The Brains of Anxious People May Perceive the World Differently

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iStock

A study showed that people with generalized anxiety disorder unconsciously label harmless things as threats, which may serve to further their anxiety. These findings were published in the journal Current Biology.

Psychologists recognize several forms of clinical anxiety. The most common is generalized anxiety disorder, or GAD, in which people frequently feel very worried or anxious even when it seems like there’s nothing to worry about. Some studies have suggested that anxiety disorders may stem from a process called overgeneralization.

In overgeneralization, the brain lumps both safe and unsafe things together and labels them all unsafe. For this reason, the researchers also call this the “better safe than sorry” approach. Our brains naturally pay more attention to negative or threatening information in our environments. If anxious people perceive more threats in the world around them, it would make a lot of sense for them to be worried.

To find out if overgeneralization was involved, researchers recruited 28 people diagnosed with GAD and 16 people without anxiety and brought them into the lab. The experiment had two parts: training and testing. In the training section, study participants learned to differentiate between three different sounds. Each sound was tied to a different outcome; pressing a key could lead to winning money (the “positive” tone), losing money (the “negative” tone), or nothing (the “neutral” tone).

In the second phase of the experiment, researchers played 15 different sounds for the participants and asked them to press a key when they heard a sound they recognized from the training phase. If they guessed right, they’d win money, but if they guessed wrong, the researchers would take some of their money back.

Because of the risk of losing money, the best strategy for everyone would be a conservative one—not pressing the button much at all based on the assumption that most of the tones were new. But anxious participants were trigger-happy, believing they’d heard many of the unfamiliar tones before. The experience of winning and losing money in training had made a strong emotional impression on them, which led them to overgeneralize new information as relevant.

The researchers also administered brain scans during the testing phase. They found notable differences between anxious and non-anxious brains. While they were focused on parsing new information, anxious people showed more activation in several parts of the brain, including the amygdala, a region associated with fear and worry.

"We show that in patients with anxiety, emotional experience induces plasticity in brain circuits that lasts after the experience is over," senior co-author Rony Paz said in a press release. "Such plastic changes occur in primary circuits that later mediate the response to new stimuli, resulting in an inability to discriminate between the originally experienced stimulus and a new similar stimulus. Therefore, anxiety patients respond emotionally to such new stimuli as well, resulting in anxiety even in apparently irrelevant new situations. Importantly, they cannot control this, as it is a perceptual inability to discriminate."

Paz noted that in dangerous circumstances, the hyper-vigilance associated with anxiety might be a good thing. The problem is that most circumstances aren’t dangerous. "Anxiety traits can be completely normal, and even beneficial evolutionarily," he says. "Yet an emotional event, even minor sometimes, can induce brain changes that might lead to full-blown anxiety."

Florida Is Home to 'Skull-Collecting' Ants, Because Florida

Florida’s Formica archboldi ants are not to be messed with. As Newsweek reports, a North Carolina-based researcher recently discovered that the species applies a waxy coat to its body to chemically mimic its intended prey, a kind of trap-jaw ant in the genus Odontomachus. Then, the predator sprays its unsuspecting prey with acid to immobilize it and drags it back to its underground lair, where it dismembers the body and presumably eats everything but the hollowed-out heads.

The Florida ant’s habit of letting the heads pile up in its nest has earned it a pretty grisly nickname: the “skull-collecting ant.” This behavior has been observed since the 1950s. However, scientists have only recently learned how the Florida ant manages to kill trap-jaw ants, which are formidable predators in their own right (they can snap their jaws shut at speeds of over 100 miles an hour).

Researcher Adrian Smith, head of the Evolutionary Biology & Behavior Research Lab at the North Carolina Museum of Natural Sciences, observed the F. archboldi ants mimicking trap-jaw ants at the chemical level by coating their bodies in the same waxy substance that covers their prey. Smith says they’re probably disguising themselves, but the extent to which they do so isn’t yet known.

The ants were also seen shooting formic acid from their abdomens to render the trap-jaw ants motionless. The new findings were published in the journal Insectes Sociaux, and Smith even captured the gruesome action on camera, which you can check out in the video below.

Smith says he’s been fascinated with the ants—which are also found in parts of Alabama and Georgia—since he was an undergrad student at Florida State.

