The brain is a small, three-pound jelly-like mass that we can hold in our hands. And yet, within this little blob, lies everything that makes the vast majority of our fauna who they truly are. It has birthed various inventions, such as the wheel and the hydraulic screw; made amazing discoveries, such as fire and electricity; and developed concepts, such as religion and algebra. It is what makes us pull our hand back when we touch a hot stove, smile at the sight of a loved one, comprehend the very meaning of space and time, and even think introspectively. From the ants scurrying on our windowsill to the tiger prowling in the Sunderbans, each and every higher animal possesses a brain in one form or another. Thus, it is difficult to imagine that, around 600 million years ago, the concept of electrical communication, let alone neurons and brains, was non-existent in life.
The First Nervous Systems
At first, life had not yet moved out of the ocean. The seabed was covered with sponges, which latched themselves onto the ocean floor and waited for edible detritus to float by and into their bodies, through which they constantly filtered water. They had the ability to constrict and inflate these channels to prevent them from clogging up. They did this by releasing chemical messengers such as glutamate, the most abundant neurotransmitter in the human brain, into the surrounding water, which were picked up by the other cells. However, this slow diffusion of chemicals meant it took the sponge many agonizing minutes to open or close these channels .
Then about 40 million years later, a new animal arose. Jellyfish, more precisely Cnidaria phylum, had the world’s first nervous system. Nature figured out that all cells generate a potential by pumping out ions across their membranes. Opening these ion gates can cause changes in potential, and by extension, an electric current. If nearby cells also detect this and open their own channels, this current can be conducted across the organism’s body at high speeds. However, these early nervous systems were nothing like ours: they did not have a centralized ‘brain’ or command center. Instead, the neurons were spread across the body in a net-like structure known as a ‘nerve net.’ When any neuron gets excited, a charge is conducted across the entire net, and the organism is able to react to the stimulus. For the first time, animals could actively move about, seek out prey, and avoid predators. Thus, the animals who had developed nerve nets gained an evolutionary advantage and proliferated.
The Rise of Centralisation - The True Brain Appears
Evolution sped up, and within 30 million years, the next big innovation arose. However, the original progenitor of this is highly debatable. Most scientists assume that it was the urbilaterian, a worm-like animal that is the ancestor of almost all modern vertebrates, molluscs, insects, and virtually all animals that are bilaterally symmetrical. The flatworm figured that the nervous system would be a lot more useful if it could actually process and store information instead of just receiving and reacting to it. Thus, the neurons arranged themselves into a sort of central command structure: a dense ball of nerves, which represented the first brain. Now, instead of a net, all neurons branched out from a single bundle of nerves. The evolution of the brain allowed the urbilaterian to not only relay electric messages, but actually process them and act in response. This new system quickly caught on, and pretty soon, everyone had to have this new “technology”.
As life progressed to land, ever-more complex organisms such as fish, amphibians, and even reptiles arose. Organs such as the heart, gills and later lungs, and the stomach began to populate bodies. And as the animals evolved, so did their brain, stretching and enlarging to accommodate for all the new functions it was equipped to perform.
Welcome to the World of the Living - The Social Brain
Then came the mammals, which arose around 225 million years ago. Compared to the old guard of the animal world, they were extremely complex. Yes, their hearts needed to beat, and they needed oxygen to survive, but suddenly, survival wasn’t life’s only purpose. Mammals developed emotions. The old reptilian brain was not equipped to handle these new emotions, so it accepted some outside help. It decided to limit itself to activities essential for survival, and for the new requirements of the mammalian world, a new part of the brain developed, creating a mammalian brain with two separate parts: the basal ganglia, inherited from the reptiles, and the limbic system.
The limbic system, also known as the paleomammalian brain, was concerned almost exclusively with emotions. It handled rivalry and love, decided who were friends and who were enemies, infused moments with appropriate emotions, and essentially brought some colour to a rather dull world.
I Think Therefore I am - The Rational Brain
As the years passed, mammals grew more and more complex, and one day, a new need presented itself. In the tree-dwelling mammals, which lived 80 million years ago, rational thinking developed. For the first time, alongside living and feeling, animals could engage in thinking. For this purpose, a new part of the brain was brought into play. Developing on top of the already present mammalian brain, a new layer called the neocortex formed. At this stage, it was very underdeveloped and rudimentary, but as mammalian life progressed, it became more complex and led to the intellectual development of animals.
Around 4 million years ago, hominids appeared. With the most highly developed neocortices in history, they quickly became the smartest animals around. They figured out tool-making, fire, clothing, and even complex group-forming strategies. The neocortex had granted them the power of rational thought, and they used it to the fullest. They could make their own little playground inside their head, where they could visualize complex thoughts, apply reason to real-life problems, and even think long-term!
