In parallel to current density imaging, dipole source localization can be approached using nonlinear optimization [59–62, 92, 93] or sub-space scanning procedures [94–99] Moreover, the beamforming techniques based on linear spatial filtering can be used to estimate the source activity at a region of interest (ROI) or every individual location in the source space [100–103]. The beamformer for a specific ROI or source location is derived in an attempt to minimize the interference from other locations.
