Eyes-closed resting-state EEGs were recorded using an EEG-1200 Nihon Kohden (Neurofax 1200, Tokyo, Japan) system. We used 30 Ag/AgCl sintered ring electrodes (Waveguard; ANT-Neuro, Enschede, Netherlands). Data were sampled at 500 Hz, and recorded with a low-pass filter at 0·5 Hz and a high-pass filter at 60 Hz. The recordings lasted 5 min and were carried out twice for each participant.
For processing, raw EEG data were bandpass filtered at 1–30 Hz. EEG fragments contaminated with muscle artifacts and eye blink noise were excluded by visual inspection. After removing the contaminated fragments, we used an artifact detector in LORETA-KEY software (http://www.uzh.ch/keyinst/loreta.htm ) 30 (link) and distinguished possible artifacts autonomously. We adopted 2-min epochs with as few artifacts as possible in each session.
Current densities were calculated from the EEG data using standardized low-resolution brain electromagnetic tomography (sLORETA)30 (link). The region of interest (ROI) for the rACC (x = 0, y = 45, z = 0 in the Montreal Neurological Institute space) was selected based on a previous study investigating neurophysiological mechanisms in patients with MDD22 . The ROI for the DLPFC is defined by the location under the stimulation site, based on the 10–10 EEG coordinates (x = –52, y = 26, z = 28)31 (link). We analysed the alpha band between 8.5 and 13 Hz.
For processing, raw EEG data were bandpass filtered at 1–30 Hz. EEG fragments contaminated with muscle artifacts and eye blink noise were excluded by visual inspection. After removing the contaminated fragments, we used an artifact detector in LORETA-KEY software (
Current densities were calculated from the EEG data using standardized low-resolution brain electromagnetic tomography (sLORETA)30 (link). The region of interest (ROI) for the rACC (x = 0, y = 45, z = 0 in the Montreal Neurological Institute space) was selected based on a previous study investigating neurophysiological mechanisms in patients with MDD22 . The ROI for the DLPFC is defined by the location under the stimulation site, based on the 10–10 EEG coordinates (x = –52, y = 26, z = 28)31 (link). We analysed the alpha band between 8.5 and 13 Hz.