This blog post explores how brain-machine interface technology extends human capabilities and opens new evolutionary paths beyond natural selection. We examine the potential for technology to transform humans into cyborgs and its implications.
How wonderful would it be to effortlessly leap over giant leaves tens of meters high and easily befriend adorable animals through telepathic communication? While impossible for humans in reality, it’s entirely possible for the Na’vi in the movie “Avatar.” The Na’vi, inhabitants of the planet Pandora, are about twice the height of humans but possess extremely light bodies, allowing them to leap through the vast jungle with the flexibility and freedom of Tarzan. Furthermore, through an organ called the “Q” located at the back of their heads, they establish a neural connection with Pandora’s diverse animals, enabling emotional and sensory communion with them. The fact that they can directly feel the emotions of other beings is truly astonishing and mysterious.
So how did the Na’vi acquire this ability? Of course, as a race created in imagination, they might have special settings, but in the real world, all living things acquire abilities through the principle of natural selection. Natural selection is the core principle explaining how a population of organisms acquires and maintains new traits. If an individual gains a new trait through a random mutation, and that trait proves advantageous for survival, the offspring of that individual will survive better than the offspring of individuals without that trait. Over time, the entire population eventually shares that ability. This process is called natural selection because nature “selects” traits that are advantageous for survival.
However, a species has recently emerged that no longer strictly follows this principle of natural selection, instead directly designing its own capabilities. That species is Homo sapiens, humans. Humans were originally physically weak, struggling to lift objects heavier than their own weight. Yet, after the invention of the excavator, they gained the ability to easily lift and move heavy piles of earth. Following the advent of smartphones, we gained the ability to communicate instantly with people far away. These abilities are not the result of natural selection, but rather the outcome of “intelligent design” chosen and created by humans themselves. Historian Yuval Harari has even described this shift as the “end of Homo sapiens” as we knew it, following natural selection.
Of course, excavators and smartphones are merely external tools and cannot be considered part of the human biological body. However, this boundary is gradually breaking down due to the rapid advancement of Brain-Machine Interface (BMI) technology. BMI refers to technology that enables the exchange of information between the brain and machines. It encompasses two key aspects: technology that allows machines to read information from the brain and technology that transmits information from machines to the brain. So, how does this technology work, and how does it blur the boundary between humans and machines? Let’s examine its principles step by step.
The most widely used method for reading brain information is Electroencephalography (EEG), which measures the electrical signals generated by brain cells. The brain is a vast network of countless brain cells interconnected in complex ways. Every time we think, brain cells exchange electrical signals with each other, and this process also spreads electrical changes to the surrounding area. EEG detects these signals from outside the skin and analyzes their patterns to infer what a person is thinking.
If EEG could read human thoughts and transmit them to machines, people could use robotic arms and legs that move as naturally as their own bodies, without needing a joystick. A research team at the University of Houston successfully controlled the X1–Exoskeleton, a robotic leg that assists human muscle strength, using only thoughts. This technology opens the possibility for people paralyzed from the waist down due to accidents to walk again. Additionally, a Georgia Institute of Technology research team conducted an experiment providing a drummer with a “third arm” controllable by thought alone. As a result, the drummer was able to play music far more complex and rich than someone using only two hands.
To read thought processes far more complex than moving an arm, functional Magnetic Resonance Imaging (fMRI) is used. Just as we need oxygen to live, brain cells require oxygen to function. Red blood cells, which carry oxygen, respond differently to magnetic fields depending on how much oxygen they carry. This allows us to distinguish areas where brain cells are actively exchanging signals from those that are not. fMRI continuously records these responses to the magnetic field as a three-dimensional image, visually showing which parts of the brain are active.
Using fMRI, it is possible to determine what a person is thinking with a high degree of accuracy. Japan’s Institute for Computational Neuroscience conducted an experiment using fMRI to infer the content of dreams. The research team showed participants various images, such as human faces, beds, buildings, and cars, recorded their brain activity during this time with fMRI, and created a kind of “brain activity dictionary” by organizing the patterns of thought. Later, when they recorded fMRI data from sleeping subjects and compared it to this dictionary, they could predict what the person was dreaming about with up to 70% accuracy. In the future, robots might figure out on their own whether we want to carve an expensive steak or relax with a simple snack, without us having to explain it verbally.
Next, let’s examine technologies for delivering information to the brain. The most direct method involves connecting microelectrodes to neurons to deliver electrical stimulation. For example, the FDA-approved artificial eye “Argos 2” uses microelectrodes to stimulate optic nerve cells, providing sight to those who have lost it. Since optic nerve cells are a crucial pathway for transmitting visual information to the brain, converting camera-captured images into electrical signals and delivering them to these cells via electrodes allows the brain to interpret them as actual visual information.
A more non-invasive method is Transcranial Magnetic Stimulation (TMS). TMS is a technology that applies a strong magnetic field to specific brain regions for a brief moment, tricking brain cells into thinking they’ve received an electrical signal. This enables basic information transmission, such as inducing the perception of light or very subtle muscle movements. While it currently has limitations in conveying complex information, its effectiveness in stimulating various mental abilities—like treating depression, enhancing empathy, and recalling memories—has been confirmed. Therefore, it is anticipated that simple emotions or basic information could be transmitted in the future.
Now, imagine the possibilities that open up when we combine these two technologies—transmitting information from the brain to a machine and from a machine to the brain. First, it would become possible to transmit information directly from brain to brain without needing a smartphone as an intermediary. In fact, a research team at Harvard Medical School conducted an experiment where thoughts read via EEG were transmitted over the internet and then delivered to another person using TMS. This essentially means humans have gained abilities approaching telepathy. By the same principle, if it becomes possible to read emotions via fMRI and then transmit those emotions to others using TMS or other technologies, we could potentially develop a new form of empathetic ability, directly sensing each other’s emotions like the Na’vi on Pandora.
Furthermore, as brain-machine interface technology becomes more sophisticated, humans could potentially gain the ability to adjust their own behavioral patterns and even their values in desired directions. For instance, if someone harbors thoughts that could cause significant harm to society, or if destructive thoughts arise that the person themselves does not want, it becomes theoretically possible to design a machine that transmits negative emotions like guilt to the brain at that very moment. Through this, humans could potentially design their own desires, emotions, and values to some extent. Of course, such technology risks infringing on human free will and, if misused, could severely damage personality. Therefore, even if implemented, an extremely cautious approach is required.
All life on Earth has shaped its abilities over three billion years according to the principle of natural selection. This principle has never been deviated from once during that vast span of time. Yet, whether by nature’s mistake or as an exceptional event, humans are acquiring the ability to design their own capabilities as they desire. Humans can now mentally control legs capable of exerting far greater strength than their original muscles, have gained the ability to restore damaged vision, and have even opened the possibility of communicating with each other through thought alone. And in the not-too-distant future, we may possess the ability to share each other’s emotions and, furthermore, gradually adjust our own personalities. The rapid advancement of brain-machine interface technology clearly demonstrates that “we are now precariously poised on the very edge of becoming true cyborgs.”
