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 isolation tank was originally called the
sensory deprivation tank. Other names for the isolation tank include
flotation tank,
float tank,
John C. Lilly tank,
REST tank, and
sensory attenuation tank.