“They’re one of the most badass ants I know of. That’s why I wanted to study them—they decorate their nests with skulls,” Smith told The Verge. “A lot of other ants do cool things, but these are special to me because they’re from Florida, and I’m from Florida."

[h/t Newsweek]

The Science Behind Brining Your Thanksgiving Turkey

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iStock.com/LazingBee

At many Thanksgiving tables, the annual roast turkey is just a vehicle for buttery mash and creamy gravy. But for those who prefer their bird be a main course that can stand on its own without accoutrements, brining is an essential prep step—despite the fact that it requires finding enough room in the fridges to immerse a 20-pound animal in gallons of salt water for days on end. To legions of brining believers, the resulting moist bird is worth the trouble.

How, exactly, does a salty soak yield juicy meat? And what about all the claims from a contingency of dry brine enthusiasts: Will merely rubbing your bird with salt give better results than a wet plunge? For a look at the science behind each process, we tracked down a couple of experts.

First, it's helpful to know why a cooked turkey might turn out dry to begin with. As David Yanisko, a culinary arts professor at the State University of New York at Cobleskill, tells Mental Floss, "Meat is basically made of bundles of muscle fibers wrapped in more muscle fibers. As they cook, they squeeze together and force moisture out," as if you were wringing a wet sock. Hence the incredibly simple equation: less moisture means more dryness. And since the converse is also true, this is where brining comes in.

Your basic brine consists of salt dissolved in water. How much salt doesn't much matter for the moistening process; its quantity only makes your meat and drippings more or less salty. When you immerse your turkey in brine—Ryan Cox, an animal science professor at the University of Minnesota, quaintly calls it a "pickling cover"—you start a process called diffusion. In diffusion, salt moves from the place of its highest concentration to the place where it's less concentrated: from the brine into the turkey.

Salt is an ionic compound—its sodium molecules have a positive charge and its chloride molecules have a negative charge, but they stick together anyway. As the brine penetrates the bird, those salt molecules meet both positively and negatively charged protein molecules in the meat, causing the meat proteins to scatter. Their rearrangement "makes more space between the muscle fibers," Cox tells Mental Floss. "That gives us a broader, more open sponge for water to move into."

The salt also dissolves some of the proteins, which, according to the book Cook's Science by the editors of Cook's Illustrated, creates "a gel that can hold onto even more water." Juiciness, here we come!

There's a catch, though. Brined turkey may be moist, but it can also taste bland—infusing it with salt water is still introducing, well, water, which is a serious flavor diluter. This is where we cue the dry briners. They claim that using salt without water both adds moisture and enhances flavor: win-win.

Turkey being prepared to cook.
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In dry brining, you rub the surface of the turkey with salt and let it sit in a cold place for a few days. Some salt penetrates the meat as it sits—with both dry and wet brining, Cox says this happens at a rate of about 1 inch per week. But in this process, the salt is effective mostly because of osmosis, and that magic occurs in the oven.

"As the turkey cooks, the [contracting] proteins force the liquid out—what would normally be your pan drippings," Yanisko says. The liquid mixes with the salt, both get absorbed or reabsorbed into the turkey and, just as with wet brining, the salt disperses the proteins to make more room for the liquid. Only this time the liquid is meat juices instead of water. Moistness and flavor ensue.

Still, Yanisko admits that he personally sticks with wet brining—"It’s tradition!" His recommended ratio of 1-1/2 cups of kosher salt (which has no added iodine to gunk up the taste) to 1 gallon of water gives off pan drippings too salty for gravy, though, so he makes that separately. Cox also prefers wet brining, but he supplements it with the advanced, expert's addition of injecting some of the solution right into the turkey for what he calls "good dispersal." He likes to use 1-1/2 percent of salt per weight of the bird (the ratio of salt to water doesn't matter), which he says won't overpower the delicate turkey flavor.

Both pros also say tossing some sugar into your brine can help balance flavors—but don't bother with other spices. "Salt and sugar are water soluble," Cox says. "Things like pepper are fat soluble so they won't dissolve in water," meaning their taste will be lost.

But no matter which bird or what method you choose, make sure you don't roast past an internal temperature of 165˚F. Because no brine can save an overcooked turkey.

This piece originally ran in 2017.

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