The Next Frontier in Human Brain Exploration

The human brain is three pounds or so of jellylike tissue, and yet according to the best estimates available, it contains more than 86 billion nerve cells through which a kaleidoscope of ideas, memories and sensations live. It has confounded scientists, philosophers and physicians for centuries. We have mapped distant galaxies whose light took billions of years to reach our telescopes, observed the dissection of matter down to its fundamental particles and the nature of time itself at the smallest scales we can imagine — but the three pounds of tissue in which our minds apparently reside has proven one of the greatest challenges in all science.

For that today is an unprecedented moment in history. New technologies are enabling us to look inside the living brain as never before. They are drawing comprehensive maps of neural connections, building computers that think and even seeking ways to repair the brain if it gets damaged. And those breakthroughs aren’t just appearing in science fiction movies — they are real advances occurring inside laboratories all over the world at this very moment.

In this article, we extend the brain in better detail. From brain-computer interfaces that allow paralyzed people to walk again, to A.I. that can identify mental health problems before they begin, the emerging new field of brain tech — whether you hope for it or fear it — is promising no less than a revolution in medicine, technology and our understanding of what makes us human.

Brain Mapping Projects: Mapping the Most Complicated Organization in the Universe

Consider making a map of every street, highway and trail everywhere in the world along with tracking every car, bike and pedestrian moving on those pathways at any moment. That’s the idea behind what neuroscientists are trying to accomplish with brain mapping projects.

The Human Connectome Project

The Human Connectome Project is, without exaggeration, one of the most challenging efforts you can imagine. This global initiative to produce a detailed map of all connections between nerve cells in brain was initiated in 2009. Just think of it as making a “wiring diagram” that illustrates how various parts of the brain talk to one another.

Connections in more than 1,200 healthy adults have already been mapped by researchers. The researchers, using powerful MRI machines and cutting-edge computer algorithms, found that these brain networks are not random; rather they have a pattern. Some are “hubs,” like big airports that play middleman to a lot of cities. These hubs are essential for everything from memory to making decisions.

The BRAIN Initiative

The BRAIN Initiative (Brain Research through Advancing Innovative Neurotechnologies), initiated by the US government in 2013, is investing billions of dollars into new tools for brain studies. A big challenge will be to record the activity of thousands or even millions of neurons at once.

Among the recent innovations out of this project are microscopes to see neural activity in real time, genetic techniques to allow scientists to control specific neurons with light and a recording device the size of a grain of salt that can monitor brain activity wirelessly.

Table 1: Major Brain Mapping Projects

Brain-Computer Interfaces: When Minds and Machines Become One

Imagine if you could surf the internet with nothing more than your thoughts or communicate via email simply by thinking about it. In this futuristic situation BCI are turning sci-fi to reality.

How BCIs Actually Work

Brain-computer interfaces read electrical signals released by neurons when you imagine doing something. Special sensors — either positioned on your scalp or inserted directly into brain tissue — detect these signals. Computer algorithms subsequently interpret these patterns, converting them into commands for external devices.

The process happens incredibly fast. When you first think about moving your hand to the time it takes a robotic arm to respond, only a few hundred milliseconds elapse — roughly the length of time it takes for a blink.

Breakthrough Moments in Recent Years

In 2023, a man paralyzed from the neck down, Keith Thomas, was the first to be able to move and feel after being implanted with an in-brain computer chip coupled with nerve stimulation. Electrodes in his brain picked up his intentions to move and transmitted them into electrical commands designed for the muscles in his arm, bypassing completely his damaged spinal cord.

Another extraordinary case was a woman who had not been able to speak for 15 years, because she suffered from a stroke. Doctors at the University of California, San Francisco placed electrodes in her brain that read her attempts to talk. An avatar on a computer screen then uttered the words she was thinking — at the speed of about 80 words a minute.

Neuralink and Commercial BCIs

Companies like Elon Musk’s Neuralink are developing the technology making these impractical brain-computer interfaces available to more people. Neuralink’s implant has since been placed in its first human patient, who can now control a computer cursor and play some video games with his thoughts alone.

The system operates using wires finer than a human hair, each armed with many electrodes, that are inserted into precise locations of the brain. Neuralink’s device is wireless, in contrast to prior BCIs that had wired connections poking out of the users’ skulls and were prone to infections or other shortfalls.