As time passed, hominids developed language, writing, metalworking, printing, medicine, agriculture, and numerous other disciplines that made our lives easier and more comfortable. But where the brain came from isn’t that important today. What really matters is our destiny: where are we going?
Outsourcing - The Machines
Early on, humans had figured out that machines were the best way to produce something of value. Requiring less effort and performing better, machines opened up the floodgates to an abundance of resources, and at the same time, a supply of individuals free to dream, think, and innovate. But while we had given over the processing of everything to machines, there was one task humans still had to do themselves: information processing. Man had used his brain to decrease the strain on every body part except the brain itself. In 1940s, the first personal computers appeared. Suddenly, the scenario changed. Of course, computer were very useful as memory-enhancing machines. They could store multiple libraries’ worth of data while sitting in a corner of the room. But more importantly, they were processing machines that were able to take the strain we could not. Computers were able to do calculations in seconds, work with values, and generally act as our own little brain assistant.
In the 1990s, humans taught computers how to talk with each other: the Internet was born. The ability to communicate always speeds up development, and before we knew it, computer had become powerful multitasking beasts, the greatest asset to human civilization. If all of humanity could be considered a single organism, computers gave this organism a nervous system. For the first time, all the individual cells had the ability to communicate with each other at lightning speed. The development of all of civilization was boosted, and as we realized how useful our new friends were, we poured a vast amount of resources into upgrading them. Computers shrank from room-sized monstrosities to sleek laptops and the Internet was translated from clumsy bundles of wire to the air, suddenly swarming with radio waves.
Today, computers are powerful with programs that can even learn on their own. But even now, one critical ability remains unassisted: thinking. While computers can store and process information, they cannot use that information to lead to new information. Moreover, our human superorganism suffers from a critical disability: its nervous system is outside its body. It must use clumsy and lossy methods to transfer information to and from its nerves.
The Future - Brain Computer Interfaces
Computers shouldn’t become isolated centres of power, but rather, they should be utilized in tandem with human ability to correct the fallacies of human beings. Thus, the next step in BMIs, or brain-machine interfaces. When, instead of putting the computer in front of us, we put it inside us, the numbers change. Suddenly, even as our intellect has access to the vast computational power the machines offer, the computers have their abilities bolstered by our capacity for free thought . This meld will open the floodgates to new possibilities: we will be able to do complex and gigantic calculations, erstwhile entrusted to computers, inside our very head because like the basal ganglia, the limbic system, and the cortex, the computer will seamlessly integrate into our brain as its fourth layer. Instead of asking Alexa for the weather, the weather will automatically come to one when one thinks of it. One will be able to assimilate the machine.
And it doesn’t end here. If the computers are conjoined to one’s brain, so are its networks. Imagine being able to send thoughts and emotions to another person on the other side of the globe. Imagine chatting with someone, not on a computer monitor, but inside one’s head. Human creativity and intellect will explode, because we will, quite literally, be able to meld our minds into one large superbrain, holder of the thoughts, opinions, memories and experiences of each of its members. And as we all have heard, the whole is greater than the sum of its parts.
The best thing is security. Some may be thinking that if BMIs become reality, anyone could reach into one’s mind and pull out anything of his/her/its choosing. But just as the brain’s various parts have compartmentalized tasks, there is no reason why one wouldn't be able to control, through mere thought, what sort of information the BMI can access, and what sort it cannot. What’s stopping someone from even setting people-specific permissions?
Even medicine would be revolutionized, as doctors would be able to use instruments that would interface directly with the brain and pull out all the data, creating a 'log’ which could then be examined to easily uncover problems. Doctors thousands of miles away will be able to talk to their patients any time they wished to prescribe medicine or to give advice. The doctor-patient relationship would change drastically. In fact, what's there to stop someone from developing a diagnosis program that anyone could download into their brains, run, and then pass on the results to medical experts?
Instead of today's poor, lossy streaming formats, we could stream thoughts and experiences right into people's brains. Anybody interested in watching the stream would open it, and instantly, input from one’s sensory nerves would override someone else’s, and that individual would be able to see what one sees, hear what one hears, and even feel what one feels. Never before has there been such a powerful mode of transmission.
Think my vision of the future is implausible? In fact, Elon Musk had it first. Neuralink, founded by Musk in 2016, has made it its mission to develop BMIs for implantation into the human brain . One day, when we can assimilate machinery instead of simply use it, humanity will finally transcend its boundaries and enter a brave new world of previously unthought-of discovery, innovation and invention.
I am a 15 year old (as of 2018) student of DPS Megacity, Kolkata. I am studying in the science stream. My parents are both doctors, and they were instrumental in inculcating a love for biological systems within me. I was drawn to two sectors in specific: neuroscience and immunology. Within neuroscience itself, I would like to specialize in the evolution and plasticity of the brain, and at the other end of the spectrum, I would like to put my interest in computers to good use and work on the integration of the nervous system with computers and machines in general.