Below the Edge of Darkness Read online

  The most intriguing thing to me about NDEs is their commonalities. Sometime later, when I read Elisabeth Kübler-Ross’s On Death and Dying, I discovered that my experience was not unique. A frequently cited feature of NDEs is the sense of peace felt both during and immediately after the experience. All the usual brain chatter related to time and tasks is silenced. After my NDE, I felt present, fully in the moment, in a way that I had never experienced before and haven’t since. I was the opposite of solitary and separate, but rather at one with, and connected to, everything. As a result, I was unfazed by the fact that when I regained consciousness I was a total mess—a veritable pincushion with tubes and wires running everywhere, on a breathing machine with a tube down my throat that prevented me from speaking. And I was blind.

  It’s strange, in retrospect, that none of this bothered me in the slightest. When the doctors and my parents explained to me what had happened, it all sounded familiar and understandable. Somehow, I was at peace with it.*5 In fact, I had accepted my blindness so completely that I didn’t tell anyone I couldn’t see until several days after the surgery, and when I did say it out loud, it still didn’t seem that important.

  That sense of peace lasted for a week in the ICU and persisted for a few more days after I was moved to the pediatric ward in the Wyman wing of the hospital. At eighteen years old, I no longer qualified for that ward, but it was the only floor with an available observation room where the nurses could keep an eye on high-risk patients. I would remain there for the next four months.

  Once out of the ICU, I was allowed visitors other than family. Friends brought flowers, including one especially beautiful bouquet of roses that everyone commented on when they entered my room. On one such day, someone mentioned the beautiful “yellow” roses. Wait. WHAT? Yellow? I felt a shock of adrenaline as I abruptly came to grips with the extent of my blindness. It was as if someone had slapped me awake. I thought the roses were red, but that’s merely the color I assumed they were. My analytical brain jump-started and I quickly ran through an assessment of what I could actually see. The answer was not much. I couldn’t see the roses; I had just imagined them to look like stereotypical red roses. I couldn’t see the door to my room, but I had mentally sketched it in based on the direction of sounds as people entered and exited. I couldn’t even see my own hand held up in front of my face; I just knew it was there because I could feel myself holding it up.

  I thought I was seeing the people I knew who visited me, but now I realized that, too, was a fabrication of my imagination, because I couldn’t remember the faces of any of the parade of doctors, nurses, and technicians coming in and out of my room every day—faces I hadn’t met before I crumped. There were brief glimpses of light and shadow, but no real visual information.

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  The disparity between light and dark is striking, so much so that it figures significantly in many creation stories. Out of darkness and nothingness come light and somethingness. We associate darkness with chaos and light with a sense of order, but that order is contingent upon the capacity to see and make sense of what the light reveals. Being able to detect light and dark is certainly better than nothing, but it’s a far cry from the phenomenal advantages afforded by true eyesight.

  Vision occurs in three phases. Phase one happens in the eye, which, like a camera, focuses an image of the world onto a light-sensitive surface. But where a camera uses film, our eyes have retinas, each composed of 126 million light-sensitive cells called photoreceptors. Phase two converts light energy into electrical signals that travel through a sequential series of neurons to the brain. And in phase three, the brain interprets those electrical signals, forming a mental image. That’s the purpose of vision: to create a link between the physical world and that all-important central processor, the brain. The survival advantage that results from being able to respond appropriately to threats and opportunities requires much more than just recognizing images. Objects must be identified from multiple perspectives, distances gauged, and motion and trajectories calculated. And all of this needs to be possible even when the viewer is on the move. The fact that when you tilt your head, the whole world doesn’t appear to tilt is just one small example of the enormous processing power your brain affords.

  How our visual system handles information reveals a lot about our perception biases. For example, we are far more interested in detecting contrast—differences in intensity—than we are in absolute intensities. There are some fantastic optical illusions that demonstrate this. One of my favorites is what’s known as the checker shadow illusion, which is a shades-of-gray graphic of a checkerboard with a large cylinder sitting on one corner. The scene is side-lit, creating a shadow of the cylinder across the board. It looks perfectly reasonable until someone tells you that one of the “white” squares inside the shadow is the exact same shade of gray as one of the “black” squares outside the shadow. Nobody believes it. The only way to convince yourself that it’s true is by somehow eliminating the surrounding cues that your brain is using to interpret the scene. For example, you can cut out the two squares and hold them side by side. They really are the same, but when you view them as part of the whole scene, your brain adjusts your perception by pumping up the apparent brightness of the one in shadow, thereby enhancing the contrast.

  At the neural level, this contrast bias can be detected by measuring the electrical activity of ganglion cells in the retina. A ganglion cell, which receives input from a small patch of photoreceptors, gives a much bigger electrical response to a small spot of light shining on the center of that patch than to diffuse illumination across the whole area. And farther up the chain, in the optical processing center of the brain, neurons are so enamored of contrast that they are essentially unresponsive to uniform illumination.

