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7 Reasons Sleep Makes You a Better Person

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Sleep may be thought of as down time for the body, but as we rest, the brain is still up and running. No, you can’t learn a foreign language while you snooze. But sleep does play a pivotal role in learning and development. The brain that went to sleep last night isn’t exactly the same as the one that woke up this morning. While scientists still aren't sure why we sleep, they have conducted extensive research on the impact of sleep on our waking lives. Here are seven areas where the science backs up the common-sense idea that a good night’s rest is not just good for you. It's essential.   

1. Sleep helps you learn. 

While we sleep, the brain isn’t just resting. It’s busy rearranging and connecting its neuron networks in different ways. This helps you make associations, recognize patterns, and recall information. That old adage about getting a good night’s rest before a big test isn’t just about feeling alert while you’re bubbling in the answers. People recall information better after they sleep, even if it’s just a daytime nap. For instance, one study of auditory memory found that after people trained themselves on a pitch memory task, they performed better after they slept compared to before they slept. 

Scientists suggest that as we sleep, memories are being consolidated and transferred to other parts of the brain. This could be one reason we dream. Lab rats, for example, have been found to run mazes in their dreams, just as they do during the day. 

Memory improvements after sleep may be even more dramatic in children than in adults. Maybe that’s why kids need so much sleep!

2. Sleep helps you remember.  

While you may not be conscious of it, you can hear and smell during your sleep. When you hear or smell something as you learn, and then are exposed to it again as you sleep, it improves recall once you awaken. In a 2007 study, volunteers learned the locations of picture cards in a game similar to “concentration.” While they learned, they smelled the scent of a rose. Those who were exposed to the odor again while they slept that night remembered 97 percent of the locations, compared to only 86 percent for the people who didn’t stop to smell the roses as they slept. 

The smell (or sound) might help reactivate memories of the day, improving the ability to recall that memory in the morning.

3. Sleep improves motor skills. 

Researchers at Brown University identified a specific brainwave that occurs during sleep that seems to be vital to learning motor tasks, like playing the piano. Multiple studies have shown that musicians’ performance improves when practicing a new melody is followed by sleep. Further studies have shown sleep to improve other skills that involve coordination, like walking a complicated route, or, in the case of one 1988 study, trampolining

4. Sleep can make you less prejudiced. 

In a recent study, researchers put a group of 40 white individuals through an anti-bias training to reduce implicit, unconscious prejudice against women and people of color. While they looked at images that paired women and black men with non-stereotypical descriptors (like women and science words), an auditory cue pinged. Those who heard the sound again while they slept showed further reduction in measures of bias when they woke up. The result lasted for at least a week. 

5. Sleep helps you speak a new language—if you’ve already put some time in.

Sleep’s memory-boosting affects do apply to language-learning, though you can’t learn brand-new words while you’re unconscious. When German-speaking students were assigned to learn Dutch words for the first time, those who heard the same words played back to them while they slept could remember the German translation of the words better than the group who had the words played back while they were still awake. 

6. Sleep helps you navigate. 

When people dream, they may work out problems relevant to their waking lives—including spatial problems. When almost 100 people were taught to navigate a virtual maze as part of Harvard Medical School research, some of them has maze-related dreams (though, in the way of dreams, they weren’t necessarily solving that particular maze). Those who did performed better on the virtual maze later that day—better than those who didn’t sleep, and better than those who slept but didn’t dream. Other studies also suggest that sleep improves accuracy in navigating mazes. 

7. Sleep improves your immune system. 

Even if you’re a healthy person, sleep boosts your immune system. Just like you need sleep to remember foreign language vocabulary, your immune system needs it to remember how to fight off infection. In a study of healthy men, sleeping after a hepatitis vaccination improved the body’s immune response, making the vaccine more potent. In another study, people who slept fewer than six hours a night were 11.5 times more likely to remain unprotected from hepatitis B after getting the vaccine compared to people who slept more than seven hours, because their immune systems didn’t create antibodies to fight the virus. 

