equal to three electrodes with excessive artifact; otherwise, the EEG was excluded from the analysis. Afterward, the EEGs were re-referenced to average reference, and independent component analysis was performed using the extended infomax algorithm (Lee et al., 1999) for each file. The components that contained eye blinks, eye movement, or specific line noise artifacts were removed. Lastly, the EEGs were inspected visually again, and the epochs with excessive noise or artifacts were removed. The investigator performing the preprocessing was blinded to the diagnosis.
