Without sense

There comes a moment, halfway through your session in the isolation tank, when you almost lose your mind. Like a marathon runner hitting the wall of exhaustion, you hit a wall of oblivion. You're floating weightless in a sea of sensory deprivation, feeling nada, seeing nada, and suddenly you can't take it anymore -- the nothingness, the vastness of the void. You want to claw the insides of the tank, beg them to let you out.

Then a funny thing happens. You pass through it -- the wall. You float through to the other side, and just as suddenly you're OK again. And now you don't mind the utter lack of sensation, the zero gravity, the darkness. You experience a feeling of submission, a surrender to the neutralizing forces of the Big Nada. You begin to love the tank.

The isolation tank -- aka sensory deprivation tank, aka flotation tank -- was created back in the 1950s as a government research tool to study the physical origins of consciousness. Scientists hoping to solve the ancient mind-body dichotomy saw the tank as a vehicle for liberating the brain from its routine workload, thereby creating access to a range of higher brain functions.

During the '60s and '70s, the sensory deprivation experience became popular with the counterculture crowd, due in part to the writings of Dr. John Lilly, the neuroscientist, author and acid-dropper who, while working at the National Institute of Mental Health, went looking for altered states of consciousness in the tank. The movie "Altered States" is based on Lilly's explorations.

Isolation tanks fell out of favor during Reagan's '80s, but lately they're gaining new respectability and popularity, as tank-equipped spas and flotation centers pop up around the country. Back in the psychedelic '60s, sensory deprivation was pitched to mind explorers as a porthole to higher consciousness -- whereas now it's peddled more as a quick fix for '90s-style stress.

Tank promoters say that flotation releases muscular tension, reduces stress, bolsters circulation, jacks up your immune system, heightens your powers of concentration and imagination and makes you generally happier and ennui-free. And, the pitch goes, these effects are cumulative -- that is, every time you float you increasingly fortify your body and mind.

So is sensory deprivation the ultimate cure for millennial malaise? Or a throwaway relic of misguided hippiedom? I went to the void to find out.

The H&H Flotation Spa is located in Tenleytown, a trendy shop-and-cafi zone a few miles north of downtown Washington. I arrive on a Sunday afternoon with a straightforward mission: Do a one-hour session in the isolation tank, soak up all immediate impressions, and jot them down for end-point journalistic rendering.

Wanda, my friendly H&H attendant, escorts me through the spa's maze of corridors to a dimly lit room in the back, where I get my first glimpse of the tank. Lilly's original creation was basically a big upright fish tank outfitted for human use, but today's tanks, as advertised on flotation Web sites, are sleek horizontal affairs made of heavy molded plastic or fiberglass. Some high-tech models, built more for recreation than isolation, come equipped with underwater stereos, video systems, aromatherapy vaporizers -- even intercoms.

My tank, however, is the stripped-down model designed for total sensory deprivation -- a plain, all-white monolith with a side hatch for climbing in and out, no high-tech accessories, no frilly accouterments. The tank is about as wide as a twin bed, and stands chest-high. Basically, it looks like a scale model of the space shuttle, sans wings.

The tank room is white-walled and completely bare, except for a shower stall set off in one corner, a bench and a towel rack. Wanda tells me to get naked and rinse off in the shower, then she'll come back and put me in the tank.

And now I begin to experience the first rumblings of pre-tank anxiety. For starters, I've brought along my trusty 6-by-9-inch Universal Steno Book for recording my in-tank impressions, but it dawns on me now -- as I'm peering into the tank's dim interior -- that my notebook cannot possibly go in there, into the watery dark, with me. And I'm going to be sealed inside for a full hour, which means my constitutional inability to remember anything for more than, like, 10 minutes could render the entire tank experience null and void in my consciousness by the time I come scrambling out the hatch -- my journalistic enterprise shot, blown, a bust.

And, too, there's the issue of those hallucinogens I ingested back in college, the residue of which now sits congealed like leftover gravy in my neural network. So, of course, I'm concerned that, once sealed inside the tank, my much-anticipated super-serene sensory deprivation experience will swiftly morph into some godawful flashbacky nightmare -- though of course I won't be able to recall any of this trippy stuff for post-tank documentation due to my absolute notebook-dependency.

