Grimes said she got a brain gadget for her birthday from a company competing with Elon Musk's Neuralink

• Grimes got a headset called "The Crown" that she said let her move a computer mouse with her mind.
• Neurocity CEO AJ Keller said the company made a custom white version for the singer.

Grimes got a new brain gadget for her 35th birthday.

"Getting a non invasive brain computer interface for my birthday (!!!!?)," she tweeted Friday. "Yeah it's a good time to be alive."

Neurosity CEO AJ Keller confirmed that the singer, named Claire Boucher, had asked for one of the company's headsets, known as the Crown, in a custom white color.

Grimes' birthday 'Crown' measures brain activity, and is designed to help people focus

Neurosity's headset uses electroencephalogram technology, or EEG, to measure brain activity by placing small metal electrodes on a person's scalp. If the electrodes detect decreased electrical activity in the brain, the Crown plays music and sounds, or pulses vibrations, hoping those actions will help the user focus.

But some developers, it seems, have taken Neurosity's tech a step further, turning the Crown into a more traditional brain computer interface that can allow users to control a computer using only their mind.

One owner of the gadget claimed they've used it to drive a Tesla, moving the electric car short distances by doing some mental math, which signals to the device that the person wearing it is exerting a lot of cognitive effort:

And Grimes, it seems, has used her Crown instead of a computer mouse. In a tweet she later deleted, the singer said Neurosity's device allowed her to use her mind to move a cursor.

Learning to use BCIs is hard — there's no 'Fitbit' for your skull yet

It's not clear whether the kind of reverse mind control Grimes and others are describing is actually possible with Neurosity's headset, or how well it works, if it does. BCI devices usually come with a steep learning curve, and users can spend months, or years, learning how to operate them.

In the deleted tweet, the singer also described Neurosity as younger and more low tech than Neuralink — Elon Musk's startup, which aims to implant brain chips into humans that the billionaire said would be like having a "Fitbit in your skull."

Grimes, who dated Musk for several years and has two children with the billionaire, has said in the past that she eventually plans to get one of Neuralink's devices implanted in her brain. Neuralink has yet to receive permission for any human trials. The startup's application for human testing in the US was rejected by the US Food and Drug Administration last year, according to Reuters.

But there are a number of other, more successful BCI devices that have been implanted in the heads of people around the world to control their computers using only their minds.

Keller told Insider that Grimes tried out the Crown earlier this month at the company's lab in San Francisco.

"Just did a bci test at @neurosity and the way the thing 'spiked' when I talked versus 'just thinking' seemed like 'a lot,'" Grimes tweeted on Wednesday.

Keller said that his company does not aim to compete with Neuralink. He said he sees them as completely different types of companies — one working on permanent, implantable devices, the other making headsets you can take off whenever you want.

"It's like the difference between a microscope and a telescope," Keller said. "Both do imaging, but both are doing totally different types of imaging."

Musk has said that Neuralink aims to combat neurological diseases like Parkinson's and eventually facilitate telepathic messaging, but the billionaire's timeline for human trials has repeatedly shifted. Meanwhile, Neurosity's device is already on the market.

Keller said Neurosity is already using its device to help increase people's productivity. Ultimately, Keller said the company aims to offer the Crown as an alternative to stimulants like Adderall or caffeine.

The company introduced its first device that could read brain waves in 2020. Over the past few years, Keller says the company has continued to update the device and has shipped hundreds of Crowns. The company has about 500 to 600 active users every month, he said. The Crown currently costs about $1,000, and it's also available as a $99 per month subscription.