A century ago, the understanding of the brain by science was primitive, like astronomy before telescopes. It is known that certain brain injuries caused specific problems, such as loss of speech or vision, but these findings offered diffuse vision.
Anatomists had identified nerve cells, or neurons, as key components of the brain and nervous system. But no one knew how these cells collectively manage the sophisticated control of the brain’s behavior, memory, or emotions. And no one knew how neurons communicate or the complexities of their connections. On the other hand, the field of research known as neuroscience – the science of the nervous system – did not exist, being known as such only in the 1960s.
For the past 100 years, brain scientists have built their telescopes. Powerful tools for peeking inside revealed cellular constellations. More than 100 different types of brain cells are likely to communicate with dozens of different chemicals. Scientists have discovered that a single neuron can connect to tens of thousands of other cells.
However, neuroscience, although no longer in its infancy, is far from mature.
Nowadays, making sense of the irritating complexity of the brain is harder than ever. Advanced technologies and expanded computing capacity produce torrents of information. “We have a lot more data than ever before, period,” says Christof Koch, a neuroscientist at Seattle’s Allen Institute. However, we still do not have a satisfactory explanation of how the brain works. We may never understand brains the way we understand rainbows, black holes, or DNA.
Deeper revelations can come from studying the vast arrays of neural connections that move information from one part of the brain to another. Using the latest brain mapping technologies, scientists began drawing detailed maps of those neural highways, compiling a complete atlas of the brain's communication systems, known as the connectome.
These maps offer a more realistic picture than the initial work that emphasized the role of certain brain areas on the connections between them, says Michael D. Fox, a neuroscientist who heads the Center for Brain Circuit Therapeutics at Boston’s Brigham and Women’s Hospital.
Scientists now know that the point on the map is less important than the roads entering and leaving.
“With the construction of the human connectome, this wiring diagram of the human brain, we suddenly had the resources and tools to start seeing (the brain) differently,” Fox says.
Scientists are already beginning to use these new brain maps to treat disorders. That’s the main goal of the Fox Center, dedicated to changing brain circuits in ways that relieve disorders like Parkinson’s disease, obsessive-compulsive disorder, and depression. “Perhaps for the first time in history we have the tools to map these symptoms into human brain circuits and we have the tools to intervene and modulate these circuits,” Fox says.
The goal sounds great, but Fox doesn’t think it’s a stretch. “My deadline is within a decade,” he says.
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Whether in 10 years or 50 years, imagining what lies ahead, we can remember the progress that has already been made, the neural galaxies that have been discovered and mapped. And we can afford a wonderful moment about what might come next.
The three fictional vignettes that follow illustrate some of those future possibilities. No doubt they will be wrong in the details, but each has its roots in the research that is underway today, as described in the “reality checks” that follow each imagined scenario.
Scientific future: brain bots
Sarah had decided. After five years, he was going to get the neural network out of him. The millions of nanobots in his brain had brought him back to life by helping his mind work again. They had done their job. It was time to take them out.
After Sarah’s baby was born on the summer solstice, things darkened. The following months brought Sarah down in a postpartum depression that prevented her from enjoying her beautiful perfect baby girl.
Unable to feel much of anything, Sarah barely went through those early days. I rarely looked at the baby. He forgot to eat. I would sit in a dark room for hours, the air conditioning in full blast, looking at nothing. Those endless days extended into an invaluable hot September morning. Her mother watched the baby as Sarah's husband drove her to the Neuroprosthetic Institute, a low-rise brick building in the suburbs of Nashville.
Inside, Sarah barely heard the clinic coordinator re-describe the technology. An injection would deliver the nanobots to the blood. Then a technology would guide the bots, using a magnet, from arm to head. A fast, strong pulse of ultrasound would temporarily open the blood-brain barrier, allowing an army of tiny particles to slip.
Driven by the molecular motion inherent in the brain, nanobots would spread forming a network of microscopic electrodes. That neural network could identify where Sarah’s brain circuits were firing and repair them with precise but persuasive electrical pushes.
Over the next few weeks, Sarah’s nanobots learned the neural rhythms of her brain as she progressed through her life with debilitating depression. With powerful computer help and regular play by the clinic technologist, the system soon learned to detect the first neural rumors of a deteriorated mood. Once these warning signs became clear, Sarah’s network of nanobots could end the incipient episodes before they knocked her down.
