You could sleep for days and think it was a nap.
We take natural light for granted. We don’t realize it, but it gets us up in the morning, takes us through our regular day, and its absence sends us into our nightly slumber. So what happens when our body is deprived of light? Very strange things, indeed.
Two cave explorers, Josie Laures and Antoine Senni, took on a particularly gloomy mission in the name of science — living alone in a dark, desolate cave for months to test the effects of isolation, loneliness, and darkness. They didn’t even have the company of one another; they resided in separate caves a few hundred yards apart.
The only people Laures and Senni stayed in touch with were researchers at a control point who tracked their sleeping and eating habits, as well as memory and vital signs, according to The Atlantic. Laures and Senni weren’t given any insight about how time was passing outside of their dark living holes. When they finally emerged, they had to wear dark goggles to shelter their eyes from the bright sunlight, and their senses of time were insanely warped.
Laures spent 88 days in the cave, while Senni spent 126. When Laures came out of her cave on March 12, 1965, she thought the date was February 25. Senni’s sense of time was even more distorted — just a few days before emerging from his cave on April 5, he thought it was February 4. In their minds, they’d lost months.
Even crazier, the researchers reported that Senni would sleep for stretches of 30 hours at a time, but wake up believing he had just taken a quick nap. Further research done on human physiology in total isolation reveals that humans can even stretch their sleep cycles out for 48 hours.
When it comes down to it, our body’s natural cycle and circadian rhythm rely on natural light, and without it, our physiology goes wonky. The same goes for living in complete isolation — being deprived of interaction of any sort can make us lose our minds. Exhibit A: Tom Hanks making friends with a volleyball in Cast Away.
In fact, Laures and Senni turned to creatures most of us would reject with disgust: rodents. The Atlantic recaps Senni’s experience of spreading jam on cave floor to try and attract a mouse he could keep as a pet. His attempt went awry after he tried to trap the mouse in a dish and, due to poor aim, accidentally crushed the rodent instead. Laures, more fortunate than Senni, reported that a white mouse was her sole companion throughout the whole ordeal.
Since this type of sensory deprivation is often used as a torture technique during wartime, a British study locked up six volunteers in dark, solitary confinement for 48 hours to test its effects. According to the Daily Mail, Adam Bloom, an extroverted stand-up comic, fared particularly terribly. He says at one point, he started singing and then suddenly burst into tears, feeling as if his emotions were running out of control. “Then, I found myself suspecting the whole experiment was a trick,” he recalls. “How did I know who these people really where? What if they’d gone home and I was trapped down there forever?”
He says that the utter darkness caused him to completely lose his sense of time. He’d doze off and then wake up not knowing whether it was night or day, and even meals didn’t help restore a feeling of normalcy. In fact, he and some of the other volunteers actually started hallucinating — a heap of 500 oysters, tiny cars, snakes, zebras, fighter planes, mosquitos, and even the sensation of the room taking off. The BBC went on to produce a documentary using footage of these six volunteers called Total Isolation.
Bottom line: humans need light and interaction to stay sane. Without light, we lose our sense of time, and without interaction, we become consumed with loneliness and boredom. With this sensory deprivation comes the strangest, most unimaginable psychological effects.
Care to see the effects of sensory deprivation with your own eyes? Watch a fascinating clip from Total Isolation as the volunteers begin to hallucinate.