The Stroop Effect Is A Window Into Perception

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The Stroop Effect Is A Window Into Perception

How easy is it to name the color of a word? As it turns out, not that easy—at least when it clashes with what the word says. This difficulty is known as the Stroop Effect, named for J. Ridley Stroop, whose 1935 study was the first to demonstrate this phenomenon. When you see the word "black" written in black ink, naming the color of the ink is easy. Same with seeing the word "pillow" in black ink. But when "black" is written in green, it may take you at least a moment to figure out the right answer. This is a demonstration of how our brain is so comfortable with some tasks that they happen automatically; in this case, we read and interpret words without paying attention to the physical characteristics of the letters themselves. This effect is so reliable that it's used in many psychology studies to test attention. Try it yourself in the videos below.

You Won't See All The Dots At Once In This Optical Illusion

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You Won't See All The Dots At Once In This Optical Illusion

A seemingly simple line and dot optical illusion by Akiyoshi Kitaoka, a professor of Psychology at the College of Letters, Ritsumeikan University, Kyoto, Japan, went viral online. Why? This black dot illusion can trip anyone up, as it shows a network of gray lines on a white background. Within this matrix, there are 12 black dots, each at the intersection of some gray lines. The maddening part about this is that you can't see all the black dots at once. One reason we can't see all the dots at once is due to our not-perfect peripheral vision. The density of photoreceptors in our eyes plummets in our peripheral vision, meaning if you're not staring straight at something, it becomes a lot harder to make out. But you can also blame lateral inhibition. Because the black dots sitting at gray line intersections do not contrast as much, our brain washes over the dots with gray, rendering them invisible. To see it in action, check out the video below.

This Bionic Lens Could Give You Superhuman Vision

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This Bionic Lens Could Give You Superhuman Vision

There are plenty of ways to fix imperfect vision, but none of them last. Even LASIK, the most popular long-term solution, leaves your eyes at risk of cataracts later in life. In May of 2015, a Canadian ophthalmologist announced that he's created a bionic lens that could correct a person's vision for life, potentially resulting in vision three times better than 20/20. The product of eight years of research and $3 million in funding, the Ocumetics Bionic Lens is said to require a painless 8-minute in-office procedure that requires no anesthesia. The custom-made lens is folded up like a taco in a saline-filled syringe, then placed in the eye and left to unravel over about 10 seconds. Because the bionic lens is designed to replace a patient's natural one, the procedure may eliminate any risk of cataracts in the future. Wondering what you can do to improve your vision? Check out these videos.

Why Does Space Impair Your Vision?

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Why Does Space Impair Your Vision?

Humans have been going into space for 50 years, but scientists are still discovering new things about what microgravity does to the human body. For example, astronauts have been reporting worsening vision since the first crewed space flights, but it wasn't until flights stretched to weeks and months at a time that the extent of this problem came to light. In post-flight examinations on 300 astronauts since 1989, 29% of astronauts experienced worse vision after a two-week mission in the space shuttle and 60% experienced it after a five- to six-month tour of duty in the International Space Station. Most of the time, astronauts notice more far-sightedness, usually from a strange "flattening" of the eyeball and swelling of the optic nerve. Scientists aren't entirely sure what's causing the vision problems, but they have a few guesses. Some think it could be elevated intracranial pressure, that is, pressure in the brain and spinal fluid, since people with this issue have similar vision problems. Other hypotheses involve the elevated carbon dioxide levels in the air astronauts breathe, the large amount of sodium in their diets, or radiation exposure. To help figure out the cause, astronauts use advanced medical equipment to perform eye exams on each other in space while physicians examine the results from Earth. We've collected some awesome videos on this topic. Watch them now to learn more.

The Psychic Staring Effect Is That Sense You're Being Stared At

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The Psychic Staring Effect Is That Sense You're Being Stared At

You've probably felt it before: you don't see anyone looking at you, but you just kind of sense that someone is watching you. This psychic staring effect, also called scopaesthesia, is the supposed phenomenon of knowing when you're being stared at. But is it real? Studies say this effect seems to be purely illusory. Psychologist Edward Titchener wrote about the feeling in 1898 in a study published in Science magazine. Titchener concluded that the effect may just be a self-fulfilling prophecy: you feel like your back is being stared at so you start feeling anxious and twitch around. The twitching and nervous behavior gains attention, so by the time you look around, people actually are staring. We've collected some awesome videos on this topic. Watch them now to learn more.