“…The feature extraction methods mainly include time domain analysis, frequency domain analysis, time frequency domain analysis, multivariate statistical analysis, and nonlinear dynamic analysis (Donos et al, 2018;Rasheed et al, 2020). Principal component analysis, linear discriminant analysis (LDA; Alotaiby et al, 2017), and independent component analysis (Ur et al, 2013;Acharya et al, 2018a;Maimaiti et al, 2021) are widely used unsupervised time-domain methods to summarize EEG data. Frequency domain features include spectral center, coefficient of variation, power spectral density, signal energy, spectral moment, and spectral skewness, which can provide key information about data changes (Yuan et al, 2018;Acharya et al, 2018a).…”