The person would hold the device vertically over their breastbone and position the electrodes on their chest.

BBC: Hand-held heart test devised

He would position his more than 6ft-tall frame practically chest-to-chest with someone he wanted to influence, and lean in nearly nose-to-nose as his quarry would try to squirm away.

BBC: A presidential tour of Austin

When he tapped his volunteers on their chests at the same time as he tapped the air at chest-height below the cameras, they reported feeling that the core of their identity inhabited the camera's position.

ECONOMIST: Consciousness