Organoids in a Dish and Mini-Brains: The Reliance on Brain Tissue Grown in the Laboratory

Among the weirdest and most radical fronts in brain science is the effort to grow wee, simplified versions of human brains in laboratory dishes. These “brain organoids” are transforming our understanding of how the brain develops and what goes wrong in developmental disorders and disease.

What Are Brain Organoids?

Brain organoids begin with human stem cells — cells that, in principle, have the potential to develop into virtually any type of cell in the body. Researchers coax these stem cells to turn into brain cells and arrange themselves in three dimensions, in parts of the developing human brain.

These mini-brains, smaller than a pea, have no blood vessels, complex connectivity or consciousness. But they have many of the same cell types as a real brain and can develop for months or even years in special culture dishes.

Why Scientists Are Excited About Them

These brain organoids give researchers a model for studying human brain development without the ethical constraints of experimenting on real human brains. They are especially useful for learning about what can go wrong in conditions such as autism, schizophrenia and microcephaly (a condition in which babies are born with unusually small heads).

And researchers have linked brain organoids to spinal cord tissue and muscle cells, assembling a basic “body-brain-muscle” system in a dish. When the scientists stimulated the brain organoid with light, muscle cells contracted — an indication that even these simplified systems can command movement.

The Ethical Questions They Raise

With that complexity, brain organoids raise intriguing ethical questions. Is it possible for a brain organoid advanced enough to become conscious? Do we have cause to be concerned about these mini-brains causing pain? Most researchers think the current organoids are far below what would be necessary for even basic forms of consciousness, but as the technology improves, these questions will loom larger.

Artificial Intelligence Meets Natural Intelligence

The combination of artificial intelligence and brain science, for instance, is proving to be extremely potent. AI is helping scientists to decipher the brain data, and brain research is providing ideas for new AI architectures.

AI in Brain Research

Today’s brain imaging generates huge data files. A single brain scan produces hundreds of gigabytes of information — too much for humans to analyze manually. But an AI algorithm is good at spotting patterns in this data that human researchers might overlook.

Machine learning models can now predict Alzheimer’s disease years before symptoms appear by looking for subtle changes in brain scans. Other A.I. systems can find out which patients with depression will respond to certain treatments from their patterns of brain activity.

Brain-Inspired Artificial Intelligence

The connection works both ways. The human brain is still vastly more efficient than any computer we know. To accomplish feats that would typically require a supercomputer, your brain uses on the order of 20 watts of power, which is as much as two standard light bulbs.

This efficiency has spurred a new generation of “neuromorphic” computer chips that try to model the behavior of biological neurons when they process information. Rather than working as classical computers in serial fashion, the chips are based on large parallel processing networks that more closely resemble brain architecture. Corporations including Intel and IBM have also produced neuromorphic chips that are able to perform some AI tasks while consuming only a fraction as much energy.

Genetic Engineering and Brain Enhancement

For the first time in history, we have tools that let us edit not only the genetic code but also the genes themselves — including in the human brain. The technique, called CRISPR gene editing, has opened up a host of new possibilities for treating many other human diseases and even, perhaps, for enhancing an individual’s ability to learn.

Treating Genetic Brain Disorders

And a lot of conditions in the brain are genetic. Take something like Huntington’s disease, which is the result of a single mutated gene that kills off brain cells slowly. CRISPR technology could, in theory, correct this mutation to prevent the disease before it starts.

Clinical trials are already underway in patients to test gene therapy for some inherited forms of blindness and neurodegenerative diseases. Early results look promising, but the technology requires refinements before it will be a part of common practice.

• ✨ Want to know which discoveries changed our view of space forever? Check this out: 7 Discoveries That Changed Space Exploration Forever

The Enhancement Question

If we can correct a gene that causes disease, could we manipulate one to improve healthy brain function? Can we edit people’s genes to enhance memory, or to increase intelligence or creativity?

These are the questions that take us from medical to murky, ethical territory. Nearly all scientists and ethicists support treating serious diseases, although the specter of “enhancement” in neuroscience stirs fears about fair play as well as safety, values and what it is to be human. Then there’s the inconvenient fact that intelligence and creativity are the products of hundreds if not thousands of genes acting in complex, even chaotic, ways that we don’t fully understand.