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Jamie McCarthy/Getty Images for Bill & Melinda Gates Foundation
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Medicine
Bill Gates is Spending $100 Million to Find a Cure for Alzheimer's
Jamie McCarthy/Getty Images for Bill & Melinda Gates Foundation
Jamie McCarthy/Getty Images for Bill & Melinda Gates Foundation

Not everyone who's blessed with a long life will remember it. Individuals who live into their mid-80s have a nearly 50 percent chance of developing Alzheimer's, and scientists still haven't discovered any groundbreaking treatments for the neurodegenerative disease [PDF]. To pave the way for a cure, Microsoft co-founder and philanthropist Bill Gates has announced that he's donating $100 million to dementia research, according to Newsweek.

On his blog, Gates explained that Alzheimer's disease places a financial burden on both families and healthcare systems alike. "This is something that governments all over the world need to be thinking about," he wrote, "including in low- and middle-income countries where life expectancies are catching up to the global average and the number of people with dementia is on the rise."

Gates's interest in Alzheimer's is both pragmatic and personal. "This is something I know a lot about, because men in my family have suffered from Alzheimer’s," he said. "I know how awful it is to watch people you love struggle as the disease robs them of their mental capacity, and there is nothing you can do about it. It feels a lot like you're experiencing a gradual death of the person that you knew."

Experts still haven't figured out quite what causes Alzheimer's, how it progresses, and why certain people are more prone to it than others. Gates believes that important breakthroughs will occur if scientists can understand the condition's etiology (or cause), create better drugs, develop techniques for early detection and diagnosis, and make it easier for patients to enroll in clinical trials, he said.

Gates plans to donate $50 million to the Dementia Discovery Fund, a venture capital fund that supports Alzheimer's research and treatment developments. The rest will go to research startups, Reuters reports.

[h/t Newsweek]

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Used by permission of Johannes Zanker
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science
10 Award-Winning Optical Illusions and Brain Puzzles
"The Spinning Disks Illusion"
"The Spinning Disks Illusion"
Used by permission of Johannes Zanker

When the new book Champions of Illusion: The Science Behind Mind-Boggling Images and Mystifying Brain Puzzles arrived at the Mental Floss offices, we couldn't flip through it—and flip our brains out—fast enough.

Created by Susana Martinez-Conde and Stephen Macknik, professors of ophthalmology, neurology, physiology, and pharmacology at SUNY Downstate Medical Center in Brooklyn, New York, the book is a fascinating compilation of award-winning images from the Best Illusion of the Year contest, which Martinez-Conde and Macknik first created for a neuroscience conference in 2005. Since then, the contest has produced some truly mind-bending mind tricks that challenge our sense of perception of the world around us. As the authors write:

Your brain creates a simulation of the world that may or may not match the real thing. The "reality" you experience is the result of your exclusive interaction with that simulation. We de­fine "illusions" as the phenomena in which your perception differs from physical reality in a way that is readily evident. You may see something that is not there, or fail to see something that is there, or see something in a way that does not reflect its physical properties.

Just as a painter creates the illusion of depth on a flat canvas, our brain creates the illusion of depth based on information arriving from our essentially two-dimensional retinas. Illusions show us that depth, color, brightness, and shape are not absolute terms but are subjective, relative experiences created actively by our brain's circuits. This is true not only of visual experiences but of any and all sensory perceptions, and even of how we ponder our emotions, thoughts, and memories. Whether we are experiencing the feeling of "redness," the appearance of "square­ness," or emotions such as love and hate, these are the result of the activity of neurons in our brain.

Yes, there is a real world out there, and you perceive events that occur around you, however incorrectly or incompletely. But you have never actually lived in the real world, in the sense that your experience never matches physical reality perfectly. Your brain instead gathers pieces of data from your sensory systems—some of which are quite imprecise or, frankly, wrong.

