A famous political thriller opens with a scene of KGB officials deploying a dreaded torture technique: complete sensory deprivation. A man is suspended in a vat, in complete darkness, all his senses rescinded. The point of the test is to determine how long it takes for this man to panic to the point of seizure. Without sound, sight, touch, or taste, the poor sap is left alone with only his thoughts for company. A shivering brain suspended in nothing, turning in on itself.