Resting State EEG Data Acquisition and Processing: A Comprehensive Overview

We obtained resting state EEG data for 10 minutes at two separate time points. The EEG data was collected using 66 scalp channels with Ag/AgCl electrodes positioned according to the international 10-20 EEG system (SynAmps2TM 8500; Neurscan, USA). The EEG signal was digitized at a sampling rate of 2500Hz, with electrode impedance remaining below 5 K\u03A9. The reference electrode was placed between Cpz and Cz, and a vertical and horizontal electrooculogram (EOG) was recorded above and below the left eye, with an electrode placed at the outer canthus of each eye. Throughout the data collection process, all patients were instructed to keep their eyes open. If the patients became drowsy, verbal and tactile stimulation was administered as recommended by the CRS-R scale. \n\nOffline EEG processing was performed using the eeglab14.1.1b toolbox in the MATLAB environment (R2016a, MathWorks Inc, USA). Initially, non-scalp channels (CB1, CB2, M1, M2, HEOG, VEOG) were discarded, resulting in a total of 60 electrodes for subsequent analysis. The EEG signal was filtered between 1-45Hz and down-sampled to 500Hz. Bad channels were interpolated using the spherical method. The data was then segmented into epochs of 10 seconds with 50% overlap. Epochs containing obvious artifacts were manually excluded from the analysis. Independent component analysis (ICA) was subsequently employed to remove ocular and muscle artifacts. Custom scripts were used to reject epochs with electrical activity exceeding \u00B1100\u03BCV. Finally, the EEG signal was re-referenced to the average reference. After data processing, 36 epochs were randomly selected for further analysis, which falls within the range of other EEG resting state studies.