Table 2.

Main features extracted from the EEG by the SDA.

Groups	Feature list
Frequency domain	•Total power (0–12 Hz) •Peak frequency of spectrum •Spectral edge frequency (80%, 90%, 95%) •Power in 2 Hz width sub-bands (0–2 Hz, 1–3 Hz, ...10–12 Hz) •Normalised power in sub-bands •Wavelet energy (the EEG is decomposed into 8 coefficients using the Daubechy 4 wavelet, the energy in the 5th coefficient corresponding to 1–2 Hz is used as a feature)
Time domain	•Curve length •Number of maxima and minima •Root mean squared amplitude •Hjorth parameters •Zero crossings (raw epoch, Δ, ΔΔ) •Autoregressive modelling error (model order 1–9) •Skewness •Kurtosis •Nonlinear energy •Variance (Δ, ΔΔ)
Information theory:	•Shannon entropy •Singular value decomposition entropy •Fisher information •Spectral entropy