The scalp maps and equivalent dipole source locations after IC clustering across 15 subjects. (a) the frontal components and (b) the left motor components are shown here. There are 14 subjects in the frontal cluster and 11 subjects in the left motor cluster. The grand scalp map is the mean of the total component maps in each cluster. The smaller maps are the individual scalp maps. The right panels (c) and (d) show the 3-D dipole source locations (colored spheres) and their projections onto average brain images. The colored source locations correspond to their own scalp maps by the same color of the text above.