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Close your eyes and picture a red apple. Now is the apple that you're picturing actually red?

For most people, the answer is “Yeah, of course, that's what you asked me to do.” But others might say, “Well, I don't actually see anything. No one, no one sees something, right?” And that is because some people don't have or use visual imagination, or what's sometimes called the “mind's eye.” And those folks can be kind of surprised to learn that it's not just a metaphor. This condition is called aphantasia, and it was only really noticed by the scientific community in 2010.

But aphantasia is more than just a different way of experiencing the world. It's also a new window into how the brain processes imagination, emotion, and even memory. Broadly-speaking, the scientific community first really learned about aphantasia after a man had what seemed like a small stroke and lost his ability to create visual imagery.

After his story was covered in the news, 21 others contacted the original researcher to report similar experiences. Only for them, life had been that way as long as they could remember. As scientists studied these folks, they found that aphantasia falls on a spectrum.

Some people report their visual imagination as just being less vivid, making them less likely to use it. Meanwhile, others seem to be unable to make visual imagery at all. If you were to ask a person in that second group something like how many windows there are in their home, they wouldn't picture every room.

Instead, they would likely say they used knowledge or memory to answer your question. At first glance, it's tempting to chalk this up to miscommunication. Maybe what someone with aphantasia calls “memory” is actually what others might mean by “mind's eye.” But experiments have shown that there does seem to be something going on at a physiological level.

For example, most people with sight experience an illusion called binocular rivalry. If a researcher shows each eye a different image, the brain can get overwhelmed and sometimes just ignore one. Like, say I flash red, horizontal stripes to your left eye, and green, vertical stripes to your right eye.

The odds are pretty good that your brain will just randomly pick one of those to focus on. But! Let's say you don't have aphantasia.

If I tell you to visualize red, horizontal stripes before the experiments start, you're more likely to see red than green. But if you do have aphantasia, the results basically stay 50-50. That suggests that the folks with aphantasia really do have less of a “mind's eye,” it's not a miscommunication.

Now, as for why aphantasia happens? The discovery is so new that we really don't know yet. This idea is so new that we're not even sure how to pronounce the word yet.

I say aphantasia, other people say aphantasia; I think aphantasia sounds better. And if we are collectively right now in the process of deciding what the pronunciation is, we should go with the cooler sounding one. But, we're also not sure if it's something genetic that someone is born with, or a trait that's acquired early in life.

One thing we do know is that damage to the brain can remove some ability to generate visual imagery, like in that first identified case. More specifically, some patients who have acquired aphantasia later in life had damage in one of two key regions:. Either the occipital lobe, which processes visual input from the eyes, or the parietal lobe, which is responsible for keeping track of where things are in space.

But there are also plenty of people with aphantasia who've never had any kind of brain injury. And looking at their brains has told us how they compensate for not having a mind's eye. Overall, it seems like these folks do it using brain areas including the anterior cingulate, which helps us identify errors or inconsistencies.

This might help explain why these people perform just fine with memory tests like remembering facts, or recognizing which images they've seen before. And a preliminary study from 2020 offered some insight into how this might work. The study involved 61 people with aphantasia, and the researchers asked them to study photos of different rooms in a house, then recreate them from memory.

The participants generally used less color in their recreations and, on average, they remembered significantly fewer objects in the scene than a control group without aphantasia. But, they were just as accurate with where they put those objects and also had fewer mistaken additions that weren't in the original pictures. To do all this, they seemed to make use of verbal scaffolding, or descriptions that helped them remember what was in the images and where.

The researchers found that people with aphantasia also put more text on the drawings, and that they described storing the pictures as words and descriptions. Finally, studying aphantasia has also helped scientists realize that emotion can come from just visual imagery. Like, pretty much every person with sight gets a bit startled when they see a scary image.

And researchers can quantify that reaction by measuring a change in how the skin conducts electricity. That's because you sweat a little more when you're stressed, and sweat conducts electricity better than dry skin. One study found that people without aphantasia can get a similar fear reaction just by reading a story designed to evoke vivid, scary images.

But people with aphantasia don't respond that way. This means that emotions might be more connected to visual imagery than we realized, which could change how we think about improving mood and well-being. Overall, aphantasia has been a striking discovery, not only because it's teaching us things about the brain, but because it's a reminder of how different our everyday experiences can be from one another.

Many with aphantasia don't realize for years, or ever, that they're experiencing the world differently. And these differences aren't a bad thing, but they are important. And the more we learn about them, the more we can understand what it's like to walk in each others' shoes.

Thanks for watching this episode of SciShow Psych. This show is produced by Complexly, and we also make a bunch of other shows, including a new show that I'm excited about, and hosting with my friend Sarah, called Bizarre Beasts. Once a month, my co-host Sarah Suta and I get to introduce you to a downright weird animal, but we also get to talk about what it is about humans that makes these animals seem so weird.

From birds whose babies have claws on their wings, to lizards with glowing bones, the show examines the how and why of some of the world's most amazingly strange critters. And if you want to take one of these animals home with you, we even have a pin club. The links for the channel and the pin club are in the description below! [♪ OUTRO].