Isolation tank

An **isolation tank**, **sensory deprivation tank**, **float tank**, **float pod**, **float cabin**, **flotation tank**, or **sensory attenuation tank** is a pitch-black, light-proof, soundproof environment heated to the same temperature as the skin. Flotation tanks are widely advertised as a form of alternative medicine. The tank is filled with 10 inches of water which contains enough dissolved Epsom salt to create a specific gravity of approximately 1.26 - 1.275. This environment allows an individual to float effortlessly on the surface of the water. The primary function of the isolation tank is to eliminate as many of the external senses as possible. They were first used in 1954 to test the effects of sensory deprivation.

# History

The isolation tank was developed in 1954 by John C. Lilly, a medical practitioner and neuropsychiatrist. During his training in psychoanalysis at the US National Institute of Mental Health (NIMH), Lilly experimented with sensory deprivation.

Widespread commercial interest and use of the isolation tank didn't occur until 1972, when Glenn Perry, a computer systems programmer, began selling the first commercial tanks after he attended a five-day workshop by Lilly.

In 1981, there were about $4 million in sales and rentals in the industry, and expectations were that the market would grow, spurred by the film *Altered States* (a film starring William Hurt as a psychopathologist experimenting with a flotation tank), which came out in 1980. According to one source in the industry, in the 1980s the rise of AIDS and the fear of shared water reduced demand for flotation centers. By 2013, flotation was more popular in Europe than the US, but had undergone some growth in the area around San Francisco; at that time a low-end tank cost about $10,000, and an hour-long flotation session cost about $70.

# Floatation-REST

Scientific research with float tank therapy generally uses the term "Floatation-REST" (restricted environmental stimulation therapy) to refer to the technique.  This term is preferred over "sensory deprivation" due to the fact that 1) the float tank experience actually enhanced sensory input from the body (e.g., cardiorespiratory sensations) and can also be conceptualized as a form of sensory enhancement and 2) the term "sensory deprivation" carries negative connotations of torture and hallucinations that have likely impeded legitimate research in this field. A study of 50 individuals with anxiety disorders only reported simple pseudo-hallucinations such as colored lights or abstract shapes (e.g., *“Visual lights and color*, *very pretty and relaxing*”), which were described positively by participants and not mistaken for real stimuli.

# Potential treatment for anxiety disorders

Recent work by Justin Feinstein and colleagues at Laureate Institute for Brain Research has shown a very large effect size (Cohen's d = 2.15) for anxiety reduction in a cohort of 50 participants with anxiety disorders after a 60-minute float.Participants floated in an open fiberglass pool without an enclosure (which is optimal for comfort in individuals with anxiety) in a lightproof and soundproof room and had the option to float with lights on or off. The experience was well tolerated by the participants with no serious adverse events. Another study by this group found that a 90-minute float session greatly enhances attention toward, intensity of, and subjective pleasantness of cardiorespiratory sensations in 31 participants with anxiety sensitivity (i.e., individuals who are normally disturbed by feeling their heart beating, intense breathing, or other sensations that might be associated with a panic attack) relative to a control condition in which participants watched a nature documentary. The authors have hypothesized that Floatation-REST allows individuals to forget associations between visceral sensations and anxiety and learn new associations between visceral sensations and relaxation.

# Notable users

* Carl Lewis, track and field athlete, used in-tank visualization techniques to prepare himself for his gold medal long jump at the 1988 Seoul Olympics.
* Richard Feynman, Nobel Prize-winning physicist, discussed his experiences with isolation tanks in *Surely You're Joking, Mr. Feynman!*
* Two-time NBA MVP Stephen Curry reportedly uses a sensory-deprivation tank every two weeks.
* Carl Lawson, football player for the Cincinnati Bengals, uses the tank for muscle recovery and visual training.
* Joe Rogan has stated in his podcast on numerous occasions that he owns an isolation tank and credits it for allowing a state of deeper meditation.
* John Lennon treated his heroin addiction in 1979 with the help of 90-minute floats in a cedar-wood box.[*dubious – discuss*]
* Several NFL teams, including the New England Patriots, Los Angeles Rams and New Orleans Saints, reportedly use floating as a way to increase players’ quality of sleep as well as help with recovery.
* During Super Bowl XLIX, both NFL teams (the New England Patriots and Seattle Seahawks) rented out a local float spa during the week of the event. One team would float in the morning and the other would float in the afternoon.
* Marvin Jones, wide receiver for the Detroit Lions and formerly of the Cincinnati Bengals, began using flotation therapy to help him in his recovery from an ankle injury while in Cincinnati, and continues to float after discovering how beneficial it was in other areas as well.
* Phil Lester visited a flotation center for a YouTube video on his channel "AmazingPhil" on February 17, 2020.

# In popular culture

* In The Simpsons episode *Make Room for Lisa*, Homer and Lisa have a spiritual journey upon a session in an isolation tank.

* Joe Rogan

# See also

* Dark retreat
* Prisoner's cinema
* Psychedelic experience