Fatigue Assessment of Cognitive Tasks Using Ear-EEG

This study assessed mental fatigue using ear-EEG. Fatigue is a significant issue in Japanese society, where overwork is a severe problem. EEG frequency analysis is a common method for evaluating fatigue; however, it places a burden on participants due to the attachment of scalp electrodes. This study verified the accuracy of measuring fatigue in cognitive tasks while reducing the burden using ear-EEG. Alpha and beta waves were used for the measurement, and the frequency change with fatigue was used as an evaluation index. In addition, steady-state visual evoked potential and critical fusion frequency were used to measure concentration and fatigue, respectively, and subjective fatigue was evaluated to comprehensively assess the effectiveness of ear-EEG in measuring fatigue. The ear-EEG experimental results exhibited trends similar to those observed in case of head EEG. Therefore, ear-EEG is suitable for fatigue evaluation. However, compared to the head EEG setup, the ear-EEG setup is smaller, which renders detailed evaluation more challenging. Moreover, the ear-EEG results contained considerable noise, such as electromyograms. Therefore, further efforts are required for the fatigue level evaluation with the same accuracy as that of head EEG by applying a correction.