Sensory deprivation
Encyclopedia
Sensory deprivation or perceptual isolation is the deliberate reduction or removal of stimuli
from one or more of the senses. Simple devices such as blindfold
s or hoods
and earmuffs can cut off sight and hearing respectively, while more complex devices can also cut off the sense of smell, touch, taste, thermoception (heat-sense), and 'gravity'. Sensory deprivation has been used in various alternative medicine
s and in psychological
experiments (e.g., see isolation tank
).
Short-term sessions of sensory deprivation are described as relaxing and conducive to meditation
; however, extended or forced sensory deprivation can result in extreme anxiety
, hallucinations, bizarre thoughts, and depression.
In flotation REST, the room contains a tank or pool. The flotation medium consists of a skin-temperature solution of water and Epsom salts at a specific gravity that allows for the patient to float supine without worry of safety. In fact, to turn over while in the solution requires “major deliberate effort.” Fewer than 5% of the subjects tested leave before the session duration ends, which is usually around an hour for flotation REST.
For the first forty minutes it is reportedly possible to experience itching in various parts of the body (a phenomenon also reported to be common during the early stages of meditation). The last 20 minutes often end with a transition from beta or alpha brainwaves to theta, which typically occur briefly before sleep and again at waking. In a float tank the theta state can last for several minutes without the subject losing consciousness. Some use the extended theta state as a tool for enhanced creativity
and problem-solving
. Spas
sometimes provide commercial float tanks for use in relaxation. Flotation therapy has been academically studied in the USA and in Sweden with published results showing reduction of both pain and stress. The relaxed state also involves lowered blood pressure and maximal blood flow.
, obesity
, alcohol
intake or chronic pain were analyzed. The statistic of interest, d, is a measure of the size of the treatment effect. For reference, d=0.5 is considered a moderate effect and d=0.8 a large effect. The 19 subjects who underwent chamber REST had d=0.53 and 6 flotation REST subjects showed d=0.33. Additionally, when examining subjects undergoing REST treatment and REST in conjunction with another treatment method, there was little difference
Second, due to the inherent immobilization that is experienced in flotation REST (due to not being able to roll over), which can become uncomfortable after several hours, the subject is unable to experience the session durations of chamber REST, which may not allow the subject to experience the changes in attitudes and thinking that are associated with chamber REST
.
Third, the research questions asked between each technique are different. Chamber REST questions stemmed out of research that began in the 1950s and explored a variety of questions about the need for stimulation, nature of arousal and its relationship with external stimulation. Practitioners of this explored its utility in the treatment of major psychiatric dysfunctions such as autism
and substance misuse. On the contrary, flotation REST was seen as more of a recreational tool as it was tested more for its use with stress-related disorders, pain reduction and insomnia.
alone has a success rate of 5%.
Alcoholism
has been the target of research associated with REST. In conjunction with anti-alcohol educational messages, patients who underwent 2 hours of REST treatment reduced alcohol consumption by 56% in the first two weeks after treatment. The reduction in consumption was maintained during follow-ups conducted 3 and 6 months after first treatment.
Results from a study conducted by Washington State University are listed in the table below.
Lastly, REST has been tested to determine its effect on drug abusers. A University of Arizona study used chamber REST as a complement to traditional outpatient substance abuse treatment and found that 43% of the patients after 4 years continued to be sober and drug-free. No one in the control group remained clean after 8 months.
s and hallucinations.
According to the Journal of Nervous and Mental Disease the hallucinations are caused by the brain misidentifying the source of what it is currently being experienced, a phenomenon
called faulty source monitoring.
aired a Horizon special entitled "Total Isolation." The premise of the show centered around 6 individuals who agreed to be shut inside a cell in a nuclear bunker, alone and in the dark. Prior to isolation, the volunteers underwent tests of visual memory
, information processing, verbal fluency and suggestibility
. After, they spent two days and two nights in isolation. The subjects noted that their inability to sense time and the hallucinations and visions that they experienced made the 48 hours inside the cell very difficult on their mind.
Of the six volunteers, two coped well. One woman was convinced her sheets were wet. Three experienced auditory and visual hallucinations - snakes, oysters, tiny cars and zebras. After the 48 hours were complete, the same tests were conducted. The results indicated that the volunteers' ability to complete the simplest tasks had deteriorated. One subject's memory capacity fell 36% and all the subjects had trouble thinking of words beginning with the letter "F". All four of the men (neither of the two women) had markedly increased suggestibility.
