Neuralink

Neuralink Corp. is an American neurotechnology company that has developed, as of 2024, implantable brain–computer interfaces (BCIs), and is based in Fremont, California. Founded by Elon Musk and a team of seven scientists and engineers, Neuralink was launched in 2016 and was first publicly reported in March 2017.

Since its founding, the company has hired several high-profile neuroscientists from various universities. By July 2019, it had received $158 million in funding (of which $100 million was from Musk) and was employing a staff of 90 employees. At that time, Neuralink announced that it was working on a "sewing machine-like" device capable of implanting very thin (4 to 6 μm in width) threads into the brain, and demonstrated a system that reads information from a lab rat via 1,500 electrodes. They had anticipated starting experiments with humans in 2020, but have since moved that projection to 2023. As of May 2023, they have been approved for human trials in the United States.

The company has faced criticism for a large amount of euthanization of primates that underwent medical trials. Veterinary records of the monkeys showed a number of complications with electrodes being surgically implanted. On January 29, 2024, Musk announced that Neuralink had successfully implanted a Neuralink device in a human and that the patient was recovering.

History
Neuralink was founded in 2016 by Elon Musk and a founding team of seven scientists and engineers. The group of initial hires consisted of experts in areas such as neuroscience, biochemistry and robotics. The trademark "Neuralink" was purchased from its previous owners in January 2017.

In April 2017, Neuralink announced that it was aiming to make devices to treat serious brain diseases in the short-term, with the eventual goal of human enhancement, sometimes called transhumanism. Musk had said his interest in the idea partly stemmed from the science fiction concept of "neural lace" in the fictional universe in The Culture, a series of 10 novels by Iain M. Banks.

Musk defined the neural lace as a "digital layer above the cortex" that would not necessarily imply extensive surgical insertion but ideally an implant through a vein or artery. He said the long-term goal is to achieve "symbiosis with artificial intelligence", which he perceives as an existential threat to humanity if it goes unchecked. He believes the device will be "something analogous to a video game, like a saved game situation, where you are able to resume and upload your last state" and "address brain injuries or spinal injuries and make up for whatever lost capacity somebody has with a chip."

, Neuralink was headquartered in San Francisco's Mission District, sharing the Pioneer building with OpenAI, another company co-founded by Musk. , Neuralink's headquarters were in Fremont, California. Jared Birchall, the head of Musk's family office, was listed as CEO, CFO and president of Neuralink in 2018. , Musk was the majority owner of Neuralink but did not hold an executive position. By August 2020, only three of the eight founding scientists remained at the company, according to an article by Stat News which reported that Neuralink had seen "years of internal conflict in which rushed timelines have clashed with the slow and incremental pace of science."

In April 2021, Neuralink demonstrated a monkey playing the game "Pong" using the Neuralink implant. While similar technology has existed since 2002, when a research group first demonstrated a monkey moving a computer cursor with neural signals, scientists acknowledged the engineering progress in making the implant wireless and increasing the number of implanted electrodes. In May 2021, co-founder and president Max Hodak announced that he no longer works with the company. Only two of the eight co-founders remained at the company by January 2022.

Technology
In 2018, Gizmodo reported that Neuralink "remained highly secretive about its work", although public records showed that it had sought to open an animal testing facility in San Francisco; it subsequently started to carry out research at the University of California, Davis. In 2019, during a live presentation at the California Academy of Sciences, the Neuralink team revealed to the public the technology of the first prototype they had been working on. It is a system that involves ultra-thin probes being inserted into the brain, a neurosurgical robot to perform the operations and a high-density electronic system capable of processing information from neurons. It is based on technology developed at UCSF and UC Berkeley.

Probes
The probes, composed mostly of polyimide, a biocompatible material, with a thin gold or platinum conductor, are inserted into the brain through an automated process performed by a surgical robot. Each probe consists of an area of wires that contains electrodes capable of locating electrical signals in the brain, and a sensory area where the wire interacts with an electronic system that allows amplification and acquisition of the brain signal. Each probe contains 48 or 96 wires, each of which contains 32 independent electrodes, making a system of up to 3072 electrodes per formation.

