Twitch streamer plays Elden Ring with only her brain

When you turn on the Twitch streamer Channel of Perrikaryalyou might see them in FromSoftware’s RPG epic Elder Ring with fourteen unknown black sensors taped to her scalp. It’s her — as she said earlier today in an information stream — “just for fun” electroencephalogram (EEG), something researchers use to record the brain’s electrical activity, which she’s repurposed to let them play Elder Ring hands free

“Okay, what and how”, publisher Bandai Namco replied to a clip of Perri (whose name seems to refer to it the perikaryonthe cell body of a neuron) describes how she linked brain activity to key bindings to help her play, shared by eSports reporter Jake Lucky on twitter

Cue the disbelief (“I got a lot of stuff online like, […] ‘Are you real?'” says Perri in this Twitter clip) and cries Ex Machina.

It looks incredible – in the clip you can see Perri simply say “attack” to her screen like a gamer girl Matilda and then, after a short delay, she says Elder Ring Character responds with Casting Rock Sling with an irritable boss. But I spent my college days attaching eye-tracking devices to my friends’ heads while they helped me stuff my lab requirements, and I know that while brain technology can look complicated, some of it was simple enough for me when I was 19. So I turned to my former classmate from the University of Michigan’s cognitive ndollarscience department PhD student Cody Caofor his thoughts.

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“The EEG has really good temporal resolution,” he said, “which means that the recorded neural response to game stimuli goes down to milliseconds. When the neural responses corresponding to available actions have very different neural patterns, post-training algorithms can decipher or distinguish which is which. Then you play the game with the EEG.”

But playing a game with the brain — something Elon Musk tried to shock the public with in 2021 when his brain-computer interface company released Neuralink a video of a playing monkey pong using its technology – gives you no advantage.

“Decoding is still choppy,” Cao said, “60 to 70 percent accuracy is considered pretty good,” compared to 90 to 100 percent accuracy when performing an action manually (which your brain also requires!).

“It takes algorithms a lot of training to achieve acceptable performance. You probably need to experience many different instances of the same thing (like Perri saying “attack” before attacking) to be able to explain a vast majority of attacks,” Cao continued. “It’s like FaceID on your iPhone — it gets better the more samples it sees.”

Perri also emphasized in today’s stream that she is not necessarily innovative, but rather making the public aware of the possibilities of EEG use.

“It’s not that crazy, it’s really easy to do. And it’s done since 1988‘ she said of playing with her brain. “It’s not necessarily something new that I’m doing, I’m just not sure if it’s very well known.” But now you know, and maybe next you’re figuring out how to control a grilled cheese, mine stomach does not hurt.