How one streamer learned to play video games with only her mind

Perrikaryal uses an EEG to translate her brain activity into beating bosses in Elden Ring and beyond.

Gamers love a challenge, but sometimes there isn’t enough challenge in the video games themselves, so they up the ante with all manner of self-imposed dares. Speedrunners finish games in mere minutes that take most players hours. Crafty types have beaten Super Mario 64 using a drum kit and completed Castlevania: Symphony of the Night blindfolded. My son has even cobbled together a working controller out of orange and banana slices.

But it’s Twitch streamer Perrikaryal who gets the top spot on the gaming challenges leaderboard. During her streams, Perri plays video games using only her mind. Well, her mind, an electroencephalogram (EEG), and some impressive tinkering.

An EEG uses electrodes placed on the scalp to measure and record electromagnetic brain activity — brain activity that Perri found can be translated into digital commands. That description risks oversimplifying things, as though the player can simply think, “Kick this boss’s butt” and said butt is kicked.

In fact, the process requires perseverance and dedication but, as Perri tells Freethink in an interview, that ultimately makes the victories all the more rewarding.

Stream starting soon…

Like most young adults, Perri at first found the thought of performing in front of people distressing — a fact she admits made her dream of becoming a stand-up comedian rather daunting. Then one day, a friend suggested she try streaming to practice performing in front of a screen rather than a nerve-wracking theater of expectant faces.

Perri gave it a shot, and because she holds a master’s in psychology, her early content focused on topics in that field. She analyzed the news, debunked crank claims about the mind, and played games with unique psychological perspectives (titles such as Superliminal, The Closing Shift, and Detroit: Become Human).

Her streaming funds built over time, and she decided to use them to purchase an Emotiv EEG. While commercial EEGs aren’t as powerful as their medical-grade counterparts — which are used for neuroscientific research or to diagnose brain disorders — Perri was still curious to experiment with the device and see what she could do.

A girl is holding a microphone in front of a purple background.
Perrikaryal wearing her EEG during a stream. Next to her is a 3D visualization of the brain activity her EEG is reading. (Credit: Perrikaryal)

She initially wore it while playing horror games. She would display a 3D visualization of her brain activity, allowing viewers to watch as her gray matter lit up during a jump scare or crackled with energy amid an intense chase. But she soon noticed that the EEG’s brain-computer interface came with another interesting feature: It could identify and remember the patterns that arise when a user thinks certain words or visualizes specific images. 

Using this feature, she started to experiment with turning her mind into a video game controller.

Insert brain to play

Perri starts with a unique mental visualization — say, a plate spinning on a pole. As she’s picturing the plate, the EGG reads her brain activity. It picks up things such as her brainwaves, their frequency, and a rough approximation of where the signals are occurring. That creates a unique pattern that Perri can train the EEG’s interface to recognize. Over several eight-second recordings, the interface comes to reliably pick up the pattern.

Actually, it’s a tad more than several: “You do that 600, 700 times until you want to cry. It’s fueled by sadness,” Perri says, laughing. “Actually, it’s really satisfying and fun to use.”

Those eight seconds eventually add up to hours, but once the interface is trained, Perri can map that pattern onto a virtual XBox controller. The pattern then serves as a brain-command input. So instead of pressing the B button to make her character dodge, Perri thinks of a spinning plate, and the character rolls out of harm’s way.

That’s ideally how things play out, but as with overcoming any challenge, there’s a lot of trial and error involved.

“The mind-control training — figuring out which visualizations would work — that took me the longest, and you only really find out that they don’t work once you’re 700 trials in. Then you have to start again, which is painful,” she says.

For instance, Perri eventually learned that her spinning-plate visualization was a problem in fast-paced action games. The speedy swings of the in-game camera made it difficult for her to keep her mental plate in mind, and the eye movement necessary to track the on-screen action further interrupted the signals sent to the EEG. 

For the visualization to work for her, she needed to make it more specific. Very specific. It couldn’t be just any plate. It had to be a distinct plate spinning at a speed set to the tune of Dead or Alive’s “You Spin Me Round.” The more she practiced and experimented, the better she got at her character dodging round (like a record, baby, right round) the projectiles thrown by the game’s enemies.

