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In the 1960s, a rather original researcher attempted a world first: to annihilate all external stimulation of the mind and body to see the effects on the brain. His aim: to find out whether consciousness exists once the senses are occluded or whether it really needs external stimulation. This experience of sensory deprivation will give birth, little by little, to a new practice that goes much further than simple relaxation. This is the rich history of floating in sensory deprivation.

John Cunningham Lilly
American physician, neuroscientist, neuropsychologist, psychoanalyst, psychotherapist, ketologist, mammalogist, inventor and writer.

Sensory deprivation or isolation is not a new practice, on the contrary. From time immemorial, men and women have sought ultimate peace and quiet, often for mystical purposes. Anachoretes, hermits, monks of different religions isolate themselves from the world to reach the divine. In many tribes, spending time away from the group through hard fasting, meditation or other practices of deprivation found in asceticism, allows the passage to adulthood.

However, we owe the invention of sensory deprivation tanks, for an entirely different reason, to a hard-nosed but slightly offbeat scientist: Dr John C. Lilly.

Studying the brain in detail

John Lilly is a scientist in a class of his own, deeply influenced by the American counterculture. He is a pure product of the 50s and 60s: he is a jack-of-all-trades, passionate, eclectic and pioneering.

He built his first chemistry laboratory in the family home at the age of 13. His classmates gave him a nickname: Einstein Junior.

In turn a philosopher, physicist and biologist, he finally turned to medicine, psychoanalysis and neurophysiology. And as part of his brain research, he developed the first sensory isolation chamber.

Its aim is first of all to explore the correspondence between the physical data of the brain and the mind. He was looking for an answer to a question that was not yet clear at the time: does the brain need external stimuli to be conscious or not?

Two theories were current at the time: without stimulation, brain activity tended to be zero and the body went into sleep. On the other hand, some scientists thought that consciousness was governed within the brain and maintained itself without external excitations.


Having gone to the end of the possible experiments without damaging the brain, he focuses on a non-invasive method to study the issue.
His approach seems simple: to see if the brain really needs stimuli to function, let’s abolish the external stimuli, i.e. the main senses: sight, smell, taste, touch, and hearing.

This is how the first sensory deprivation float tank was born.

Towards floating for all

Word of mouth is spreading and more and more people are flocking to Lilly’s for sensory deprivation workshops.

Among them, engineer Glenn Perry emerged from the isolation chamber literally transformed: ” My senses were heightened and my sense of time was distorted. (…) It was fantastic and I felt in an incredible state. “He who was usually so shy that would easily share his experience with the other participants.

He first decided to build one for his own use and very quickly offered it for sale because the demand was there: all the people who took part in the workshops wanted to “float at home”.

Perry is redesigning to produce more insulating, compact and lightweight tanks that can be easily produced. But as he puts it, “I don’t float well. It must be said that the pool is not very deep. It therefore goes further than Lilly’s recommendations by saturating the water with salt to really float: from an isolation chamber, it becomes a real float tank. He soon turned to Epsom salt or magnesium sulphate, known for its antiseptic and relaxing properties, but above all for its density, which allows easy and unhindered floating.

They both started marketing the first floatation capsules for the general public: the Samadhi.


Football, basketball and baseball stars are adopting it, not only for its concentration and stress-reducing benefits, but also for the undeniable muscle recovery benefits of a session.

Because if sensory deprivation is good for the mind, one realises from the first experiences the positive effects on the body: weightlessness allows an unprecedented relaxation of muscles, joints, tendons and organs.

The first float centre opened in 1979 in Beverly Hills.


The success is there, but the benefits of float therapy make it more than just a fad.

Sportsmen and women, business leaders, artists, intellectuals, will be the best ambassadors for the float sessions. John Lennon, for example, attributed the end of his heroin addiction to sensory isolation.

Apart from the obvious reduction in stress and the beneficial effects on sport, some people take advantage of this moment out of time to focus on a specific problem. Carl Lewis took the opportunity to visualise the perfect gesture for the long jump; he won the gold medal at the Seoul Olympics.

More and more scientists are adopting the float tanks for their experiments. Perry will meet his wife who works with children with learning disabilities and hyperactivity.

As his invention became successful, John Lilly continued his amazing research. He was responsible for the first attempts to communicate with dolphins, participated in the SETI programme, studied the effects of LSD, and was interested in Buddhism, Sufism, meditation and trance practices, always in search of the limits of the mind.

In the 1990s, the popularity of float centres declined. The salesmen explain this change of heart by the fear of AIDS, of which the public is unaware of the transmission vectors.

Nowadays, when calm is a luxury, when modern life multiplies excitements, stimuli, injunctions, when our smartphones and computers do not cease to alert us continuously, floating makes a welcome return in a context of hyperactivity of the senses.


Scientifically proven health benefits

By seeking to deprive the brain of sensations, the scientist has invented a holistic treatment : one that acts on the body, mind and spirit.

More than 200 studies prove the benefits of simply floating in zero gravity, without stimuli, in a wide range of health areas.

At the physical level, the relaxation of muscle tissue, tendons and joints during the session shows positive effects on :

– recovery of athletes,

– chronic or postural pain,

– joint problems, etc.

At the brain level, the drop in cortisol has a lasting effect on anxiety, stress and sleep quality. The ability to concentrate increases, as does creativity.

Out of time and space, free from constraints, the beta brain waves leave more room for their theta “counterparts”, synonymous with a deep meditative state. A unique brain relaxation that increases the feeling of well-being tenfold and relieves symptoms of depression and anxiety.

Find a list of the benefits of floating and the scientific studies published here.

So what are you waiting for to live this once-in-a-lifetime experience in our GRAVITI centres in Bordeaux and Lyon?

Don’t worry: our float pods are a far cry from Lilly’s prototypes.

The latest generation of float capsules, they allow your body to float optimally in a bath at the ideal temperature and offer complete isolation of the senses.

The concentration of Epsom salt and the large size of each tank allow true weightlessness in any position.

Inside the capsule, music accompanies you during the first minutes of the session, and will also be played at the end for a soft landing.

Complete isolation may be prohibitive for some people with excessive anxiety or claustrophobia. Aware of this, we have chosen float tanks in which you can keep the light and music on, and the lid open.

Of course, our centre is at the top of hygiene. Not only do the float pods incorporate optimised filtration and water treatment systems between each session, but we also disinfect all areas: showers, cabins, decompression lounge, etc.

And far from the equipment of the first guinea pigs of sensory deprivation, you will need absolutely nothing, the session being more effective naked. Of course, you can still float around in a swimming costume if you want to.


For almost 70 years, float therapy has been a unique experience in the world and its benefits are still being studied and proven. Contact our centres in Lyon or Bordeaux to experience this unique sensation at least once.