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Ninio, J. and Stevens, K. A., Variations on the Hermann Grid: An Extinction Illusion // Facebook
Ninio, J. and Stevens, K. A., Variations on the Hermann Grid: An Extinction Illusion // Facebook

Your Brain Won’t Let You See Every Dot in This Illusion at Once

Ninio, J. and Stevens, K. A., Variations on the Hermann Grid: An Extinction Illusion // Facebook
Ninio, J. and Stevens, K. A., Variations on the Hermann Grid: An Extinction Illusion // Facebook

Stare at the above image long enough and you’ll start to notice something peculiar: When your eyes focus on one of the gray intersections in the picture, two or three black dots will appear. But as you hold your gaze, the dots in your periphery seem to fade from view, and if your direct your vision elsewhere, they’ll hop to a different area altogether.

This optical illusion has been baffling the internet since it was shared by Japanese psychology professor Akiyoshi Kitaoka on Sunday, September 11. Most people are incapable of seeing all 12 black dots in the image at once, a phenomenon The Verge reports is due to humans’ poor peripheral vision.

Because our eyes can’t process the visual information in our peripheries as well as what’s directly in front of us, our brains make guesses with what's available to fill in any mental gaps, according to researchers who first introduced the world to the illusion. So when we stare at a black dot surrounded by a pattern of gray lines against a white background, our mind assumes what the intersection of the gray lines will look like without adding a black dot in the center.

A paper published in 2000 in the journal Perception, where the optical illusion first appeared, explains how our brains react to the image:

“When the white disks in a scintillating grid are reduced in size, and outlined in black, they tend to disappear. One sees only a few of them at a time, in clusters which move erratically on the page. Where they are not seen, the grey alleys seem to be continuous, generating grey crossings that are not actually present.”

Seeing objects in our periphery isn't the only task the human eye struggles with. The imperfect way we process color also makes for some mind-bending optical illusions.

[h/t The Verge]

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Animals
Where Do Birds Get Their Songs?
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iStock

Birds display some of the most impressive vocal abilities in the animal kingdom. They can be heard across great distances, mimic human speech, and even sing using distinct dialects and syntax. The most complex songs take some practice to learn, but as TED-Ed explains, the urge to sing is woven into songbirds' DNA.

Like humans, baby birds learn to communicate from their parents. Adult zebra finches will even speak in the equivalent of "baby talk" when teaching chicks their songs. After hearing the same expressions repeated so many times and trying them out firsthand, the offspring are able to use the same songs as adults.

But nurture isn't the only factor driving this behavior. Even when they grow up without any parents teaching them how to vocalize, birds will start singing on their own. These innate songs are less refined than the ones that are taught, but when they're passed down through multiple generations and shaped over time, they start to sound similar to the learned songs sung by other members of their species.

This suggests that the drive to sing as well as the specific structures of the songs themselves have been ingrained in the animals' genetic code by evolution. You can watch the full story from TED-Ed below, then head over here for a sample of the diverse songs produced by birds.

[h/t TED-Ed]

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Animals
Watch the First-Ever Footage of a Baby Dumbo Octopus
NOAA, Wikimedia Commons // Public Domain
NOAA, Wikimedia Commons // Public Domain

Dumbo octopuses are named for the elephant-ear-like fins they use to navigate the deep sea, but until recently, when and how they developed those floppy appendages were a mystery. Now, for the first time, researchers have caught a newborn Dumbo octopus on tape. As reported in the journal Current Biology, they discovered that the creatures are equipped with the fins from the moment they hatch.

Study co-author Tim Shank, a researcher at the Woods Hole Oceanographic Institution in Massachusetts, spotted the octopus in 2005. During a research expedition in the North Atlantic, one of the remotely operated vehicles he was working with collected several coral branches with something strange attached to them. It looked like a bunch of sandy-colored golf balls at first, but then he realized it was an egg sac.

He and his fellow researchers eventually classified the hatchling that emerged as a member of the genus Grimpoteuthis. In other words, it was a Dumbo octopus, though they couldn't determine the exact species. But you wouldn't need a biology degree to spot its resemblance to Disney's famous elephant, as you can see in the video below.

The octopus hatched with a set of functional fins that allowed it to swim around and hunt right away, and an MRI scan revealed fully-developed internal organs and a complex nervous system. As the researchers wrote in their study, Dumbo octopuses enter the world as "competent juveniles" ready to jump straight into adult life.

Grimpoteuthis spends its life in the deep ocean, which makes it difficult to study. Scientists hope the newly-reported findings will make it easier to identify Grimpoteuthis eggs and hatchlings for future research.

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