"Romantic reductionist" neuroscientist Christof Koch discusses the scientific side of consciousness, including the notion that all matter is, to varying degrees, sentient.MGM
If you had to list the hardest problems in science -- the questions even some scientists say are insoluble -- you would probably end up with two:
- Where do the laws of physics come from?
- How does the physical stuff in our brains produce conscious experience?
Even though philosophers have obsessed over the "mind-body problem" for centuries, the mystery of consciousness wasn't considered a proper scientific question until two or three decades ago. Then, a couple of things happened. Brain-imaging technologies finally gave neuroscience some high-powered tools to peer inside our brains while we think. And a few renowned scientists -- most famously, Francis Crick -- claimed that neuroscientists had to tackle consciousness if they were ever going to understand the brain.
By the 1980s, Crick had jumped from molecular biology to neuroscience and moved from England to California. There he found a brilliant young collaborator, Christof Koch, the son of German diplomats who'd recently landed a job as an assistant professor of biology and engineering at the California Institute of Technology. For the next 16 years -- until Crick's death in 1994 -- they worked together, searching for the neural correlates of consciousness.
Koch remains on the front lines of neurobiology. In fact, he will soon leave Caltech to work full-time as Chief Scientific Officer of the Allen Institute for Brain Science in Seattle. After years of publishing scientific papers, he has now written a trade book, Consciousness: Confessions of a Romantic Reductionist. Somewhere between memoir and popular science, the book offers a highly personal glimpse into the mind of an unconventional scientist: a lapsed Catholic who teamed up with the staunch atheist Crick, and the eminent neuroscientist who speculates about the consciousness of bees and squid and even bacteria. In the first of a two-part interview, we talked about the wiring of our brains and the possibility that the Internet itself may become conscious.
Why have you devoted so much of your life searching for the neural roots of consciousness?
Koch: Consciousness is the central factor of our lives. The only way I know I exist is because I'm conscious. I might be mistaken about who exactly I am -- for example, how attractive I am to the opposite sex -- but there's no doubt I have feelings of pain, pleasure, anger, of being a man, of waking up. Until recently, science has neglected to incorporate the fact of consciousness into its theories. If science wants a complete understanding of everything in the universe, it has to include consciousness.
What matters is not the stuff the brain is made of, but the relationship of that stuff to each other.
What makes consciousness such a difficult problem for scientists to explain?
Koch: Well, unlike black holes or the Higgs boson or molecules, consciousness has both an external perspective and an intrinsic perspective. In other words, you can weigh the Higgs boson and the molecule. You can poke them. You can measure them. Scientists and engineers are very good at doing that, but we don't think a black hole feels like anything. We don't believe the Higgs boson or a single nerve cell feels like anything. But a healthy human brain feels something if it's awake.
You actually see a world. How does this picture get into your head? That's the mystery. And because it has both an exterior, third-person perspective as well as an interior, first-person perspective, it's unique among all the phenomena in the universe. This means it's a little bit more difficult to attack using a scientific point of view. It doesn't mean it's impossible.
Or maybe a lot more difficult if we consider the complexity of the brain. How many neurons and synapses are in the human brain?
Koch: The average human brain has a hundred billion neurons and synapses on the order of a hundred trillion or so. But it's not just sheer numbers. It's the incredibly complex and specific ways in which these things are wired up. That's what makes it different from a gigantic sand dune, which might have a billion particles of sand, or from a galaxy. Our Milky Way, for example, contains a hundred billion suns, but the way these suns interact is very simple compared to the way neurons interact with each other.
So it doesn't matter so much what the neurons are made of. It's how they're organized and wired together.
Koch: Correct. Unless you believe in some magic substance attached to our brain that exudes consciousness, which certainly no scientist believes, then what matters is not the stuff the brain is made of, but the relationship of that stuff to each other. It's the fact that you have these neurons and they interact in very complicated ways. In principle, if you could replicate that interaction, let's say in silicon on a computer, you would get the same phenomena, including consciousness.