Stimulus (physiology)
In physiology, a stimulus is a detectable change in the internal or external environment. The ability of an organism or organ to respond to external stimuli is called sensitivity....
from one or more of the senses. Simple devices such as blindfold
Blindfold
A blindfold is a garment, usually of cloth, tied to one's head to cover the eyes to disable the wearer's sight. It can be worn when the eyes are in a closed state and thus prevents the wearer from opening them...
s or hoods
Hood (headgear)
A hood is a kind of headgear that covers most of the head and neck and sometimes the face. They may be worn for protection from the environment, for fashion, as a form of traditional dress or uniform, to prevent the wearer from seeing or to prevent the wearer from being identified.-History and...
and earmuffs can cut off sight and hearing respectively, while more complex devices can also cut off the sense of smell, touch, taste, thermoception (heat-sense), and 'gravity'. Sensory deprivation has been used in various alternative medicine
Alternative medicine
Alternative medicine is any healing practice, "that does not fall within the realm of conventional medicine." It is based on historical or cultural traditions, rather than on scientific evidence....
s and in psychological
Psychology
Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
experiments (e.g., see isolation tank
Isolation tank
An isolation tank is a lightless, soundproof tank inside which subjects float in salt water at skin temperature. They were first used by John C. Lilly in 1954 to test the effects of sensory deprivation. Such tanks are now also used for meditation and relaxation and in alternative medicine. The...
).
Short-term sessions of sensory deprivation are described as relaxing and conducive to meditation
Meditation
Meditation is any form of a family of practices in which practitioners train their minds or self-induce a mode of consciousness to realize some benefit....
; however, extended or forced sensory deprivation can result in extreme anxiety
Anxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
, hallucinations, bizarre thoughts, and depression.
Chamber REST
There are two basic methods of restricted environmental stimulation therapy (REST): chamber REST and flotation REST. In chamber REST, subjects lie on a bed in a completely dark and sound reducing (on average, 80 dB) room for up to 24 hours. Their movement is restricted by the experimental instructions, but not by any mechanical restraints. Food, drink and toilet facilities are provided in the room and are at the discretion of the tester. Subjects are allowed to leave the room before the 24 hours are complete, however fewer than 10% actually do.Flotation REST
For the first forty minutes it is reportedly possible to experience itching in various parts of the body (a phenomenon also reported to be common during the early stages of meditation). The last 20 minutes often end with a transition from beta or alpha brainwaves to theta, which typically occur briefly before sleep and again at waking. In a float tank the theta state can last for several minutes without the subject losing consciousness. Some use the extended theta state as a tool for enhanced creativity
Creativity
Creativity refers to the phenomenon whereby a person creates something new that has some kind of value. What counts as "new" may be in reference to the individual creator, or to the society or domain within which the novelty occurs...
and problem-solving
Problem solving
Problem solving is a mental process and is part of the larger problem process that includes problem finding and problem shaping. Consideredthe most complex of all intellectual functions, problem solving has been defined as higher-order cognitive process that requires the modulation and control of...
. Spas
Hot Springs
Hot Springs may refer to:* Hot Springs, Arkansas** Hot Springs National Park, Arkansas*Hot Springs, California**Hot Springs, Lassen County, California**Hot Springs, Modoc County, California**Hot Springs, Placer County, California...
sometimes provide commercial float tanks for use in relaxation. Flotation therapy has been academically studied in the USA and in Sweden with published results showing reduction of both pain and stress. The relaxed state also involves lowered blood pressure and maximal blood flow.
Statistical Data
Numerous studies have debated which method is a more effective treatment process, however, only one has explored this statistically. 19 subjects, all of whom used chamber and/or flotation REST to induce relaxation and/or treat smokingSmoking
Smoking is a practice in which a substance, most commonly tobacco or cannabis, is burned and the smoke is tasted or inhaled. This is primarily practised as a route of administration for recreational drug use, as combustion releases the active substances in drugs such as nicotine and makes them...
, obesity
Obesity
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
, alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
intake or chronic pain were analyzed. The statistic of interest, d, is a measure of the size of the treatment effect. For reference, d=0.5 is considered a moderate effect and d=0.8 a large effect. The 19 subjects who underwent chamber REST had d=0.53 and 6 flotation REST subjects showed d=0.33. Additionally, when examining subjects undergoing REST treatment and REST in conjunction with another treatment method, there was little difference
Differences between chamber and flotation REST
Several differences exist between flotation and chamber REST. For example, with the presence of a medium in flotation REST, the subject has reduced tactile stimulation while experiencing weightlessness. The addition of Epsom salts to attain the desired specific gravity may have a therapeutic effect on hypertonic muscles. Since one of the main effects of chamber REST has been the resulting state of relaxation, the effects of chamber REST on arousal are less clear-cut, which can be attributed to the nature of the solution.Second, due to the inherent immobilization that is experienced in flotation REST (due to not being able to roll over), which can become uncomfortable after several hours, the subject is unable to experience the session durations of chamber REST, which may not allow the subject to experience the changes in attitudes and thinking that are associated with chamber REST
.
