Christof Koch is Chief Scientist of the Tiny Blue Dot Foundation, which funds neuroscience research on the spaces of possible conscious experiences. He was previously a professor at Caltech, and President and Chief Scientist of the Allen Institute for Brain Science.
Christof is the author of several books on neuroscience and consciousness including his most recent book, Then I Am Myself the World. He is known for his close collaborations with many well-known scientists and philosophers, among them Francis Crick - the co-discoverer of the structure of DNA.
We discuss:
Paradigm shifts in our understanding of consciousness
Psychedelic experiences and whether there is anything meaningful to be learned from them
What exotic experience might teach us about the relationship between consciousness and the brain
Whether conscious entities can be engineered or simulated, including whether consciousness might emerge in AI systems
New technologies for detecting and measuring levels of consciousness
The hard problem of consciousness
… and other topics
Watch on YouTube. Listen on Spotify, Apple Podcasts, or any other podcast platform. Read the full transcript here. Follow me on LinkedIn or Twitter/X for episodes and infrequent social commentary.
Episode links
Books:
Guest website: https://christofkoch.com/
Photo credit: Erik Dinnel @ Allen Institute
Timestamps
Timestamps for video episode:
00:00 Psychedelic experiences
15:30 David Chalmers & the Hard Problem
22:20 Neural Correlates of Consciousness (NCCs)
29:10 Integrated Information Theory (IIT)
36:20 Panpsychism
43:15 Paradigm shifts in theories of consciousness
48:30 LLMs & AIs - could they be conscious?
1:03:50 Technology for detecting consciousness
1:14:20 Death 1:19:30 Book recommendations
Intro - Consciousness, Comas, and AI
Discussions about consciousness often start with a philosophical question such as.
What is it like to be a bat?
But I want to introduce this conversation with a story. A real story, about a real person.
Several years ago, a young boy named Martin Pistorius developed a mysterious neurological illness. For no apparent reason, he started to lose control of his body, and his symptoms continued to worsen until he was unable to speak or move at all. By this point the doctors treating him assumed he was in a vegetative state, lacking any meaningful conscious experience. His heart was still beating, but the assumption was that the lights were off inside.
Martin’s body went on living in this seemingly vegetative state for years, completely immobile and unresponsive to the external world, like a body without a mind.
Many years passed, and one day, with no apparent cause, Martin began to awaken. Day-by-day he slowly regained motor control and started responding to external stimuli. Eventually he was able to communicate, and the world learned a tragic truth - that throughout the course of his coma, Martin had been fully conscious and aware, but unable to move.
Everyone had assumed that nobody was home, but in reality Martin was locked inside, fully aware of what was happening, a prisoner in an immobile body.
This is an example of a rare condition known as Locked In Syndrome (LIS) - when a patient in a coma is in fact aware and locked inside their own body. And there are plenty of strange conditions like this.
Patients with severe comas like this can often remain on external life support for years on end. On rare occasions, they might awaken from their comas and make partial or even full recoveries. But usually they don’t awaken, and eventually the life support is turned off.
How can we tell whether a person in a coma is conscious? Unfortunately, we don’t yet know how to answer this question.
Perhaps for most of them it is just void, and eventually turning off life support simply turns off the physical body with no implications for conscious experience. Perhaps in some cases these patients are experiencing deep, ongoing suffering. Perhaps others are locked into states of continual bliss. These questions do have definitive answers. But we don’t yet know what those answers are.
While the image of a young child with Locked In Syndrome certainly tugs at the emotions, the phenomenon itself is a relatively rare occurrence. But I’ve chosen to spend so much time on this topic not because of the importance of this ailment itself, but because it’s representative of a broader, deeply consequential issue that has challenged scientists and philosophers for generations.
It is the question of how we can know if another entity is conscious, and what we can know about the nature of its conscious experience. These are well-posed questions with definitive answers. Yet we’re currently unable to answer them.
These questions are more pressing today than ever before. Given recent advances in synthetic biology, we are now able to engineer new and exotic forms of life, but we have little idea of what it might feel like to be that life, or even what range of possible experiences might be available to these beings. What if these beings are suffering, and we don’t know it?
Similarly, in the field of artificial intelligence, we’re now developing AI systems with superhuman abilities across a vast range of domains. We don't yet know whether the systems we’re building might, at some point, become conscious, and what it would feel like to be those systems.
The idea that we might end up engineering thousands of deeply suffering beings is worth worrying about. It is something I worry about. And all this without even mentioning the vast amounts of suffering our species inflicts on non-human animals.
We need to take these questions seriously. At present, we have no rational basis for believing that consciousness is something confined to the realm of human minds, or mammals, or even biological systems more generally. Doing so would be an act of faith, and history has shown us that this type of anthropocentric thinking often leads us to misunderstanding.
The fact that we can’t even tell whether a human being in a coma is conscious should give us reason to pause. On the spectrum of questions I hope we’ll someday be able to answer about consciousness, and its relationship to the physical world, this would classify as a warm up.
And yet, we can’t answer it.
We still understand very little about this topic, and as long as that’s the case, my view is that it’s wise to approach these questions from a place of openness and humility.
This question is one of the main reasons that I’m speaking with Christof Koch today. Christof has made important contributions to our understanding of the brain basis of consciousness, and the question of what kinds of entities might be conscious, and what the nature of their experiences may be. This is an important topic for our times and one we’ll continue to explore on this podcast.
Christof Koch: Consciousness, Physics and Neurotechnology