In 1954 a neuroscientist named John C. Lilly needed to eliminate incoming sensory information to create a control group for his experiments. He ended up discovering that sensory deprivation has a load of benefits that far superseded whatever wild experiments he was doing. By the 1970’s, the tank’s design had evolved from Lilly’s original laboratory chambers to the comfortable individual pods that we have now.
A floating pod, originally called a sensory deprivation tank (also known as float tank, flotation tank or sensory attenuation tank) is a lightless, soundproof tank with high epsom salt (magnesium sulphate) content filled with salt water at skin temperature, in which individuals float.
Floatation therapy is based on a scientific approach to deep relaxation called Restricted Environmental Stimulation Technique or R.E.S.T. for short. The idea was developed in 1954 at NIMH (National Institute of Mental Health) in Washington. Floating in a floatation tank triggers a deep relaxation response, much deeper than normal sleep. It enables us to drift into the elusive Theta state, which is hard to achieve.