  Individual cells are also biased in favor of detecting movement. You can demonstrate this if you place someone before a motionless scene, secure their head with a skull clamp, and anesthetize their eye muscles.*6 With no motion in their visual field, they become essentially blind. You can sometimes approximate this effect when you “zone out” in a relaxed state, staring fixedly at a point without moving or blinking, causing your peripheral vision to “white out.”

  For the brain to make sense of the three-dimensional world based on the upside-down, two-dimensional image projected on the retina, it must deal with an astonishing amount of ambiguity. In fact, for any retinal image there is actually an infinite number of possible three-dimensional forms that might have generated it. Consequently, the brain is constantly having to extrapolate information from sparse input.

  One of the early investigators working on how the brain interprets sensory input was Karl Lashley (1890–1958), an American scientist best known for his research on learning and memory. Lashley suffered from migraines so intense that they were both figuratively and literally blinding. During one such attack, he made the intriguing observation that, while the area of complete blindness in the center of his visual field obscured the head of the colleague he was looking at, the vertical stripes on the wallpaper behind him appeared to pass right through where his colleague’s head should be. If the man’s head had been visible, it would have masked the stripes, but in the absence of actual input from that part of the visual field, Lashley’s brain filled in the most likely image based on the surrounding visual field. That’s a heck of a trick, but it’s a trick that should give you pause and raise questions about how much of what you see is biased by what you expect to see.

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  My vision loss was in phase one. I had hemorrhaged into the large space between where light is focused at the front of the eye (through the cornea and lens) and the retina, at the back of the eye. This region, known as the vitreous chamber, is filled with a transparent, colorless, gel-like substance called the vitreous humor, which functions primarily to hold the spherical shape of the eye, transmitting l
ight unimpeded with a sharp focus on the retina.

  The process of vision depends on being able to make comparisons between light rays coming from different directions. Two factors determine performance: sensitivity and resolution. Sensitivity is all about the number of photons it takes to generate a recognizable signal. Resolution is akin to the number of pixels that make up a photograph—specifically, it is the number of photoreceptors per area of retina in combination with the clarity of the image created by the eye’s optics.

  The blood that had leaked into my eyes was absorbing and scattering the light, thereby impeding both sensitivity and resolution. Through my right eye I could make out a little light, but the left eye was a full eight-ball hemorrhage, letting virtually nothing in. My visual world was swirling darkness with occasional glimpses of meaningless light.

  The doctors were distressingly noncommittal about my prognosis. There was so much blood in the vitreous humors that they couldn’t see the retinas, which meant they couldn’t be sure they hadn’t detached. All they would say was that the body would clear blood from the vitreous chamber, but it can take months. There was nothing to be done but wait and hope for the best. In the interim, I was simply trying to hang on tight to the roller coaster of recovering from major trauma. It’s a freakish, terrifying ride, where the lows always seem so much lower than the highs.

  Then they discovered a massive infection in my surgical site, and cleaning out that pocket of infection required emergency surgery. This was done with only local anesthetic, because of concerns that general anesthesia may have contributed to the DIC. It was agonizing*7 and terrifying and had to be repeated every other day for a month. At the same time, I was receiving antibiotics intravenously at maximum dosages that burned through my veins and required lots of poking and prodding with IV needles to reestablish the drip. I had a variety of interesting adverse reactions to the different antibiotics, like rashes and boils. Then, just as those woes subsided, I came down with serum hepatitis, thanks to the twenty-three blood transfusions I had received. This involved intense liver pain, lots of vomiting, and a general yellow tinge that looked like a cheap spray-on tan.

  And somewhere in the midst of all this, my doctor informed me that my spinal fusion was no good. The “glue” for the fusion was supposed to be made of bone chips taken from my hip and packed around my vertebrae. However, as my doctor regretfully explained, all the flipping around I had done on the recovery room table had sent the bone chips flying: X-rays revealed there was virtually nothing left to grow into a fusion. I was devastated. It was inconceivable that I had suffered through all this for nothing.

  Everything that was happening to me seemed so out of my control that I came to realize that my only power came from my mindset. Small things mattered a lot. The big picture was far too scary to contemplate. It was like being trapped on the side of a cliff face with no clue how long I would have to climb to reach safety. “Don’t look down” is good advice if doing so will give you vertigo; “don’t look up” is also sage counsel if there is no end in sight. The only thing I could do, I realized, was concentrate on finding that next handhold.

  That ability to shift mental focus became my key to coping with what seemed like an endless series of setbacks. Instead of looking ahead toward a very uncertain and possibly highly debilitated future, or backward to dwell on all I had lost, I pulled my focus in tight and concentrated simply on not panicking. It’s a mind control trick that would later come to serve me well.

