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Airing TONIGHT on PBS - NOVA: What Are Dreams?

NOVA: What Are Dreams? airs on PBS stations in the US tonight, Tuesday, November 24. This is a terrific documentary on dreams, packed with specifics on the science of sleep. If you've ever wondered about sleepwalking, why we dream, or why sleep is necessary, this is the documentary for you! Note: after the air date, the entire program will be available for streaming for one full week on the Nova: What Are Dreams website.

I'm a big fan of NOVA, the science program aired on PBS stations in the US. I recently got an advance look at tonight's program, What Are Dreams?, and I think it's awesome. It's very reminiscent of a Radiolab episode on dreams from 2007 (you may remember it as the "dreaming about Tetris" episode), as the NOVA team interviews many of the same scientists, though they are further along in their research at this point. The difference is that this is NOVA, so you get to see scientists in the lab, as well as bizarre video of people sleepwalking, video of rats running mazes, and so on. This adds a new dimension that the Radiolab program lacked (although the Radiolab episode is very much worth listening to -- it's a classic.)

Discussed in this NOVA program: REM sleep and "NREM" sleep; how people waking up from different stages of sleep feel about themselves (hint: waking up from REM makes you feel like you're a pretty crappy person!); how REM/NREM sleep ratios may affect depression (!); REM Sleep Disorder -- a frightening brain disorder in which your body is not paralyzed during dreams, so you act them out; the (surprisingly brief/recent) history of sleep research; how sleep studies work (electrodes all over your head!); dreaming about videogames; how "sleeping on a problem" actually improves performance the next day; and how rats dream about running through mazes.

Here's a trailer:

Remember, it airs TONIGHT, Tuesday, November 24, on PBS stations in the US. Check your local listings for the time, though is most markets it's at 8pm.

See also: 5 Full Episodes of NOVA, Inside Oliver Sacks's Brain (As He Listens to Music), My Sleep Apnea: The Sleep Study, and Sleepwalk With Me.

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The Brain Chemistry Behind Your Caffeine Boost
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iStock

Whether it’s consumed as coffee, candy, or toothpaste, caffeine is the world’s most popular drug. If you’ve ever wondered how a shot of espresso can make your groggy head feel alert and ready for the day, TED-Ed has the answer.

Caffeine works by hijacking receptors in the brain. The stimulant is nearly the same size and shape as adenosine, an inhibitory neurotransmitter that slows down neural activity. Adenosine builds up as the day goes on, making us feel more tired as the day progresses. When caffeine enters your system, it falls into the receptors meant to catch adenosine, thus keeping you from feeling as sleepy as you would otherwise. The blocked adenosine receptors also leave room for the mood-boosting compound dopamine to settle into its receptors. Those increased dopamine levels lead to the boost in energy and mood you feel after finishing your morning coffee.

For a closer look at how this process works, check out the video below.

[h/t TED-Ed]

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Sophie Nightingale / University of Warwick
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Can You Spot Which Photo Is Fake? Most People Can’t
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Sophie Nightingale / University of Warwick

In a digital world, it’s easier than ever to fool people. Sophisticated Photoshop jobs, social media, and viral news cycles mislead readers into mistaking shots from a Lebanese music video for real scenes of destruction from Aleppo, thinking that Vladimir Putin was the center of attention at the G-20 summit, or believing that Elizabeth Taylor and Marilyn Monroe posed together for a photo shoot in the park.

While it would be nice to tell ourselves that we would never be duped by such fake images, the truth is, most people can’t distinguish between a manipulated photo and a real one. That’s the takeaway from a new study in Cognitive Research: Principle and Implications. As the team at Science reports, the participants were only able to pinpoint fake images two-thirds of the time.

First, psychologists from the University of Warwick asked more than 700 volunteers to look at real and fake images and identify the changes. The researchers used 10 color photographs sourced from Google searches, manipulating them through airbrushing, adding elements in, subtracting elements, and distorting shadows, and shearing trees. They applied each of these five manipulation techniques separately to a portion of the photos, eventually creating 30 manipulated photos and 10 real ones. All the participants saw one of each of the manipulation types in different photos.

An older man stands in the street in front of a house.
Can you spot the differences between the manipulated image at the top of the page and the original version above?
Sophie Nightingale / University of Warwick

The participants performed slightly above chance rates, identifying photos correctly as real only 58 percent of the time and spotting manipulations 66 percent of the time. Even when they did identify a manipulated photo, though, they didn’t necessarily know where it had been altered.

In a second study, the researchers did the same thing, but using photos study co-author Sophie J. Nightingale took with her Nikon camera, controlling for the fact that images found online could be manipulated before the researchers even downloaded them. They then had almost 660 people take an online survey testing their ability to spot fakes. They had to look at photos and label whether it was fake and if they could see where it was manipulated, whether it was fake but they didn’t know where it had been altered, or whether it was an original. At the end of the study, the subjects identified just 62 percent of the fake images correctly.

Woman standing outside
The first image is the original. The second was manipulated to add in a water spout, airbrush the woman's face, and make other slight changes.
Sophie Nightingale / University of Warwick

The results were the same regarding images that had been manipulated in both overtly unrealistic ways and photos that featured more plausible changes. One reason might be the way that our visual system simplifies information. As long as object geometries and shadows are roughly correct, our eyes accept them as accurate.

“It remains to be determined whether it is possible to train people to make use of physically implausible inconsistencies,” the researchers write. “Perhaps one possibility would entail ‘teaching' the visual system to make full use of physical properties of the world as opposed to automatically simplifying them.”

You can still take a 10-minute online survey for the project here and test your own manipulation awareness skills. (I had to take wild guesses on most of them.)

If this makes you weep for the future of the world, at least know that it’s a timeless problem. Manipulated, misleading images have been around since the earliest days of photography.

[h/t Science]

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