Scientists Created "Ghosts" in the Lab

istock collage
istock collage

Have you ever experienced the creepy sensation that you’re not the only person in the room? You get a chill, maybe the hair on the back of your neck stands up, and for a second you think maybe you do believe in ghosts. 

This sensation is commonly reported in people with certain neurological or psychiatric disorders, or those exposed to extreme conditions. In 1970, mountaineer Reinhold Messner reported seeing a “phantom” climber descending the slopes of a particularly extreme summit alongside him. This also happens in people who have recently experienced another extreme condition: the loss of a spouse. In most cases, the sufferer reports the very real sensation of an unseen presence. This is the stuff of which ghost stories are made, but researchers say they know why this feeling occurs, and they’ve even recreated it in the lab. 

Olaf Blanke, a researcher from the Swiss Federal Institute of Technology in Lausanne, Switzerland (EPFL), first had to find the scientific culprit for these strange sensations. He and his team analyzed brain scans of patients suffering from neurological disorders who experience the ghostly feeling. They found abnormalities in the areas controlling how the brain sees the body, or one’s own spatial self-awareness. These abnormalities “can sometimes create a second representation of one’s own body, which is no longer perceived as ‘me’ but as someone else, a ‘presence,’” says Giulio Rognini, who led the study. 

Armed with an understanding of where the feeling of being haunted comes from, the researchers set out to recreate it in “healthy” people. A group of subjects—oblivious as to the experiment’s purpose—were blindfolded, their fingers connected to a robotic device. When the test subjects moved the device, a robotic arm behind them mimicked the movement, poking them in the back. Sounds pretty straightforward, but when researchers introduced a slight delay between the subject’s movement and the resulting poke, the subjects were spooked. They felt they were being touched by another presence. Some even reported sensing more than one “ghost.” 

“Actually some subjects reacted very strongly and they reported not only that they felt that somebody else was touching them but that somebody else was also present,” Blanke says. For some people the sensation was so strong, they didn’t want to finish the experiment. 

“This confirms [the sensation] is caused by an altered perception of their own bodies in the brain,” Blanke says. So the next time you feel like you’re being watched, remember it might just be your brain playing tricks on your perception.

Aside from disappointing ghost hunters, this research could someday help treat disorders like schizophrenia or other neurological and psychiatric conditions. 

Lítla Dímun: The Smallest of the Faroe Islands Has Its Very Own Cloud

While some islands are known for their unusual geography or unique history, Lítla Dímun is notable for its weather. The island, which is the smallest of Denmark's Faroe Islands chain, is often capped by a lens-shaped cloud, making it resemble a scene from a fairytale.

According to Mental Floss's own Kerry Wolfe writing for Atlas Obscura, the cloud floating above Lítla Dímun is a lenticular cloud. This type of cloud forms when moist air flows over a protruding geological feature, like a mountain top. When the wind moving up the landmass hits the air current directly above it, a sort of wave is created on the downwind side of the mountain. The moist air falling down this wave evaporates and then condenses into a large, flying-saucer-shaped cloud atop the mountain peak as a result.

Another factor that makes Lítla Dímun distinct is that it's the only one of the 18 main Faroe Islands without human inhabitants. Visitors to the mystical location will instead find a thriving population of sheep. Originally, Lítla Dímun was home to a group of feral sheep likely dating back to the Neolithic era. But they were hunted to extinction in the 19th century. Domesticated sheep were introduced there around the same time, and today, farmers visit the island once a year to round up their flocks.

One of the few signs of human life are the ropes farmers use to scale the cliff faces bordering the island. Even if you have rock-climbing skills, Lítla Dímun may be dangerous to visit. A boat ride to the rocky shore is only possible when the surrounding sea is calm.

[h/t Atlas Obscura]

Why Are Sloths So Slow?

Sloths have little problem holding still for nature photographers.
Sloths have little problem holding still for nature photographers.
Geoview/iStock via Getty Images

When it comes to physical activity, few animals have as maligned a reputation as the sloth. The six sloth species, which call Brazil and Panama home, move with no urgency, having seemingly adapted to an existence that allows for a life lived in slow motion. But what makes sloths so sedate? And what horrible, poop-related price must they pay in order to maintain life in the slow lane?

According to HowStuffWorks, the sloth’s limited movements are primarily the result of their diet. Residing mainly in the canopy vines of Central and South American forests, sloths dine out on leaves, fruits, and buds. With virtually no fat or protein, sloths conserve energy by taking a leisurely approach to life. On average, a sloth will climb or travel roughly 125 feet per day. On land, it takes them roughly one minute to move just one foot.

A sloth’s digestive system matches their locomotion. After munching leaves using their lips—they have no incisors—it can take up to a month for their meals to be fully digested. And a sloth's metabolic rate is 40 to 45 percent slower than most mammals' to help compensate for their low caloric intake. With so little fuel to burn, a sloth makes the most of it.

Deliberate movement shouldn’t be confused for weakness, however. Sloths can hang from branches for hours, showing off some impressive stamina. And because they spend most of their time high up in trees, they have no need for rapid movement to evade predators.

There is, however, one major downside to the sloth's leisurely lifestyle. Owing to their meager diet, they typically only have to poop once per week. Like going in a public bathroom, this can be a stressful event, as it means going to the ground and risking detection by predators—which puts their lives on the line. Worse, that slow bowel motility means they’re trying to push out nearly one-third of their body weight in feces at a time. It's something to consider the next time you feel envious of their chill lifestyle.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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