Robot
Neuralink says they have engineered a surgical robot capable of rapidly inserting many flexible probes into the brain, which may avoid the problems of tissue damage and longevity issues associated with larger and more rigid probes. This surgical robot has an insertion head with a 25 μm diameter needle made of tungsten-rhenium designed to attach to the insertion loops, inject individual probes, and penetrate the meninges and cerebral tissue; it is capable of inserting up to six wires (192 electrodes) per minute. A linear motor powers the needle, enabling fast retraction acceleration and varying insertion speeds. A 50-μm tungsten wire that has been bent at the tip and is driven both axially and rotationally makes up the pincher. An imaging stack is also included in the inserter head for needle guidance, real-time insertion viewing, and verification.

Electronics
Neuralink has developed an application-specific integrated circuit to create a 1,536-channel recording system. This system consists of 256 amplifiers capable of being individually programmed, analog-to-digital converters within the chip and peripheral circuit control to serialize the digitized information obtained. It aims to convert information obtained from neurons into an understandable binary code in order to achieve a greater understanding of brain function and the ability to stimulate these neurons back. With the present technology, Neuralink's electrodes are still too big to record the firing of individual neurons, so they can record only the firing of a group of neurons; Neuralink representatives believe this issue might get mitigated algorithmically, but it is computationally expensive and does not produce exact results.

In July 2020, according to Musk, Neuralink obtained a FDA breakthrough device designation which allows limited human testing under the FDA guidelines for medical devices.

Public Compression Challenge
On May 29, 2024, Elon Musk issued a request for public input on a challenge facing Neuralink. Musk suggested that due to the size of the data in need of transmission, a compression rate of more than 200x was needed for its proper function. The challenge also specified that compression needed to be lossless, work under low power, and be able to compress data in real time. Software consultant Roy van Rijn was quoted by the Canadian Broadcasting Corporation as saying the prospect of 200x lossless compression was "just outlandish."

Animal testing and alleged harm
Neuralink tests their devices by surgically implanting them in the brains of live monkeys, pigs and other animals. Neuralink's animal testing has been criticized by groups such as PETA. From 2017 to 2020, Neuralink's experiments on monkeys were conducted in partnership with UC Davis. At the end of their partnership, UC Davis transferred seven monkeys to Neuralink. In 2022, the Physicians Committee for Responsible Medicine (PCRM), an animal welfare advocacy group, alleged that Neuralink and UC Davis had mistreated several monkeys, subjecting them to psychological distress, extreme suffering, and chronic infections due to surgeries. Experiments conducted by Neuralink and UC Davis have involved at least 23 monkeys, and the PCRM believes that 15 of those monkeys died or were euthanized as a result of the experiments. Furthermore, the PCRM alleged that UC Davis withheld photographic and video evidence of the mistreatment.

In February 2022, Neuralink said that macaque monkeys died and were euthanized after experimentation, denying that any animal abuse had occurred. In December 2022, it was reported that Neuralink was under federal investigation by the United States Department of Agriculture (USDA) regarding animal welfare violations. Additionally, a report by Reuters cited claims from several Neuralink employees that testing was being rushed due to Musk's demands for fast results, which was leading to needless suffering and deaths among the animals. A September 2023 exposé by Wired provided additional details on the primate deaths based on public records and confidential interviews with a former Neuralink employee and a current researcher at the California National Primate Research Center. Those records showed complications with the installation of electrodes, including partial paralysis, bloody diarrhea, lost fingers and brain swelling.

In July 2023, an investigation by the USDA found no evidence of animal welfare breaches in the trials other than a previous, self reported incident from 2019. The PCRM disputed the results of the investigation.

