Two years ago Elon Musk launched a company called Neuralink. Musk already leads high-profile companies including Tesla, SpaceX, and Hyperloop, but Neuralink may be the 48 year-old entrepreneur’s most ambitious plan yet: to surgically connect human brains with artificial intelligence through an ultra high bandwidth brain-machine interface.
Neuralink had so far remained silent regarding its research. But that changed last night, when the San Francisco-based company live-streamed a progress report showcasing its experimental brain-machine-interface (BMI) system, which inserts sensor and electrodes into brains to connect neurons for data transfer.
Neuralink President Max Hodak says the company will start experiments with human subjects in 2020 and hopes to quickly leverage the BMI system to treat patients with brain diseases or spinal cord injuries.
The ultimate goal of Neuralink however lies beyond disease treatment. Musk’s dream was spawned by AI’s unprecedented progress over recent years and its potential for human cognitive enhancement toward the new superintelligence that people like futurist Ray Kurzweil believe is approaching. In a 2018 interview with podcaster Joe Rogan, Musk said Neuralink will do this by symbiotically merging human brains with a super digital intelligence that will serve as a tertiary cognition layer augmenting the human cortex and limbic systems.
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Musk proposes that humans today can already be regarded as cyborgs, thanks to cyborganic extensions such as smartphones and computers that enable us to gain knowledge, run quicker calculations, and generally expand our capabilities. Data transfer however remains a major bottleneck in the communication between humans and their digital devices. Although we have evolved interfaces from keyboards to mouses and now voice in order to speed up data transfer, Musk believes he can eliminate the bottleneck altogether with digital implants that read our minds.
Inside the Neuralink BMI system
Neuralink’s BMI system consists of three main components: ultra-thin threads, a sort of robotic sewing machine, and sensors.
Musk’s brain machine implants synthetic threads of 4 to 6 μm in width (about one quarter the diameter of a human hair). These threads have electrodes that receive and transfer information from neurons in brains to dedicated sensors connected to the outside digital world. In their experiments, Neuralink researchers have already implanted 96 threads with 32 electrodes each (3072 electrodes) in primate brains.
Because even experienced human surgeons lack the dexterity required to insert such thin and flexible threads into brains, Neuralink has developed a sophisticated robotic electrode inserter comprising a loaded needle pincher cartridge, low-force contact brain position sensor, light modules, needle monitor, and multiple cameras.
Neuralink isn’t the first entity to design a brain implant system. In 2006 Brown University researchers proposed BrainGate to help patients who have lost control of their limbs or other bodily functions due to conditions such as amyotrophic lateral sclerosis (ALS). BrainGate consists of a sensor implanted in the brain, known as the “Utah Array,” which consists of 100 electrodes that can receive signals firing in specific areas of the brain. Compared to BrainGate, the Neuralink BMI system uses many more electrodes for data transfer and is made of materials that are better matched to the properties of human brain tissues, and so promises better compatibility and durability.
The robotic electrode inserter can automatically insert up to six threads with 192 electrodes per minute. It is also integrated with a custom software to target insertion sites before execution and avoid thread entanglement. According to a project white paper credited to Elon Musk and Neuralink, the robotic inserter has demonstrated an average of 87.1 percent (+- 12.6 percent) insertion success rate over 19 primate surgeries.
As the electron threads record neuron activities, a processor connected to the threads amplifies, filters, and digitalizes the signals and sends them to the BMI system. Over the last 24 months the Neuralink team has designed multiple neural processing application-specific-integrated-circuits (ASIC) equipped with 256 individually programmable amplifiers to handle this part of the process.
A complete packaged Neuralink sensor device contains threads and 12 ASICs with 3072 amplifiers corresponding to 3072 electrodes and is wired with USB-C access for data transfer. Musk says that a monkey equipped with this Neuralink BMI system is now able to control a computer.
Researchers are now developing a wireless BMI system for use in human subjects. The N1 sensor can connect to 1,024 electrodes wired to a wearable pod (with bluetooth and battery) worn behind the ear. Each sensor is able to run spike detection algorithms to process digitalized broadband signals.
Neuralink plans to implant four such sensors in a human subject, three in the motor cortex and one in the somatosensory cortex. Neuralink Senior Scientist Philip Sabes says the BMI system can decode neural signals recorded from the motor cortex and could one day use that information for direct brain stimulation to help in the treatment of neurological disorders such as Parkinson’s disease, epilepsy, dystonia, etc.
Neuralink says that in the future its BMI system could be controlled through an iPhone app.
In the bid to realize their high-tech, Black Mirror-like vision, Neuralink has assembled a team of top scientists, including:
- Philip Sabes, a UC San Francisco professor whose lab has worked on brain-machine interfaces
- Vanessa Tolosa, a biocompatible materials researcher at the Lawrence Livermore National Laboratory
- Benjamin Rapoport, a neurosurgeon who also has a PhD in electrical engineering and computer science from MIT
- Timothy Gardner, an associate professor of biology at Boston University who has implanted devices in birds
- Max Hodak, who worked on brain-machine interface technology while at Duke University
- Paul Merolla, a veteran designer for more than 10 brain-inspired chips
Musk stressed that the “primary purpose” of last night’s Neuralink livestream event was to recruit additional talent to work on the project. The company has raised US$158 million and employs over 90 people.
Journalist: Tony Peng | Editor: Michael Sarazen