I. Who Could Object?

“Tonight I would like to share with you an idea that I am extremely passionate about,” the young man said. His long black hair was swept back like a rock star’s, or a gangster’s. “Think about this,” he continued. “Throughout all human history, the way that we have expressed our intent, the way we have expressed our goals, the way we have expressed our desires, has been limited by our bodies.” When he inhaled, his rib cage expanded and filled out the fabric of his shirt. Gesturing toward his body, he said, “We are born into this world with this. Whatever nature or luck has given us.“

His speech then took a turn: “Now, we’ve had a lot of interesting tools over the years, but fundamentally the way that we work with those tools is through our bodies.” Then a further turn: “Here’s a situation that I know all of you know very well—your frustration with your smartphones, right? This is another tool, right? And we are still communicating with these tools through our bodies.”

So began “Beyond Bionics,” a talk by Justin C. Sanchez, then an associate professor of biomedical engineering and neuroscience at the University of Miami, and a faculty member of the Miami Project to Cure Paralysis. He was speaking at a tedx conference in Florida in 2012. What lies beyond bionics? Sanchez described his work as trying to “understand the neural code,” which would involve putting “very fine microwire electrodes”—the diameter of a human hair—“into the brain.” When we do that, he said, we would be able to “listen in to the music of the brain” and “listen in to what somebody’s motor intent might be” and get a glimpse of “your goals and your rewards” and then “start to understand how the brain encodes behavior.”

He explained, “With all of this knowledge, what we’re trying to do is build new medical devices, new implantable chips for the body that can be encoded or programmed with all of these different aspects. Now, you may be wondering, what are we going to do with those chips? Well, the first recipients of these kinds of technologies will be the paralyzed. It would make me so happy by the end of my career if I could help get somebody out of their wheelchair.”

A year later, Justin Sanchez went to work for the Defense Advanced Research Projects Agency, the Pentagon’s R&D department. At darpa, he now oversees all research on the healing and enhancement of the human mind and body. And his ambition involves more than helping get disabled people out of their wheelchair—much more.

DARPA has dreamed for decades of merging human beings and machines. Some years ago, when the prospect of mind-controlled weapons became a public-relations liability for the agency, officials resorted to characteristic ingenuity. They recast the stated purpose of their neurotechnology research to focus ostensibly on the narrow goal of healing injury and curing illness. The work wasn’t about weaponry or warfare, agency officials claimed. It was about therapy and health care. Who could object? But even if this claim were true, such changes would have extensive ethical, social, and metaphysical implications. Within decades, neurotechnology could cause social disruption on a scale that would make smartphones and the internet look like gentle ripples on the pond of history.

II. High Risk, High Reward

In his 1958 State of the Union address, President Dwight Eisenhower declared that the United States of America “must be forward-looking in our research and development to anticipate the unimagined weapons of the future.” A few weeks later, his administration created the Advanced Research Projects Agency, a bureaucratically independent body that reported to the secretary of defense. This move had been prompted by the Soviet launch of the Sputnik satellite. The agency’s original remit was to hasten America’s entry into space.

During the next few years, arpa’s mission grew to encompass research into “man-computer symbiosis” and a classified program of experiments in mind control that was code-named Project Pandora. There were bizarre efforts that involved trying to move objects at a distance by means of thought alone. In 1972, with an increment of candor, the word Defense was added to the name, and the agency became darpa. Pursuing its mission, darpa funded researchers who helped invent technologies that changed the nature of battle (stealth aircraft, drones) and shaped daily life for billions (voice-recognition technology, GPS devices). Its best-known creation is the internet.

The agency’s penchant for what it calls “high-risk, high-reward” research ensured that it would also fund a cavalcade of folly. Project Seesaw, a quintessential Cold War boondoggle, envisioned a “particle-beam weapon” that could be deployed in the event of a Soviet attack. The idea was to set off a series of nuclear explosions beneath the Great Lakes, creating a giant underground chamber. Then the lakes would be drained, in a period of 15 minutes, to generate the electricity needed to set off a particle beam. The beam would accelerate through tunnels hundreds of miles long (also carved out by underground nuclear explosions) in order to muster enough force to shoot up into the atmosphere and knock incoming Soviet missiles out of the sky. During the Vietnam War, darpa tried to build a Cybernetic Anthropomorphous Machine, a jungle vehicle that officials called a “mechanical elephant.”