Third, the research questions asked between each technique are different. Chamber REST questions stemmed out of research that began in the 1950s and explored a variety of questions about the need for stimulation, nature of arousal and its relationship with external stimulation. Practitioners of this explored its utility in the treatment of major psychiatric dysfunctions such as autism
Autism
Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...
and substance misuse. On the contrary, flotation REST was seen as more of a recreational tool as it was tested more for its use with stress-related disorders, pain reduction and insomnia.
Other uses
The use of REST has been explored in aiding in the cessation of smoking. In studies ranging between 12 months and 5 years, 25% of REST patients achieved long term abstinence. REST, when combined with other effective smoking cessation methods (for example: behavior modification), resulted in long term abstinence of 50%. Lastly, when combined with weekly support groups, REST resulted in 80% of patients achieving long term abstinence. Comparatively, the use of the nicotine patchNicotine patch
A nicotine patch is a transdermal patch that releases nicotine into the body through the skin. It is used as an aid in nicotine replacement therapy , a process for smoking cessation. The first published study of the pharmacokinetics of a transdermal nicotine patch in humans was authored by Jed E....
alone has a success rate of 5%.
Alcoholism
Alcoholism
Alcoholism is a broad term for problems with alcohol, and is generally used to mean compulsive and uncontrolled consumption of alcoholic beverages, usually to the detriment of the drinker's health, personal relationships, and social standing...
has been the target of research associated with REST. In conjunction with anti-alcohol educational messages, patients who underwent 2 hours of REST treatment reduced alcohol consumption by 56% in the first two weeks after treatment. The reduction in consumption was maintained during follow-ups conducted 3 and 6 months after first treatment.
Results from a study conducted by Washington State University are listed in the table below.
| Alcoholic Beverage Consumption (oz/day) | |
|---|---|
| Prior to REST | 42.7 |
| Immediately post-REST | 23.3 |
| 3 months post-REST | 16.0 |
| 6 months post-REST | 12.7 |
Lastly, REST has been tested to determine its effect on drug abusers. A University of Arizona study used chamber REST as a complement to traditional outpatient substance abuse treatment and found that 43% of the patients after 4 years continued to be sober and drug-free. No one in the control group remained clean after 8 months.
Negative effects
Studies have been conducted to test the effect of sensory deprivation on the brain. One study took 19 volunteers, all of whom tested in the lower and upper 20th percentiles on a questionnaire which measures the tendency of healthy people to see things not really there, and placed them into a pitch black, soundproof booth for 15 minutes. After, they completed another test that measures psychosis-like experiences, originally used to study recreational drug users. Five people reported seeing hallucinations of faces, six reported seeing shapes/faces not actually there, four noted a heightened sense of smell and two people reported sensing a "presence of evil" in the room. Not surprisingly, people who scored lower on the first test experienced fewer perceptual distortions; however, they still reported seeing a variety of delusionDelusion
A delusion is a false belief held with absolute conviction despite superior evidence. Unlike hallucinations, delusions are always pathological...
s and hallucinations.
According to the Journal of Nervous and Mental Disease the hallucinations are caused by the brain misidentifying the source of what it is currently being experienced, a phenomenon
Phenomenon
A phenomenon , plural phenomena, is any observable occurrence. Phenomena are often, but not always, understood as 'appearances' or 'experiences'...
called faulty source monitoring.
José Padilla
Padilla was convicted of aiding terrorists in 2007 and was sentenced to 17 years, 4 months in prison. While awaiting trial, reports surfaced that he was being tortured for information with the use of sensory deprivation for weeks at a time. For 1,307 days, Padilla was kept in a 9' x 7' cell with no natural light, clock or calendar. When Padilla left his cell, he was shackled and fitted with heavy goggles and headphones. His counsel argues that while he was being interrogated Padilla was subjected to harsh lights and pounding sounds. While meeting with his counsel, they reported Padilla exhibiting facial tics, random eye movements and unusual contortions of his body. According to them, Padilla had become so "shattered" that he became convinced his lawyers were part of a continuing interrogation program and saw his captors as protectors."Total Isolation"
In January 2008, the BBCBBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
aired a Horizon special entitled "Total Isolation." The premise of the show centered around 6 individuals who agreed to be shut inside a cell in a nuclear bunker, alone and in the dark. Prior to isolation, the volunteers underwent tests of visual memory
Visual memory
Visual memory describes the relationship between perceptual processing and the encoding, storage and retrieval of the resulting neural representations. Visual memory occurs over a broad time range spanning from eye movements to years in order to visually navigate to a previously visited location...
