What happens when people spend a lot of time in the dark

Our aversion to darkness is rooted in our eyes. We are daily active creatures, meaning that our ancestors, up to the best natural points, adapted to inflate, navigate and seek shelter while the sun was over. Sure enough from the light of day, our eyes are wonderful. We have an abundance of photoreceptor cells called "cell," which allow us to put them in bold detail: our ancestors could choose the animal's animals on the horizon or see a piece of fruit on a tree and know from the exact shade even though it was mature. But without the sunlight, our eyes are all useless: for our bowel of bowel cells, we lack the other type of photoreceptor – "rod" – that allows low-light vision. As the sun stood every night, our ancestors became vulnerable, transforming them from predator into prey as they entered a world dominated by night hunters, all endowed with strong night vision: lions, hyenas, sword tigers, poisonous snakes. For our ancestors, the height of terror would wander over the savanna in the dark, listening to the legs of the raptor wrapped in the ground.

In the modern West, we are not afraid more of the night ambush with curly-toothed tigers, but we are still climbing in the dark. "After thousands of years," wrote Annie Dillard, "we are still strangers in the dark, afraid of aliens in a hostile camp, with our hands crossing our breasts." I have often been disturbed by the darkness. In child sardine games, hiding in the corner of my father's wardrobe, my heart struck. In the bush of Australia, lifting the glass without a lens, losing sight of the scene, stumbling into the dark, thinking of packs of dingoes. After Hurricane Sandy in New York, walking through Lower Manhattan, down blocks following the block of blackened city grid, the hair hanging on the back of my neck. But these were some darkness, always with a light spot through a keyhole, or a star-glow from the sky. Here the eye will always adapt, the iris will always open to collect the photons. It is not a basement. There is no photon in the darkness of the cave. Here is a heavy, ancient dark, dark book of Genesis.

My thoughts were broken into my body, and I was chewing through my inner architecture. It was the feeling of being peeled open, turned out. I felt the rhythmic sphinx of my heart, my lungs ballooning in my ribs, my epiglottis opened and closed. In the absence of vision, my other senses bloom. The sound of the stream, which I just noticed when I entered the cave, now filled the entire chamber, unfolding in breathing patterns. Smell-mud, wet limestone-thick to the point of aesthetic material. I could try the cave. When a drop of water fell from the ceiling and burst into my forehead, I almost fled from the sleeping bag.

Our first studies on sensory deprivation evolved from an illegal military warfare experiment on mind control. In the early 1950s, Korea brought extracts of American prisoners of war denouncing capitalism and exhorting the virtues of communism. The CIA, convinced that the soldiers had brainwashed, immediately launched a Project Bluebird research initiative in mind control techniques. Part of the research team was a psychologist named Donald Hebb, who offered to conduct an experiment on what is called "aesthetic isolation".

Hebb was not so much interested in brainwashing, but he was very curious about the response of the brain to the absence of stimuli. He wondered about the reports, for example, of the Royal Air Force pilots who, after many hours of flying alone and staring at an unchanging horizon, would suddenly, for apparently no reason, lose control of the plane and crash. And the seafarers, who, after lands overlooking a static sea horizon, watched the bots. And by the Inuit who warned against solo fishing, because without human contact, without visual evidence in a white Arctic landscape, they will be disoriented and fall into the sea, never to return. By examining the neurological reaction to isolation, Hebb wondered if he could answer questions about the brain's structure.

For the X-38 project, Hebb created a four-cell grid with air conditioning and sound insulation, and then recruited volunteers, whom they paid $ 20 a day to be found in cells where they were subjected to "perceptual isolation." Their eyes, the people they wore froze plastic protective glasses that blocked the "draft vision". To reduce tactile stimulation, they wore cotton gloves and cardboard handcuffs. Above their ears, a U-shaped foam cushion. The cells were equipped with observation windows, as well as intercommunication so that the research team could communicate with themes. Hebb instructed his volunteers to stay in the cells for as long as they could.

Initially, Hebb honestly expressed the X-38 Project, joking that the worst part of the isolation on the subjects would be the meals prepared by his post-doctoral students. When the results came, however, he was surprised: the disorientation of the subjects was far more extreme than he had imagined. A volunteer, at the end of the study, pulled out of the lab and crashed his car. In several cases, when people took a break to relieve themselves, they lost to the bathroom and had to call a researcher to help them find the way out.

The most impressive were the illusions. Just a few hours isolated, almost all the issues saw and felt things that did not exist there. First there will be pulsating signs and simple geometric motifs. these were developed into complex individual images around the room, which then evolved into elaborately integrated sceneries that play out of the eyes of the subjects – "they dream when they wake up," as a participant described it. A participant reportedly was watching a squirrel parade deliberately in a snowy field, wearing snowballs and backpacks while another saw a bathtub headed by an old man with a metal helmet. In a particularly extreme case, a subject faced a second version of himself in the room: he and his appearance began to mix together until he was unable to discern who was who. "It's one thing," Hebb wrote, "to hear that the Chinese brainwashes their prisoners on the other side of the world. It's another thing to find in your lab that you just remove ordinary images, sounds and physical contacts a healthy university student for a few days can shake him up to the bottom: he can upset his personal identity. "

Today, the neurological mechanism behind these reactions is more or less understood. At any given moment, our brain receives a stream of sensory information – visual, acoustic, tactile, and so on. We are so familiar with this input stream that when cut off, our brain produces virtually its own stimuli. It identifies its own motifs, combining a small glimpse into the visual cortex with the images stored in memory to design scenes that can be lively, yet disconnected from the present reality. During a particularly luminous experiment in 2007, researchers at the Max Planck Institute of Brainstorm Study in Frankfurt worked with a German artist Marietta Schwarz, who volunteered to live with an eye for twenty-two days. Blindversuch, as it was called Schwarz's work, was part of a larger work of art called Space Knowledge, which incorporated interviews with the blind about perception, image, space and art. Schwarz was sitting with his eyes at the lab, recording a Dictaphone in a real-time, real-time calendar of everything that's going on in his brain. It reports a series of illusions, including complex abstract motifs, such as bright amoeba, yellow clouds and animal prints. The researchers, meanwhile, have used a fMRI scanner, which monitors changes in blood flow in the brain – to follow the neurological functions behind its hallucinations. Despite the total absence of visual entry, Schwarz's visual cortex was illuminated like a traffic light, just as if it were not blind.

That is, in the world of her brain, hallucinations were as real and real as anything she could touch or taste or smell.

Excerpt from UNDERGROUND: A Human History of the Worlds Under Our Feet, © 2018 by Will Hunt. Reprinted with permission from Spiegel & Grau.