Shortly after the injection, Sarah's laughter began to reappear, though sometimes at the wrong times. She remembered the day she and her husband took the baby to a family birthday party. In the middle of a story about her uncle’s treatment of dementia, Sarah’s laughter silenced the room.
Those closest to him understood, but most of his family and friends did not know of the millions of bots working to support his brain.
After a few months and some adjustments, Sarah’s emotions matched. The cold, dormant depression was gone. Gone are the inadequate gusts, flashes of white rage, and insatiable appetites. He was able to settle in with his new family and feel, really feel, the joy of it all.
But was this joy alone in her? Perhaps he belonged to the army of ever-vigilant little helpers, who reworked and took out the brain. Without the neural network, she could be in tears watching her daughter, still her baby, enter the kindergarten classroom on the first day. Instead, Sarah waved, turned around, and went to work, feeling only slightly melancholy, nothing more intense than that.
The science that supports the success of neural networks has been amazing. They could efficiently solve huge problems: addiction, dementia, eating disorders, and more. But science could not answer bigger questions of identity and control: what it means to be a person.
That search by itself was what took Sarah back to the clinic, five years after she had hosted the nanobots.
Her technologist reviewed the simple extraction procedure: a quick ultrasound pulse to loosen the blood-brain barrier again, a strong magnet on the inside of Sarah’s elbow, and a blood draw. He looked at her. "Are you ready?"
He took a deep breath. "Yes."
Reality check: brain bots
In this story, Sarah received a treatment that does not exist in the real world. But the idea that scientists will be able to change certain brain networks and improve health is not a fiction. It's happening.
Already, a technique known as deep brain stimulation, or DBS, uses electrodes surgically implanted in people’s brains to modify the behavior of brain cells. These electrode implants are helping to reduce Parkinson’s tremors, epileptic seizures, and uncontrollable movements caused by Tourette’s syndrome. Mood disorders such as Sarah's were also targeted.
Zephyr / Science Source
The central idea of DBS – that the brain can be fixed by stimulating it – is not new. In the 1930s, psychiatrists discovered that a huge amount of electricity that caused seizures could sometimes relieve psychiatric symptoms. In the 1940s and 1950s, researchers studied whether more limited electrical stimulation could help with disorders such as depression.
In 1948, for example, neurosurgeon J. Lawrence Pool of Columbia University’s New York Neurological Institute implanted electrodes to stimulate the brain of a woman with severe Parkinson’s who had become depressed and lost weight. He soon began to "eat well, gain weight, and react in a more cheerful manner," Pool reported in 1954.
The experiment ended three years later when one of the wires broke. “The writer’s conviction is that focally controlled stimulation of the human brain is a new technique in psychosurgery that is here to stay,” Pool wrote.
Compared to those early days, today’s scientists understand much more about how to selectively influence brain activity. But before a treatment like Sarah’s is possible, two main challenges need to be addressed: Doctors need better tools – agile, powerful systems that are durable enough to function consistently within the brain for years – and they need to know where it is found in the brain. the treatment. That situation differs between disorders and even between people.
These are big problems, but the different parts needed for this type of precision healing are starting to come together.
The specifications of the technology that will be able to listen to brain activity and intervene as needed is an assumption of either. However, those nanobots that have crept into Sarah’s brain from her blood have roots in current research. For example, Mikhail Shapiro of Caltech and his colleagues are working towards nanoscale robots that traverse the body and act as doctors (SN: 10/10/20 and 24/10/20, p. 27).
Other types of sensors are growing fast. In the last 20 years, electrodes have improved by an astonishing amount, becoming smaller, more flexible, and less likely to heal the brain, says biomedical engineer Cynthia Chestek. When she began working on electrode development in the early 2000s, there were still insoluble problems, she said, including scars that can leave large, rigid electrodes and the energy they need to function. "We didn't know if anyone was going to deal with them."
But those problems have been largely overcome, says Chestek, whose laboratory team at the University of Michigan at Ann Arbor is developing carbon fiber electrodes. Imagine the future, by Chestek. "It could have thousands of electrodes that securely interface with neurons. At that point, it becomes a really standard medical practice."
Neural dust (tiny electrodes fed by external ultrasound) can already capture nerve and muscle activity in rats. Neuropixels can record the electrical activity of more than 10,000 sites in the brains of mice. And mesh electrodes, called neural notches, were injected into the brains of mice.
