Source localization using eventrelated desynchronization (ERD) within the alpha band

Abstract

Voluntary finger movements result in a maximal ERD in the 10–12 Hz band close to electrodes C₃ and C₄, overlying the sensorimotor hand areas. This ERD focus is not very pronounced with EEG data recorded against a common reference electrode (monopolar recording). After transformation of the raw data using common average, local average and weighted average reference and the Hjorth method, respectively, the ERD becomes enhanced over electrodes C₃ or C₄. Movement-related EEG data were studied with 17, 19, 30 and 56 electrode montages using large and small interelectrode distances. The best focused ERD was obtained with a 56 electrode montage with small interelectrode distances and local average reference data.