I quite enjoy your articles. You flush out more quackery than my cousin Billy's Cocobolo Rosewood Duck Holler. So tell me your opinion of those sensory deprivation tanks? I was recently offered an opportunity to try one, but the prospect of emerging as a drowned corpse or worse yet, William Hurt on mushrooms, was just too terrible to imagine.
I won't even try to figure out exactly what your cousin Billy has; I'm just going to assume it's a duck call so that your joke makes sense. Clearly, you're getting a bit too much alone time already, so I'm considering recommending against a sensory deprivation tank. However, since insight into oneself is a definite benefit of time spent floating in these chambers, I cannot deny your need. Perhaps, though, I should consider trying the experience myself, since I'm noticing some unhealthy competitiveness for the cleverest wisecracks.
William Hurt, as you've mentioned, first brought isolation or flotation tanks to the attention of the general public in the 1980 movie, Altered States. In it, he floats naked in total darkness as hallucinogenic drugs physically transform him further and further back along our evolutionary lineage, from caveman to slimy invertebrate. In reality, floating peacefully in a pitch-black, dead-silent chamber on ten inches of salty, body temperature water rarely regresses you into a developmental throw-back (except, perhaps, in the case of comedian Michael Richards). Instead, one usually reports feelings of exceptional pleasure, accompanied by free association of thoughts with frequent visual, and sometimes spiritual, experiences.
In fact, in one of the few studies of the personal experience, more than 70 people were classified according to the intensity of their religious belief--without regard to denomination--from non-religious to devout. After examining reports of their episodes in the tank, it was clear that the intensity of the spiritual nature of the experience was directly related to the strength of their prior beliefs. This phenomenon of "expectation" may explain reports of out-of-body experiences by certain New Age travelers, while most others encounter only relaxation, insight or extraordinary physical rest.
In 1954, Dr. John C. Lilly, a neurophysiologist with strong interest in consciousness, built the first sensory deprivation chamber. His purpose was to solve the debate over what the brain might do without any outside stimulation: enter a deep coma or create it's own activity. In his laboratory, Dr. Lilly was the first to enter an isolation tank, emerging shortly thereafter understanding that an isolated mind does not go to sleep, but is highly creative and active. Over the next few years, Dr. Lilly published three major studies on the broad uses of this technique. Peaking a bit too early, his later career attempts to create a language for human to dolphin communication apparently failed (with the single curious exception of an insult regarding the doctor and a blowhole).
Over the past half-century, isolation chambers have shown potential in treatment of some medical conditions. There are few actual studies, but early data indicates that blood pressure, arthritic and musculoskeletal conditions, as well as chronic pain, may be helped by floating. Additionally, mild psychological conditions like anxiety and depression seem to also respond well to the experience. I suspect, however, that treatment of fear of the dark or claustrophobia might have a low expectation of success. By far, though, these chambers are used for pleasure, leisure or self-exploration into the inner world of the mind.
There are many possible explanations for the effect sensory deprivation has on the human brain. One hypothesis says that isolation from physical input slows or stops most of the activity of the brain's left hemisphere (the analytical logical side). This allows the usually overshadowed right hemisphere (the creative intuitive side) to dominate. Another, slightly nutty idea states that the vast majority of our nervous system is preoccupied with gravity-related coordination, so becoming weightless frees immeasurable energy for internal awareness. The most plausible answer, in my opinion, is a direct neurochemical explanation: clear evidence shows that production of stress hormones (adrenaline and cortisol) decrease, while pleasurable substances (endorphins) increase during the typically hour-long sessions.
John, your fears of trying an isolation tank are understandable, but not really warranted. The chambers may be dark, but all have a lightweight door that will open with a gentle touch. Generally, the only discomfort is the half-ton of dissolved Epsom salt stinging your shaving rash--not usually a problem for a man since the face is above the water. But to avoid agony, you should definitely delay any creative manscaping until after you emerge. Plus, if you come out as a Neanderthal, it would all have to be redone anyway.
Dr. Ed Rabin is a chiropractor practicing at Life Chiropractic Center in Boise. Send Pimsleur Dolphin language tapes and health-related questions to firstname.lastname@example.org (on the Web at www.edrabin.com).