The five percent electrode system for high-resolution EEG and ERP measurements

Objective: A system for electrode placement is described. It is designed for studies on topography and source analysis of spontaneous and evoked EEG activity. Method: The proposed system is based on the extended International 10-20 system which contains 74 electrodes, and extends this system up to 345 electrode locations. Results: The positioning and nomenclature of the electrode system is described, and a subset of locations is proposed as especially useful for modern EEG/ERP systems, often having 128 channels available. Conclusion: Similar to the extension of the 10-20 system to the 10-10 system ('10% system'), proposed in 1985, the goal of this new extension to a 10-5 system is to further promote standardization in high-resolution EEG studies. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.