8 Brain 'Facts' We All Get Wrong

iStock
iStock

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.

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]

Could Leonardo da Vinci's Artistic Genius Be Due to an Eye Condition?

Young John the Baptist, Leonardo da Vinci (1513-16, Louvre, Paris).
Young John the Baptist, Leonardo da Vinci (1513-16, Louvre, Paris).
Christopher Tyler, JAMA Ophthalmology (2018)

Leonardo da Vinci was indisputably a genius, but his singular artistic vision may have been the result of seeing the world differently in more ways than one. A new paper argues that he had strabismus, a vision disorder where the eyes are misaligned and don’t look toward the same place at the same time. This disorder, visual neuroscientist Christopher Tyler argues, may have helped the artist render three-dimensional images on flat canvas with an extra level of skill.

Tyler is a professor at City, University of London who has written a number of studies on optics and art. In this study, published in JAMA Ophthalmology, he examined six different artworks from the period when Leonardo was working, including Young John the Baptist, Vitruvian Man, and a self-portrait by the artist. He also analyzed pieces by other artists that are thought to have used Leonardo as a model, like Andrea del Verrocchio’s Young Warrior sculpture. Leonardo served as the lead assistant in the latter artist’s studio, and likely served as the model for several of his works. Leonardo was also a friend of Benedetto da Maiano, and possibly served as a model for his 1480 sculpture of John the Baptist. Tyler also looked at the recently auctioned Salvator Mundi, a painting that not all experts believe can be attributed to Leonardo. (However, at least one scientific team that examined the painting says it’s legit.)

With strabismus, a person’s eyes appear to point in different directions. Based on the eyes in Leonardo’s own portraits of himself and other artworks modeled after him, it seems likely that he had intermittent strabismus. When he relaxed his eyes, one of his eyes drifted outward, though he was likely able to align his eyes when he focused. The gaze in the portraits and sculptures seems to be misaligned, with the left eye consistently drifting outward at around the same angle.

'Vitruvian Man' with the subject's pupils highlighted
Vitruvian Man, Leonardo da Vinci (~1490, Accademia, Venice)
Christopher Tyler, JAMA Ophthalmology (2018)

“The weight of converging evidence suggests that [Leonardo] had intermittent exotropia—where an eye turns outwards—with a resulting ability to switch to monocular vision, using just one eye,” Tyler explained in a press release. “The condition is rather convenient for a painter, since viewing the world with one eye allows direct comparison with the flat image being drawn or painted.” This would have given him an assist in depicting depth accurately.

Leonardo isn’t the first famous artist whose vision researchers have wondered about. Some have speculated that Degas’s increasingly coarse pastel work in his later years may have been attributed to his degenerating eyes, as the rough edges would have appeared smoother to him because of his blurred vision. Others have suggested that Van Gogh’s “yellow period” and the vibrant colors of Starry Night may have been influenced by yellowing vision caused by his use of digitalis, a medicine he took for epilepsy.

We can never truly know whether a long-dead artist’s work was the result of visual issues or simply a unique artistic vision, but looking at their art through the lens of medicine provides a new way of understanding their process.

SECTIONS

arrow
LIVE SMARTER