Adults who played Pokémon as kids have specialized “Pokémon regions” in their brains that respond more to the digital characters compared to people who have never played the game, a new study revealed.

University of Pennsylvania doctoral student Michael Barnett and former Stanford colleague Jesse Gomez — both Pokémon aficionados — detailed their discovery in a study published in the journal Nature Human Behavior on Monday.

The idea for the project came about when the pair discussed a paper about young macaque’s brain regions lighting up on imaging scans when they view letters, cartoons and Tetris pieces, according to a press release from the University of Pennsylvania.

“We were joking around and said, ‘Wouldn’t it be funny if we essentially played the role that the monkeys did?’” Barnett, a third-year graduate student, said in the release.

Except this time, instead of tetris pieces, they used first-generation Pokémon characters that appeared in the game’s original red and blue versions.

“As children we had extensive experience playing Pokémon, hundreds of hours. Everyone played on the same Game Boy device, which has the same screen, and kids’ arms are roughly the same length,” Barnett added. “It was like this unintended but well-controlled experiment.”

So the pair gathered 11 “experts” — who had started playing Pokémon between ages 5 and 8, and have revisited the game at least once as an adult — and 11 novices who had no experience playing Pokémon.

The participants were asked to name 40 randomly selected Pokémon characters, and then were shown a series of images, including faces, animals and words — as well as the characters they had grown to love.

Using a functional magnetic resonance imaging scan, the researchers were able to observe which region of the brain showed the most activity.

For the Pokémon experts, it turned out that the occipitotemporal sulcus, a part of the brain’s temporal and occipital lobes known for processing animal images, responded more to the Pokémen than novice noodles.

Conducting the study was a nostalgic experience for the researchers — as Pokémon turned 23 years old in February — but the pair also gained some important insights into the brain’s functioning.

“Pokémon nowadays does not look like the original Game Boy graphics, so this was a trip down memory lane, and it yielded some interesting results,” Barnett said in the release. “Our message isn’t that video games change your brain. Everything changes your brain.”