io9 - Everything You Ever Wanted to Know about Sensory Deprivation Tanks

I was fortunate during my first stint in grad school to have a roommate who owned a sensory deprivation tank - we just called it the float tank. I did many sessions in that watery cave, some of them simply using breath meditations, some using holotropic breathwork techniques, and some using ethneogens.

On more than one occasion I came out of the tank feeling incoherent (in a rational sense) and dissociative. But given the chance, I would do it again in an instant - no hesitation. It's a phenomenal tool for exploring inner space. 

Everything You Ever Wanted to Know about Sensory Deprivation Tanks

By Robert T. Gonzalez
August  12, 2011
 
On Fringe, a sensory deprivation tank can activate your mental powers and even open a gateway to another universe. But what can floating in a dark warm tank do for you in real life? And why would people even want to do such a thing?

The sensory deprivation tank — a temperature-regulated, salt-water filled, soundproof, lightproof tank that can isolate its occupant from numerous forms of sensory input all at once — has gone by many names over the years, but its overall design and purpose have remained largely unchanged: to find out what your brain does when it's shoved into a box all by itself and left alone for a while. Here's the complete lowdown on sensory deprivation tanks.

Back in the old days, if you wanted to experience sensory deprivation you wore a blindfold or stuck your fingers in your ears like everybody else. But that all changed in 1954, when neuroscientist John C. Lilly dared to question what would happen if the mind was deprived of as much external stimulus as possible.



In the original deprivation tank, you were suspended in 160 gallons of water with everything but the top of your head completely submerged. A nightmarish-looking "black-out" mask, similar to the ones pictured here, supplied you with air and blocked any light from reaching your eyes. The water and air temperature were kept at the same temperature as your skin, roughly 34 degrees celsius.

The masks were eventually done away with (apparently people found having their heads wrapped in latex distracting), and the requirement of total submersion along with them; instead, the water was saturated with 800 pounds of Epsom salt, which made the water so dense that you could float with your entire body at or near its surface in spite of its shallow depth.



Inside the tank there is no light, and therefore no sense of vision. You experience the kind of quiet that allows you to hear your muscles tense, your heart beat, and your eyelids close. The extreme buoyancy of the water lends your environment an almost zero-gravity quality. The lack of a temperature differential plays with your ability to perceive where your body ends and where the water and air begin.

But then what happens? What do people experience while they're in the tank? Can an isolation chamber really transport you to a parallel universe like it does on Fringe?

Read the rest of the article.