, information processing, verbal fluency and suggestibility
Suggestibility
Suggestibility is the quality of being inclined to accept and act on the suggestions of others.A person experiencing intense emotions tends to be more receptive to ideas and therefore more suggestible. Generally, suggestibility decreases as age increases...
. After, they spent two days and two nights in isolation. The subjects noted that their inability to sense time and the hallucinations and visions that they experienced made the 48 hours inside the cell very difficult on their mind.
Of the six volunteers, two coped well. One woman was convinced her sheets were wet. Three experienced auditory and visual hallucinations - snakes, oysters, tiny cars and zebras. After the 48 hours were complete, the same tests were conducted. The results indicated that the volunteers' ability to complete the simplest tasks had deteriorated. One subject's memory capacity fell 36% and all the subjects had trouble thinking of words beginning with the letter "F". All four of the men (neither of the two women) had markedly increased suggestibility.
"It's really hard to stimulate your brain with no light. It's blanking me. I can feel my brain just not wanting to do anything."
—Adam Bloom, "Total Isolation"
See also
- ApopheniaApopheniaApophenia is the experience of seeing meaningful patterns or connections in random or meaningless data.The term was coined in 1958 by Klaus Conrad, who defined it as the "unmotivated seeing of connections" accompanied by a "specific experience of an abnormal meaningfulness", but it has come to...
- Enhanced interrogation techniquesEnhanced interrogation techniquesEnhanced interrogation techniques or alternative set of procedures are terms adopted by the George W. Bush administration in the United States to describe certain severe interrogation methods, often described as torture...
- Human experimentation in the United StatesHuman experimentation in the United StatesThere have been numerous experiments performed on human test subjects in the United States that have been considered unethical, and were often performed illegally, without the knowledge, consent, or informed consent of the test subjects....
- Ganzfeld effectGanzfeld effectThe Ganzfeld effect is a phenomenon of visual perception caused by staring at an undifferentiated and uniform field of color. The effect is described as the loss of vision as the brain cuts off the unchanging signal from the eyes...
- Ganzfeld experimentGanzfeld experimentA ganzfeld experiment is a technique used in the field of parapsychology to test individuals for extrasensory perception . It uses homogeneous and unpatterned sensory stimulation to produce an effect similar to sensory deprivation. The deprivation of patterned sensory input is said to be conducive...
- Johnny Got His GunJohnny Got His GunJohnny Got His Gun is an anti-war novel written in 1938 by American novelist and screenwriter Dalton Trumboand published by J. B. Lippincott company.-Plot:...
- Prisoner's cinemaPrisoner's cinemaThe Prisoner's Cinema is a phenomenon reported by prisoners confined to dark cells and by others kept in darkness, voluntarily or not, for long periods of time. It has also been reported by truck drivers, pilots, and practitioners of intense meditation...
- Dark retreatDark retreatDark retreat refers to advanced practices in the Dzogchen lineages of the Nyingmapa, Bönpo and other schools of Tibetan Buddhism.The time period dedicated to dark retreat varies from a few hours to decades. Dark Retreat in the Himalayan tradition is a restricted practice only to be engaged by the...
Further reading
- Goldberger, L. Experimental isolation: An overview. Amer. J. Psychiat., 1966, 122, 774-782.
- Heron, W. The pathology of boredom. Sci. Amer, 1957, 196, 52-56.
- John LillyJohn LillyJohn Lilly may refer to:* John C. Lilly , American physician, psychoanalyst and writer* John Lilly , former Chief Executive Officer of the Mozilla Corporation...
, (inventor of the flotation tank),"The Deep Self: Profound Relaxation and the Tank Isolation Technique" (See also John Lilly, in Flaherty, B.E. (Ed) Psychophysiological aspects of space flight, Columbia U Press, 1961) - Solomon, P. et al. (eds.) (1961) Sensory deprivation. Harvard U Press.
- Suedfeld, P. (1980). Restricted environmental stimulation: Research and clinical applications. Wiley Interscience.
- Zuckerman, M., et al. Experimental and subject factors determining responses to perceptual and social isolation. J. abnorm. Psychol. 1968, 73, 183-194.
- Zubek, J. (Ed.) 1969, Sensory deprivation: Fifteen years of research. Appleton Century Crofts.
- By the Numbers Findings of the Detainee Abuse and Accountability Project Report of the Detainee Abuse and Accountability Project (26 April 2006).