|
Sensory deprivation is the reduction of sensory input into the human system, whether naturally occurring or induced. Simple artificial systems can reduce visual and auditory input while more complex designs can also reduce olfactory, tactile, thermoceptive, gustative and 'gravitational' sensations. Sensory deprivation has been used in various alternative medicines, for torture or punishment, and in psychological experimentation.
The beneficial use of a sensory deprivation system is termed a floatation tank. The subject is suspended in a large tub that is enclosed for temperature control. The tub is filled to 10 inches with skin-temperature water and 800-1000 pounds of dissolved Epsom salt to make the subject neutrally buoyant. Since the ears are underwater when the subject is in a relaxed position, ear plugs are typically used and therefore hearing is greatly reduced. When the subject's arms float to the side, the sense of touch is greatly reduced due to the air and water being the same temperature as the skin. Vision is completely reduced. The sense of smell is greatly reduced, especially if the water has not been treated with chlorine. The float session typically lasts one hour. For approximately the first 40 minutes, the mind looks for sensory input. As a result, it's not uncommon for itching in different areas of the body to occur, a phenomena which is also common with practitioners of meditation. The last 20 minutes often end with a transition from beta or alpha brainwaves to theta, which is the hypnogogic state that occurs briefly before every human falls asleep and again when we wake up. In the float tank environment, the theta state can last for several minutes without the subject losing consciousness. Many use the extended theta state as a tool for enhanced creativity and problem-solving. Many spas include commercial float tank facilities for use as a relaxation aid.
Examples on Film
Altered States starring Blair Brown and William Hurt
Simon starring Alan Arkin
The five sensory deprivation techniques
In 1978 in the European Court of Human Rights trial "Ireland v. the United Kingdom" the facts were not in dispute and the court published the following in their judgement:
- These methods, sometimes termed "disorientation" or "sensory deprivation" techniques, were not used in any cases other than the fourteen so indicated above. It emerges from the Commission's establishment of the facts that the techniques consisted of:
- (a) wall-standing: forcing the detainees to remain for periods of some hours in a "stress position", described by those who underwent it as being "spreadeagled against the wall, with their fingers put high above the head against the wall, the legs spread apart and the feet back, causing them to stand on their toes with the weight of the body mainly on the fingers";
- (b) hooding: putting a black or navy coloured bag over the detainees' heads and, at least initially, keeping it there all the time except during interrogation;
- (c) subjection to noise: pending their interrogations, holding the detainees in a room where there was a continuous loud and hissing noise;
- (d) deprivation of sleep: pending their interrogations, depriving the detainees of sleep;
- (e) deprivation of food and drink: subjecting the detainees to a reduced diet during their stay at the centre and pending interrogations.
It referred to the above as "the five techniques" and ruled:
- 167. ... Although the five techniques, as applied in combination, undoubtedly amounted to inhuman and degrading treatment, although their object was the extraction of confessions, the naming of others and/or information and although they were used systematically, they did not occasion suffering of the particular intensity and cruelty implied by the word torture as so understood. ...
- 168. The Court concludes that recourse to the five techniques amounted to a practice of inhuman and degrading treatment, which practice was in breach of [the European Convention on Human Rights] Article 3 (art. 3).
See also
References
- Richard Feynman, a famous physicist, writes about his experiences with sensory deprivation in a floatation tank in one of his popular books, Surely You're Joking, Mr. Feynman!.
|