The diverse and sometimes even opposing goals of darpa scientists and their Defense Department overlords merged into a murky, symbiotic research culture—“unencumbered by the typical bureaucratic oversight and uninhibited by the restraints of scientific peer review,” Sharon Weinberger wrote in a recent book, The Imagineers of War. In Weinberger’s account, darpa’s institutional history involves many episodes of introducing a new technology in the context of one appealing application, while hiding other genuine but more troubling motives. At darpa, the left hand knows, and doesn’t know, what the right hand is doing.

The Biological Technologies Office, created in 2014, is the newest of darpa’s six main divisions. This is the office headed by Justin Sanchez. One purpose of the office is to “restore and maintain warfighter abilities” by various means, including many that emphasize neurotechnology—applying engineering principles to the biology of the nervous system. For instance, the Restoring Active Memory program develops neuroprosthetics—tiny electronic components implanted in brain tissue—that aim to alter memory formation so as to counteract traumatic brain injury. Does darpa also run secret biological programs? In the past, the Department of Defense has done such things. It has conducted tests on human subjects that were questionable, unethical, or, many have argued, illegal. The Big Boy protocol, for example, compared radiation exposure of sailors who worked above and below deck on a battleship, never informing the sailors that they were part of an experiment.

III. “We Try to Find Ways to Say Yes”

Medicine and biology were of minor interest to darpa until the 1990s, when biological weapons became a threat to U.S. national security. The agency made a significant investment in biology in 1997, when darpa created the Controlled Biological Systems program. The zoologist Alan S. Rudolph managed this sprawling effort to integrate the built world with the natural world. As he explained it to me, the aim was “to increase, if you will, the baud rate, or the cross-communication, between living and nonliving systems.” He spent his days working through questions such as “Could we unlock the signals in the brain associated with movement in order to allow you to control something outside your body, like a prosthetic leg or an arm, a robot, a smart home—or to send the signal to somebody else and have them receive it?”

Human enhancement became an agency priority. “Soldiers having no physical, physiological, or cognitive limitation will be key to survival and operational dominance in the future,” predicted Michael Goldblatt, who had been the science and technology officer at McDonald’s before joining darpa in 1999. To enlarge humanity’s capacity to “control evolution,” he assembled a portfolio of programs with names that sounded like they’d been taken from video games or sci-fi movies: Metabolic Dominance, Persistence in Combat, Continuous Assisted Performance, Augmented Cognition, Peak Soldier Performance, Brain-Machine Interface.

Dick Cheney relished this kind of research. In the summer of 2001, an array of “super-soldier” programs was presented to the vice president. His enthusiasm contributed to the latitude that President George W. Bush’s administration gave darpa—at a time when the agency’s foundation was shifting. Academic science gave way to tech-industry “innovation.” Tony Tether, who had spent his career working alternately for Big Tech, defense contractors, and the Pentagon, became darpa’s director. After the 9/11 attacks, the agency announced plans for a surveillance program called Total Information Awareness, whose logo included an all-seeing eye emitting rays of light that scanned the globe. The pushback was intense, and Congress took darpa to task for Orwellian overreach. The head of the program—Admiral John Poindexter, who had been tainted by scandal back in the Reagan years—later resigned, in 2003. The controversy also drew unwanted attention to darpa’s research on super-soldiers and the melding of mind and machine. That research made people nervous, and Alan Rudolph, too, found himself on the way out.

Ling talks fast. He has a tough-guy voice. The faster he talks, the tougher he sounds, and when I met him, his voice hit top speed as he described a first principle of Defense Sciences. He said he had learned this “particularly” from Alan Rudolph: “Your brain tells your hands what to do. Your hands basically are its tools, okay? And that was a revelation to me.” He continued, “We are tool users—that’s what humans are. A human wants to fly, he builds an airplane and flies. A human wants to have recorded history, and he creates a pen. Everything we do is because we use tools, right? And the ultimate tools are our hands and feet. Our hands allow us to work with the environment to do stuff, and our feet take us where our brain wants to go. The brain is the most important thing.”

No invention since the internet has been such a reliable source of good publicity for darpa. Milestones in its development were hailed with wonder. In 2012, 60 Minutes showed a paralyzed woman named Jan Scheuermann feeding herself a bar of chocolate using a robotic arm that she manipulated by means of a brain implant.

