New Study Shows It's Surprisingly Easy to Make People Have Auditory Hallucinations

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iStock

If you’ve ever heard something that wasn't there—an auditory hallucination—you know that the sound seems very, very real. A new study suggests that it's easy to induce auditory hallucinations in people, but it's even easier in people who already claim to hear things that aren't there. The research was published in the journal Science.

Co-author Al Powers is a psychiatric researcher at Yale. Speaking in a study, he said hallucinations “…may arise from an imbalance between our expectations about the environment and the information we get from our senses.”

In other words, he says, "You may perceive what you expect, not what your senses are telling you."

Powers and his colleagues recruited 59 people to help them test that hypothesis. There were four groups of participants: people who heard voices and had been diagnosed with psychosis; people who had been diagnosed with psychosis but didn’t hear voices; people who heard voices but had not been diagnosed with any mental illness (we'll come back to that in a moment); and people who just plain didn't hear voices.

The third group was an unusual one: 15 self-professed psychics. These participants said that they heard voices every day, but unlike people in the first group—those diagnosed with psychosis who heard voices—they weren't bothered by the voices they claimed to hear. In fact, they took them to be communications from supernatural forces or entities.

All the participants then underwent brain scans. While they were in the scanner, the researchers used a combination of sounds and images to trick their brains into producing auditory hallucinations. First, participants were shown a checkerboard and played a sound. Then they were told to listen for the sound. Sometimes it played when the checkerboard appeared. Sometimes it didn't play at all, but the checkerboard showed, which led their brains to expect the sound would be played.

Members of all four groups experienced the hallucinations, hearing noises even in the silence. Their brain scans showed that they really were "hearing" the nonexistent sounds.

Unsurprisingly, the two groups of hallucination-prone people were more susceptible to hearing things. But when they were told that there had in fact been no sound, people with psychosis were less likely to believe it. 

The authors say this difference could potentially help doctors spot, diagnose, and treat psychosis in their patients before it becomes severe.

No Venom, No Problem: This Spider Uses a Slingshot to Catch Prey

Courtesy of Sarah Han
Courtesy of Sarah Han

There are thousands of ways nature can kill, and spider species often come up with the most creative methods of execution. Hyptiotes cavatus, otherwise known as the triangle weaver spider, is one such example. Lacking venom, the spider manages to weaponize its silk, using it to hurl itself forward like a terrifying slingshot to trap its prey.

This unusual method was studied up close for a recent paper published in the Proceedings of the National Academy of Sciences by researchers at the University of Akron in Ohio. They say it's the only known instance of an animal using an external device—its web—for power amplification.

Hyptiotes cavatus's technique is simple. After constructing a web, the spider takes one of the main strands and breaks it in half, pulling it taut by moving backwards. Then, it anchors itself to a spot with more webbing in the rear. When the spider releases that webbing, it surges forward, propelled by the sudden release of stored energy. In the slingshot analogy, the webbing is the strap and the spider is the projectile.

This jerking motion causes the web to oscillate, tangling the spider's prey further in silk. The spider can repeat this until the web has completely immobilized its prey, a low-risk entrapment that doesn’t require the spider to get too close and risk injury from larger victims.

The triangle weaver spider doesn’t have venom, and it needs to be proactive in attacking and stifling prey. Once a potential meal lands in its web, it’s able to clear distances much more quickly using this slingshot technique than if it crawled over. In the lab, scientists clocked the spider’s acceleration at 2535 feet per second squared.

Spiders are notoriously nimble and devious. Cebrennus rechenbergi, or the flic-flac spider, can do cartwheels to spin out of danger; Myrmarachne resemble ants and even wiggle their front legs like ant antennae. It helps them avoid predators, but if they see a meal, they’ll drop the act and pounce. With H. cavatus, it now appears they’re learning to use tools, too.

[h/t Live Science]

Bad News: The Best Time of the Day to Drink Coffee Isn’t as Soon as You Wake Up

iStock.com/ThomasVogel
iStock.com/ThomasVogel

If you depend on coffee to help get you through the day, you can rest assured that you’re not the world's only caffeine fiend. Far from it. According to a 2018 survey, 64 percent of Americans said they had consumed coffee the previous day—the highest percentage seen since 2012.

While we’re collectively grinding more beans, brewing more pots, and patronizing our local coffee shops with increased frequency, we might not be maximizing the health and energy-boosting benefits of our daily cup of joe. According to Inc., an analysis of 127 scientific studies highlighted the many benefits of drinking coffee, from a longer average life span to a reduced risk for cancer, heart disease, type 2 diabetes, and Parkinson’s disease.

Sounds great, right? The only problem is that the benefits of coffee might be diminished depending on the time of day that you drink it. Essentially, science tells us that it’s best to drink coffee when your body’s cortisol levels are low. That’s because both caffeine and cortisol cause a stress response in your body, and too much stress is bad for your health for obvious reasons. In addition, it might end up making you more tired in the long run.

Cortisol, a stress hormone, is released in accordance with your circadian rhythms. This varies from person to person, but in general, someone who wakes up at 6:30 a.m. would see their cortisol levels peak in different windows, including 8 to 9 a.m., noon to 1 p.m., and 5:30 to 6:30 p.m. Someone who rises at 10 a.m. would experience cortisol spikes roughly three hours later, and ultra-early risers can expect to push this schedule three hours forward.

However, these cortisol levels start to rise as soon as you start moving in the morning, so it isn’t an ideal time to drink coffee. Neither is the afternoon, because doing so could make it more difficult to fall asleep at night. This means that people who wake up at 6:30 a.m. should drink coffee after that first cortisol window closes—roughly between 9:30 a.m. and 11:30 a.m.—if they want to benefit for a little caffeine jolt.

To put it simply: "I would say that mid-morning or early afternoon is probably the best time," certified dietitian-nutritionist Lisa Lisiewski told CNBC. "That's when your cortisol levels are at their lowest and you actually benefit from the stimulant itself."

[h/t Inc.]

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