Credit:
Four leads are placed on the right ear: the grounding lead on the ear lobe, a 4-pronged lead superior to the temporal process of the zygomatic bone, and single-pronged leads on the antihelix and the posterolateral auricle. The positions of the grounding lead (G), the 4-pronged lead (4), and the single-pronged lead (1) are demonstrated. The posterior lead (single prong) is not shown. The external ear receives peripheral projections of the auriculotemporal nerve (CN V), auricular branch of the vagus nerve (CN X), the great auricular nerve (C2, C3), and the lesser occipital nerve (C3).