Dr. John C. Lilly, a medical practitioner and neuroscientist, developed the floatation tank in 1954. While at his job studying neurophysiology at the National Institute of Mental Health, Dr. Lilly conducted experiments with the intent of isolating the brain from external stimulation. It was hypothesized that if all stimuli were cut off to the brain then the brain wouldn’t need to process anything and would go to sleep. Lilly decided to test this hypothesis and, with this in mind, created an environment, which totally isolated an individual from external stimulation. Lilly created a head-mask and submerged himself underwater to achieve sensory deprivation. Dr. Lilly ended up discovering that the brain doesn’t shut off when external stimulation is removed, it does quite the opposite. The sensory deprived state of consciousness, in fact, yields a host of benefits way beyond his original hypothesis.