8 Brain 'Facts' We All Get Wrong

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Are you left-brained or right-brained? The correct answer is “neither.” Read on to find out the science behind this and seven other brain “facts” we all get wrong.

1. A BIGGER BRAIN IS A BETTER BRAIN.

Nope. After all, humans believe we’re the smartest animals on the planet, but elephant brains are three times larger than ours. And whale brains? Forget it. 

Intelligence isn’t about relative size, either. Human brains make up about 2 percent of our body mass, which is pretty impressive. But tree shrew brains are a full 10 percent of their body mass, and they drink beer for a living.

So when it comes to brains, size isn't the most important thing. Hominid brain size did increase as we evolved, but scientists say that the secret to our smarts is complexity. And nobody can beat us there; neuroscientist Gerard Edelman has even described the human brain as “the most complicated object in the universe.” Your cerebral cortex alone has between 19 and 23 billion neurons, and each neuron can connect to other neurons tens of thousands of times. 

2. PEOPLE ARE EITHER LEFT-BRAINED OR RIGHT-BRAINED.

There are certain tasks that draw more on one side of your brain than the other, but everything you do uses both hemispheres. There’s no evidence that the right half of your brain is more creative, or that the left is more analytical. The myth originated in the 1970s, from a paper by CalTech neuroscientist Roger W. Sperry. Sperry reported finding cognitive differences between the hemispheres. The media took the idea and ran with it. Sperry warned against oversimplifying or misinterpreting his findings, but by then the proverbial horse was out of the barn. 

The only people who are truly left- or right-brained are those who have undergone hemispherectomies—a surgery in which half of the brain is removed. The procedure is more common than you might think, and patients often go on to live full lives with no cognitive troubles. We'll have a story about this procedure and the impact it had on the life of one remarkable young woman later this week. 

3. WE ONLY USE 10 PERCENT OF OUR BRAINS.

Oh yeah? Which part are you using right now? The entire brain may not be active every second of every day, but if you want to breathe, sleep, and digest your food, you need the whole thing. 

Modern brain imaging techniques have given us actual pictures of the whole brain in action, which should have put this myth to bed. Instead, the 10 percent legend has persisted for years and years, in part thanks to movies and psychics who argue that the “other 90 percent" of your brain must be reserved for some supernatural purpose. This is absolute bunk. We'll look at this myth in more detail later in the week too.

4. GETTING OLDER MEANS LOSING YOUR MENTAL EDGE.

It’s not that black and white. Yes, certain cognitive functions like short-term memory, attention, and language learning begin to decline with age, but other mental skills actually improve. Many of these are social and emotional in nature, rather than analytical. This may be why these gains haven’t gotten as much attention as the losses: Laboratory tests focus more on cerebral tasks than on practical mental skills. 

Studies have shown that older people have larger vocabularies than younger people, and that they make better use of them. Older adults are happier with their lives, and their relationships are more harmonious. Being older means that you have access to a mental database of past problems and solutions, which helps you make choices in the present. Scientists call this a “cognitive template,” but most of us know it better as wisdom.

5. CLASSICAL MUSIC MAKES YOU SMARTER.

Making yourself (or your baby) sit through symphonies won’t do anything for your IQ. A 1993 study [PDF] did show that listening to Mozart improved spatial reasoning—but only spatial reasoning, and only for 15 minutes. Even that modest effect might have been overstated. A 2010 review of 40 studies on the subject found that none of them could reproduce the results of the original experiment.

And those classical music videos for babies aren’t doing anybody any favors. Infants and toddlers who watch TV—even Baby Mozart—learn fewer words than their peers.

Classical music is not like broccoli. You can’t put cheese on it, and the only reason to consume it is if you (or your baby) actually like it.

6. CROSSWORD PUZZLES WILL KEEP YOU SHARP.

Like classical music, crossword and Sudoku puzzles are terrific—but only if you actually enjoy them. 

In an interview on the subject with The New York Times, neuroscientist Molly Wagster of the National Institute on Aging was unequivocal: “People who have done puzzles all their lives have no particular cognitive advantage over anyone else.” 

There is one thing that doing crossword puzzles will make you good at: doing crossword puzzles. The more puzzles you complete, the better equipped you’ll be to notice patterns and recognize frequently used clues.

7. MEN ARE NATURALLY BETTER THAN WOMEN AT MATH.

Just like women are naturally better at washing the dishes, right? No. Come on.

