De Vos Maarten, Kroesen Markus, Emkes Reiner, Debener Stefan
Methods in Neurocognitive Psychology, Department of Psychology, University of Oldenburg, Oldenburg, Germany. Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany. Cluster of Excellence Hearing4all, University of Oldenburg, Oldenburg, Germany.
J Neural Eng. 2014 Jun;11(3):036008. doi: 10.1088/1741-2560/11/3/036008. Epub 2014 Apr 24.
In a previous study, we presented a low-cost, small and wireless EEG system enabling the recording of single-trial P300 amplitudes in a truly mobile, outdoor walking condition (Debener et al (2012 Psychophysiology 49 1449-53)). Small and wireless mobile EEG systems have substantial practical advantages as they allow for brain activity recordings in natural environments, but these systems may compromise the EEG signal quality. In this study, we aim to evaluate the EEG signal quality that can be obtained with the mobile system.
We compared our mobile 14-channel EEG system with a state-of-the-art wired laboratory EEG system in a popular brain-computer interface (BCI) application. N = 13 individuals repeatedly performed a 6 × 6 matrix P300 spelling task. Between conditions, only the amplifier was changed, while electrode placement and electrode preparation, recording conditions, experimental stimulation and signal processing were identical.
Analysis of training and testing accuracies and information transfer rate (ITR) revealed that the wireless mobile EEG amplifier performed as good as the wired laboratory EEG system. A very high correlation for testing ITR between both amplifiers was evident (r = 0.92). Moreover the P300 topographies and amplitudes were very similar for both devices, as reflected by high degrees of association (r > = 0.77).
We conclude that efficient P300 spelling with a small, lightweight and quick to set up mobile EEG amplifier is possible. This technology facilitates the transfer of BCI applications from the laboratory to natural daily life environments, one of the key challenges in current BCI research.
在之前的一项研究中，我们展示了一种低成本、小型且无线的脑电图（EEG）系统，该系统能够在真正的移动户外行走条件下记录单次试验的P300波幅（德贝纳等人，（2012年，《心理生理学》，49卷，1449 - 1453页））。小型无线移动EEG系统具有显著的实际优势，因为它们允许在自然环境中记录大脑活动，但这些系统可能会影响EEG信号质量。在本研究中，我们旨在评估使用该移动系统可获得的EEG信号质量。
我们在一个流行的脑机接口（BCI）应用中，将我们的移动14通道EEG系统与一个先进的有线实验室EEG系统进行了比较。13名受试者重复执行一个6×6矩阵的P300拼写任务。在不同条件之间，仅更换了放大器，而电极放置、电极准备、记录条件、实验刺激和信号处理均保持相同。
对训练和测试准确率以及信息传递率（ITR）的分析表明，无线移动EEG放大器的表现与有线实验室EEG系统一样好。两种放大器之间测试ITR的相关性非常高（r = 0.92）。此外，两种设备的P300地形图和波幅非常相似，高度相关性（r >= 0.77）就反映了这一点。
我们得出结论，使用小型、轻便且易于设置的移动EEG放大器进行高效的P300拼写是可行的。这项技术有助于将BCI应用从实验室转移到自然的日常生活环境中，这是当前BCI研究中的关键挑战之一。
