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The Brains of Anxious People May Perceive the World Differently

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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."

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Space
Look Up! The Orionid Meteor Shower Peaks This Weekend
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Ethan Miller/Getty Images

October is always a great month for skywatching. If you missed the Draconids, the first meteor shower of the month, don't despair: the Orionids peak this weekend. It should be an especially stunning show this year, as the Moon will offer virtually no interference. If you've ever wanted to get into skywatching, this is your chance.

The Orionids is the second of two meteor showers caused by the debris field left by the comet Halley. (The other is the Eta Aquarids, which appear in May.) The showers are named for the constellation Orion, from which they seem to originate.

All the stars are lining up (so to speak) for this show. First, it's on the weekend, which means you can stay up late without feeling the burn at work the next day. Tonight, October 20, you'll be able to spot many meteors, and the shower peaks just after midnight tomorrow, October 21, leading into Sunday morning. Make a late-night picnic of the occasion, because it takes about an hour for your eyes to adjust to the darkness. Bring a blanket and a bottle of wine, lay out and take in the open skies, and let nature do the rest.

Second, the Moon, which was new only yesterday, is but a sliver in the evening sky, lacking the wattage to wash out the sky or conceal the faintest of meteors. If your skies are clear and light pollution low, this year you should be able to catch about 20 meteors an hour, which isn't a bad way to spend a date night.

If clouds interfere with your Orionids experience, don't fret. There will be two more meteor showers in November and the greatest of them all in December: the Geminids.

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science
11-Year-Old Creates a Better Way to Test for Lead in Water
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In the wake of the water crisis in Flint, Michigan, a Colorado middle schooler has invented a better way to test lead levels in water, as The Cut reports.

Gitanjali Rao, an 11-year-old seventh grader in Lone Tree, Colorado just won the 2017 Discovery Education 3M Young Scientist Challenge, taking home $25,000 for the water-quality testing device she invented, called Tethys.

Rao was inspired to create the device after watching Flint's water crisis unfold over the last few years. In 2014, after the city of Flint cut costs by switching water sources used for its tap water and failed to treat it properly, lead levels in the city's water skyrocketed. By 2015, researchers testing the water found that 40 percent of homes in the city had elevated lead levels in their water, and recommended the state declare Flint's water unsafe for drinking or cooking. In December of that year, the city declared a state of emergency. Researchers have found that the lead-poisoned water resulted in a "horrifyingly large" impact on fetal death rates as well as leading to a Legionnaires' disease outbreak that killed 12 people.

A close-up of the Tethys device

Rao's parents are engineers, and she watched them as they tried to test the lead in their own house, experiencing firsthand how complicated it could be. She spotted news of a cutting-edge technology for detecting hazardous substances on MIT's engineering department website (which she checks regularly just to see "if there's anything new," as ABC News reports) then set to work creating Tethys. The device works with carbon nanotube sensors to detect lead levels faster than other current techniques, sending the results to a smartphone app.

As one of 10 finalists for the Young Scientist Challenge, Rao spent the summer working with a 3M scientist to refine her device, then presented the prototype to a panel of judges from 3M and schools across the country.

The contamination crisis in Flint is still ongoing, and Rao's invention could have a significant impact. In March 2017, Flint officials cautioned that it could be as long as two more years until the city's tap water will be safe enough to drink without filtering. The state of Michigan now plans to replace water pipes leading to 18,000 households by 2020. Until then, residents using water filters could use a device like Tethys to make sure the water they're drinking is safe. Rao plans to put most of the $25,000 prize money back into her project with the hopes of making the device commercially available.

[h/t The Cut]

All images by Andy King, courtesy of the Discovery Education 3M Young Scientist Challenge.

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