The imaging performance of all linear and nonlinear EEG/MEG inverse algorithms varies from case to case, depending on the nature of the brain electrical activity. The methodological choice is up to the users' own judgment as to whether the activity is sparse or extended, stationary or non-stationary, etc. Although the evaluation of some typical algorithms have been done in a few experimental and simulation settings [55,104–106], a general conclusion or agreement regarding a single optimal source imaging approach, if possible at all, has not been reached.