It's these stressful issues I'm dealing with when Wanda comes back and says it's tank time. She stands on the tank's far side to raise the hatch as I drop my towel and climb in from the near side. As she's about to lower the door, I toss out a final question: "What should I expect?"

"Are you on acid?" she asks, and when I respond in the negative she says, "Then you probably won't feel much. You'll get really relaxed. You'll feel more relaxed than you ever have before. You might go out of your body."

"Out of my body?"

"You know: out-of-body experience. Mind travel. It's a good thing." She smiles, the hatch comes down and darkness descends.

You lie supine in the tank, exactly as you would in a coffin. The water is 10 inches deep and heated to skin temperature -- 93.5 degrees. A half-ton of magnesium sulfate, commonly known as Epsom salts, is dissolved in the water, making it five times as dense as sea water. So as soon as you stretch out on your back in the shallow water, you come bobbing to the surface like a human cork. There's about two feet between your body and the tank's ceiling, a foot between you and the walls. The sensation is of being entombed in some strange hybrid of a casket and a kiddie pool. This is no place for a claustrophobe.

For the first few minutes I can't see anything at all. Then my vision begins to adjust to the tank's darkness and, by rolling my eyeballs around in their sockets, I can vaguely make out some features of the interior -- the molded walls, the air vents in the ceiling, the razor-thin leak of light from the seams of the hatch.

My face is above water but my ears are submerged, so the sound of my own breathing is amplified to a thunderous level -- it sounds like the loud, labored breathing in scream movies when you're seeing things from the murderer's P.O.V. I can hear my heart thumping out a steady beat, too, and there's a constant thrumming noise that might be a filter running somewhere nearby -- either that or my own blood slurping around in my head, it's hard to tell. Every time I blink, I hear the sinewy hydraulics of my eyelids crank shut and open again. Shut, open. Shut, open.

Getting settled in the tank takes a while. At first I let my arms float out to the sides in a sort of crucifix position, but then I'm startled out of oblivion when my hand drifts into a wall. I push off from the wall, gently, trying to center myself, but I overcompensate and end up sailing all the way across the tank into the opposite wall. For a while I experiment with crossing my hands over my chest, but in that position I'm robbing myself of total sensory deprivation, letting skin touch skin. Finally I settle into the traditional dead man's float -- arms close at my sides, legs straight down. Still, it's hard to stay centered. Little tides and cross-currents send you bopping around the tank. What you need is an anchor.

The water in isolation tanks is periodically filtered and sterilized with a mixture of chlorine and hydrogen peroxide, a process that leaves the water cleaner, they say, than your drinking water. The water in my tank, though, is sort of oily-feeling, syrupy -- almost viscous. There's a briny smell to it. And the encapsulated warmth from the heated water creates a sauna effect that makes it hard, at first, to breathe normally.

Once you get acclimated, though, you really start to relax. Flotation Web sites quote scientists as saying that 90 percent of the brain's workload is generated by routine environmental stimulation -- the collective shock of gravity, temperature, touch, light and sound on the body's muscles, organs and nervous system. As a resident of modern America, you're bombarded by ten zillion sensory stimuli: daytime's bewildering blur of color and light, the night's neon commotion, the endless parade of advertisers' eye-candy, the slamming jackhammers, the screaming firetrucks, the car stereos' cacophony, the B.O. of a half-million rank bodies, the fragrance of uncountable flowers, the stink of tons of rotting garbage -- all jammed into the channels of your neural network, vying for processing.

According to Richard Wurman's book "Information Anxiety," a single weekday edition of the New York Times contains more information than the average person absorbed in an entire lifetime in 17th century England. Modern cars have as many as 100 different pieces of information displayed on the dashboard -- no wonder drivers are wrecking into each other all the time.

All that sensory information is bad for you. It wears down your body, lowers your resistance to illness and injury, upsets your delicate emotional balance, reduces your ability to think clearly and makes you more accident-prone. A 1996 Reuters report titled "Dying for Information" said that one-third of job managers suffer from ill health as a direct consequence of stress related to sensory overload.

In the tank, sealed off from stimulation, good things happen to your body. Stress-related chemicals like adrenaline, lactate and cortisol are filtered from the bloodstream. Heart rate, muscle tension, cell metabolism -- they all drop to healthier levels. Your blood vessels dilate, and circulation to the extremities and GI tract goes up. The level of T-cells rises, boosting your immune system. And your brain releases kaboodles of those feel-good endorphins as you drift into the theta brain state of deepest relaxation.