Mental Health: Reading Feelings and Anticipating Problems

Mental health problems affect hundreds of millions of people around the world, and yet we still largely rely on talking to patients to diagnose them. New tools are starting to bring objective ways of measuring and monitoring mental health.

Biomarkers for Mental Health Conditions

Researchers are identifying “biomarkers” — quantifiable biological signs — linked to conditions like depression, anxiety and P.T.S.D. These are some of the unique patterns of brain activity, levels of certain chemicals in the blood and even voice patterns.

Some research groups have created smartphone apps that track typing speed, word choice and other behavior for signs of depression. Although such tools would raise thorny privacy issues, they could serve to flag people who need support before they reach a crisis point.

Brain Stimulation Therapies

When drugs and talk therapy don’t work for crushing depression, doctors now have a range of options. Transcranial magnetic stimulation (TMS) induces the excitation of specific regions of brain through application of a magnetic field. It’s non-invasive, has few side effects and offers relief to many patients for whom other therapies have provided no help.

Deep brain stimulation, where electrodes are surgically implanted, has been tested for treatment-resistant depression and obsessive-compulsive disorder. It is a little more invasive than TMS, but has brought stunning results to some patients.

The Quest to Understand Consciousness

But the single greatest mystery in all of neuroscience is consciousness itself. How does the brain generate subjective experiences — the perception of the color red, the sound of a musical tone, the sensation of pain or pangs of hunger? This is what scientists refer to as the “hard problem of consciousness.”

New Theories About Consciousness

Competing theories have no certainty to explain consciousness. According to Integrated Information Theory, consciousness results when a system does the work of information in an integrated fashion. According to Global Workspace Theory, consciousness is the result of information being “broadcast” among disparate brain regions.

Experiments are testing such hypotheses by recording brain activity in varying states of consciousness — wakefulness, sleep, anesthesia and coma. The objective is to find a “signature” of when consciousness can be assumed with great reliability.

Altered States and Psychedelic Research

Psychedelics such as psilocybin (the active ingredient in magic mushrooms) and LSD are back in legitimate research after decades of being banned. Brain scans of people on these drugs reveal that they transiently change the interaction statistics of the human brain, placing within reach some evidence about how normal consciousness functions.

Clinical trials are underway in the spiritual and scientific hopes of a use for psychedelic-assisted therapy to treat depression, PTSD and addiction. Early results have been dramatic — certain patients receive lasting benefits after just one or two guided sessions.

Learn more about consciousness research at the National Institutes of Health.

Challenges Standing in Our Way

While great strides have been achieved, major hurdles still exist in the exploration of the brain.

The Complexity Problem

The mass and intricacy of the organ exceeds our ability to grasp it. If you wanted to create a map of every synapse (a connection between neurons) in the human brain, for example, you’d need to record about 100 trillion connections. That data would take up about a zettabyte of computer memory, which is more or less the amount of digital information that exists on Earth today.

Ethical and Privacy Concerns

If the ability to read brains evolves, with it will come concerns about “neural privacy.” If you can read thoughts with a machine, who owns those thoughts? Might employers or governments one day require brain scans? How do we guard the last dark, fathomless, truly private domain of our lives — our minds?

The Funding Gap

Brain research is expensive. State-of-the-art brain scanners sell for millions of dollars. Human trials require years of work and massive amounts of money. And despite increased investment in brain research, it’s still much less than most other research.

What the Future Might Hold

In the decades to come, a few advancements appear imminent.

Personalized Brain Medicine

As cancer treatment is now increasingly personalized based on the genetic profile of a tumor, treatments for the brain might one day be tailored to the specific rhythm and connectivity patterns of an individual’s brain. Brain scans, together with genetic information, could assist doctors in determining which drug will work best for a given patient.

Memory Enhancement and Restoration

There is rapid progress in the field of memory research. Researchers have enhanced memory in mice, which may seem like a disadvantage but could eventually be part of therapy. There are already human trials for memory-enhancing devices going on in impairing memory patients. These devices monitor when the brain is making memories and provide an electrical jolt to strengthen this process.

Brain-to-Brain Communication

Primitive forms of brain-to-brain communication have already been demonstrated in laboratory experiments. In one such experiment, a person in India imagined moving their hand; brain-computer interface technology then sent this signal over the internet to the motor cortex of a person in France, which caused their hand to move.