It's never been so fun to be wrong. Here are 10 of our favorite images from Champions of Illusion, accompanied by explanations from the book of how and why they work.

1. "THE COFFER ILLUSION," ANTHONY NORCIA, SMITH-KETTLEWELL EYE RESEARCH INSTITUTE, U.S.A., 2007 FINALIST

coffer illusion by Anthony Norcia, Stanford University
Used by permission of Anthony Norcia, Stanford University

Information transmitted from the retina to the brain is constrained by physical limitations, such as the number of nerve fibers in the optic nerve (about a million wires). If each of these fibers was responsible for producing a pixel (a single point in a digital image), you should have lower resolution in your everyday vision than in the images from your iPhone camera, but of course this is not what we perceive.

One way our visual system overcomes these limitations—to present us with the perception of a fully realized world, despite the fundamental truth that our retinas are low-resolution imaging devices—is by disregarding redundant features in objects and scenes. Our brains preferentially extract, emphasize, and process those unique components that are critical to identifying an object. Sharp discontinuities in the contours of an object, such as corners, are less redundant—and therefore more critical to vision—because they contain more information than straight edges or soft curves. The perceptual result is that corners are more sa­lient than non-corners.

The Coffer Illusion contains sixteen circles that are invisible at first sight, obscured by the rectilinear shapes in the pattern. The illusion may be due, at least in part, to our brain's preoccupation with corners and angles.

2. "THE ROTATING SNAKES ILLUSION," AKIYOSHI KITAOKA, RITSUMEIKAN UNIVERSITY, JAPAN, 2005 FINALIST

"The Rotating Snakes Illusion" by Akiyoshi Kitaoka
Used by permission of Akiyoshi Kitaoka

This illusion is a magnificent example of how we perceive illusory motion from a stationary image. The "snakes" in the pattern appear to rotate as you move your eyes around the figure. In reality, nothing is moving other than your eyes!

If you hold your gaze steadily on one of the "snake" centers, the motion will slow down or even stop. Our research, conducted in collaboration with Jorge Otero-Millan, revealed that the jerky eye motions—such as microsaccades, larger saccades, and even blinks—that people make when looking at an image are among the key elements that produce illusions such as Kitaoka's Rotating Snakes.

Alex Fraser and Kimerly J. Wilcox discovered this type of illusory motion effect in 1979, when they developed an image showing repetitive spiral arrangements of luminance gradients that appeared to move. Fraser and Wilcox's illusion was not nearly as effective as Kitaoka's il­lusion, but it did spawn a number of related effects that eventually led to the Rotating Snakes. This family of perceptual phenomena is characterized by the periodic placement of colored or grayscale patches of particular brightnesses.

In 2005, Bevil Conway and his colleagues showed that Kitaoka's illusory layout drives the responses of motion-sensitive neurons in the visual cortex, providing a neural basis for why most people (but not all) perceive motion in the image: We see the snakes rotate because our visual neurons respond as if the snakes were actually in motion.

Why doesn't this illusion work for everyone? In a 2009 study, Jutta Billino, Kai Ham­burger, and Karl Gegenfurtner, of the Justus Liebig University in Giessen, Germany, tested 139 subjects—old and young—with a battery of illusions involving motion, including the Rotating Snakes pattern. They found that older people perceived less illusory rotation than younger subjects.

3. "THE HEALING GRID," RYOTA KANAI, UTRECHT UNIVERSITY, THE NETHERLANDS, 2005 FINALIST

healing grid illusion by Ryota Kanai
Used by permission of Ryota Kanai

Let your eyes explore this image freely and you will see a regular pattern of intersecting horizontal and vertical lines in the center, flanked by an irregular grid of misaligned crosses to the left and right. Choose one of the intersections in the center of the image and stare at it for 30 seconds or so. You will see that the grid "heals" itself, becoming perfectly regular all the way through.