Geoff Ling’s efforts have been carried on by Justin Sanchez. In 2016, Sanchez appeared at darpa’s “Demo Day” with a man named Johnny Matheny, whom agency officials describe as the first “osseointegrated” upper-limb amputee—the first man with a prosthetic arm attached directly to bone. Matheny demonstrated what was, at the time, darpa’s most advanced prosthetic arm. He told the attendees, “I can sit here and curl a 45-pound dumbbell all day long, till the battery runs dead.” The next day, Gizmodo ran this headline above its report from the event: “darpa’s Mind-Controlled Arm Will Make You Wish You Were a Cyborg.”

Since then, darpa’s work in neurotechnology has avowedly widened in scope, to embrace “the broader aspects of life,” Sanchez told me, “beyond the person in the hospital who is using it to heal.” The logical progression of all this research is the creation of human beings who are ever more perfect, by certain technological standards. New and improved soldiers are necessary and desirable for darpa, but they are just the window-display version of the life that lies ahead.

IV. “Over the Horizon”

Consider memory, Sanchez told me: “Everybody thinks about what it would be like to give memory a boost by 20, 30, 40 percent—pick your favorite number—and how that would be transformative.” He spoke of memory enhancement through neural interface as an alternative form of education. “School in its most fundamental form is a technology that we have developed as a society to help our brains to do more,” he said. “In a different way, neurotechnology uses other tools and techniques to help our brains be the best that they can be.” One technique was described in a 2013 paper, a study involving researchers at Wake Forest University, the University of Southern California, and the University of Kentucky. Researchers performed surgery on 11 rats. Into each rat’s brain, an electronic array—featuring 16 stainless-steel wires—was implanted. After the rats recovered from surgery, they were separated into two groups, and they spent a period of weeks getting educated, though one group was educated more than the other.

The less educated group learned a simple task, involving how to procure a droplet of water. The more educated group learned a complex version of that same task—to procure the water, these rats had to persistently poke levers with their nose despite confounding delays in the delivery of the water droplet. When the more educated group of rats attained mastery of this task, the researchers exported the neural-firing patterns recorded in the rats’ brains—the memory of how to perform the complex task—to a computer.

“They could inject memory using the precise neural codes for certain skills,” Sanchez told me. He believes that the Wake Forest experiment amounts to a foundational step toward “memory prosthesis.” This is the stuff of The Matrix. Though many researchers question the findings—cautioning that, really, it can’t be this simple—Sanchez is confident: “If I know the neural codes in one individual, could I give that neural code to another person? I think you could.” Under Sanchez, darpa has funded human experiments at Wake Forest, the University of Southern California, and the University of Pennsylvania, using similar mechanisms in analogous parts of the brain. These experiments did not transfer memory from one person to another, but instead gave individuals a memory “boost.” Implanted electrodes recorded neuronal activity associated with recognizing patterns (at Wake Forest and USC) and memorizing word lists (at Penn) in certain brain circuits. Then electrodes fed back those recordings of neuronal activity into the same circuits as a form of reinforcement. The result, in both cases, was significantly improved memory recall.

Even if the interface problems that limit us now didn’t exist, Weber went on to say, he still would not believe that neuroscientists could enable the memory-prosthesis scenario. Some people like to think about the brain as if it were a computer, Weber explained, “where information goes from A to B to C, like everything is very modular. And certainly there is clear modular organization in the brain. But it’s not nearly as sharp as it is in a computer. All information is everywhere all the time, right? It’s so widely distributed that achieving that level of integration with the brain is far out of reach right now.”

To test this hypothesis, Weber directed the creation of a new program in the Biological Technologies Office, called Targeted Neuroplasticity Training (TNT). Teams of researchers at seven universities are investigating whether vagal-nerve stimulation can enhance learning in three areas: marksmanship, surveillance and reconnaissance, and language. The team at Arizona State has an ethicist on staff whose job, according to Weber, “is to be looking over the horizon to anticipate potential challenges and conflicts that may arise” regarding the ethical dimensions of the program’s technology, “before we let the genie out of the bottle.” At a TNT kickoff meeting, the research teams spent 90 minutes discussing the ethical questions involved in their work—the start of a fraught conversation that will broaden to include many others, and last for a very long time.

Weber and a darpa spokesperson related some of the questions the researchers asked in their ethics discussion: Who will decide how this technology gets used? Would a superior be able to force subordinates to use it? Will genetic tests be able to determine how responsive someone would be to targeted neuroplasticity training? Would such tests be voluntary or mandatory? Could the results of such tests lead to discrimination in school admissions or employment? What if the technology affects moral or emotional cognition—our ability to tell right from wrong or to control our own behavior?