Still primitive, this technology holds promise for brain-to-brain communication. Due to it still being early days in terms of B2B communication — and highly untested on human users so far — it is likely many years before anything resembling telepathic capabilities could ever be achieved.

Real-World Applications Already Happening

Some brain technologies are still experimental; others are already changing people’s lives.

Epilepsy Prediction Devices

Wearable devices can now detect and record the brain activity that signals an epileptic seizure, in time for a patient to take medication or move to a safe place. They have drastically increased quality of life for those with epilepsy.

Prosthetic Limbs with Sensation

Contemporary prosthetic arms can be guided by thought and transmit touch feedback to the brain. Users can feel what they’re touching and even how hard they are pressing — sensations that had long been out of reach with older prosthetic technology.

Virtual Reality Therapy

Virtual reality with brain monitoring is showing promising results when it comes to treating phobias, PTSD and even chronic pain. Patients can confront fears in controlled virtual settings, while therapists monitor the brain’s response and can tailor the experience.

Frequently Asked Questions

Are we close to being able to read minds?

Today’s technology can identify general thoughts — that you’re thinking of a face, say, or an object — but isn’t good at picking up specific detailed thoughts. We are decades or more from anything resembling the ability to read minds in detail, if ever. To read a particular thought, however, something close to the contents of an email or picture in your head would require knowing how brains store specific kinds of information and being able to compare that brain’s code with another person’s.

Are brain-computer interfaces safe?

Most non-invasive BCIs using sensors placed on the scalp are perfectly safe. Implanted devices do pose surgical risks, such as of infection or tissue injury, although those are in line with the medical complications associated with other implanted devices. It’s also unclear what long-term effects may result from having electrodes in the brain for years or decades, given how new the technology is.

Is it possible to download our brains into a computer?

Most neuroscientists think that’s either impossible or a very distant prospect. It is the structure or physicality of neurons, and not just the information they carry or process, that apparently makes consciousness supervene on biological substrates. And even if we could map every connection in a brain, there is no reason to assume that running a simulation of that brain would be conscious.

Will brain enhancement create inequality?

This is a major concern. If safe and effective brain enhancement technologies were to become accessible, well-off people might invest in them while others could not, potentially leading to cognitive inequality. Many ethicists contend that if such technologies are developed, society should guarantee equal access.

Do brain training apps really work?

Scientific support for most of the commercial apps is slim. You can get better at doing a particular task if you practice, but this improvement doesn’t necessarily make it easier to do other things. The best ways to protect brain health are old-fashioned: regular exercise, good sleep, social interaction, learning new things and a good diet.

What is the new brain technology we’re most excited about?

Many scientists point at so-called closed-loop brain devices — systems that continuously monitor and respond to brain activity in real time. These could be triggered automatically to detect and halt seizures, fine-tune deep brain stimulation according to existing symptoms or deliver a drug at just the time it is required. A few such devices are in clinical trials now.

The Path Forward: Hope and Responsibilities

The further we delve into the brain, though, the more we realize that we’re not studying just another organ of the body; rather, we are getting closer and closer to questions about what it means to be a human. Every thought you have, every memory you treasure, every decision you make and every emotion you feel comes from pools of electrical and chemical worker-bees in your brain.

I am talking about these technologies all curing horrendous brain diseases, giving back lost abilities and making us smarter. Someone paralyzed by injury could walk again. A person robbed of memories by Alzheimer’s might be able to retain their identity. Babies born with genetic defects of the brain could one day be treated with custom micro-doses targeted to their cells — doses that would be beyond minuscule today, but that could mean the difference between ending up in an institution and leading a relatively normal life.

Yet these awesome powers bring profound responsibilities. We need to think through the ethics of brain technologies while there is still time to prevent widely-accessible implementation. Questions of privacy, fairness, augmentation and what it means to be human demand thoughtful responses from scientists, ethicists, policymakers and society as a whole.

The next age of exploration for the brain isn’t just one of scientific achievement but of deciding what kind of future we want to live. As we attain an ever-increasing capacity to read, alter and even improve the human brain, we must go forth with ambition — but also with wisdom. The treasures of knowledge that await us are unimaginably vast, and yet how we use these discoveries will shape the future of our species for generations to come.

The journey to the brain, in essence, is a voyage into ourselves. And that adventure is only getting started.