Performance evaluation of the earphone-type electroencephalogram for alpha wave detection

Electroencephalography (EEG) is useful for monitoring brain functions. Recently, wearable earphone-type EEG devices that can be easily used at home have emerged. Although their application scope is expanding, their comfort and detection validity have yet to be sufficiently validated. Herein, we examined the capability of an earphone-type EEG device to record EEG phenomena and compared with conventional scalp EEG. Simultaneous scalp and earphone-type EEG measurements were performed for 30 min, including eyes-open /eye-closed and sleeping tasks, on 25 healthy participants. We compared the detection validity of alpha waves using power spectrum analysis and statistical procedures. Among the 25 participants, 11 participants with available sleep EEG data were included in the final analysis. Compared with the eyes-closed, a reduction in alpha power was observed under the eyes-open condition in the alpha frequency band (8-13 Hz). Similarly, most participants exhibited decreased alpha power during sleep compared with wakefulness. These results indicate that the earphone-type EEG systems record canonical brainwaves in healthy individuals.