Anxiety Could Be an Inherited Condition, and Scientists Think They Know Why

iStock
iStock

If you have an anxiety disorder, you might be able to blame your parents for it. A new study in The Journal of Neuroscience reveals that some monkeys may pass a tendency toward anxiety down from generation to generation, and it might work the same way in humans, Science Alert reports.

It's known that anxiety can run in families, but how the heritability of anxiety works, and which areas of the brain are involved, is more mysterious. Researchers at the University of Wisconsin-Madison used functional magnetic resonance imaging (fMRI) to monitor the brain activity of 378 young rhesus macaques who were placed in an anxiety-inducing situation. For the study, a person stood in their cage and avoided eye contact with the monkeys for 30 minutes, which likely made the monkeys wonder whether their visitor was a potential threat. It’s the same approach often used in psychology labs to study anxiety in children, the study’s co-author tells Discover.

After analyzing the results of the stress test, scientists discovered increased activity in two regions of the amygdala—the part of the brain that processes fear and other emotions—in monkeys that had outwardly expressed the most anxiety. Using information about the monkeys’ lineage dating back eight generations, scientists determined that the ancestors of the high-anxiety monkeys had elicited a similar brain response. In other words, their anxiety may have been inherited. Genetics aren't fully to blame for anxiety, however, because environmental factors are often at play.

Because of the similarities between monkeys and humans, the results could lend insight into treatments for children with extreme anxious temperament (AT), which often develops into an anxiety disorder later in life. "Looking first at the monkeys has provided us with clues about which systems to focus on in our studies of at-risk young children," senior author Ned Kalin said in a statement.

Studies like this may help lay the groundwork for addressing the underlying cause of anxiety, rather than just treating the symptoms.

[h/t Science Alert]

New Study Reveals 'Hyper-Alarming' Decline of Rainforest Insect Populations

iStock/jmmf
iStock/jmmf

Climate change is decimating yet another vital part of the world's ecosystem, according to a startling new paper. Rainforest insects are dying off at alarming rates, according to a new study spotted by the The Washington Post. In turn, the animals that feed off those insects are decreasing, too.

In the study, published in Proceedings of the National Academy of Sciences, a pair of scientists from the Rensselaer Polytechnic University in New York and the National Autonomous University of Mexico studied populations of rainforest arthropods (an invertebrate classification that includes insects and spiders) in the El Yunque National Forest in Puerto Rico. They compared the number of insects lead author Bradford Lister found on trips in 1976 and 1977 with the number he and co-author Andres Garcia found on trips they took between 2011 and 2013.

Lister and Garcia used nets and sticky traps to collect insects on the ground and several feet above the ground in the forest canopy. They dried these captured bugs and measured the mass of their haul against the mass of insects found in the 1970s, finding that the modern net sweeps captured only an eighth to a fourth of the insects captured in the '70s. The mass of insects captured by sticky traps on the ground declined by 30 to 60 times what they were a few decades ago. They also tracked populations of lizards, frogs, and birds that live off those rainforest insects, finding that those populations had declined significantly, too, at levels not seen in other rainforest animals that don't rely on insects for food.

Tropical insects are particularly vulnerable to climatic changes, since they can't regulate their body temperature. During the time of the study, average maximum temperatures in El Yunque rose by almost 4°F (2°C). The warming climate is "the major driver" of this decline in arthropod populations, the study authors write, triggering a collapse of the forest food chain.

The paper has other scientists worried. "This is one of the most disturbing articles I have ever read," University of Connecticut entomologist David Wagner, who wasn't involved in the research, told The Washington Post, calling the results "hyper-alarming." Other studies of insect populations have found similarly dire results, including significant declines in butterflies, moths, bees, and other species. One recent study found that Germany's flying insect populations had decreased by as much as 75 percent in the last three decades. Scientists don't always attribute those population losses directly to warmer temperatures (habitat loss, pesticide use, droughts, and other factors might play a role), but it’s clear that insect populations are facing grave threats from the modern world.

Not all insect species will be equally affected by climate change, though. While we may see a sharp drop in the populations of tropical insects, scientists project that the number of insects in other regions will rise—leading to a sharp increase in crop-eating pests in some parts of the world and broadening mosquitos' geographical range.

[h/t The Washington Post]

This 'Time-Traveling Illusion' Is Designed to Trick Your Brain

A team of researchers from the California Institute of Technology (Caltech) have designed an illusion that might trick your brain into seeing things that aren’t there, the New Atlas reports.

Dubbed the Illusory Rabbit, it provides instructions that are simple enough to follow. Start playing the YouTube video below and look at the cross in the middle of the screen while also watching for flashes that appear at the bottom of the screen. Most importantly, you’ll want to add up the number of flashes you see throughout the video. (And make sure your volume is up.)

We don’t want to spoil the fun, so before we explain the science of how it works, check out the video and try it for yourself.

Did you see three flashes paired with three beeps? You’re not alone. This is due to a phenomenon called postdiction, which is a little like the opposite of prediction. According to a paper outlining these findings in the journal PLOS ONE, postdiction occurs when the brain processes information retroactively [PDF]. This occurs in such a way that our perception of earlier events is altered by stimuli that come later. In this case, you might think you missed the flash paired with the second of the three beeps, so your mind goes back and tries to make sense of the missing information. That's why you may see an “illusory flash” in the middle of the screen, sandwiched between the two real flashes.

For this reason, the researchers call the mind trick a “time-traveling illusion across multiple senses” (in this case, vision and hearing). It’s successful because the beeps and flashes occur so rapidly—in less than one-fifth of a second. The senses essentially get confused, and the brain tries to fill in the gaps retroactively.

"Illusions are a really interesting window into the brain," the paper’s first author, Noelle Stiles, said in a statement. "By investigating illusions, we can study the brain's decision-making process.” Researchers wanted to find out how the brain “determines reality” when a couple of your senses (in this case, sight and hearing) are bombarded with noisy and conflicting information. When the brain isn’t sure of what’s going on, it essentially makes up information.

“The brain uses assumptions about the environment to solve this problem,” Stiles said. “When these assumptions happen to be wrong, illusions can occur as the brain tries to make the best sense of a confusing situation. We can use these illusions to unveil the underlying inferences that the brain makes."

[h/t New Atlas]

SECTIONS

arrow
LIVE SMARTER