Weightlessness is cool. When you close your eyes, the feeling of buoyancy transmutes into an enveloping sensation of floating up, up, up. It's as if you've been cut loose from all earthly moorings and set adrift in some amorphous abyss. You could be anywhere -- the womb, the afterworld, the far side of the moon.

But my sensory-deprived state suffers a wicked reversal when, reaching up to swipe beads of sweat from my face, I accidentally dribble a little of the super-salty water into my eyes and spend the next five minutes squinting in pain. Another disruption comes sometime later when the steam that's been condensing on the ceiling begins to drip droplets into the water, making clamorous doink, doink noises as they hit the surface. At one point the drips are dropping squarely onto the center of my forehead, repeatedly but at lengthy intervals -- Chinese water torture.

But mostly its just total nothingness. One truism of the tank experience is that the effect of sensory deprivation on the floater fluctuates in direct proportion to the level of stimulation the floater normally undergoes. That is, if you're accustomed to receiving a heavy load of sensory data, the sudden and total lack of it may drive you absolutely ape-shit.

In the movie "Altered States," William Hurt portrays Dr. Lilly as a renegade genius who undergoes some sort of genetic regression in the tank, emerging as a furry Neanderthal with a taste for the Boston Zoo's gazelles. As you drift deeper and deeper into sensory deficit, you begin to expect some similarly radical transmogrification. You lose the sense of yourself as a corporeal being, a tangible body with organs and appendages. You're just a neural hub, a bodiless thought processor afloat in a borderless vacuum, and when they open the hatch, you fear, they'll find nothing but a swirl of water where your body disappeared. (It's about now that you want to bang on the tank door and scream for Wanda to let you out.)

Then, more toward the end of your session, once you've floated past the freak-out point, you loosen up and slip into pseudo-philosophical silliness. Lilly wrote, "In the province of the mind, in the inside reality, what one believes to be true, either is true or becomes true within certain limits. When so determined, these limits are found to be further beliefs to be transcended."

So, if I believe Lilly's rhetoric is full of shit, then my belief is true within limits that I must then transcend to get at the greater truth of his rhetoric? I'm plumbing the depths of this Zen riddle when Wanda hauls open the hatch.

"How was it?" she says, proffering a dry towel.

"That's an hour? No way!" I'm guessing that something like 15 minutes has passed, but when Wanda displays her watch I see that indeed a full hour has whizzed by. That's the single most remarkable aspect of the tank experience -- your sense of time just positively collapses. Every minute is an hour, every hour a minute. You've got no clue.

Out of the tank and down the hall I'm hustled, first for a 10-minute dip in the whirlpool, then onto the massage table for a thorough rubdown under Wanda's sure, strong hands. Showered and clothed, I emerge from the spa's tranquility into the bustle of Tenleytown.

And now I feel -- what? -- relaxed, rejuvenated, a little loose in the knees, mildly spaced-out. Nothing truly radical, though, no post-tank hallucinations, no burning desire to scale the zoo walls and gobble a gazelle. I have traveled into the void and out the other side, back into the sensory world, basically unaltered.

But when I stop by the supermarket on my way home, I notice a strange after-effect. As I'm steering my cart through the produce section, I get so overwhelmed by sights and smells, so inundated by the flood of sensory data, that I have to actually stop and catch my breath.

For a moment I just stand there, a tourist in a strange land, and look around at everything -- the green grapes over here, the red radishes over there, mountains of golden potatoes and sunny lemons, all on fire with color and emitting their distinctive fragrances, sour and sweet and earthy and tangy. Such abundance of color and shape, such variety of aroma. After an hour of sensory deprivation, my neural receptors have clicked into some sort of infantile overdrive. I can't stop paying attention.

I pick up a Braeburn apple, but instead of bagging it right away I feel the need to hold onto it, turning it around and around in my hand, observing the gently sloping contours, the skin's waxy texture, the microscopic nicks and abrasions accrued in transit from tree to produce bin. There's so much to notice -- the tiny crater that gives rise to the stem, the withered blossom at the butt end, the skin's vertical bands of red and green and the yellow dots clustered in among them like starry constellations.

An apple is a universe. And if you can't see that now, pay a visit to the void.