8 Myths About Dead Bodies You Probably Think Are True

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iStock

Bodies are weird enough, but it's the dead ones that hold real intrigue. The fact that most of us just don't spend that much time around them means it's hard to separate truth from fiction; corpses have been thought to be responsible for plagues, as well as to carry magic healing properties. Below, some dead body myths that won't give up the ghost—and explanations for the real-life science behind them.

1. HAIR AND NAILS GROW AFTER DEATH.

Corpse under sheet with hand sticking out

Not true! The cell division driving hair and nail growth stops when the body dies and the heart no longer pumps oxygen-filled blood throughout the circulatory system. It does look like things keep growing, though. When a dead body's skin loses hydration, it retracts—and retraction along the nail bed makes it appear as if the nails are getting longer. As for hair, drying skin on the face and head "pulls back towards the skull, making stubble appear more prominent," writes Claudia Hammond for the BBC. "Goosebumps caused by the contraction of the hair muscles can add to the effect."

2. DEAD BODIES ARE DANGEROUS.

There's no science to back up the idea that a dead and decomposing body is harmful to the living just by virtue of its being dead. This might sound obvious, but the belief that disease came from breathing in air infected by corpses was once common.

Miasmatic theory, as it was called, was a widespread belief among members of the medical profession (and the public) in the 19th century. Miasma, an ancient Greek word for "pollution," was the bad air coming from "rotting corpses, the exhalations of other people already infected, sewage, or even rotting vegetation" and was thought to be responsible for the spread of disease. Fortunately, this belief was eventually replaced by germ theory.

3. … AND MULTIPLE DEAD BODIES ARE EXTRA DANGEROUS.

In a publication from the Pan American Health Organization (a division of the World Health Organization), Donna Eberwine explains that the belief that dead bodies spread disease "remains a chronic problem in disaster relief efforts." After natural disasters, there is often a hysteria around dead bodies and a rush to immediately bury them, which distracts relief efforts from more pressing concerns. "The microorganisms that are involved in decomposition are not the kind that cause disease," Eberwine writes. "And most viruses and bacteria that do cause disease cannot survive more than a few hours in a dead body."

There are some exceptions. The level of Ebola virus in dead victims remains high, and their remains should only be handled by people in protective gear (and buried quickly). HIV can live for up to 16 days in a body held under refrigeration, and other blood-borne viruses like hepatitis, along with tuberculosis and gastrointestinal infections, can pose a risk. "The risk of contagion can be minimized with basic precautions and proper hygiene," Eberwine writes.

4. EMBALMING MAKES DEAD BODIES "SAFER."

Egyptian sarcophagus

"Embalming provides no public health benefit," according to the Funeral Consumer's Alliance (a nonprofit focused on affordable death care), citing the Centers for Disease Control and Canadian authorities. While individual morticians might say that a body must be embalmed before viewing, burial, or cremation, the process is generally not legally required. Moreover, since a dead body is usually not in itself harmful, embalming does not make it any safer. On the flip side, embalming chemicals are actually quite toxic, and embalmers must cover their entire body and wear a respirator while working. 

5. DEAD BODIES SIT UP ON THE MEDICAL TABLE.

This horror-movie trope just isn't real. During decomposition, a body might twitch or make small movements and noises due to the gas and waste released by bacteria. A decomposing corpse can definitely move a little, but sitting straight up is just not going to happen.

6. BURYING A BODY WITHOUT A COFFIN OR VAULT MEANS IT WILL CONTAMINATE THE GROUNDWATER.

Nope! Burials usually occur at 3.5 feet below the surface, whereas water can be 75 feet underground. "Mandatory setbacks from known water sources also ensure that surface water is not at risk," the Green Burial Council explains [PDF]. Additionally, because microorganisms living in the soil will break down the chemical compounds that remain in a dead body, we actually give out "more toxic chemicals during a day of living than a whole body will decomposing."

7. CREMAINS ARE "ASH."

Wall of cremation urns

Though we often talk of "scattering ashes," cremains are a little more complicated. Once a body intended for cremation has been burned in what's called a retort, what's left will be put in a cremulator. Sort of like a blender, the cremulator uses ball bearings or rotating blades to pulverize the bones and other remnants into a "grayish, coarse material, like fine gravel," as HowStuffWorks puts it.

8. ALL IN ALL, MAYBE DEATH ISN'T AS SCARY AS WE THINK.

According to psychological scientist Kurt Gray, it's possible that death isn't quite as terrifying as we think it is. Gray studied the responses of death row inmates and terminally ill patients as well as those of people asked to imagine they had untreatable cancer, and found that "while it's natural to fear death in the abstract, the closer one actually gets to it, the more positive he or she becomes," as New York Magazine explains. This may be due to something called the "psychological immune system," a term coined by Harvard psychologist Dan Gilbert in his book Stumbling on Happiness. According to Gray, our psychological immune system is engaged when bad things happen. "So when one is faced with death, all sorts of rationalization and meaning-making processes come in," he told New York Magazine. That may sound like your brain's trying to give you a cop-out, but it's much better than living in terror.

