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.

Why Thousands of 'Penis Fish' Washed Up on a California Beach

Kate Montana, iNaturalist // CC BY-NC 4.0
Kate Montana, iNaturalist // CC BY-NC 4.0

Nature works in mysterious ways. The latest example materialized at Drakes Beach near San Francisco, California, in early December, when visitors strolling along the shore stumbled upon what looked to be the discarded inventory of an adult novelty shop. In fact, it was thousands of Urechis caupo, a marine worm that bears more than a passing resemblance to a human penis.

The engorged pink invertebrate, which is typically 10 inches in length, is native to the Pacific coast and frequently goes by the less salacious name of “fat innkeeper worm.” Burrowing in sand, the worm produces mucus from its front end to ensnare plankton and other snacks, then pumps water to create a vacuum where the food is directed into their tunnel. Since it builds up a small nest of discarded food, other creatures like crabs will stop by to feed, hence the “innkeeper” label.

You can see the worm in "action" here:

Because the worms enjoy a reclusive life in their burrows, it’s unusual to see thousands stranded on the beach. It’s likely that a strong storm broke up the intertidal sand, decimating their homes and leaving them exposed. The event is likely to thrill otters, as they enjoy dining on the worm. So do humans: Penis fish are served both raw and cooked in Korea and China.

[h/t Live Science]

The Horrors of Anglerfish Mating

Masaki Miya et al. "Evolutionary history of anglerfishes (Teleostei: Lophiiformes): a mitogenomic perspective," BMC Evolutionary Biology 10, article number: 58 (2010), Wikimedia Commons // CC BY 2.0
Masaki Miya et al. "Evolutionary history of anglerfishes (Teleostei: Lophiiformes): a mitogenomic perspective," BMC Evolutionary Biology 10, article number: 58 (2010), Wikimedia Commons // CC BY 2.0

When you think of an anglerfish, you probably think of something like the creature above: Big mouth. Gnarly teeth. Lure bobbing from its head. Endless nightmares. 

During the 19th century, when scientists began to discover, describe, and classify anglerfish from a particular branch of the anglerfish family tree—the suborder Ceratioidei—that’s what they thought of, too. The problem was that they were only seeing half the picture. The specimens that they were working with were all female, and they had no idea where the males were or what they looked like. Researchers sometimes found some other fish that seemed to be related based on their body structure, but they lacked the fearsome maw and lure typical of ceratioids and were much smaller—sometimes only as long as 6 or 7 millimeters—and got placed into separate taxonomic groups.

It wasn’t until the 1920s—almost a full century after the first ceratioid was entered into the scientific record—that things started to become a little clearer. In 1922, Icelandic biologist Bjarni Saemundsson discovered a female ceratioid with two of these smaller fish attached to her belly by their snouts. He assumed it was a mother and her babies, but was puzzled by the arrangement.

“I can form no idea of how, or when, the larvae, or young, become attached to the mother. I cannot believe that the male fastens the egg to the female,” he wrote. “This remains a puzzle for some future researchers to solve.”

When Saemundsson kicked the problem down the road, it was Charles Tate Regan, working at the British Museum of Natural History in 1924, who picked it up. Regan also found a smaller fish attached to a female ceratioid. When he dissected it, he realized it wasn’t a different species or the female angler’s child. It was her mate.

The “missing” males had been there all along, just unrecognized and misclassified, and Regan and other scientists, like Norwegian zoologist Albert Eide Parr, soon figured out why the male ceratioids looked so different. They don’t need lures or big mouths and teeth because they don’t hunt, and they don’t hunt because they have the females. The ceratioid male, Regan wrote, is “merely an appendage of the female, and entirely dependent on her for nutrition.” In other words, a parasite.

When ceratioid males go looking for love, they follow a species-specific pheromone to a female, who will often aid their search further by flashing her bioluminescent lure. Once the male finds a suitable mate, he bites into her belly and latches on until his body fuses with hers. Their skin joins together, and so do their blood vessels, which allows the male to take all the nutrients he needs from his host/mate’s blood. The two fish essentially become one.

With his body attached to hers like this, the male doesn't have to trouble himself with things like seeing or swimming or eating like a normal fish. The body parts he doesn’t need anymore—eyes, fins, and some internal organs—atrophy, degenerate, and wither away, until he’s little more than a lump of flesh hanging from the female, taking food from her and providing sperm whenever she’s ready to spawn.

Extreme size differences between the sexes and parasitic mating aren’t found in all anglerfish. Throughout the other suborders, there are males that are free-swimming their whole lives, that can hunt on their own and that only attach to the females temporarily to reproduce before moving along. For deep-sea ceratioids that might only rarely bump into each other in the abyss, though, the weird mating ritual is a necessary adaptation to keep mates close at hand and ensure that there will always be more little anglerfish. And for us, it’s something to both marvel and cringe at, a reminder that the natural world is often as strange as any fiction we can imagine.

Naturalist William Beebe put it nicely in 1938, writing, “But to be driven by impelling odor headlong upon a mate so gigantic, in such immense and forbidding darkness, and willfully eat a hole in her soft side, to feel the gradually increasing transfusion of her blood through one’s veins, to lose everything that marked one as other than a worm, to become a brainless, senseless thing that was a fish—this is sheer fiction, beyond all belief unless we have seen the proof of it.”

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