The illusion derives, in part, from "perceptual fading," the phenomenon in which an unchanging visual image fades from view. When you stare at the center of the pattern, the grid's outer parts fade more than its center due to the comparatively lower resolution of your peripheral vision. The ensuing neural guesstimates that your brain imposes to "reconstruct" the faded outer flanks are based on the available information from the center, as well as your nervous system's intrinsic tendency to seek structure and order, even when the sensory in­put is fundamentally disorganized.

Because chaos is inherently unordered and unpredictable, the brain must use a lot of energy and resources to process truly chaotic information (like white noise on your TV screen). By simplifying and imposing order on images like this one, the brain can reduce the amount of information it must process. For example, because the brain can store the image as a rectilinear framework of white rows and columns against a black background—rather than keeping track of every single cross's position—it saves energy and mental storage space. It also simplifies your interpretation of the meaning of such an object.

4. "MASK OF LOVE," GIANNI SARCONE, COURTNEY SMITH, AND MARIE-JO WAEBER, ARCHIMEDES LABORATORY PROJECT, ITALY, 2011 FINALIST

mask of love by Gianni Sarcone, Courtney Smith, and Marie-Jo Waeber
Courtesy of Gianni Sarcone, Courtney Smith, and Marie-Jo Waeber. Copyright © Gianni A. Sarcone, giannisarcone.com. All rights reserved.

This illusion was discovered in an old photograph of two lovers sent to Archimedes' Laboratory, a consulting group in Italy that specializes in perceptual puzzles. Gianni Sarcone, the leader of the group, saw the image pinned to the wall and, being nearsighted, thought it was a single face. After putting on his eyeglasses, he realized what he was looking at. The team then superimposed the beautiful Venetian mask over the photograph to create the final effect.

This type of illusion is called "bistable" because, as in the classic Face/Vase illusion, you may see either a single face or a couple, but not both at once. Our visual system tends to see what it expects, and because only one mask is present, we assume at first glance that it surrounds a single face.

5. "AGE IS ALL IN YOUR HEAD," VICTORIA SKYE, U.S.A., 2014 FINALIST

age is all in your head illusion by Victoria Skye
Used by permission of Victoria Skye

The magician, photographer, and illusion creator Victoria Skye was having a hard time taking a picture of a photo portrait of her father as a teen. The strong overhead lighting was ruining the shot, so she tilted the camera to avoid the glare, first one way and then the other. As she moved her camera back and forth, she saw her father morph from teen to boy and then to adult.

Skye's illusion is an example of anamorphic perspective. By tilting her camera, she created two opposite vanishing points, producing the illusion of age progression and regression. In the case of age progression, the top of the head narrows and the bottom half of the face expands, creating a stronger chin and a more mature look. In the case of age regression, the opposite happens: the forehead expands and the chin narrows, producing a childlike appearance.

Skye thinks that her illusion may explain why, when we look at ourselves in the mirror, we sometimes see our parents, but not always. "I wonder if that is what happens to me when I look in the mirror and see my mom. Do I see her because I tilt my head and age myself just as I did with the camera and my dad?" she asked.

6. "THE ROTATING-TILTED-LINES ILLUSION," SIMONE GORI AND KAI HAMBURGER

rotating tilted lines illusion by Simone Gori and Kai Hamburger
Used by permission of Simone Gori and Kai Hamburger

To experience the illusion, move your head forward and backward as you fixate in the central area (or, alternatively, hold your head still and move the page). As you approach the image, notice that the radial lines appear to rotate counterclockwise. As you move away from the image, the lines appear to rotate clockwise. Vision scientists have shown that illusory motion activates brain areas that are also activated by real motion. This could help explain why our perception of illusory motion is qualitatively similar to our perception of real motion.