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  The human brain has been called the most complex structure in the universe. Since we know so little about the universe, there seems a reasonable chance this might be overstating the case, but there is no question that it’s an impressive collection of cells. What we think of as reality is merely a construct of our brains. We can’t begin to appreciate or comprehend to what extent our understanding is biased by our brain’s filtering of all the data that streams in through our sensors.

  If you think your senses provide a true interpretation of the world around you, then consider this: The conduction velocities of the electrical signals coming in from your various senses are not all the same. They don’t arrive at the same time, and yet your brain adjusts things so you perceive them as doing so. If you watch your puppy nip your nose and then your toe, for example, you’d perceive, in both cases, that the sight of the nip and the feel of it occurred simultaneously, even though the travel time from the toe to the brain takes longer (about thirty extra milliseconds) than from the nose to the brain. And besides dealing with varying conduction distances, the brain must cope with different processing times. It takes almost five times longer for the brain to process sights than sounds (about fifty milliseconds as opposed to ten milliseconds). On the other hand, light travels through air about 880,000 times faster than sound, which is why you see the lightning strike before you hear it. Given these differences, it turns out that the sweet spot for humans, what’s known as the horizon of simultaneity, is approximately thirty to fifty feet from the observer. At closer distances, what you hear precedes what you see, whereas farther away it’s the reverse. Yet if you watch someone clap their hands, it doesn’t matter if they’re right in front of you or fifty feet away—in both cases, your brain will tell you that the sight and the sound occurred simultaneously. If you don’t think this is utterly extraordinary, then you need to close your eyes and try to imagine your life playing out as a badly synced movie.

  The point is that our brains aren’t simply passive receivers of sensory input. How we experience the world is the result of a dialogue between the senses and the brain that integrates data from the external world with calculations and forecasts from our inner central processor. This dialogue evolved to enhance our chances of survival. We see, hear, smell, taste, and feel only what is needed. Much is hidden, but our ingenuity provides a capacity for revealing what is concealed from our immediate senses, if only we choose to see.

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  My recovery roller-coaster highs were few and far between, and when they did occur, it was difficult to trust them, knowing that they could be yanked away by some new complication at any moment. There was no single moment when I knew my vision would return. Rather, it was an achingly slow process. Initially, it was like seeing through a dirty, heavy lace curtain that moved around a lot, but if I stared long enough at something that didn’t move, I could gather sufficient glimpses through my right eye to piece together an image. Eventually my sight came back enough that my father brought me a book to read—one he had selected for its length rather than its subject matter, so he was unaware that Love Story is about a young woman who dies of a blood disease. It was a short book, but it took me an inordinately long time to read; I had to hold my finger under each word, waiting for a passing hole in my blood curtain, but eventually I finished. And it felt like such a triumph to get through it that the downer ending had little impact.

  My highest high came at the beginning of May, when I was finally allowed to sit up for the first time. To make this possible, I was fitted with a back brace that looked like a corset and was intended to provide support to compensate for my diminished muscle mass; I was told that the infection had eaten away 50 percent of the muscles in my lower back. The hole had begun to fill in with scar tissue, but there was still sterile packing that needed to be changed every couple of days. The day the doctor appeared in my room with the brace was one I had been anticipating for weeks. He slid the brace under me and cinched it up. Then, as I lay on my side with my legs extending over the edge of the bed, he rotated me into a sitting position. It was the first time I had been upright in three months. I was taking in all the sensations of being vertical when one of my favorite floor nurses walked by my room. I called out, “Hey, Adrienne, look at me!” and then I dissolved into tears, overwhelmed by happiness.

  There was indeed much to be happy about; this outcome had been in
serious doubt. As it turned out, my doctor’s pronouncement that the spinal fusion had failed proved untrue. Instead, I was the beneficiary of a totally unexpected medical phenomenon: The massive infection in my back had produced increased calcification at the site of the fusion. Even though most of the bone chips had dispersed, a few had stayed put, and these had been enough to seed bone growth and create a solid fusion.

  It was the end of May when I was finally allowed to leave the hospital. My sight had greatly improved, and the car ride was a visual cornucopia. I’d entered the hospital at the beginning of February; the trees had been bare and there was snow on the ground. Now everything was green and lush. The leaves on the trees vibrated with color and life. I felt desperate to drink them in. The heavy lace curtain in my right eye had broken apart and turned into floaters, dark spots that drifted through my field of vision—a distraction, but not a hindrance. My left eye was also progressing. A lot more light came through, although more around the edges than in the center. Turning onto our tree-lined street and seeing our two-story white clapboard house, with a magnificent spray of bright red tulips lining the walkway, I felt humbly grateful and elated all at once. Even the sight of the stairs leading to the front door and the longer flight to my bedroom on the second floor was exhilarating. Getting up those stairs the first time was tough, but with each day it got easier, and I was highly motivated. After four months of captivity, I was desperate to be outside. Five days after returning home, I managed to walk to my old climbing tree by the edge of the pond and give it a pat.