Uniqueness of the generators of brain evoked potential maps

Using the physical and mathematical properties of the volume conductor model we discuss the question of uniqueness of the neuronal generators of human brain evoked potentials (BEP). We show that in a realistic head shape: (1) Two spatially distinct point generators cannot create the same scalp potential map. (2) Two non-overlapping distributed generators cannot create the same scalp potential map. We also discuss the properties of non-unique (equivalent) generators.