Isolation Tank Stages Of Experience

Exerpts of J. C. Lilly

"We have been seeking answers to the queston of what happens to a brain & its contained mind in the relative absence of physical stimulation. In neurophysiology, this is one form of the question: Freed of normal efferent and afferent activities, does the activity of the brain soon become that of coma or sleep, or is there some inherent mechanism which keeps it going, a pacemaker of the "awake" type of activity" -JCL


In our experiments, the subject is suspended with the body and all but the top of the head immersed in a tank containing slowly flowing water at 34.5 degrees C. (94.5 degrees F.), wears a blacked-out mask (enclosing the whole head) for breathing and wears nothing else. The water temperature is such that the subject feels neither hot nor cold. The experience is such that one actually feels the supports and the mask, but not much else; a large fraction of the usual pressures on the body caused by gravity are lacking. The sound level is low, one hears only one's own breathing and some faint water sounds from the piping; the water-air interface does not transmit airborne sounds very efficiently. It is one of the most even and monotonous environments I have experienced. After the initial training period, no observer is present. Immediately after exposure, the subject writes personal notes on his experience.

In these experiments, the subject always has a full nights rest before entering the tank. Instructions are to inhibit all movement as far as possible. An initial set of training exposures overcomes the fears of the situation itself.


In the tank, the following stages have been experienced

(1) For about the first three-quarters of an hour, the day's residues are predominant. One is aware of the surroundings, recent problems, etc.

(2) Gradually, one begins to relax and more or less enjoy the experience. The feeling of being isolated in space and having nothing to do is restful and relaxing at this stage.

(3) But slowly, during the next hour, a tension develops which can be called a "stimulus-action" hunger; hidden methods of self-stimulation develop: twitching muscles, slows swimming movements (which cause sensations as the water flows by the skin), stroking one finger with another, etc. If one can inhibit such maneuvers long enough, intense satisfaction is derived from later self-stimulations.

(4) If inhibition can win out, the tension may ultimately develop to the point of forcing the subject to leave the tank.

(5) Meanwhile, the attention is drawn powerfully to any residual stimulus: the mask, the suspension, each come in for their share of concentration. Such residual stimuli become the whole content of consciousness to an almost unbearable degree.

(6) If this stage is passed without leaving the tank, one notices that one's thoughts have shifted from a directed type of thinking about problems to reveries and fantasies of a highly personal and emotionally charged nature. These are too personal to relate publicly, and probably vary greatly from subject to subject. The individual reactions to such fantasy material also probably varies considerably, from complete suppression to relaxing and enjoying them.

(7) If the tension and the fantasies are withstood, one may experience the furthest stage which we have yet explored: projection of visual imagery. I have seen this once, after a two-and-one-half hour period. The black curtain in front of the eyes (such as one "sees" in a dark room with eyes closed) gradually opens out into a three-dimensional dark, empty space in front of the body. This phenomenon captures one's interest immediately, and one waits to find out what comes next. Gradually forms of the type sometimes seen in hypnogogic states appear. In this case they were small, strangely shared objects with selfluminous borders. A tunnel whose inside "space" seemed to be emitting a blue light then appeared straight ahead. About this time this experiment was terminated by a leakage of water into the mask through a faulty connector to the inspiratory tube

In our experiments, we notice that after immersion the day apparently is started over, i.e. the subject feels as if he has just arisen from bed afresh, this effect persists, and the subject finds he is out of step with the clock for the rest of that day. He also has to re-adjust to social intercourse in subtle ways. The night of the day of the exposure he finds that his bed exerts great pressure against his body. No bed is as comfortable as floating in water.


One day in 1958 John entered the tank room, put on the mask, and immersed himself in the water for the last time at the National Institutes of Health. He had finally realized that within the government it was impossible to do the research that he wished to do. Inevitably, subtly, those in charge of research for the National Institute of Mental Health were asking to control the isolation-tank work. And those in charge of brain research in the National Institute of Neurological Diseases and Blindness were beginning to exert controls on the work on the brain. In this session in the tank, he planned to review what he had learned over the last five years in regard to research on the brain and the mind and the support of this research.

