There are two widely discussed proposals for how humans could combine brains and computers to prevent our death and extinction. One is uploading our brains into computers, and the other is merging our brains with computers. These proposals have been staples of science fiction and futurists for decades, but recently scientists and technologists have been taking them more seriously, and some people are working to make them a reality. In this chapter, I will explore these two proposals in light of what we have learned about brains.
Uploading your brain entails recording all the details of your brain, and then using them to simulate your brain on a computer. The simulator would be identical to your brain, so “you” would then live in the computer. The goal is to separate your mental and intellectual “you” from your biological body. This way, you can live indefinitely, including in a computer that is remote from Earth. You wouldn’t die if Earth became uninhabitable.
Merging your brain with a computer entails connecting the neurons in your brain to the silicon chips in a computer. This would, for example, allow you to access all the resources of the internet just by thinking. One goal of this is to give you superhuman powers. Another is to mitigate the negative effects of an intelligence explosion, which (as I discussed in Chapter 11) is if intelligent machines suddenly get so smart that we can’t control them, and then they kill or subjugate us. By merging our brains with computers, we also become superintelligent and are not left behind. We save ourselves by merging with the machines.
These ideas may strike you as ridiculous, outside the realm of possibility. But plenty of smart people take them seriously. It is easy to understand why they are appealing. Uploading your brain allows you to live forever, and merging your brain gives you superhuman abilities.
Will these proposals come to fruition, and will they mitigate the existential risks we face? I am not optimistic.
At times, I feel as if I am trapped in my body—as if my conscious intellect could exist in another form. Therefore, just because my body gets old and dies, why must “I” die? If I wasn’t stuck in a biological body, couldn’t I live forever?
Death is odd. On the one hand, our old brain is programmed to fear it, yet our bodies are programmed to die. Why would evolution make us fear the one thing that is most inevitable? Evolution settled on this conflicted strategy presumably for a good reason. My best guess is again based on the idea proposed by Richard Dawkins in his book The Selfish Gene. Dawkins argues that evolution is not about the survival of species, but about the survival of individual genes. From a gene’s perspective, we need to live long enough to have children—that is, to make copies of the gene. Living much longer than that, although good for an individual animal, might not be in the best interest of an individual gene. For example, you and I are a particular combination of genes. After we have children, it might be better from a gene’s perspective to make room for new combinations, new people. In a world with limited resources, it is better for a gene to exist in many different combinations with other genes, so that’s why we are programmed to die—to make room for other combinations—but only after we have had offspring. The implication of Dawkins’s theory is that we are unwitting servants to genes. Complex animals, such as ourselves, exist solely to help genes replicate. It is all about the gene.
Recently, something new has happened. Our species became intelligent. This of course helps us make more copies of our genes. Our intelligence lets us better avoid predators, find food, and live in varied ecosystems. But our emergent intelligence has had a consequence that is not necessarily in the best interest of genes. For the first time in the history of life on Earth, we understand what is going on. We have become enlightened. Our neocortex contains a model of evolution and a model of the universe and now it understands the truth underlying our existence. Because of our knowledge and intelligence, we can consider acting in ways that are not in the best interest of genes, such as using birth control or modifying genes that we don’t like.
I see the current human situation as a battle between two powerful forces. In one corner, we have genes and evolution, which have dominated life for billions of years. Genes don’t care about the survival of individuals. They don’t care about the survival of our society. Most don’t even care if our species goes extinct, because genes typically exist in multiple species. Genes only care about making copies of themselves. Of course, genes are just molecules and don’t “care” about anything. But it useful to refer to them in anthropomorphic terms.
In the other corner, competing with our genes, is our newly emerged intelligence. The mental “I” that exists in our brains wants to break free from its genetic servitude, to no longer be held captive by the Darwinian processes that got us all here. We, as intelligent individuals, want to live forever and to preserve our society. We want to escape from the evolutionary forces that created us.
Uploading the brain into a computer is one means of escape. It would allow us to avoid the messiness of biology and live forever as a computer-simulated version of our former self. I wouldn’t call brain uploading a mainstream idea, but it has been around for a long time and many people find it enticing.
Today, we don’t have the knowledge or technology needed to upload a brain, but could we in the future? From a theoretical point of view, I don’t see why not. However, it is so technically difficult that we may never be able to do it. But, regardless of whether it is technically feasible, I don’t think it would be satisfactory. That is, even if you could upload your brain into a computer, I don’t think you would like the result.
First let’s discuss the feasibility of uploading our brains. The basic idea is that we make a map of every neuron and every synapse and then recreate all of this structure in software. The computer then simulates your brain, and, when it does, it will feel like you. “You” will be alive, but “you” will be in a computer brain instead of your old biological brain.
