There exist two types of methods for analyzing multichannel electroencephalography(EEG) and/or magnetoencephalography(MEG) data: namely inverse and noninverse methods. The inverse methods seek to estimate current sources or current distribution in the brain and are still mainstream among researchers regarding brain function imaging. The noninverse methods, which are not popular naming, are methods whose common purpose is not reductionism to the current source in the brain. Although the purposes of these two methods are exclusively different, the mathematical methodologies of them are sometimes quite similar. Use both of them together may be useful for the brain function imaging.