John went through his now more-or-less standard procedure of relaxing every muscle in his body while floating in the water. He then relaxed his mind and let go of the residues of the day's activities. Quite suddenly he was in a new space, a new domain.

He left his human body behind. He left his human mind behind. He became a point of consciousness, of awareness, in an empty, infinite space filled with light.

Slowly two presences, two Beings, began to approach him from a distance. There was a three-way exchange of direct thought, of direct meaning, of direct feeling with no words.

Later he was to write up the experience as if words were used, as if the two Beings had spoken to him in English, as if he had become the Third Being.

The conference of the three Beings was taking place in a dimensionless space, the spaceless set of dimensions somewhere near the third planet of a small solar system dominated by a type-G star. The organization which they represented he would later call the Earth Coincidence Control Office (ECCO).

The First Being speaks: "We are meeting at this particular space-time juncture in order to review the evolution of a vehicle that we control on the planet Earth. He is at another transition point in his training. We need to review what he has done, what he is thinking, what his motivations are. We must determine what the future of his mission can be within the evolutionary speed limit allowed the humans on that planet."

Second Being: "You, the First Being, and I, the Second Being, have been controlling the coordination of coincidences of this agent on Earth. I feel it is important that we state all of this very clearly for the benefit of the Third Being, who has been responsible for that human agent. It is important that he not exceed the evolutionary speed limit at this particular time; however, we realize that there is a certain discrepancy existing among the humans, that their evolution is proceeding extremely rapidly in certain areas and is going backward in others. It is the purpose of this conference among the three of us to make sure that the Third Being controls him so that he stays within certain well-defined limits and avoids the kinds of catastrophes certain other agents of ours have experienced o:n that planet. Let us listen to the report of the Being who has been in charge of the vehicle on the planet."

Third Being: "Currently my agent is in a quandary. I need this conference to know in what direction he is to move next. The vehicle that he inhabits is now in a deep trance state and is willing to share with us the sources of this quandary.

"As you both know he has a carefully constructed cover story in which he has invested a good deal of time, effort, and training. All three of us are well acquainted with the rather arduous steps that he has been taking in his human form. There have been many times when he has lost contact with me, has repressed his knowledge of me, and has had to be guided through his unconscious mind. There were times when he had too much knowledge of me, necessitating repression so that he could continue to function as an acceptable human being in the society in which he lives. His main worry at times was being made persona non grata by his fellow humans in various fields of endeavor. "He went through a process which humans call psychoanalysis. Psychoanalysis to us is a means of educating humans in how to remain human, at the same time keeping sufficient independence of that state so as to be aware of our existence. Psychoanalysis also furnishes the human agents with the current rationalizations and basic assumptions upon which humans operate. It helps them develop their cover story so that they will not reveal our existence or our influence. It allows them to reconstruct their past history and understand it in terms of the present human society.

"In the area of self-awareness, his awareness of me, of his deeper self, our agent is on the threshold of recognizing us and our influence on him.

"In his brain research he has discovered the difference between small brains (monkeys) and large brains (human and dolphin). He has realized that in order to do research on the brain and the mind, he must work in an institution which he himself controls, insofar as is possible in the current human reality. He sees that human society interacts with him in a way that allows certain areas of research and not others. He realizes that the laboratory work in relation to the isolation tank is difficult to support. He has learned that the brain work can be supported openly and that the tank work must be done covertly. As long as the tank work was done in solitude, he was unimpeded in the directions in which he could carry it. "He is becoming aware of the political and social realities of what he is doing. His mission to thoroughly investigate the brain with thousands of electrodes and with feedback between his own brain and its recorded activity has implications which he knows he cannot reveal at the present state of development of the human species. His analyst taught him to look more critically at this particular aspect of his mission. His work for the last five years has been in the direction of perfecting electrodes so that he can use them safely in his own brain. He found on monkeys and dolphins that this was not a safe procedure. The brain sections revealed damage along every electrode track to the extent that he would not wish to insert electrodes into himself or another human.

"From his interactions with the government agency in which he has worked, he finally realizes that the isolation tank gives him more information in more dimensions than can be absorbed by those in control.

"He now wishes to abandon the study of electrodes. They are too damaging to brains. He wants to pursue other methods not including brain electrodes or damage to either his own brain or monkey or dolphin brains.

