Dean Radin the celebrated scientist from the Institute of Noetic Sciences, once made an important discovery: that we often receive a physical foreboding of an event. He set up a computer that would randomly select photos designed to calm, to arouse, or to upset a participant.
His volunteers were wired to physiological monitors that recorded changes in skin conduction, heart rate and blood pressure, and they sat in front of a computer that would randomly display color photos of tranquil scenes (landscapes), or scenes designed to shock (autopsies) or to arouse (erotic materials).
Radin was fascinated to discover that his subjects were registering physiological responses before they saw the photo. As if trying to brace themselves, their responses were highest before they saw an image that was erotic or disturbing.