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Zombies, Fire Drills, and Bad Decision-Making

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Imagine that the dead have risen from their graves. They’ve gotten into a building you’re hiding out in. You slink down the hallway and enter what you think is a safe room.

It’s empty, and looks like a good place to hide. As you stand in the middle of the room, you look around. There’s only two doors: the one that you came through and one on the opposite side of the room. You should be able to barricade them both with furniture. But, oh no! The zombies have found the room, too. They’re shambling around both doors, with more crowding the doorway you just used, and now you have to get out. Which door do you exit through?

The less crowded one, I’m sure you’re saying. Of course, that makes the most sense. If both doors are the same distance from where you’re standing, why not use the one that’s got fewer obstacles?

Well, science has some bad news for you: You’ll probably wind up as a snack for the living dead, or at least stuck in a crowded doorway. Stress makes us do stupid things, like seek familiar routes even if they’re not the best ones. Over and over, eyewitness reports from real-life evacuations have suggested that, in emergencies, people tend to exit buildings from the main entrance that they used to enter the building, ignoring one or more emergency exits along the way. The crowding at these entryways slows evacuation times and sometimes results in injuries and even deaths.

Earlier this year, the Science Museum of London held a zombie-themed science festival called “ZombieLab.” Researchers Nikolai Bode and Edward Codling, from the University of Essex, took advantage of the event to look at the decisions people make in emergencies. They set up a computer simulation of a room evacuation similar to what I described above. One hundred and eighty-five museum guests took control of a computer person in a virtual environment filled with 80 virtual zombies.

At the start of the experiment, the participants just had to move their person from the hallway and into the central room. Next, they had to move back out again, through one of two doors, to where they started in the hall. During this second part, the researchers presented the visitors with a few different conditions. Some just had to simply exit the room. Others were encouraged to beat the fastest exit time. Others were presented with a crowd of zombies split unevenly between the two exits. A last group had to deal with the crowed exits while trying to beat the best time.

In the normal exit scenario and when they were trying to set the best time, the museum visitors split evenly between the two exit routes and showed no clear preference for one or the other. Faced with zombie-crowded exits, though, the visitors started to show some bias for the doorway they had come through, even if it was more crowded. Presented with the zombie obstacles alone, some of the visitors went for they door they came through, and then changed their mind when they realized how crowded the doorway was. With the added pressure of the time clock, fewer people changed their mind and stuck with trying to get out that exit, even though it was the slowest route.

Bode and Codling’s results fit with what other researchers have found in theoretical models and real-life evacuations. Under stress, people make irrational decisions. Here, the museum visitors under pressure to exit quickly were more likely to stick to the route they knew even if it wound up taking them longer to get out, and were less likely to change their mind and adapt to the situation.

In a real-world situation, the researchers say, their results suggest some strategies for minimizing risks during stressful evacuations. One idea they offer is having people in large, crowded buildings enter from several different locations. If they have to get out quickly, and their preference for the way they came in holds up, they’ll spread out to different routes and avoid overcrowding any one exit.

It’s worth mentioning that the idea that the other virtual characters in the room were zombies was just meant to fit the experiment in with the theme of the festival and keep participants blind to the purpose of the experiment. In the simulation, the zombies didn’t attack participants or pose any danger, but simply blocked the doorways. The study participants didn’t have to treat them as a threat, so they focused on choosing one door or the other without worrying about getting their brains eaten. I wonder if, or how, the results would differ if the “zombies” acted more like zombies, and how decision-making in an evacuation is affected if there are obstacles at exits that pose active threats.

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Can You 'Hear' These Silent GIFs?
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GIFs are silent—otherwise they wouldn't be GIFs. But some people claim to hear distinct noises accompanying certain clips. Check out the GIF below as an example: Do you hear a boom every time the structure hits the ground? If so, you may belong to the 20 to 30 percent of people who experience "visual-evoked auditory response," also known as vEAR.

Researchers from City University London recently published a paper online on the phenomenon in the journal Cortex, the British Psychological Society's Research Digest reports. For their study, they recruited more than 4000 volunteers and 126 paid participants and showed them 24 five-second video clips. Each clip lacked audio, but when asked how they rated the auditory sensation for each video on a scale of 0 to 5, 20 percent of the paid participants rated at least half the videos a 3 or more. The percentage was even higher for the volunteer group.

You can try out the researchers' survey yourself. It takes about 10 minutes.

The likelihood of visual-evoked auditory response, according to the researchers, directly relates to what the subject is looking at. "Some people hear what they see: Car indicator lights, flashing neon shop signs, and people's movements as they walk may all trigger an auditory sensation," they write in the study.

Images packed with meaning, like two cars colliding, are more likely to trigger the auditory illusion. But even more abstract images can produce the effect if they have high levels of something called "motion energy." Motion energy is what you see in the video above when the structure bounces and the camera shakes. It's why a video of a race car driving straight down a road might have less of an auditory impact than a clip of a flickering abstract pattern.

The researchers categorize vEAR as a type of synesthesia, a brain condition in which people's senses are combined. Those with synesthesia might "see" patterns when music plays or "taste" certain colors. Most synesthesia is rare, affecting just 4 percent of the population, but this new study suggests that "hearing motion synesthesia" is much more prevalent.

[h/t BPS Research Digest]

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The Surprising Link Between Language and Depression
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Skim through the poems of Sylvia Plath, the lyrics of Kurt Cobain, or posts on an internet forum dedicated to depression, and you'll probably start to see some commonalities. That's because there's a particular way that people with clinical depression communicate, whether they're speaking or writing, and psychologists believe they now understand the link between the two.

According to a recent study published in Clinical Psychological Science, there are certain "markers" in a person's parlance that may point to symptoms of clinical depression. Researchers used automated text analysis methods to comb through large quantities of posts in 63 internet forums with more than 6400 members, searching for certain words and phrases. They also noted average sentence length, grammatical patterns, and other factors.

What researchers found was that a person's use (or overuse) of first-person pronouns can provide some insight into the state of their mental health. People with clinical depression tend to use more first-person singular pronouns, such as "I" and "me," and fewer third-person pronouns, like "they," "he," or "she." As Mohammed Al-Mosaiwi, a Ph.D. candidate in psychology at the University of Reading and the head of the study, writes in a post for IFL Science:

"This pattern of pronoun use suggests people with depression are more focused on themselves, and less connected with others. Researchers have reported that pronouns are actually more reliable in identifying depression than negative emotion words."

What remains unclear, though, is whether people who are more focused on themselves tend to depression, or if depression turns a person's focus on themselves. Perhaps unsurprisingly, people with depression also use more negative descriptors, like "lonely" and "miserable."

But, Al-Mosaiwi notes, it's hardly the most important clue when using language to assess clinical depression. Far better indicators, he says, are the presence of "absolutist words" in a person's speech or writing, such as "always," "constantly," and "completely." When overused, they tend to indicate that someone has a "black-and-white view of the world," Al-Mosaiwi says. An analysis of posts on different internet forums found that absolutist words were 50 percent more prevalent on anxiety and depression forums, and 80 percent more prevalent on suicidal ideation forums.

Researchers hope these types of classifications, supported by computerized methods, will prove more and more beneficial in a clinical setting.

[h/t IFL Science]

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