Once inside, these networks integrate into the tissue and record the brain activity of many cells. So far, these mesh electrodes have captured neuronal activity over months as mice have run off.
Other developing systems can be controlled with magnets, light or ultrasound. There are still problems to be solved, says Chestek, but none are insurmountable. “We just need to figure out the latest set of practical tricks,” he says.
Once scientists know how to reliably change brain activity, they need to know where to make the change. Precision orientation is complicated by the fact that ultimately all parts of the brain are connected to other parts, in a very Kevin Bacon way.
Advances in tractography (the study of physical connections between groups of nerve cells) point to which parts of these neural highways could be directed to treat certain problems.
Other studies of people with implanted electrodes reveal brain networks in action. When certain electrodes were stimulated, people experienced immediate and obvious changes in their mood (SN: 16/02/19, p. 22). These electrodes were near the neural tracts that converge in a brain region just behind and above the eyes called the lateral orbitofrontal cortex.
In the future, we may all have mapped our custom brain wiring diagrams, Fox says. And perhaps for any symptoms (anxiety, food cravings or addiction) doctors could find the brain circuit responsible. “Now we have our goal,” he says. "We can keep the neuromodulation tool out of the scalp or implant a tool inside the head and we'll fix that circuit."
The obstacles to building an agile, powerful, and accurate system similar to the one that helped Sarah are high. But past successes suggest that innovative and aggressive research will find ways to bypass current barriers. For people with mood disorders, addiction, dementia, or any other brain-rooted disease, those advances may not come quickly.
Scientific future: fused mind
Sofia could not sleep. Tomorrow was the big day. As project manager for the Nobel Committee on Physiology or Medicine, she had overseen years of award announcements, but never one like this.
At 11:30 a.m. Central European Daylight Saving Time, the prize would be awarded to a bird named Harry, a 16-year-old Clark nutcracker. Sofia smiled in the darkness as she thought about how the news would come.
Harry should be recognized for benefiting humanity "in its role as a pioneering memory collective that enhances human minds." Harry would share the prize (and the money) with his two human trainers.
Tomorrow morning, the world would be bubbling, Sofia knew. But as with all Nobel Prizes, the story began long before the announcement. Even in the 20th century, scientists dreamed and played with merging different types of minds.
As technology became more accurate and less invasive, man-to-man links were perfected, drawing inspiration from ancient and intriguing examples of joint twins with shared consciousness. External headphones could send and receive signals between brains, such as "silent speech" and sight and sound.
Then scientists began to search the brains of other species for different types of abilities that could increase our human abilities. Other animals have different ways of seeing, feeling, experiencing, and remembering the world. That's where Harry came in.
Crows, crows and other crows have prodigious memories. This is especially true for Clark nutcrackers. These gray and black birds can remember the location of approximately 10,000 seed strains at any given time. These powerful memory skills soon caught the attention of scientists eager to increase human memory.
Scientists did not talk about remembering where the car is parked at the airport. They put their eyes up. Done right, these improvements could allow a person to build surprisingly complete internal maps of their world, remembering all the places they had been. And it turned out that these feats of memory did not just stop at physical places. Strengthening one type of memory has also led to improvements in other types of memories. The systems have become stronger around.
Harry was not the first bird to interact with humans, but he was one of the best. Again, Harry underwent several years of intense training (helped by his favorite delicacy, the whitebark pine seeds). Using a sophisticated implanted brain chip, he learned to combine his neural signals with those of a person who had memory problems or needed a temporary boost. The connection used to last a few hours a day, but its effects lasted. Notable improvements in people’s memories remained steady for months after a session with Harry. The people who tried it called the change "impressive." The bird made history.
Showing this kind of human-animal mind was possible and beneficial, Harry and his coaches had helped create a completely new field, worthy of Nobel recognition, Sofia thought.
Some scientists are now building what Harry’s brain could do during these mixing sessions. Others extend to different animal abilities: allowing people to “see” in the dark like echolocating bats or “try” with their arms like octopuses. Imagine that doctors are able to smell diseases, an olfactory ability taken from dogs. The media was already starting to conduct interviews with people who had raised animal awareness.
Still awake, Sofia’s mind went through the meetings she had held with her communication team over the past week. Tomorrow’s announcement would bring fun and delight. But he also hoped to hear strong objections from religious groups, animal rights activists and even some ethics concerned about species blurring. The team was ready for protests, many of them.
