a particular electrode location estimates the amount of the brain's electrical current flowing in and out of superficial scalp regions adjacent to that electrode. The CSD-reference might thus be preferred as the reference most likely to link surface recorded frontal EEG asymmetry to activity generated in frontal systems (as opposed to activity from distal non-frontal sources that can be reflected at frontal recording sites under other reference montages such as average or linked-mastoids). No EEG asymmetry studies of clinical depression using a CSD re-reference appear in the literature.
