Consciousness is a thriving industry. It’s not just the meditation retreats and ayahuasca shamans. Or the conferences with a heady mix of philosophers, quantum physicists, and Buddhist monks. Consciousness is a buzzing business in neuroscience labs and brain institutes. But it wasn’t always this way. Just a few decades ago, consciousness barely registered as a credible subject for science.
Perhaps no one did more to legitimize its study than Francis Crick, who launched a second career in neurobiology after cracking the genetic code. In the 1980s Crick found a brilliant collaborator in the young scientist Christof Koch. In some ways, they made an unlikely team. Crick, a legend in science, was an outspoken atheist, while Koch, 40 years younger, was a Catholic yearning for ultimate meaning. Together, they published a series of pioneering articles on the neural correlates of consciousness until Crick died in 2004.
Koch went on to a distinguished career at Caltech before joining the Allen Institute for Brain Science in Seattle. Today, as the president and chief scientific officer, he supervises several hundred scientists, engineers, and informatics experts trying to map the brain and figure out how our neural circuits process information. The Institute recently made news with the discovery of three giant neurons connecting many regions of the mouse brain, including one that wraps around the entire brain. The neurons extend from a set of cells known as the claustrum, which Crick and Koch maintained could act as a seat of consciousness.
Koch is one of the great thinkers about consciousness. He has a philosophical frame of mind and jumps readily from one big idea to the next. He can talk about the tough ethical decisions regarding brain-impaired patients and also zoom out to give a quick history of Christian thinking on the soul. In our conversation, he ranged over a number of far-out ideas—from panpsychism and runaway artificial intelligence to the consciousness of bees and even bacteria.
You’ve said you always loved dogs. Did growing up with a dog lead to your fascination with consciousness?
I’ve wondered about dogs since early childhood. I grew up in a devout Roman Catholic family, and I asked my father and then my priest, “Why don’t dogs go to heaven?” That never made sense to me. They’re like us in certain ways. They don’t talk, but they obviously have strong emotions of love and fear, hate and excitement, of happiness. Why couldn’t they be resurrected at the end of time?
Are scientific attitudes about animal consciousness simplistic?
The fact is, I don’t even know that you’re conscious. The only thing I know beyond any doubt—and this is one of the central insights of Western philosophy—is Cogito ergo sum. What Descartes meant is the only thing I’m absolutely sure of is my own consciousness. I assume you’re conscious because your behavior is similar to mine, and I could see your brain if I put you in an MRI scanner. When you have a patient who’s locked-in, who can’t talk to me, I have to infer it. The same with animals. I can see they’re afraid when it’s appropriate to be afraid, and they display all the behavioral traits of being afraid, including the release of hormones in their bloodstream. If you look at a piece of dog brain or mouse brain and compare that to a piece of human brain the same size, only an expert with a microscope can tell for sure that this is a dog brain or a human brain. You really have to be an expert neuroanatomist.
We share much of our evolutionary history with dogs and even dolphins. But what about lizards or ants? What about bacteria? Can they be conscious?
It becomes progressively more difficult. The brain of a bird or a lizard has a very different evolutionary history, so it becomes more difficult to assert without having a general theory. Ultimately, you need a theory that tells us which physical systems can be conscious. By the time you get to a worm, let alone to bacteria, you can believe that it feels like something to be a worm because that’s ultimately what consciousness is. If it feels like something to be a worm, then it’s conscious. Right now, most people believe it doesn’t feel like anything to be my iPhone. Yet it may well be true that it feels like something to be a bee. But it’s not easy to test that assertion in a scientific way.
What do you mean when you say “it feels like something?”
It feels like something to be you. I can’t describe it to you if you’re a zombie. If you were born blind, I can never describe what it means to see colors. You are simply unable to comprehend that. So it is with consciousness. It’s impossible to describe it unless you have it. And we have these states of consciousness unless we are deeply asleep or anesthetized or in a coma. In fact, it’s impossible not to be conscious of something. Even if you wake up discombobulated in a dark hotel room, you’re jet-lagged and your eyes are still closed, you are already there. Before there was just nothing, nada, rien. Then slowly some of your brain boots up and you realize, “Oh, I’m here. I’m in Beijing and I flew in last night.” The difference between nothing and something is a base-level consciousness…