Sensory deprivation tanks today are featured on popular media and are being used more frequently by average people looking to relieve stress, pain, and other chronic ailments. How did floatation therapy come into being? How does it work?
The first sensory deprivation tank was created by neuroscientist John C. Lilly. He was curious about what the effects the elimination of external stimulus would have on the mind. An LSD enthusiastic who believed in creatures from other dimensions, he had some particular expectations on the effects the tank would yield. This first tank had 160 gallons of water, and participants were submerged completely from the neck down. They wore a “blackout” mask to eliminate any light pollution. The temperature of the air and the water were tightly controlled to be the same as average skin at 34 degrees Celsius.
The tanks eventually morphed to become more like what they are today. The masks were done away with, and rather than facilitating complete submersion, newer tanks contained a high concentration of dissolved Epsom salts, allowing participants to float easily.