In the middle of the night, these worries seemed a more substantial suffocation to Sofia. Then he thought Harry was spinning, hiding seeds, and the threat was gone. Sofia marveled at how far science had come since she was a child and how far she was destined. Totally exhausted, overturned, ready to sleep, ready for tomorrow. He smiled again as he thought about what he would say to people, if the opportunity arose: for better or for worse, resistance is useless.
Reality check: combination of mind
Accepting that a bird could win a Nobel Prize requires a fairly long flight of fancy. But scientists have already directly connected several brains.
Today, the technology that makes these connections possible is about to begin. We are in the “Kitty Hawk” days of brain interface technologies, says computational neuroscientist Rajesh Rao of the University of Washington in Seattle, who works on brain-based communication systems. In the future, these systems will inevitably fly higher.
Such technology can even take people beyond the confines of their body, creating a kind of extended cognition, which will possibly allow for new skills, Rao says. "This direct connection between brains, maybe that's another way to take a leap in our human evolution."
Rao helped organize a three-way live brain chat, in which three people sent and received messages using only their minds while playing a Tetris-like game. Signs of thoughts from two players ’brains moved over the internet and back from the receiver’s brain through a burst of magnetic stimulation designed to mimic information coming from the eyes.
Senders could transmit signals that had told the receiver to spin a piece, for example, before dropping it. Those results, published in 2019 in Scientific Reports, represent the first time several people have communicated directly with their brain.
Mark Stone / Univ. of Washington
Other projects have been done on animals, although there are no birds yet. In 2019, people took control of six awake rat brains, guiding the animals ’movements through mazes through thought. A well-trained mouse cyborg could achieve a spin accuracy of nearly 100 percent, the researchers reported.
But those rats took orders from a person; they did not send information back. Continuous back and forth exchanges are a prerequisite for an achievement like Harry’s.
Such experiments are also happening. A recent study linked the brains of three monkeys, allowing their minds to collectively move an avatar arm on a 3D screen. Each monkey was in charge of moving in two or three dimensions; left or right, up or down and near or far. Those jobs that overlapped but caused the networked monkeys to initially loot. But soon their neural cooperation became perfect when they learned to move the avatar’s arm to be rewarded with a sip of juice.
With technological improvements, the variety of signals that can move between brains will increase. And with that, these brain collectives could achieve even more. “A brain can only do so much, but if you put together many brains, connected directly into a network, it’s possible that they can create inventions that no mind could think for itself,” says Rao.
Brain groups can be very good at certain jobs. A collective of surgeons, for example, could put together their experience for an especially difficult operation. A collective of fast-thinking pilots could drive a drone over hostile territory. A collective of intelligence experts could sift through murky spy material.
Maybe someday an animal’s brain information can boost human brains, though the neural signals from a well-trained Clark nutcracker are unlikely to be the best option to aid memory. Artificial intelligence, or even human intelligence, can be better memory partners. Whatever the source, these external “nodes” could eventually expand and change the connectome of a human brain.
Still, connecting brains directly is fraught with ethical issues. One aspect, the idea of an “extended mind,” poses especially wild riddles, says bioethicist Elisabeth Hildt of the Illinois Institute of Technology in Chicago.
“Part of me is connected and extended to this other human being,” she says. “Is it me? Is it anyone else? Am I doing this myself? she asks.
Some scientists think it is too early to contemplate what it may feel like if we have the mind spread over several brains (SN: 2/13/21, p. 24). Others disagree. “It may be too late if we wait until we understand the brain to study the ethics of the brain interface,” says Rao. "Technology is already advancing."
So feel free to think about what it would be like to connect minds with a bird. If you were the human being who could link to the mind of Harry the Clark’s breaker, for example, you might have to dream of flying.
Scientific future: thoughts for sale
Javier had just been fired. “They’re done with me,” he told his co-worker Marcus. "They're done with the whole Signal program."
Marcus shook his head. "I'm sorry, man."
Javier continued: “It gets worse; they are transferring all Signal data to the information market ".
The two were in the transportation business. Javier was the director of Zou’s commitment to neural systems, an on-demand messaging and travel system in Los Angeles. After the auto driving industry exploded because of too many accidents, Zou headed to L.A. with a promise of safety, so the company needed to make sure its drivers were the best.
