Here Are the Major Advances in Brain Implants That Happened in 2020
By: Emily Mullin
Tags: Biotech, Science, Neuroscience, Technology, Brain

For decades, scientists have been trying to forge a direct connection from the human brain to external devices to allow people to control machines with their minds. And over the years, there’s been incremental success. Known as brain-computer interfaces, these devices have allowed paralyzed people to control robotic arms and a mouse on a computer screen just by thinking about it. But these interfaces require clunky setups and trained engineers to supervise their use. They can’t yet be used at home to help people in their everyday lives.

This year, neuroscientists got closer to that reality. Here are some of the notable advancements in brain implants we saw in 2020.

A startup achieved the largest-ever electrical recording of cortical activity

In July, startup Paradromics said in a research paper that it achieved the largest-ever electrical recording of neural activity from the cerebral cortex, the thin protective layer that covers the brain. The Austin, Texas-based company has developed a brain chip with 65,000 electrode channels — tiny conductors that carry neural signals into and out of the brain (current brain chips have just hundreds).

The company also says its chip has the highest-ever data rate of any neural recording system. In an interview with Future Human, CEO Matt Angle, PhD, said the data rate “is about one DVD per second.” In sheep, the device allowed scientists to observe brain activity in response to sound stimuli. The paper has yet to be peer-reviewed.

Angle thinks his company’s device is a vast improvement over the Utah array, the brain chip that’s most commonly used in human clinical trials of brain implants. The Utah array has about 100 pin-like electrode channels or probes that nestle into the brain tissue. But the size of the probes can cause inflammation and tissue scarring around the implant over time, which affects its ability to record neural signals. As a result, these implants only last a few years at most.

The Utah array also connects to a heavy metal pedestal that sits atop the head and attaches to a computer via a thick wire. People who have gotten these implants can’t use a brain-computer interface setup at home, only in research labs. By contrast, Paradromics’ implant contains microwires that are much smaller than the pins of the Utah array, so Angle expects it to last longer and do less damage to brain tissue.

The company is developing a wireless device that could be used at home in daily life. Angle says he wants to first test the system in people with paralysis to provide them with a means of fast and reliable communication. The company estimates that around 165,000 people in the United States could benefit from such a system.

Neuralink demoed its brain implant in a pig

This August, in a much-anticipated live-streamed demonstration that involved three pigs, Elon Musk shared an update on his secretive company Neuralink. To show off the Link device, he brought out three pigs that were Neuralink test subjects. One pig had been implanted with the company’s newly unveiled brain chip, and a screen showed spikes of activity corresponding to neurons firing in real time. A second pig, which seemed perfectly healthy, previously had a Link but had gotten it removed. Musk said that the pig demonstrated the “reversibility” of the implant. A third pig, which never had an implant, acted as a control.

Musk also unveiled the Link itself: a coin-sized implant that fits into the skull and lays against the cortex. “It’s like a Fitbit for your skull with tiny wires,” he said. Attached to it are 1,024 threadlike, flexible electrodes. The implant is designed to wirelessly transmit these recorded signals to an app that can run on a smart device.

During the demo, Musk claimed that the device will be able to do everything from cure deafness to treat mental illness. These applications, however, are far from becoming reality. The company’s first application of the technology will be to help people with severe spinal cord injury control computers and mobile devices directly with their brains. The company still imagines, though, that the Link could be used for a variety of different purposes depending on its placement in the brain. In the visual and auditory cortices, it could help process vision and sound; in the somatosensory cortex, touch; and in the motor cortex, movement.

In a 2019 company update, Musk said the first human subjects could be implanted with the device as early as 2020. That hasn’t happened yet, but during the August demo, he said the company is in talks with the U.S. Food and Drug Administration to begin clinical trials soon.

An implant inserted in the vein allows paralyzed people to type with their minds

In October, Future Human wrote about a type of brain-computer interface that is inserted and threaded through the jugular vein in the neck instead of implanted directly into the brain. The Stentrode is a flexible mesh tube that resembles a heart stent and is designed to capture nearby brain activity using tiny electrodes on its surface. It sends those brain signals to a second device embedded in the chest, which in turn wirelessly transmits that data to a computer or phone and converts it into computer commands.

The company that developed the system, Silicon Valley-based Synchron, has implanted it in two people with paralysis caused by amyotrophic lateral sclerosis, or ALS. After months of learning how to use the system, the two patients were able to do things like send emails, write Word documents, surf the web, and do online banking using just their thoughts.

Synchron is hoping to be the first commercially available implantable brain-computer interface. The company thinks its device will be safe since it’s based on heart stent surgery, a common procedure that’s been performed for decades.

Robert Kirsch, PhD, a brain-computer interface expert and chair of biomedical engineering at Case Western Reserve University, told Future Human in October that Synchron’s device is an elegant approach to simple keyboard tasks but may not be able to carry out more complicated tasks since it doesn’t pick up as many brain signals as devices that rest in or on the brain.

A brain implant provided artificial vision in monkeys

In a step toward restoring vision to blind people, scientists used a brain-stimulating implant in monkeys that allowed them to “see” shapes without the use of their eyes. The high-resolution neuroprosthesis, developed by scientists at the Netherlands Institute for Neuroscience, contains more than 1,000 electrodes and sits on top of the visual cortex — the part of the brain that receives and processes information relayed from the retina.

The researchers, led by Pieter Roelfsema, PhD, wanted to test whether it was possible to create interpretable images by delivering electrical stimulation through these electrodes. They implanted the device in two macaque monkeys and found that the monkeys could recognize lines, moving dots, and letters using their artificial vision. The findings were published in the journal Science in December.

Most efforts to restore vision have focused on stimulating cells in the retina using a pair of glasses outfitted with a camera. The Argus II, made by Sylmar, California-based Second Sight, was the first such device to come onto the market in 2011. But the Argus II and other similar devices are limited in the amount of vision they can restore. They also don’t work for many types of blindness caused by damage to the optic nerve, the main nerve that transmits visual information from the retina to the brain. The implant developed by Dutch researchers interfaces directly with the brain, bypassing damage in the optic nerve.

Second Sight is currently conducting human clinical trials of a similar brain implant. Its device, a modified version of the Argus II, sits on the surface of the visual cortex. At least six blind patients have received the experimental device, called the Orion. In November 2019, one of those patients, Jason Esterhuizen, spoke with OneZero about how the device has improved his life.