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Are brain implants the future of thinking? | Science



Two years ago, Dennis Degray sent a strange text message to a friend. "Hold in your hand the first text message ever sent from a neuron of one mind to another's mobile device," she remembers reading it. "You just made history."

Degray, 66, was paralyzed from the collar down from an unfortunate fall decades ago. He was able to send a message because in 2016 he had two tiny squares of silicone with protruding metal electrodes, surgically embedded in his motor cortex, a part of the brain that controls movement. They record activity in his neurons for translation into external action. By imagining how to control the lever by hand, he can move the pointer to select letters on the screen. With the power of mind, he also bought products on Amazon and moved his robotic arm to stack the blocks.

Degray is embedded with these devices, known as Utah arrays, as a participant in the BrainGate program, a longstanding multi-institution research effort to develop and test new neurotechnology to restore communication, mobility and independence in people whose minds are fine. but who have lost physical connection due to paralysis, loss of limbs or neurodegenerative disease.

But while a series in Utah has proven that brain implants are viable, technology has yet to cross the path. Degray had open brain surgery to get him a place. The system is not wireless – a socket protrudes from its skull through which wires transmit a signal to computers for decoding machine learning algorithms. The tasks that can be done and how well they are performed are limited, because the system records only a few dozen to several hundred neurons in the brain of an estimated 88 billion (each electrode typically records between one and four neurons).

BrainGate electrode with dime for size comparison.



BrainGate electrode with dime for size comparison. Photo: Matthew McKee / Brown University

And it is unlikely to last forever. The scar, the brain's response to damage caused by the insertion of the device, gradually accumulates on the electrodes, leading to a progressive decline in signal quality. And when the research sessions – which take place Degray twice a week at his daycare in Palo Alto, California – end, Degray's telepathic powers will cease and desist.

Barely a few dozen people have been implanted with Utah strings around the world. Much progress has been made, says Leigh Hochberg, a Massachusetts General Hospital neurologist and professor of engineering at Brown University who co-directs BrainGate, but "a system that patients can use on a daily basis that reliably provides complete, fast, intuitive brain control over the computer yet there is not ".

Help may be at hand. Silicon Valley chutzpah injection has generated energy in the brain-computer or brain-machine interface fields in recent years. Preoccupied with BrainGate and other demonstrations, large entrepreneurs and start-ups and startups are looking to develop a new generation of commercial hardware that can ultimately help not only Degray and others with disabilities, but all of us. While some, including Facebook, run non-invasive versions, wireless neural implant systems are also being worked on.

In July, Elon Musk, best known as CEO of Tesla's electric car company, presented details about an implantable wireless system being built by his company, Neuralink. Mask is already being studied on monkeys, and it is hoped that human testing will begin before the end of 2020. To date, Neuralink has received $ 158 million in funding, of which Musk has received $ 100 million.

Although the developing implant is still the same size as one of the Utah arrays in Degray's brain, it has far more electrodes, meaning he can record with far more neurons. While a Utah string – of which up to four or five can be inserted – typically has 100 electrodes, Neuralink says its version will have more than 1,000. And the company thinks it's feasible to fit up to 10. A very thin, flexible biocompatible polymer material with protruding electrodes would "slip in" to avoid puncturing the microvessels, which Neuralink hopes will alleviate the scars, thus increasing how long the device lasts. "Our goal is to capture and stimulate spikes in neurons in a way that is larger than anything that's done so far, and it's safe and good enough that it's not like a major surgery," Musk said in his presentation, adding that the procedure would look more like laser eye surgery than brain surgery. Musk is concerned about the development of the device, according to Musk, but he is also concerned about the threat posed by artificial intelligence and believes it could provide a way to keep up with it.

There are also smaller rival startups. Paradomics, like Neuralink, focuses on many more and smaller electrodes, but targets an even higher density of probes across the face of its neural implant. In shape, their device would look closer to the Utah series – a needle bearing with metal electrodes – and there would be no robotic operations. "We want to get to the market as soon as possible," says founder and CEO Matt Angle, adding that he hopes to start a clinical trial in the early 2020s. The company has raised about $ 25 million to date, including significant sums from the Pentagon's research agency, Darpa, who became interested in BCI after realizing the sophisticated robotic limbs it builds for injured soldiers returning from abroad needed brain control.

Dennis Degray uses a Utah array of implants to manipulate the pointer on a computer screen.



Dennis Degray uses a Utah array of implants to manipulate the pointer on a computer screen. Photo: PBS

Synchron, based in Australia and Silicon Valley, takes a different approach. The company, which has received $ 21 million in funding to date, including a portion of Darpa, has revealed that the first clinical trial of its Stentrode device has begun in Australia – ahead of Neuralink and Paradromics.

The device avoids open brain surgery and scars as it is inserted using a stent through a vein at the back of the neck. Once placed next to the motor cortex, the stent will fit 16 metal electrodes into the blood vessel walls from which neural activity can be recorded. So far, one patient has been implanted in the trial – paralyzed with motor neural disease, with four more. The security of the device will be studied along with how far the system can monitor the computer for typing and messaging. Although it can only read the aggregate activity of a population of neurons, of which it will take about 1,000, there is enough data to make the system useful to patients – and the smaller nuances in the signal actually make it more stable and robust, says founder and CEO Tom Oxley.

Meanwhile, challenges remain for Neuralink and Paradromics. Whether the scars will be mitigated by very small electrodes is yet to be seen. There is also the question of which electrodes dissolve and corrode in the body – the problem gets worse the smaller they are. It is unknown how long the new polymeric probes of Neuralink will last.