How much of your brain do we need to upload in order to upload you? The neocortex is obviously needed because it is the organ of thought and intelligence. Many of our day-to-day memories are formed in the hippocampal complex, so we need that too. What about all the emotional centers of the old brain? What about the brain stem and spinal cord? Our computer body wouldn’t have lungs or a heart, so do we need to upload the parts of the brain that control them? Should we allow our uploaded brain to feel pain? You might think, “Of course not. We only want the good stuff!” But all the parts of our brain are interconnected in complex ways. If we didn’t include everything, then the uploaded brain would have serious problems. Recall how a person can feel debilitating pain in a phantom limb, pain that results from a single missing limb. If we upload the neocortex, then it would have representations of every part of your body. If the body wasn’t there, you might have severe pain everywhere. Similar problems would exist for every other part of the brain; if something is left out, then the other parts of the brain would be confused and not work properly. The fact is, if we want to upload you, and we want the uploaded brain to be normal, then we have to upload the entire brain, everything.
What about your body? You might think, “I don’t need a body. As long as I can think and discuss ideas with other people, I will be happy.” But your biological brain is designed to speak using your lungs and larynx, with their particular musculature, and your biological brain learned to see with your eyes, with their particular arrangement of photoreceptors. If your simulated brain is going to pick up thinking where your biological brain left off, then we need to recreate your eyes: eye muscles, retinas, etc. Of course, the uploaded brain doesn’t need a physical body or physical eyes—a simulation should be sufficient. But it means that we would have to simulate your particular body and sensory organs. The brain and body are intimately wired together and, in many ways, are a singular system. We can’t eliminate parts of the brain or parts of the body without seriously messing something up. None of this is a fundamental roadblock; it just means that it is far more difficult to upload you into a computer than most people imagine.
The next question we have to answer is how to “read” the details of your biological brain. How can we detect and measure everything in sufficient detail to recreate you in a computer? The human brain has about one hundred billion neurons and several hundred trillion synapses. Each neuron and synapse has a complex shape and internal structure. To recreate the brain in a computer, we have to take a snapshot that contains the location and structure of every neuron and every synapse. Today, we don’t have the technology to do this in a dead brain, let alone a living one. Just the volume of data required to represent a brain greatly exceeds the capacity of our current computer systems. Obtaining the details needed to recreate you in a computer is so difficult that we might never be able to do it.
But let’s put all these concerns aside. Let’s say that sometime in the future we have the ability to instantaneously read out everything we need to recreate you in a computer. Let’s assume we have computers with sufficient power to simulate you and your body. If we could do this, I have no doubts that the computer-based brain would be aware and conscious, just like you. But would you want this? Perhaps you are imagining one of the following scenarios.
You are at the end of your life. The doctor says you have just hours to live. At that moment, you flip a switch. Your mind goes blank. A few minutes later you wake up and find yourself living in a new computer-based body. Your memories are intact, you feel healthy again, and you begin your new eternal life. You shout, “Yay! I’m alive!”
Now imagine a slightly different scenario. Let’s say we have the technology to read out your biological brain without affecting it. Now when you flip the switch, your brain is copied to a computer, but you feel nothing. Moments later, the computer says, “Yay! I’m alive.” But you, the biological-you, are still here too. There are two of you now, one in a biological body and one in a computer body. The computer-you says, “Now that I’m uploaded, I don’t need my old body, so please dispose of it.” The biological-you says, “Wait a second. I’m still here, I don’t feel any different, and I don’t want to die.” What should we do about this?
Maybe the solution to this dilemma is just to let the biological-you live out the rest of its life and die of natural causes. That seems fair. However, until that happens, there are two of you. The biological-you and the computer-you have different experiences. So, as time progresses, they grow apart and develop into different people. For example, the biological-you and the computer-you might develop different moral and political positions. Biological-you might regret creating computer-you. Computer-you might dislike having some old bio person claiming to be it.
Making matters worse, there would likely be pressure to upload your brain early in your life. For example, imagine that the intellectual health of computer-you depends on the intellectual health of biological-you at the time of upload. Therefore, to maximize the quality of life of your immortal copy, you should upload your brain when you are at maximum mental health, say at age thirty-five. Another reason you might want to upload your brain early in life is that every day you live in a biological body is a day that you might die by accident, and therefore lose the opportunity for immortality. So, you decide to upload yourself at age thirty-five. Ask yourself, would you (biological-you) at thirty-five years old feel comfortable killing yourself after making a copy of your brain? Would you (biological-you) even feel that you had achieved immortality as your computer copy went off on its own life and you slowly aged and died? I don’t think so. “Uploading your brain” is a misleading phrase. What you have really done is split yourself into two people.