In October 2023, Wired reported that Neuralink worked to keep details of animal suffering and death hidden from the public. In November 2023, U.S. lawmakers asked the Securities and Exchange Commission to investigate whether Neuralink deceived investors in by omitting details about possible animal deaths.

On March 21, 2024, Musk stated that the company's second product would be called Blindsight and was already working in animal trials with monkeys. He noted it operates at low resolution that is expected to improve and also stated that no monkey has died due to or been seriously injured by a Neuralink device, in contradiction with earlier reports.

Human testing
Neuralink received FDA approval for human clinical trials in May 2023. The FDA had previously rejected a 2022 application to pursue human clinical trials citing "major safety concerns involving the device’s lithium battery; the potential for the implant’s tiny wires to migrate to other areas of the brain; and questions over whether and how the device can be removed without damaging brain tissue."

In September 2023, Neuralink opened up its first human trials. It recruited people with quadriplegia due to cervical spinal cord injury or amyotrophic lateral sclerosis under an investigational device exemption by the FDA.

On January 29, 2024, Musk said that Neuralink had successfully implanted a brain computer interface (BCI) device the company named Telepathy in a human on the day prior, and that the patient was recovering from the surgery. As it was a "first in human" and "early feasibility" trial to develop a concept, the company was not obligated to disclose details about the procedure or to prove safety or efficacy. Neuralink provided a few details in February on the implant in a recruitment brochure for the Precise Robotically Implanted Brain-Computer Interface (PRIME) study. On February 20, Musk stated that Neuralink's first human trial participant had been able to control a computer mouse through thought.

On March 20, 2024, Neuralink introduced the person who had received the first Neuralink implant in the clinical trial as 29-year-old Noland Arbaugh through a livestream on X. Arbaugh had become a quadriplegic after experiencing a diving accident; dislocating his C4 and C5 spinal vertebrae. Later in the livestream, Noland demonstrated his ability to move a cursor on a computer screen to allow him to control music and play games such as chess. Noland expressed support for the implant in dramatically improving his quality of life. He acknowledged that the device is not perfect yet but he is excited about the future and believes it has changed his life significantly already. Arbaugh later stated in an interview with The Wall Street Journal that 85% of the implant threads from the device had completely detached while his brain has shifted approximately three times the amount of what the company expected. The Wall Street Journal also reported that Neuralink would proceed with a second trial participant.

Reception
Scientists have cited technical challenges for Neuralink. In 2017, a journalist at the IEEE Spectrum magazine had asked for comments from five researchers that had been working on BCI implants, including Thomas Oxley who invented the Stentrode. At a live demonstration in August 2020, Musk described their device as "a Fitbit in your skull". Several neuroscientists and publications criticized these claims. MIT Technology Review accused the demonstration of having the main objective to "stir excitement", adding that "Neuralink has provided no evidence that it can (or has even tried to) treat depression, insomnia, or a dozen other diseases that Musk mentioned in a slide". Andrew Jackson, professor of neural interfaces at Newcastle University, also commented on the presentation to the BBC. To Musk's statement that he found Neuralink's advancements to be "profound", Jackson responded, "I don't think there was anything revolutionary in the presentation."

Thiago Arzua of the Medical College of Wisconsin argued that Neuralink's functions are not novel and that ideas for a brain–machine interface (BMI) are at least 50 years old. He cited successful control of a robotic prosthetic arm by a man that gave him haptic feedback, which he used in 2016 to give President Obama a fist bump. Arzua said that the 2020 Neuralink presentation "showed little more than a flashy new design for a BMI with more electrodes". Similar criticism is made by the Duke University researcher Miguel Nicolelis, stating that most of what Neuralink claims as "novelty" was already performed by his lab in the early 2000s; that there are ethical concerns on how the company markets and utilizes this technology; and that most patients don't want to perform any surgery to recover their movements, and so his team developed non-invasive techniques for BMI, as demonstrated in the opening ceremony of the 2014 FIFA World Cup, in the context of the Walk Again Project.