Study after study [PDF] has shown that the gap in math and science test scores between girls and boys can be attributed not to natural ability, but to cultural messages. It’s called the stereotype threat: When a member of a group is exposed to negative stereotypes about that group, they perform poorly. Just requiring girls to check “female” before beginning a standardized test has been shown to significantly reduce their scores. The more a person is bombarded with expectations of failure, the more likely it is that he or she will fail.

Researchers from the University of Wisconsin analyzed test scores [PDF] from 86 countries and found that average math scores for girls and boys were equal. Even in the United States, the gap has begun to narrow. 

"We have to stop selling T-shirts to girls that say, ‘I'm too pretty to do math,'” study co-author Jonathan Kane told CNN. "Our stereotypes are hurting our math education.”

8. YOUR BRAIN CAN'T CHANGE OR HEAL.

The brain you have now is the brain you’ve always had and always will … right? Wrong.

The human brain is astonishingly plastic and can adapt to all kinds of extreme situations. People who lose their sight find that their sense of hearing improves dramatically, because the brain dedicates more energy to auditory processing. And, as we’ve seen, people who’ve had half their brain removed can still function, because the remaining half takes up all the responsibilities. Our brains are not hard-wired in any sense of the word.

Our brains are also not a finite resource. Cells in the rest of our bodies are constantly dying and being replaced. For a long time, scientists believed that the brain was the exception to this rule, and that damaged brain cells would never grow back. We now know this isn’t the case.

Science Finds a Better Way to Calculate 'Dog Years'

thegoodphoto/iStock via Getty Images
thegoodphoto/iStock via Getty Images

Anyone who has ever owned a pet is likely familiar with the concept of “dog years,” which suggests that one year for a dog is like seven years for a human. Using this conversion metric, a 2-year-old dog is akin to a high school freshman, while a 10-year-old dog is ready for an assisted living facility.

If that seems rather arbitrary, that’s because it is. But now, researchers at the University of California, San Diego have come to a more data-based measurement on dog aging through DNA.

The paper, published on the preprint server bioRxiv, based the finding on DNA methylation, a process in which molecules called methyl groups attach themselves to DNA and serve as an indicator of aging. Generally speaking, the older living beings get, the faster the rate of methylation. In the study, 104 Labrador retrievers were examined, with subjects ranging from 1 month to 16 years old. The results of their DNA methylation were compared to human profiles. While the rate of methylation tracked closely between the two—young and old dogs had similar rates to young and old people—adolescent and mature dogs experienced more accelerated aging.

Their recommended formula for comparing dog and human aging? Multiply the natural logarithm of a dog’s age by 16, then add 31. Or, just use this calculator. Users will see that a 2-year-old dog, for example, wouldn’t be the canine equivalent of a 14-year-old. It would be equivalent to 42 human years old and should probably start putting money into a 401(k). But because methylation slows considerably in mid-life, a 5-year-old dog is approximately a 57-year-old human, while a 6-year-old dog is nearing 60 in human years—a minor difference. Things level out as the dog gets much older, with a 10-year-old dog nearing a 70-year-old human.

Different breeds age at different rates, so the formula might not necessarily apply to other dog breeds—only Labs were studied. The work is awaiting peer review, but it does offer a promising glimpse into how our furry companions grow older.

[h/t Live Science]

Sssspectacular: Tree Snakes in Australia Can Actually Jump

sirichai_raksue/iStock via Getty Images
sirichai_raksue/iStock via Getty Images

Ophidiophobia, or fear of snakes, is common among humans. We avoid snakes in the wild, have nightmares about snakes at night, and recoil at snakes on television. We might even be born with the aversion. When researchers showed babies photos of snakes and spiders, their tiny pupils dilated, indicating an arousal response to these ancestral threats.

If you really want to scare a baby, show them footage of an Australian tree snake. Thanks to researchers at Virginia Tech, we now know these non-venomous snakes of the genus Dendrelaphis can become airborne, propelling themselves around treetops like sentient Silly String.

That’s Dendrelaphis pictus, which was caught zipping through the air in 2010. After looking at footage previously filmed by her advisor Jake Socha, Virginia Tech Ph.D. candidate Michelle Graham headed for Australia and built a kind of American Ninja Warrior course for snakes out of PVC piping and tree branches. Graham observed that the snakes tend to spot their landing target, then spring upward. The momentum gets them across gaps that would otherwise not be practical to cross.

Graham next plans to investigate why snakes feel compelled to jump. They might feel a need to escape, or continue moving, or do it because they can. Two scientific papers due in 2020 could provide answers.

Dendrelaphis isn’t the only kind of snake with propulsive capabilities. The Chrysopelea genus includes five species found in Southeast Asia and China, among other places, that can glide through the air.

[h/t National Geographic]

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