Comparison of spatial-temporal features of human mu ERD and mean movement-related potentials. A high resolution electroencephalography study

Cortical mu (10-12 Hz) Event-Related Desynchronization (ERD) and mean Movement-Related Potentials (mMMRP8s) in response to preparation and cxecution of human internally- triggered unilateral one-digit extension were investigated with an advanced high resolution electroencephalography (EEG) technology, which included high surface sampling (128 chan- nels) and surface Laplacian estimate of the potential over a realistic magnetic resonance-constructed subject’s scalp sur- face model. The working hypothesis Was that these responses would reflect different aspects of sensorimotor cortical processes. Consistent mu ERD and mMRPs were modeled in primary sensorimotor (M1-S1), supplementary motor (SMA), and posterior parictal (arca 5) areas during the preparation and execution of the movement. M1-S1s and SMA would generate mu ERD and mMRPSs, whereas areas 5 would pro- duce only the mu ERD. Compared to the mMRPs, the mu ERD would be more represented in ipsilateral M1-S1 across the late preparation and the execution of the movement. These results indicate that the mu ERD would reflect basic changes in background activity of bilateral sensorimotor corti- cal areas, whereas the mMRPS would represent task-specific sensorimotor cortical responses prominently generated in the contralateral M1-S1 and the SMA.