“…In order to decrease the amplitude of outliers, the amplitude of obtained signals from each electrode was calculated, from which those with amplitudes higher than 90% or lower than 10% were clipped and ultimately normalized. Numerous studies have used this database in the fields of signal processing and feature extraction [240,241], feature selection [239,242], and classifiers [243][244][245]. In the present study, the acquired signals from eight electrodes, namely P8, P4, P3, P7, Oz, Pz, Cz and Fz are used.…”