The recording electrodes can be carried by a skull cap, and nothing has to penetrate the skin.

ECONOMIST: Bionics (I)

On January 7th, he dutifully donned a black skull-cap for a reverential photo-opportunity with Rabbi Ovadia Yosef, spiritual leader of the powerful Shas party.

ECONOMIST: Israel

Only later did his measurements show that the skull-cap was from a new transitional species, pithecanthropus erectus, the upright ape-like man.

ECONOMIST: How man has learned, through history, about his habitat