All photos courtesy of iStock.

Do Dogs Understand What You’re Telling Them? Scientists Are Scanning Their Brains to Find Out

iStock/kozorog
iStock/kozorog

We all know that dogs can learn to respond to human words, but it’s not always clear what’s happening in a dog’s brain when they hear and recognize words like “cookie” and “fetch.” Do they have to rely on other clues, like gestures, to figure out what we mean by that word? Do they picture a dog biscuit when you say “cookie,” or just the sensation of eating? In a new study, scientists from Emory University and the New College of Florida tried to get to the bottom of this question by training dogs to associate certain objects with words like “blue” and “duck,” then using fMRI brain scanners to see what was happening in the dogs’ heads when they heard that word.

The study, published in Frontiers in Neuroscience, examined the brains of 12 different dogs of various breeds (you can see them below) that had been trained to associate two different objects with random words like “duck,” “blue,” and “beach ball.” Those two objects, which were different for each dog, were brought by the dogs’ owners from home or chosen from a selection of dog toys the researchers compiled. One object had to be soft, like a stuffed animal, and the other one had to be something hard, like a rubber toy or squeaky toy, to make sure the dogs could clearly distinguish between the two. The dogs were trained for several months to associate these objects with their specific assigned words and to fetch them on command.

Then, they went into the fMRI machine, where they had been trained to sit quietly during scanning. The researchers had the dogs lie in the machine while their owners stood in front of them, saying the designated name for the toys and showing them the objects. To see how the dogs responded to unknown words, they also held up new objects, like a hat, and referred to them by gibberish words.

Dogs in a science lab with toys
Prichard et al., Frontiers in Neuroscience (2018]

The results suggest that dogs can, in fact, discriminate between words they know and novel words. While not all the dogs showed the same neural response, they showed activation in different regions of their brains when hearing the familiar word versus the novel one.

Some of the dogs showed evidence of a greater neural response in the parietotemporal cortex, an area of the dog brain believed to be similar to the human angular gyrus, the region of the brain that allows us to process the words we hear and read. Others showed more neural activity in other regions of the brain. These differences might be due to the fact that the study used dogs of different sizes and breeds, which could mean differences in their abilities.

The dogs did show a surprising trend in their brains’ response to new words. “We expected to see that dogs neurally discriminate between words that they know and words that they don’t,” lead author Ashley Prichard of Emory University said in a press release. “What's surprising is that the result is opposite to that of research on humans—people typically show greater neural activation for known words than novel words." This could be because the dogs were trying extra hard to understand what their owners were saying.

The results don’t prove that talking to your dog is the best way to get its attention, though—it just means that they may really know what's coming when you say, "Want a cookie?"

Scientists Find Fossil of 150-Million-Year-Old Flesh-Eating Fish—Plus a Few of Its Prey

M. Ebert and T. Nohl
M. Ebert and T. Nohl

A fossil of an unusual piranha-like fish from the Late Jurassic period has been unearthed by scientists in southern Germany, Australian news outlet the ABC reports. Even more remarkable than the fossil’s age—150 million years old—is the fact that the limestone deposit also contains some of the fish’s victims.

Fish with chunks missing from their fins were found near the predator fish, which has been named Piranhamesodon pinnatomus. Aside from the predator’s razor-sharp teeth, though, it doesn’t look like your usual flesh-eating fish. It belonged to an extinct order of bony fish that lived at the time of the dinosaurs, and until now, scientists didn’t realize there was a species of bony fish that tore into its prey in such a way. This makes it the first flesh-eating bony fish on record, long predating the piranha. 

“Fish as we know them, bony fishes, just did not bite flesh of other fishes at that time,” Dr. Martina Kölbl-Ebert, the paleontologist who found the fish with her husband, Martin Ebert, said in a statement. “Sharks have been able to bite out chunks of flesh, but throughout history bony fishes have either fed on invertebrates or largely swallowed their prey whole. Biting chunks of flesh or fins was something that came much later."

Kölbl-Ebert, the director of the Jura Museum in Eichstätt, Germany, says she was stunned to see the bony fish’s sharp teeth, comparing it to “finding a sheep with a snarl like a wolf.” This cunning disguise made the fish a fearful predator, and scientists believe the fish may have “exploited aggressive mimicry” to ambush unsuspecting fish.

The fossil was discovered in 2016 in southern Germany, but the find has only recently been described in the journal Current Biology. It was found at a quarry where other fossils, like those of the Archaeopteryx dinosaur, have been unearthed in the past.

[h/t the ABC]

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