A surprisingly high number of people are unable to name 10 US presidents but can recite all 151 original Pokémon without hesitation. It turns out, people who know their Mew from their Mewtwo have a specific brain region that's finely tuned to respond to images of Pokèmon, considerably more so than that of those who didn't play the game as kids.

Scientists led by Stanford University recently carried out brain scans of people who spent hours playing Pokémon videogames as children. Now grown-ups, these former Pokémon-lovers have a pea-sized brain region just behind the ears – known as the occipitotemporal sulcus – that’s become specialized in processing images of Pokèmon, but not other images like faces, cars, or words.

It's essentially the brain's own Pokédex.

The researchers aren’t sure what this brain region does exactly, but they’re guessing it typically responds to images of animals, which Pokémon characters resemble. That said, registering Pokémon characters appeared to spark very subtly different brain activity from viewing images of animals or cartoons. Although they share similarities with both these groups, Pokémon characters are typically presented as pixelated characters on a tiny screen held at arm's length, so the brain sees them as a separate form of visual information.

Reporting in the journal Nature Human Behaviour, the new study isn’t just a cutesy insight into the brains of people who played hours of Pokémon as kids, it’s also providing some fascinating insights into how our brain organizes visual information. It highlights the plasticity of the brain and its ability to profoundly change its organization in response to childhood experiences.

“What was unique about Pokémon is that there are hundreds of characters, and you have to know everything about them in order to play the game successfully. The game rewards you for individuating hundreds of these little, similar?looking characters,” lead author and former Stanford graduate student Jesse Gomez said in a statement.

For their research, the team gathered a small number of test subjects, 11 people, who started playing Pokémon extensively between the ages of 5 and 8. They then found 11 age-matched adults who had no childhood experience of playing Pokémon. Under the watchful eye of a functional MRI scanner, all the participants were shown hundreds of random images of faces, animals, cartoons, bodies, words, cars, corridors, and Pokémon.

The researchers found that Pokémon players experienced considerably more brain activity in the occipitotemporal sulcus when looking at images of Pokémon and animals compared to the non-Pokémon players. Otherwise, the two groups of people had reasonably similar brain activity.

It appeared that the brain had created new activations devoted to Pokémon characters, not dissimilar to changes you'd expect to see in the brain of a person who had spent hours of their life learning any other skill, like mastering an instrument.