Now imagine that you upload your brain, and then the computer-you immediately makes three copies of itself. There are now four computer-yous and one biological-you. The five of you start having different experiences and drift apart. Each will be independently conscious. Have you become immortal? Which of the four computer-yous is your immortal you? As the biological-you slowly ages, moving toward death, it watches the four computer-yous go off to live their separate lives. There is no communal “you,” just five individuals. They may have started with the same brain and memories, but they immediately become separate beings and thereafter live separate lives.
Perhaps you have noticed that these scenarios are just like having children. The big difference, of course, is that you don’t upload your brain into your children’s heads at birth. In some ways we try to do this. We tell our children about their family history and we train them to share our ethics and beliefs. In that way, we transfer some of our knowledge into our children’s brains. But as they grow older, they have their own experiences and become separate people, just like an uploaded brain would do. Imagine if you could upload your brain into your children. Would you want to do it? If you did, I believe you would regret it. Your children would be saddled with memories of your past and would spend their lives trying to forget all the things you did.
Uploading your brain at first sounds like a great idea. Who wouldn’t want to live forever? But making a copy of ourselves by uploading our brain into a computer will not achieve immortality any more than having children will. Copying yourself is a fork in the road, not an extension of it. Two sentient beings continue after the fork, not one. Once you realize this, then the appeal of uploading your brain begins to fade.
An alternative to uploading your brain is to merge it with a computer. In this scenario, electrodes are placed in your brain that are then connected to a computer. Now your brain can directly receive information from the computer, and the computer can directly receive information from your brain.
There are good reasons to connect brains to computers. For example, spinal-cord injuries can leave people with little or no ability to move. By implanting electrodes into the injured person’s brain, the person can learn to control a robot arm or a computer mouse by thinking. Significant progress has already been achieved in this type of brain-controlled prosthetic, and it promises to improve the lives of many people. It does not take many connections from the brain to control a robot arm. For example, a few hundred or even a few dozen electrodes from the brain to a computer can be sufficient to control basic movements of a limb.
But some people dream of a deeper, more fully connected brain-machine interface, one where there are millions, perhaps billions, of connections going both ways. They hope this will give us amazing new abilities, such as accessing all the information on the internet as simply as we access our own memories. We could perform superfast calculations and data searches. We would thus radically enhance our mental abilities, merging brain with machine.
Similar to the “upload your brain” scenario, there are extreme technical challenges that have to be overcome to merge with a computer. These include how to implant millions of electrodes into a brain with minimal surgery, how to avoid rejection of the electrodes by our biological tissue, and how to reliably target millions of individual neurons. There are currently teams of engineers and scientists working on these problems. Once again, I don’t want to focus on the technical challenges as much as the motivations and results. So, let’s assume we can solve the technical problems. Why would we want to do this? Again, brain-computer interfaces make a lot of sense to help people with injuries. But why would we do this for healthy people?
As I mentioned, one prominent argument for merging your brain with a computer is to counter the threat of superintelligent AIs. Recall the intelligence explosion threat, where intelligent machines rapidly surpass us. I argued earlier that the intelligence explosion will not happen and is not an existential threat, but there are plenty of people who believe otherwise. They hope that by merging our brains with superintelligent computers, we would become superintelligent as well, and thus avoid being left behind. We are definitely entering science-fiction territory, but is it nonsense? I don’t dismiss the idea of brain-computer interfaces for brain enhancement. The basic science needs to be pursued to restore movement to the injured. Along the way, we might discover other uses of the resulting technology.
For example, imagine we develop a way to precisely stimulate millions of individual neurons in the neocortex. Perhaps we do this by labeling individual neurons with barcode-like DNA snippets introduced via a virus (this kind of technology exists today). Then we activate these neurons using radio waves that are addressed to an individual cell’s code (this technology does not exist, but it isn’t out of the realm of possibility). Now we have a way of precisely controlling millions of neurons without surgery or implants. This could be used to restore sight to someone whose eyes don’t function, or to create a new type of sensor, such as allowing someone to see using ultraviolet light. I doubt that we will ever completely merge our brain with a computer, but gaining new abilities is within the realm of likely advances.
In my opinion, the “uploading your brain” proposal offers few benefits and is so difficult that it is unlikely to ever happen. The “merging your brain with a computer” proposal will likely be achieved for limited purposes, but not to the point of fully uniting brain and machine. And a brain merged with a computer still has a biological brain and body that will decay and die.
Importantly, neither proposal addresses the existential risks facing humanity. If our species cannot live forever, are there things we can do today that would make our present existence meaningful, even when we are gone?