V. “You Can Weaponize Anything”

In The Pentagon’s Brain, Annie Jacobsen suggested that darpa’s neurotechnology research, including upper-limb prosthetics and the brain-machine interface, is not what it seems: “It is likely that darpa’s primary goal in advancing prosthetics is to give robots, not men, better arms and hands.” Geoff Ling rejected the gist of her conclusion when I summarized it for him (he hadn’t read the book). He told me, “When we talk about stuff like this, and people are looking for nefarious things, I always say to them, ‘Do you honestly believe that the military that your grandfather served in, your uncle served in, has changed into being Nazis or the Russian army?’ Everything we did in the Revolutionizing Prosthetics program—everything we did—is published. If we were really building an autonomous-weapons system, why would we publish it in the open literature for our adversaries to read? We hid nothing. We hid not a thing. And you know what? That meant that we didn’t just do it for America. We did it for the world.”

I started to say that publishing this research would not prevent its being misused. But the terms use and misuse overlook a bigger issue at the core of any meaningful neurotechnology-ethics discussion. Will an enhanced human being—a human being possessing a neural interface with a computer—still be human, as people have experienced humanity through all of time? Or will such a person be a different sort of creature?

“Let’s say I gave you a third arm,” and then a fourth arm—so, two additional hands, he said. “You would be more capable; you would do more things, right?” And if you could control four hands as seamlessly as you’re controlling your current two hands, he continued, “you would actually be doing double the amount of work that you would normally do. It’s as simple as that. You’re increasing your productivity to do whatever you want to do.” I started to picture his vision—working with four arms, four hands—and asked, “Where does it end?”

“It won’t ever end,” Ling said. “I mean, it will constantly get better and better—” His cellphone rang. He took the call, then resumed where he had left off: “What darpa does is we provide a fundamental tool so that other people can take those tools and do great things with them that we’re not even thinking about.”

Judging by what he said next, however, the number of things that darpa is thinking about far exceeds what it typically talks about in public. “If a brain can control a robot that looks like a hand,” Ling said, “why can’t it control a robot that looks like a snake? Why can’t that brain control a robot that looks like a big mass of Jell-O, able to get around corners and up and down and through things? I mean, somebody will find an application for that. They couldn’t do it now, because they can’t become that glob, right? But in my world, with their brain now having a direct interface with that glob, that glob is the embodiment of them. So now they’re basically the glob, and they can go do everything a glob can do.”

VI. Gold Rush

darpa’s developing capabilities still hover at or near a proof-of-concept stage. But that’s close enough to have drawn investment from some of the world’s richest corporations. In 1990, during the administration of President George H. W. Bush, darpa Director Craig I. Fields lost his job because, according to contemporary news accounts, he intentionally fostered business development with some Silicon Valley companies, and White House officials deemed that inappropriate. Since the administration of the second President Bush, however, such sensitivities have faded.

Over time, darpa has become something of a farm team for Silicon Valley. Regina Dugan, who was appointed darpa director by President Barack Obama, went on to head Google’s Advanced Technology and Projects group, and other former darpa officials went to work for her there. She then led R&D for the analogous group at Facebook, called Building 8. (She has since left Facebook.)

darpa’s neurotechnology research has been affected in recent years by corporate poaching. Doug Weber told me that some darpa researchers have been “scooped up” by companies including Verily, the life-sciences division of Alphabet (the parent company of Google), which, in partnership with the British pharmaceutical conglomerate GlaxoSmithKline, created a company called Galvani Bioelectronics, to bring neuro-modulation devices to market. Galvani calls its business “bioelectric medicine,” which conveys an aura of warmth and trustworthiness. Ted Berger, a University of Southern California biomedical engineer who collaborated with the Wake Forest researchers on their studies of memory transfer in rats, worked as the chief science officer at the neurotechnology company Kernel, which plans to build “advanced neural interfaces to treat disease and dysfunction, illuminate the mechanisms of intelligence, and extend cognition.” Elon Musk has courted darpa researchers to join his company Neuralink, which is said to be developing an interface known as “neural lace.” Facebook’s Building 8 is working on a neural interface too. In 2017, Regina Dugan said that 60 engineers were at work on a system with the goal of allowing users to type 100 words a minute “directly from your brain.” Geoff Ling is on Building 8’s advisory board.

He seemed entirely untroubled by what may be the most troubling aspect of darpa’s work: not that it discovers what it discovers, but that the world has, so far, always been ready to buy it.

This article appears in the November 2018 print edition with the headline “The Pentagon Wants to Weaponize the Brain. What Could Go Wrong?”