"His work to date with dolphins has convinced him that they are quite as intelligent, quite as ethical, quite as sentient as humans.

"He realizes that his first marriage is to a person with whom he cannot share any important considerations. He wishes to obtain a divorce and hopes that he can find a dyadic partner who will share his particular aims and his particular mission."

Second Being: "What are his basic beliefs about the existence of the Third Being and about us?" Third Being: "He is oscillating between two belief systems. In the first he believes that the mind is the computational software of the brain, that the brain evolved on the planet Earth from the forebears of Man and generated Man's consciousness. In the second system, he believes in us. This belief is contaminated by his childhood faith in the soul. He has yet to develop a pure, integrated view of the mind as an entity not contained in the brain. He has yet to give up the view that the brain contains a computed :mind plus access to w through means at present unknown on the planet Earth. When he is in the isolation tank for a sufficient period of time, the second belief system begins to take over. When he is in the laboratory or dealing with the realities of the support of his research, the contained-mind belief system takes over."

Second Being: "I would like to suggest that we arrange for his education in more profound ways. He still needs to penetrate into his own mind deeply in the areas of interest to us."

Third Being: "He is making progress in that direction. Currently his plans are to establish his own laboratory in an isolated location in the Virgin Islands in the Caribbean Sea for research with intact dolphins."

First Being: "When he leaves the government and goes to the Virgin Islands, I suggest that we control the coincidences in the direction of encouraging the dolphin research. He has much to learn about the Beings known as dolphins. We must also control the coincidences in regard to his seeking a female partner for a dyed. He has much to learn here, not all of which can be taught him without some pain. He is not yet in sympathy with the female mind among humans on his planet. He projects too much of himself, not realizing that there are two universes of humans, male and female. Nor is he aware that in the human social reality there are many substructures of the male-female relationship. In his first marriage he was more or less detached. He must now learn to attack negatively to find the parameters of balance in the dyadic domain."

Second Being: "It is felt that coincidences must be regulated to help him continue the isolation work under better circumstances. We should also arrange for him to use L-S-D- as in the tank."

Third Being: "We must continue our cover of our existence in his mind: if he is too aware of us at his current stage of training, he will be unable to operate in the human realities. I suggest that we temporarily cut off his awareness of us until later, when he is better prepared to deal with our existence."

First Being: "Let us adjourn this conference and meet at some future time in regard to our business with this agent."


"Various L-S-D pushers at N.I.M.H. were insisting that I take it but I didn't until ten years Ister. I finally took it in the isolation tank in St. Thomas in the Virgin Islands with three dolphins there. I took L-S-D for the first time, in the tank, with three dolphins under it in a sea pool. I was scared shitless. It was 300 micrograms injected intramuscularly. As I climbed over the wall mto the saltwater, a memorandum, from N.l.M.H. appeared before me:

"Never take L-S-D alone."

"That's when I learned that fear can propel you in a rocketship to far out places. That first trip was a propulsion into domains and realities that I couldn't even recount when I came back. But I knew that I had expanded way beyond anything I had ever experienced before, and as I was squeezed back into the human frame, I cried.". - JCL

Experiences from other Tank Accounts

Tank accounts

"During a session in an isolation tank, constructed over a pool where dolphins were swimming, I participated in a conversation between the dolphins. It drove me crazy, there was too much information, they communicated so fast..." --JCL

S. Grof, male, 42 yrs; no time recorded

After about five minutes, enormous slowing down of time. Increasing stability, tranquility, a certain "inorganic quality of consciousness"_moving away from its biological characteristics. Atmosphere of ancient Egypt, becoming aware of her religion, philosophy and art. Insights into the process of mummification, becoming a mummy and experiencing the consciousness typical for it. Understanding it as an interspace vehicle



Moving into the initiation in the pyramids, feeling a parallel between a mummy and an adept in the sarcophagus. Awareness of granite, becoming the consciousness of granite. Understanding that the preoccupation with granite in Egypt was based on the appreciation of the state of consciousness associated with it. Changes occur on a scale of thousands and millions of years (as compared to seconds and minutes for the biological forms). Return of an old insight: Granite statues are the deities, not images thereof.

