Microstates Analysis for Dry and Gel-Based Multichannel Electroencephalography

Spatial analysis of EEG data, e.g. using short-term stable microstates, is increasingly used in neuroscience and clinical applications. At the same time, scenarios involving mobility, sports, and home-based activities are becoming more prevalent in EEG studies. For this purpose, dry EEG electrodes are more and more commonly used. Thus, our objective was a comparison of microstates analysis between dry and gel-based EEGs. 256-channel EEGs were recorded from 30 volunteers using dry and gel-based electrodes during resting state eyes closed and eyes open. Microstates were extracted for each measurement and time-domain parameters were calculated. We found a high degree of consistency between the microstate maps extracted from dry and gel-based measurements for both eyes closed and eyes open conditions. The topographic similarities between the average maps for dry and gel-based recordings were above 81.5% for each of the seven extracted maps. We conclude that topographic microstate analyses are feasible using multichannel EEG setups with new dry EEG electrodes.