"No one will be impressed by startup companies until they start recording life for years. The Utah range has a lot of problems – but you measure life expectancy for years, "says Cynthia Chestek, a neural interface researcher at the University of Michigan. Then, even if we are capable of recording all these additional neural signals, can we decode them? "We have no idea how the brain works," says Takashi Kozai, a biomedical engineer at the University of Pittsburgh who studies implant technologies. "Trying to decrypt this information and create something useful is a huge problem." Chestek agrees that more understanding of how neurons calculate things would be useful, but "every algorithm out there" would just start working with several hundred extra neurons at once.

None of the three companies see non-medical applications in the short term, but they argue that implant technology could be phased out into the general population as people begin to see how transformative it can be.

The most obvious application can be brain-controlled typing. Oxley imagines a scenario where people who have grown up texting and typing – and are totally dependent on it – lose functionality as they get older. Frustrated with not being able to maintain speed, they can look for other ways to preserve their technological capability. Eventually, a turning point will occur when people see that CIs perform better than the human body. "If technology becomes safe, easy to use and gives you cutting-edge technology control, people will want to pay for it," Oxley says.

Of benefit beyond that, no one is specific. Brain commands smart speakers? Driving a brain-controlled car? Brain-brain communication? Improved memory and cognition?

Had technology become outside the medical domain, we might be the first to see it by the military, says Dr. Hannah Maslen, deputy director of the Uehir Center for Practical Ethics at Oxford University. For example, it may enable the soldier to communicate quietly or allow the equipment to be activated by thinking of specific commands. It's hard to see most people opting for surgical intervention for recreational or recreational purposes, she adds. But at a recent encounter with neurotechnology in San Francisco with about two dozen confectioners, Jonathan Toomim argued that it was a logical next step. "We already use devices – our smartphones – that pump out a lot of our knowledge and increase our memory. This is just about bringing the bandwidth between the human brain and those to a higher level, "said only the described neuroscientist, engineer, entrepreneur and ecologist who devises his neurofeedback mechanism.

The public should have a clear voice in shaping the way neural interface technology is used and regulated over the coming years, a report on the Royal Society of Britain concluded this month. One of the concerns is data privacy, though Maslen says that should be mitigated by the fact that while BCIs can be portrayed as capable of "reading the mind" and "decoding thoughts" – instilling fear of revealing the most essential secrets – they capture very small areas of the brain they are mainly movement related and require the mental effort of the user to get them to work. "Ethical concerns about privacy … are not being applied in such a holistic way," she says.

A sewing machine-like robot that inserts electrodes into the brain and is developed by Neuralink.



A sewing machine-like robot that inserts electrodes into the brain and is developed by Neuralink.

Nevertheless, the questions remain. Who owns the brain data and what is it used for? And "brainjacking," where a third party could gain control of the system and modify it in a way that the brain owner did not consent to, is rooted in reality, not science fiction, Maslen says – pacemakers have been hacked before. Paradromics & # 39; Matt Angle wonders to what extent BCI data can be used as evidence in court – for example, to criminalize a journal or a computer in the same way.

Further ethical issues arise around control and agency. If your brain implant does not understand your intention, to what extent are you, as a device user, responsible for what is said or done? And how do we ensure that technology, if it receives significant benefits, does not just get rich?

The company has a few more years to think about these issues. Neuralinka's goal of launching and launching a clinical trial in humans by the end of next year is considered too ambitious, given that it remains unproven. But many experts predict that the technology will be accessible to people with disabilities or disabilities within five or 10 years. For non-medical use, the time frame is longer – maybe 20 years. For Leigh Hochberg, the focus must be on helping those who need it most. Says Degray of the Neuralinka device: "I would invest them one afternoon if I could."

Is there an alternative to implants?

A worn, non-invasive computer brain interface that does not involve brain surgery and can always be downloaded may seem appealing. But the skull dampens the reading of neural signals. "Physics [of a non-invasive device] are just extremely challenging, ”says Cynthia Chestek of the University of Michigan.

Some companies try anyway. Facebook announced in 2017 that it wanted to create a wearable device that would allow typing from the brain at 100 words per minute (by comparison, Neuralink weighs 40 words per minute – which is about our average typing speed – and Dennis Degray with his Utah array of implants works around eight words per minute). In July of this year, researchers at the University of California, funded by the social network, showed the decoding of a small series of full, spoken words and phrases from real-time brain activity – although this was done with so-called corticographic electrodes placed on the brain surface by surgery. Meanwhile, the company continues to work on how it can achieve the same thing non-invasively, and is exploring the measurement of variable oxygenation patterns in the blood – neurons use oxygen when they are active – with near-infrared light.

Also the case is Los Angeles-based startup Kernel, founded by entrepreneur Bryan Johnson who has made millions by selling Braintree to PayPal. The kernel, into which Johnson raised $ 100 million, started with a neural implant company, but then focused on wearables because, says Johnson, the invasive path seemed so long. There are many non-invasive methods for sensing and stimulating brain activity (they really form the basis of a large consumer neurotechnology industry). But no one, Johnson says, equals connecting to the next-generation interface. New ways are needed and he believes the Kernel has discovered that they missed another one. “We will be ready to share in 2020,” he says.

But assuming that technical challenges can be overcome, social factors could still be a barrier, says Anna Wexler, who studies the ethical, legal and social implications of the emergence of neurotechnology at the University of Pennsylvania. Google Glass failed not because it didn't work, but because people didn't want to wear a face computer. Will anyone trust Facebook enough to use their device if they develop it?


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