How Pokemon affects the brain

A team of researchers from Stanford University in California (USA) found that extensive exposure to video games, such as Pokemon, during childhood activates certain regions of the brain.

By the 1990s, five-year-olds were playing Pokemon. Many of them continued to play later versions of the game over the years. These games exposed children to the same characters and rewarded them when they won battles or added a new character to the game's encyclopedia.

Psychologists discovered that these visual stimuli repeated during childhood, combined with the number of hours spent in front of the screen, activate specific regions of the brain. The results have been published in Nature Human Behaviour magazine and can help shed light on some of the many questions that remain about our visual system.

"It has been an open question in this field why do we have brain regions that respond to words and faces but not to cars, for example," says Jesse Gomez, co-author of the paper.

The role of eccentricity bias

Recent monkey research by scientists at Harvard Medical School in Boston, Massachusetts, showed that regions devoted to a new category of objects tend to develop in the brain during childhood.

Gomez was interested in testing these findings in humans, so he decided to focus on video game exposure. He recalled that as a child, he spent countless hours playing video games, especially Pokemon Red and Blue.

Based on previous studies, as well as his own experience with video games, Gomez theorised that if early exposure plays a major role in the development of brain regions, the brains of adults who played Pokemon as children should respond more strongly to Pokemon characters than to other stimuli.

"What was unique about Pokemon 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 singling out hundreds of these little characters who look alike," the expert said.

The researcher realised he had all the ingredients to test the theory on humans.

Pokemon not only exposes children to the same characters repeatedly, but also rewards them after battles. In addition, most of the children played the games on the same small, square screen. These factors make the Pokemon experience an interesting way to test the so-called eccentricity bias.

The eccentricity bias states that, in the brain, the location and size of a dedicated category region depends on two main factors: "the amount of visual field objects occupy" and whether the image appears in our central or peripheral vision.

The small screen they used to play these games means that it would only occupy a small part of the players' field of vision.

Following the eccentricity theory, the preferred brain activations for Pokemon should be present in the central part of the visual cortex, the area of the brain that processes what we see.

Activation of brain regions

The researchers recruited 11 adults who had played Pokemon extensively when they were younger; Gomez also participated in the experiment. All participants underwent an MRI.

The researchers showed hundreds of Pokemon characters. As expected, the brains of those who played Pokemon as children responded more to the images than those who had not played the game as children.

The location of Pokemon's brain activations was a consistent element among the participants: an area behind the ears called the occipitotemporal groove. It appears that this region normally responds to images of animals, and Pokemon characters are similar to animals. 

"I think one of the lessons of our study," says Professor Kalanit Grill-Spector of Stanford University's School of Humanities and Sciences, "is that these brain regions that are activated by our central vision are particularly malleable to extensive experience.

He adds that the brain is a master improviser. He can create new activations dedicated to Pokemon characters, but follows specific rules in the process. One of them refers to where these activations take place.

Grill-Spector also points out that parents can consider this study as evidence that video games leave a lasting mark on the brain, though they should consider that the brain is capable of containing many different patterns, not just video game characters.


Reference: Extensive childhood experience with Pokémon suggests eccentricity drives organization of visual cortex. Jesse Gomez, Michael Barnett & Kalanit Grill-Spector. Nature Human Behaviour (2019) . DOI:

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