Fig. 4From: Transcranial magnetic stimulation for individual identification of the best electrode position for a motor imagery-based brain-computer interfaceGroup average amplitude of motor evoked potentials. The relative MEP amplitudes averaged over all participants are shown for both hemispheres. Stimulation locations are indicated with black crosses, electrode positions of the 10–6.7 system are indicated with a black “x” and the center of gravity for each hemisphere is represented as a black circle. Values between stimulation points are interpolated for better visualizationBack to article page