cEEGrid-EEG记录的潜力和可能存在的局限性。