Bryan Johnson isn’t short of ambition. The founder and CEO of neuroscience company Kernel wants “to expand the bounds of human intelligence”. He is planning to do this with neuroprosthetics; brain augmentations that can improve mental function and treat disorders. Put simply, Kernel hopes to place a chip in your brain.

It isn’t clear yet exactly how this will work. There’s a lot of excited talk about the possibilities of the technology, but – publicly, at least – Kernel’s output at the moment is an idea. A big idea.

“My hope is that within 15 years we can build sufficiently powerful tools to interface with our brains,” Johnson says. “Can I increase my rate of learning, scope of imagination, and ability to love? Can I understand what it’s like to live in a 10-dimensional reality? Can we ameliorate or cure neurological disease and dysfunction?”

The shape that this technology will take is still unknown. Johnson uses the term “brain chip”, but the developments taking place in neuroprosthesis are working towards less invasive procedures than opening up your skull and cramming a bit of hardware in; injectable sensors are one possibility.

It may sound far-fetched, but Johnson has a track record of getting things done. Within his first semester at university, he’d set up a profitable business selling mobile phones to fellow students. By age 30, he’d founded online payment company Braintree, which he sold six years later to PayPal for $800m. He used $100m of the proceeds to create Kernel in 2016 – it now employs more than 30 people.

But Johnson, 40, says he is about more than money. He was raised as a Mormon in Utah and it was while carrying out two years of missionary work in Ecuador that he was struck by what he describes as an “overwhelming desire to improve the lives of others”.

His subsequent decision to leave the faith only added to this sense of purpose. “For the first time in my life, I had to sit with the notion that the closest I’d ever come to my previous vision of heaven is whatever we can build here on Earth while I’m alive,” he explains.

“And when I surveyed the landscape of human history, including how we treat each other and our shared home, I thought we have to do better.”

The idea for Kernel also came from a “deeply personal” place, Johnson says. He suffered from chronic depression from the ages of 24 to 34, and has seen his father and stepfather face huge mental health struggles.

“I spent a decade being tortured in my own mind,” he says. “I have witnessed and experienced what happens when a brain isn’t at its best. Being able to treat Alzheimer’s disease went from ‘that’d be nice’ to ‘really important’ after my stepfather began showing early symptoms. Helping people overcome addiction went from ‘that’d be nice’ to ‘really important’ after my father suffered from drug addiction for the first 25 years of my life.”

He understands the scepticism around Kernel’s work, but argues that it has the potential to build a better, more equal society.

“What if everyone – not just the privileged– had the same access to information, learning, skill improvement, and cognitive evolution?” he asks.

As idealistic as Johnson’s vision for the brain is, there are still big ethical questions to consider about the process, from security to the squeamishness of having a chip in your head.

Johnson describes it as a “necessary tool” for cognitive evolution, and says he’ll happily be among the first to trial the augmentation.

Kernel is a for-profit company, however; Johnson claims that this gives the brand the best chance of producing a “usable product” at the end of the difficult and expensive road he is taking. While outside investment will be needed to keep the company going, public interest and funding in neuroscience has increased in the past few years, he says, and is likely to keep doing so. Elon Musk got into the field with the launch of his company, Neuralink, earlier this year, and the neuroprosthetics market is expected to be worth as much as $14.6bn by 2024.

So Johnson is keeping his focus on the future, a habit that inspired the project in the first place. He explains that, while trying to work out what to do next after selling Braintree, he hosted a series of 12 dinner parties with the brightest people he knew.

“I would begin each gathering with a question,” he recalls. “What do we need to focus on today to create a world that you would love to live in by 2050?

“With minor variations, I heard the same answers nearly every time: climate science, education, healthcare, AI, governance, and security. Not once, though, did a single person – out of the hundreds who attended – mention improving the brain itself.

“And yet, the brain is everything we are, everything we do, and everything we aspire to be. It seemed obvious to me that the brain is both the most consequential variable in the world and also our biggest blind spot as a species. I decided that if the root problems of humanity begin in the human mind, let’s change our minds.”

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