Welcome to the data repository of the EEG microstate toolbox! This repository contains resting-state EEG data from 34 participants (original duration: 3 minutes per recording) in two conditions (EC = eyes-closed condition; EO = eyes-open condition) collected in the context of the Dortmund Vital Study (Gajewski et al., 2022). Preprocessing was conducted in EEGLAB (Delorme and Makeig, 2004). The data was downsampled to 500Hz and filtered from 2-20Hz (typical frequency range in microstate analysis; see Michel & Koenig, 2018). Large artifacts were removed based on spectrum thresholding (function: pop_rejcont; recommended settings; frequency range: 15-30Hz) and average reference was applied. The PrepPipeline (Bigdely-Shamlo et al., 2015) was used to remove noisy channels, and additional artifacts were removed (function: pop_autorej; recommended settings; threshold limit of 500µV). An independent component analysis (function: pop_runica; recommended settings) followed by the ICLabel function (Pion-Tonachini et al., 2019) were used to remove regular artifacts in the EEG (i.e., components that reflected eye-movements and muscle artifacts with a probability >70%).