Moving into absolute void (experienced as consciousness of the interstellar space). Timelessness. No difference between minutes and millions of years.

Ending up the experience with feelings of regeneration, purification, refreshment, rejuvenation, clarity.

9 July 1973 J. Hart, no data given; 1 hour, 30 minutes

--From 11:15 A.M To 12 :45 P.M-- My first problem in the tank was to relax my tense muscles. I was holding myself in a floating position as if I were in fresh water. My hands were at my sides and my neck was arched; this was very uncomfortable. By putting my hands behind my head I could relieve the tension in my neck somewhat. Then came a part by part relaxation of my whole body until I could experience the saltwater supporting me, and the realization that I didn't have to keep myself afloat. With the awareness of being supported in the water, came the remembrance of becoming a green dolphin in a space I entered on a trip in Chile. The joy of moving swiftly and sensuously through the water I could now feel in the isolation tank. So once again I hecame the green dolphin diving, leaping, turning, twisting in really real joy. My body seemed to be going through these large swift moves of a dolphin, but when I rose to Joe from time to time I was aware of just the slightest actual movement of my body which was magnified into the sensation of the broad movements of the dolphin. Being a dolphin I felt a tremendous warmth and love flowing out of me. It was light, joyful, playful and delicious. At this point John checked to see if I was coping and all I could do was laugh in delight. From the dolphin space I moved into concentration on the heart center to increase the sensation of love. To do this I moved my energy from the O chakra up the rest of the chakras to the Ma'h; then brought the light down through the Ma'h [top of head], the Path [head], the 0th [chest], the Kath [abdomen] to the O chakra again. Once this circular movement of energy started, like tumo [Tibetan energy source in belly], my body heat went up and I became uncomfortably warm in the tank. So I simply moved the energy from the Ma'h to the 0th and reduced the heat. Finally, I simply rested in the 0th without any effort of concentration. My respiration and heartbeat lowered and I found that the water was becoming a little cool. Curious. So I increased the concentration on the 0th and my temperature went up to a comfortable level. Then I got out.

2 October 1975 N. E. Hellman, female, 39 yrs; 114 lbs 5' 5"; 45 minutes

Silk . . . How sweet my hand felt traveling the length of my body. Difficulty in forgetting the back of my head and neck. Effort to relay there most conscious thought (throughout the forty-five minutes) after a few arm-raising exercises first pleasant thought: I am with myself. Soon discovered my eyes open offered same experience as closed so I opened them wide and felt truly blind_(later this ease at relinquishing sight surprised me. I am an artist and certainly rely on my ability to see). I consciously tried for both blindness and deafness but unwilling to relinquish concept of hearing. I knew I could hear and provided myself with my heartbeat as proof_I thought about John's reference to a stabbing_becoming the woman stabbed and wondering what the pain would be like_ thinking in that state perhaps it would be reassuring_and that without it *_I circled on an axis my interior turning slowly (in my head) yet feeling my body cruising_I felt I understood both the barriers and ever-providing space_no matter what direction I traveled, it never felt bounded.

I would have loved to have been a little high_feeling perhaps closer to lingering less consciously on ideas. For a moment I felt myself in the glith without my usual "gear" and it seemed a different ball game altogether. I feel "curiouser and curiouser" that is where I'd like to begin again--empty of uniform.

Present Day Tanks

In the original concept, the solitude, isolation and confinement tank was devised as a research instrument in 1954. In the ensuing twenty-three years of working with tanks, I have found various ways of making the apparatus simpler and safer.

In the original tanks, we were required to wear rather complicated head masks in order to breathe underwater. These have been eliminated completely.

In the latest models of tanks, we use a saturated solution of Epsom salts ( MgSO4 - 7H2O ) at a solution density of 1.30 grams per cubic centimeter. It was discovered that this density of solution allows one to float supine and have the whole body at or near the surface of the liquid. One's hands float, one's arms, legs, feet and, most important, one's head, float. We have found that even the thinnest person with the least amount of fat floats in this way in the tank.

With these simplifications of the technique it has turned out that we have devised a method of attaining the deepest rest that we have ever experienced. The research instrument has become a practical possibility for use by those untrained in research.

These simpler, salt-water tanks are offered commercially.