Are you saying the Internet could become conscious, or maybe already is conscious?
Koch: That's possible. It's a working hypothesis that comes out of artificial intelligence. It doesn't matter so much that you're made out of neurons and bones and muscles. Obviously, if we lose neurons in a stroke or in a degenerative disease like Alzheimer's, we lose consciousness. But in principle, what matters for consciousness is the fact that you have these incredibly complicated little machines, these little switching devices called nerve cells and synapses, and they're wired together in amazingly complicated ways. The Internet now already has a couple of billion nodes. Each node is a computer. Each one of these computers contains a couple of billion transistors, so it is in principle possible that the complexity of the Internet is such that it feels like something to be conscious. I mean, that's what it would be if the Internet as a whole has consciousness. Depending on the exact state of the transistors in the Internet, it might feel sad one day and happy another day, or whatever the equivalent is in Internet space.
You're serious about using these words? The Internet could feel sad or happy?
Koch: What I'm serious about is that the Internet, in principle, could have conscious states. Now, do these conscious states express happiness? Do they express pain? Pleasure? Anger? Red? Blue? That really depends on the exact kind of relationship between the transistors, the nodes, the computers. It's more difficult to ascertain what exactly it feels. But there's no question that in principle it could feel something.
Would humans recognize that certain parts of the Internet are conscious? Or is that beyond our understanding?
Koch: That's an excellent question. If we had a theory of consciousness, we could analyze it and say yes, this entity, this simulacrum, is conscious. Or because it displays independent behavior. At some point, suddenly it develops some autonomous behavior that nobody programmed into it, right? Then, people would go, "Whoa! What just happened here?" It just sort of self-organized in some really weird way. It wasn't a bug. It wasn't a virus. It wasn't a botnet that was paid for by some nefarious organization. It did it by itself. If this autonomous behavior happens on a regular basis, then I think many people would say, yeah, I guess it's alive in some sense, and it may have conscious sensation.
I think we need to back up for a moment. How do you define consciousness?
Koch: Typically, it means having subjective states. You see something. You hear something. You're aware of yourself. You're angry. You're sad. Those are all different conscious states. Now, that's not a very precise definition. But if you think historically, almost every scientific field has a working definition and the definitions are subject to change. For example, my Caltech colleague Michael Brown has redefined planets. So Pluto is not a planet anymore, right? Because astronomers got together and decided that. And what's a gene? A gene is very tricky to define. Over the last 50 years, people have had all sorts of changing definitions. Consciousness is not easy to define, but don't worry too much about the definition. Otherwise, you get trapped in endless discussions about what exactly you mean. It's much more important to have a working definition, run with it, do experiments, and then modify it as necessary.
Certain parts of the brain seem to have a much closer association with consciousness than others.
We assume humans are conscious, and most of us also think dogs and elephants and mice have some degree of consciousness, but what about other animals? Do lizards have consciousness? Are ants conscious? What about bacteria? Are these useful questions?
Koch: Not right now. In the fullness of time, they have to be answered. But right now, let's stick with cases that are undoubtedly conscious. That includes people, although not all people. You might remember Terri Schiavo. It was very controversial whether she was actually conscious or not. She was clearly alive, but because of anoxia and the damage sustained by her brain, she couldn't communicate with the outside world, and medical and scientific opinion held that she wasn't conscious. Yet she was moaning on occasion and making reflex-like movements. So there can be controversial cases even with people. What about a newborn infant? What about a fetus? Even there it's not totally clear. As you said, most people would agree that cats, dogs, mice and elephants are conscious, but what about non-mammals? So for now, let's just stick with some simple examples that we can actually work with in a clinic or a lab. Let's understand the neural basis of consciousness in them. In the fullness of time, we can then look at the squid and the octopus, which are very complex. Also bees, birds, worms. And in the future, we'll be able to answer a question like bacteria.