Table 2.

EEG features that are consistently significant (p-value $<0.05$) across all the 18 studied driving tests. Overall, 28 features are selected by the encoder regardless of driving tests to encode the PERCLOS dynamics. These features include skewness of Alpha (all EEG channels), Delta power (all EEG channels), Theta power (all EEG channels except Cz and P08), Hjorth mobility of Delta (T8, P08, and EOG channels).

Feature	Channel	Number
Skewness of Alpha	Cz, Fz, T7, T8, C3, C4, P07, P08, EOG	9
Delta power	Cz, Fz, T7, T8, C3, C4, P07, P08, EOG	9
Theta power	Fz, T7, T8, C3, C4, P07, EOG	7
Hjorth Mobility of Delta	T8, P08, EOG	3
—	Sum	28