The techniques and technologies of torture can be grouped into three categories: hardware, software, and liveware. The term "hardware" refers to the equipment used; software refers to the techniques of torture that are taught to interrogators. Torture liveware refers to the human element of torture, typically the interrogator.
Torture hardware. Examples of torture hardware include shackles for the arms, legs, and even thumbs, whips, canes, beating devices (i.e., clubs, rubber hoses), water, electrical generators to administer electroshocks, and devices that suspend someone painfully above the ground. In fact, the list of physical harm that can be inflicted is long. Any possible route to inflict pain that can be conceived of has been used.
Machines that generate intolerable noise ("white noise") or bright pulses of ultraviolet light are sometimes used. Hardware can also have a chemical nature. Some drugs can cause physical discomfort, pain, and disruptions to the body's biochemistry. Examples include curare,
insulin, and apomorphine. Drugs such as these differ from psychoactive drugs that alter thought processes or biochemical activity in the brain. Food and water deprivation, or maintaining an uncomfortable position for a long time, can also induce biochemical changes.
Electromagnetic radiation can also be a means of torture. Studies in animals have shown that electromagnetic waves of certain wavelengths can destroy lung and brain cells. While not necessarily lethal, these effects are debilitating and can be painful. Electromagnetic stimulation can have other nonlethal effects on humans. Extreme emotions of rage, lust, and fatigue can be caused. A 1950s research program called "Operation Knockout," which was funded by the United States Central Intelligence Agency, discovered that electroshock treatments could be used to cause amnesia. Memories could be erased, and the subjects reprogrammed. This "psychic driving" is a form of torture.
The most widely used torture hardware is electro-shock. Pulses of energy, which are therapeutically useful in some medical treatments, have been adapted as a torture technique. The application of electricity stimulates muscle activity to such an extent that involuntary and painful muscular contractions occur. Longer pulses of electricity produce successively greater debilitation. For example, a five-second discharge from a cattle prod can completely immobilize someone for up to 15 minutes
Torture software. The use of intimidation, threats, harsh and comforting language, and even silence are all techniques that, when combined with the hardware of torture, can extract information from a victim.
Such interrogation techniques have become standard operating procedures for interrogators. Indeed, manuals have been written for interrogators. One example is the Human Resource Exploitation Training Manual, which was written by the U.S. Central Intelligence Agency, and whose existence became known in 1997 as part of a Freedom of Information Request. A second example is the School of the Americas at Fort Benning, Georgia, which trained interrogators until 1991. The U.S. is by no means unique in providing such training.