If you played with Pokemon as a kid, your adult brain is noticeably different: You’ve created a Pokemon brain region.

The Verge reports on a study (from Nature Human Behavior) that demonstrates that collecting all those pocket-monsters creates lasting physical changes in your brain:

…Researchers recruited 11 adults who were “experienced” Pokémon players — meaning they began playing between the ages of five and eight, continued for a while, and then played again as adults — and 11 novices. First, they tested all of the participants on the names of pokémon to make sure the pros actually could tell a Clefairy from a Chansey. Next, they scanned the participants’ brains while showing them images of all 150 original pokémon (in rounds of eight) alongside other images, like animals, faces, cars, words, corridors, and other cartoons. In experienced players, a specific region responded more to the pokémon than to these other images. For novices, this region — which is called the occipitotemporal sulcus and often processes animal images — didn’t show a preference for pokémon.

It’s not that surprising that playing many hours of Pokémon as a kid would lead to brain changes; looking at almost anything for long enough will do the same thing. We already know that the brain has cell clusters that respond to certain images, and there’s even one for recognizing Jennifer Aniston. The bigger mystery is how the brain learns to recognize different images. What predicts which part of the brain will respond?

Study co-author Jesse Gomez, a postdoctoral fellow in psychology at the University of California at Berkeley, …realized that pokémon, specifically the kind from the Game Boy games from the 1990s, would be perfect for this task. “I spent almost as much time playing that game as I did reading and stuff, at least for a couple of years when I was six and seven,” he says. For this generation, everyone saw the same images (black-and-white pokémon that didn’t move), and most people held the Game Boy about a foot away from their face, making this an ideal experiment.

The results support a theory called “eccentricity bias,” which suggests that the size of the images we’re looking at and whether we’re looking at it with central or peripheral vision will predict which area of the brain will respond. This particular region is associated with people looking directly at an image.

If you want to catch all the science, the