“I just kept doing various different things until one seemed to work. It was really hard to begin with because I had no idea what to do. I would restart and do another one or add another level of detail,” Perri says. “But when I start something, regardless of how awful it is, I have to see it through. I have to complete it.”

Here comes a new challenger

The first game Perri played using mental commands was Minecraft. She still used a controller to move the player character, Steve, around. Her self-imposed dare was simply to use a mental command to have Steve break a block. And to her delight, it worked.

“I kept thinking it was a fluke,” Perri says, “but I kept doing it, and it kept working. It wasn’t a fluke in the end.”

First success in hand, Perri sought her next challenge, and this brought her to Elden Ring. For the uninitiated, Elden Ring is the latest in From Software’s Souls series. The series has a notorious reputation for its level of difficulty, with one of its earliest games, Dark Souls, sporting the tagline “Prepare to Die.” 

Even playing with a standard controller, Perri’s initial forays into Elden Ring led to plenty of game overs, so she set a straightforward challenge: Beat the first boss, Margit the Fell Omen, using at least one mental command.

She trained the EEG’s interface on the visualization of pushing something heavy forward. She mapped it to the game’s attack button, sent some spells flying, and, in time, felled that Omen. Mission accomplished, but she wasn’t done with Elden Ring yet.

“I just kind of kept going and then as we went along, we made it harder and harder and harder,” Perri says. “It kind of all spiraled out of control, to be honest with you.”

She began taking on boss after boss while increasing the complexity. She added a mental command for dodging and another for healing. She included eye-tracking to control the game’s camera. By the time she reached Morgott the Omen King, she could stomp the boss completely hands-free. She even overcame the game’s most punishing foe, Melania Blade of Miquella, who, even for a character in this series, gained online infamy for her player-slaying antics.

Up for another game?

Since Elden Ring, Perri has continued to seek out new challenges. She has used mind commands to race in Trackmania, catch a pal in Palworld, and do battle in Smash Bros. She has even played Pac-Man, the first game she’s played using mind commands exclusively.

“Everyone has been so nice and so supportive. I think it’s an exciting achievement when I make a tiny stride or a little improvement, and I do worry that maybe this isn’t fun to be watching for the viewers. But no, they’re always excited with me, which is awesome,” Perri says.

Of course, Perri has encountered naysayers and griefers — it’s the internet after all — but she even finds these comments affirming in their way.

“I like that people think [it’s fake] because it reveals that this tech is not as well known as it should be. The fields of psychology and neuroscience aren’t as well understood or maybe people aren’t participating in them enough. So, it’s a nice sign if that makes sense.” (She adds that she gets fewer of such comments as understanding has spread.)

Looking ahead, Perri hopes that as more and more people become excited over the technology and science, it will continue to improve. A friend of hers has already created a VR mod of Skyrim that uses EEG technology to build new layers of immersion, such as having to focus to regenerate magic for spells. 

A girl in a black dress sitting in front of a microphone.
Perrikaryal continues to challenge herself. Looking ahead, she hopes to start a series of self-experiments and run two brain-computer interfaces simultaneously to double the potential number of mental commands at her disposal. (Credit: Perrikaryal)

She also hopes that the technology will increasingly provide solutions for people with accessibility issues. Traditional gaming controllers can be difficult for some people to use, and hands-free devices — not just the EEG but also voice commands and eye-tracking — could offer viable solutions to some of the barriers people face. As the technology improves and attainability increases, more and more people will be able to experiment to find those solutions.

That’s the great thing about experiments like Perri’s. As off-beat as it sounds to play a game with your mind, a drumset, or slices of fruit, these challenges do more than bring fulfillment for the tinkerers. When shared, they excite a whole community of people who share the passion, try something new for themselves, and may even spawn a new innovation for others to enjoy in turn.

“I’m definitely not done,” Perri says. “This is the thing! You’ve gotta keep going until you can’t do it anymore. And I can do more!”

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