That's where Javier and his team came in. The ambitious idea of the Signal program was to encourage drivers with cash, using their brain data, gathered by gray headphones.
Drivers with alert and focused brains got automatic bonuses; a green energy bar on the screen in the car showed minute-by-minute gains. Drivers whose brains seemed slow or aggressive didn’t win anymore. Instead, they were warned. If the problem continued, they were fired.
This carrot and stick system, developed by Javier and his team, worked very well at first. But within a few months, accidents started to go up.
It turned out that the problem was the brain itself: it changes. Human brains learn, find creative solutions, redo themselves. Encouraged to maintain a certain type of brain activity, drivers ’brains quickly learned to produce those signals, even if they had not corresponded to better driving. The neural twists caused a run that Javier eventually lost.
That failure was made worse by Zou’s latest plans. What had started out as a driving experiment turned into an irresistible way for the company to make money. The plan was to collect and sell valuable data: information on how drivers ’brains responded to a certain style of music, drivers’ enthusiasm when they saw a digital billboard for a resort, and how they reacted to a politician’s promises.
Zou was going to require employees to wear headphones when they were not driving. Plugs collected data while drivers ate, while shopping, and while talking to their children, collecting personal neural details and selling them to top bidders.
Of course, employees could refuse. They might decide to remove the lids and leave it. "But what kind of choice is that?" Javier asked. "Most of these drivers would open their skulls to receive a salary."
Marcus shook his head and then asked, "How much more will they pay?"
“Who knows,” Javier said. “Maybe nothing. Maybe just put the data consent line in the standard contract. "
The two men looked at each other and shook their heads in unison. There was not much left to say.
Reality check: thoughts for sale
Javier’s fictional program, Signal, was built with information collected externally from the drivers ’brains. The current technology is not there yet. But it’s the closest tip.
Some companies already sell brain control systems made with electrodes that measure external brain waves with a method called electroencephalography. At the moment, these headphones are sold as wellness devices. For a few hundred dollars, you can have headphones that promise to fine-tune your meditation practice, help you make better decisions, or even level your golf game. EEG limits can already measure alertness; some controversial experiments controlled schoolchildren as they listened to their teacher.
The claims of these companies are large and the deliveries have not been proven. “It’s unclear if consumer EEG devices can reveal much,” argued University of Pennsylvania ethicist Anna Wexler in a comment on Nature Biotechnology in 2019. Still, improvements in these devices and algorithms that decode the signals they detect, some day can allow more sophisticated information to be reliably extracted from the brain.
Other types of technology, such as functional MRIs, can extract more detailed information from the brain.
From the brain scans complex visual scenes can be extracted, including movie clips that people were watching. O psicólogo Jack Gallant e os seus colegas da Universidade de California, Berkeley construíron cativantes escenas visuais empregando datos do cerebro das persoas mentres se atopaban nun escáner fMRI. Un gran paxaro vermello abalanzouse sobre a pantalla, os elefantes marcharon seguidos e Steve Martin atravesou a pantalla, todas versións impresionistas de imaxes tiradas da actividade cerebral das persoas.
Ese traballo, publicado en 2011, presaxiaba trucos de lectura cerebral cada vez máis complexos. Máis recentemente, os investigadores empregaron sinais de resonancia magnética para recrear caras que a xente estaba a ver.
As escenas visuais son unha cousa; serán accesibles os nosos pensamentos, crenzas e recordos máis nebulosos? Non é imposible. Toma un estudo de Xapón, publicado en 2013. Os científicos identificaron o contido de tres soños de persoas durmidas, usando unha máquina de resonancia magnética. Pero a recreación destes soños requiriu horas para que alguén lle falase a un científico doutros soños. Para obter os datos que querían, os científicos primeiro debían ser invitados ás mentes dos soñadores, dalgún xeito. Esas tres persoas foron espertadas máis de 200 veces ao comezo dos experimentos e pedíronlles que describisen o que soñaban.
As formas máis portátiles e máis fiables de escoitar o cerebro desde o exterior avanzan rápido, unha rapidez que levou a algúns éticos, científicos e futuristas a pedir proteccións especiais dos datos neuronais. Os debates sobre quen pode acceder á nosa actividade cerebral e con que fins só serán máis intensos a medida que mellore a tecnoloxía.