How many of your friends can see all the dots in this optical illusion? Probably none.

Your brain literally won't let you win against this optical illusion:

There are 12 black dots in the picture, but I'd bet good money that you'll never be able to see all of them at once. If I squint, I can get four, and only four.

The illusion started taking over the internet after game developer Will Kerslake shared it via Twitter, but the picture itself originally came from the Facebook page of Akiyoshi Kitaoka, a psychology professor in Kyoto, Japan. It appears to be a variation of Ninio's extinction illusion, which is a grid illusion that scientists use to explain a big scientific concept.


Why you can't see all 12 dots? Basically, we can blame evolution.

The back of our eyes are full of light-sensing nerve cells, all crowded together, waiting for stimulation. You might think that when something interesting happens, they'd all start shouting and firing off signals โ€” a furious rush of noise. But that's not what happens.

Instead, excited nerve cells actually kind of "shush" their neighbor cells, a phenomenon called lateral inhibition. They do this because it helps the message get through โ€” if only a few people are shouting, the signal is clearer.

The end result is that our visual contrast goes up, but at the cost of muting whatever we're not looking at.

Meanwhile, our brain tries to be helpful by filling in that incomplete information with whatever it guesses is there. And since most of this picture is grey lines, our brain just leaves out the black dots.

So you're not going crazy, I promise. There really are 12 dots, but our eyes and brains do weird stuff sometimes to help us focus and survive. And as for what it means if you can see more dots than someone else? Well, the science doesn't really tell us much. Maybe you just have a different level of lateral inhibition than them, or maybe your brain is better at filling in the gaps.

Little mind games like this remind us of the limits of our brains.

We often assume seeing is believing, but optical illusions help show that's not true. Scientists are now using optical illusions to study how we perceive the world, why we react to certain things, and why we make quick assumptions. Optical illusions can teach us about bigger subjects like schizophrenia or even racism!

And, if nothing else, they're kind of trippy and fun.

Researchers at Harvard University have studied the connection between spanking and kids' brain development for the first time, and their findings echo what studies have indicated for years: Spanking isn't good for children.

Comments on this article will no doubt be filled with people who a) say they were spanked and "turned out fine" or b) say that the reason kids are [fill in the blank with some societal ill] these days are because they aren't spanked. However, a growing body of research points to spanking creating more problems than it solves.

"We know that children whose families use corporal punishment are more likely to develop anxiety, depression, behavior problems, and other mental health problems, but many people don't think about spanking as a form of violence," said Katie A. McLaughlin, director of the Stress & Development Lab in the Department of Psychology, and the senior researcher on the study which was published Friday in the journal Child Development. "In this study, we wanted to examine whether there was an impact of spanking at a neurobiological level, in terms of how the brain is developing."

You can read the entire study here, but the gist is that kids' brain activity was measured using an MRI machine as they reacted to photos of actors displaying "fearful" and "neutral" faces. What researchers found was that kids who had been spanked had similar brain neural responses to fearful faces as kids who had been abused.

"There were no regions of the brain where activation to fearful relative to neutral faces differed between children who were abused and children who were spanked," the authors wrote in a statement.

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Images courtesy of John Scully, Walden University, Ingrid Scully
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Since March of 2020, over 29 million Americans have been diagnosed with COVID-19, according to the CDC. Over 540,000 have died in the United States as this unprecedented pandemic has swept the globe. And yet, by the end of 2020, it looked like science was winning: vaccines had been developed.

In celebration of the power of science we spoke to three people: an individual, a medical provider, and a vaccine scientist about how vaccines have impacted them throughout their lives. Here are their answers:

John Scully, 79, resident of Florida

Photo courtesy of John Scully

When John Scully was born, America was in the midst of an epidemic: tens of thousands of children in the United States were falling ill with paralytic poliomyelitis โ€” otherwise known as polio, a disease that attacks the central nervous system and often leaves its victims partially or fully paralyzed.

"As kids, we were all afraid of getting polio," he says, "because if you got polio, you could end up in the dreaded iron lung and we were all terrified of those." Iron lungs were respirators that enclosed most of a person's body; people with severe cases often would end up in these respirators as they fought for their lives.

John remembers going to see matinee showings of cowboy movies on Saturdays and, before the movie, shorts would run. "Usually they showed the news," he says, "but I just remember seeing this one clip warning us about polio and it just showed all these kids in iron lungs." If kids survived the iron lung, they'd often come back to school on crutches, in leg braces, or in wheelchairs.

"We all tried to be really careful in the summer โ€” or, as we called it back then, 'polio season,''" John says. This was because every year around Memorial Day, major outbreaks would begin to emerge and they'd spike sometime around August. People weren't really sure how the disease spread at the time, but many believed it traveled through the water. There was no cure โ€” and every child was susceptible to getting sick with it.

"We couldn't swim in hot weather," he remembers, "and the municipal outdoor pool would close down in August."

Then, in 1954 clinical trials began for Dr. Jonas Salk's vaccine against polio and within a year, his vaccine was announced safe. "I got that vaccine at school," John says. Within two years, U.S. polio cases had dropped 85-95 percent โ€” even before a second vaccine was developed by Dr. Albert Sabin in the 1960s. "I remember how much better things got after the vaccines came out. They changed everything," John says.

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