7. "PULSATING HEART," GIANNI SARCONE, COURTNEY SMITH, AND MARIE-JO WAEBER, ARCHIMEDES LABORATORY PROJECT, ITALY, 2014 FINALIST

Pulsating Heart illusion by Gianni Sarcone, Courtney Smith, and Marie-Jo Waeber
Courtesy of Gianni Sarcone, Courtney Smith, and Marie-Jo Waeber. Copyright © Gianni A. Sarcone, giannisarcone.com. All rights reserved.

This Op Art–inspired illusion produces the sensation of expanding motion from a completely stationary image. Static repetitive patterns with just the right mix of contrasts trick our visual system's motion-sensitive neurons into signaling movement. Here the parallel arrangement of opposing needle-shaped red and white lines makes us perceive an ever-expanding heart. Any other outline delimited in a similar fashion would also appear to pulsate and swell.

8. "GHOSTLY GAZE," ROB JENKINS, UNIVERSITY OF GLASGOW, UK, 2008 SECOND PRIZE

ghostly gaze illusion by Rob Jenkins
Used by permission of Rob Jenkins

Not knowing where a person is looking makes us uneasy. That's why speaking with somebody who is wearing dark sunglasses can be awkward. And it is why someone might wear dark sunglasses to look "mysterious." The Ghostly Gaze Illusion, created by Rob Jenkins, takes advantage of this unsettling effect. In this illusion, twin sisters appear to look at each other when seen from afar. But as you approach them, you realize that the sisters are looking directly at you!

The illusion is a hybrid image that combines two pictures of the same woman. The overlapping photos differ in two important ways: their spatial detail (fine or coarse) and the direction of their gaze (sideways or straight ahead). The images that look toward each other contain only coarse features, whereas the ones that look straight ahead are made up of sharp details. When you approach the pictures, you are able to see all the fine detail, and so the sisters seem to look straight ahead. But when you move away, the gross detail dominates, and the sisters appear to look into each other's eyes.

9. "ELUSIVE ARCH," DEJAN TODOROVIC, UNIVERSITY OF BELGRADE, SERBIA, 2005 FINALIST

Elusive Arch illusion by Dejan Todorovic
Used by permission of Dejan Todorovic

Is this an image of three shiny oval tubes? Or is it three pairs of alternating ridges and grooves?

The left side of the figure appears to be three tubes, but the right side looks like a corrugated surface. This illusion occurs because our brain interprets the bright streaks on the figure's surface as either highlights at the peaks and troughs of the tubes or as inflections between the grooves. Determining the direction of the illumination is difficult: it depends on whether we consider the light as falling on a receding or an expanding surface.

Trying to determine where the image switches from tubes to grooves is maddening. In fact, there is no transition region: the whole image is both "tubes" and "grooves," but our brain can only settle on one or the other interpretation at a time. This seemingly simple task short-circuits our neural mechanisms for determining an object's shape.

10. "FLOATING STAR," JOSEPH HAUTMAN / KAIA NAO, 2012 FINALIST

floating star illusion by Joseph Hautman, aka Kaia Nao
Used by permission of Joseph Hautman, aka Kaia Nao. Copyright © Kaia Nao

This five-pointed star is static, but many observers experience the powerful illusion that it is rotating clockwise. Created by the artist Joseph Hautman, who moonlights as a graphic designer under the pseudonym "Kaia Nao," it is a variation on Kitaoka's Rotating Snakes Illusion. Hautman determined that an irregular pattern, unlike the geometric one Kitaoka used, was particularly effective for achieving illusory motion.

Here the dark blue jigsaw pieces have white and black borders against a lightly colored background. As you look around the image, your eye movements stimulate motion-sensitive neurons. These neurons signal motion by virtue of the shifting lightness and darkness boundaries that indicate an object's contour as it moves through space. Carefully arranged transitions between white, light-colored, black, and dark-colored regions fool the neurons into responding as if they were seeing continual motion in the same direction, rather than stationary edges.

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