Interview With Consciousness Expert Prof. Christof Koch

Prof. Christof Koch is a neuroscientist known for his work on the neural bases of consciousness. He is the President and Chief Scientific Officer of the Allen Institute for Brain Science in Seattle. From 1986 until 2013, he was a professor at the California Institute of Technology. Koch has published extensively, and his writings and interests integrate theoretical, computational and experimental neuroscience. His most recent book, Consciousness: Confessions of a Romantic Reductionist, blends science and memoir to explore topics in discovering the roots of consciousness. Koch also authored the book The Quest for Consciousness: A Neurobiological Approach, which stems in part from a long-standing collaboration with the late Nobel Laureate Francis Crick. His research interests include elucidating the biophysical mechanisms underlying neural computation, understanding the mechanisms and purpose of visual attention, and uncovering the neural basis of consciousness and the subjective mind. 

The following has been paraphrased from an interview with Prof. Christof Koch on January 2nd, 2018.

(Click here for the full audio version)

How has Parkinson’s disease affected you and your family and does it have any influence on your work as a neuroscientist?

My Dad was diagnosed with Parkinson’s soon after he retired. He had it for the last 12 years of his life and towards the end it became quiet severe. While it haunted my interactions with him, it hasn’t really influenced my work, when he got this I was already deeply interested in consciousness.

Given your belief in the integrated information theory of consciousness, what affect do you believe neurodegenerative diseases have on a person’s consciousness given they erode the nodes in the integrated information system that is our brain? (Put simply, what affect does neurodegeneration have on consciousness?)

It depends on the type of pathology. But in general if you have a highly organized piece of active matter like the brain that gives rise to conscious experience, the connections between the nerve cells are critical for this process, once they start degenerating you will have a conscious experience that becomes more fragmented, less integrated and less cohesive and coherent. It is very difficult to talk generally about it, but it is clear that if you take a normal brain and start selectively moving around individual elements then the experience of that brain will be different and become more fragmented as you remove larger and larger fractions of it.

With something like Parkinson’s disease, one’s consciousness would be altered through two different processes. One is simply knowing you have a disease makes you experience the world differently. In addition brain diseases affect the apparatus itself that allows you to think about the world and which gives you consciousness. So you would have these two affects superimposed at the same time.

Many people with Parkinson’s disease claim that altered states of consciousness, whether it be through psychedelic drugs or simply sleep, has an affect on their symptoms. What role do you think consciousness might play on the symptoms of this disease?

My father in the later stages of the disease did have a range of additional deficits, like auditory and visual hallucinations, that could not be explained by the standard deficit in the basal ganglia associated with the disease and which made life for him very difficult.

There are other people who study the affects of consciousness on late stage dementia where towards the end consciousness really deteriorates to the point where people don’t even know who they are anymore. It’s not clear in the later stages of the disease to what extent they are still fully conscious.

What new technologies do you expect to be available within the next 5-10 years that will give us better models of the brain and better understand what is happening in live brains? 

Most of what we know about nerve cells comes from animals because we cannot record from intact human brains. However there are brain tumors where surgeons have to cut through not only the tumor but also the overlying cortex. In such cases we can take those tiny pieces that get cut and study them using a range of tools, which is something that we specialize in and make publicly available for anyone to study. In those cases we can look at intact nerve cells from a live brain and probe them with micro-electrodes, we can also image them and even take out RNA from individual nuclei and sequence them to see what genes are expressed in individual neurons.

Over the next 10 years we first need to distinguish between invasive and non-invasive techniques. We have some non-invasive techniques that allow us to look at bundles of about a million neurons, but to really study the brain and consciousness, as well as diseases, we have to get to individual neurons and that involves invasive brain surgery. Today there are probably about 100 people walking around that have chips implanted into their brains. Many of these people are impaired, either by a stroke or accident, and the chip enables us to read their intentions and then stimulate the muscles in their arm or guide a robot to do it for them.

In the far future do you see any technologies coming along that might allow us to map degeneration happening in a living person’s brain?

People are looking at a technology called neural dust for instance, tiny particles that you inject into the brain that could record electrical activity from tens of thousands of places. You can also possibly have some sort of organic technology that grows inside the brain and forms long-term connections which can then read and transmit signals to the outside. But those technologies are 15-25 years out. Though the defense department in America is trying to pioneer a bunch of technologies, one for example use ultrasound to try and stimulate the brain from the outside. Plus companies like Neuralink from Elon Musk are pushing these technologies forward but it is not going to happen as fast as we hope because of the barrier between the inside and outside of the brain.

One of the goals of the Allen Institute for Brain Science is to build a ‘periodic table for the brain’, when do you think the institution will complete this?

What we mean by that is we know that our brains consist of a lot of cells that are all very different, but we don’t have a complete list of all those cells. We do know for example that in the cortex there are a thousand different types of neurons that communicate, but specific neurons only talk to specific other types of neurons. We know that some diseases like schizophrenia are due to specific deficits of one type of neuron that should be talking to another type of neuron but instead are influencing the wrong cell type. It is critical to be able to list these different types of neurons, the genes expressed, and who they talk to. We should have that complete within the next 5 years for the mouse brain. It’ll probably take around a decade to do the same for humans.

When the BRAIN initiative was unveiled, many believed that it would do for the brain what the human genome project did for the genome. What do you think have been its most important findings so far and what are you most looking forward to coming out of it?

The Brain Initiative started under Obama, the Europeans also have a similar one and this year the Chinese will announce their own such project. It is really to push the study of neuroscience and to understand who we are because we are what our brains are, and to better understand diseases. It hasn’t produced any fundamental breakthroughs yet, but it has given us vastly better tools so we can study the brain in much greater detail than ever before. It has really pushed to the front the study of human brains rather than model organisms.

Moving to philosophy, you’ve stated your belief that, ‘panpsychism modified for the 21st century to be the single most elegant and parsimonious explanation for the universe I find myself in’. Have you given any thought to what experiments we could devise to test panpsychism?

First we need to step back. I’m interested in understanding consciousness. Some say it is an emergent property which means if you take a little brain it isn’t conscious but if you add more and more neurons to it will gradually get more and more conscious and consciousness will emerge. Of course it is not just the size of the brain, other animals have bigger brains than we do but it’s not clear that they have more consciousness than we do. It is also the ability to have feelings, it feels like something when I am sad or happy or in pain, which is radically different from the hardware, the brain. Yet it is the feeling of life, without consciousness there is nothing. It has been very difficult over the last 2500 years of Western philosophical thought in this question to understand how something like consciousness can emerge from physical matter.

Another approach is to just say that it is a fundamental and universal property of sufficiently complex systems. To me that seems very elegant because it doesn’t say that only these special types of things have consciousness. If I look at the brain of a mouse, it is a thousand times smaller than our brains, but its cells are similar, its genes are similar, the basic hardware is all the same. So the best inference is to say that since we all share this, there must be some aspect of consciousness too that we share. I don’t mean that a mouse runs around with an inner dialogue in its head, but certainly if you live with other animals you see that they seem happy and sad or even curious, many behaviors which we associate with being conscious.

So I have adopted this view called panpsychist, ‘pan’ meaning everywhere or universal and ‘psyche’ means soul. It indicates that many more systems around us are endowed with consciousness than we would like to believe. The question is what characteristics are needed to give rise to conscious experience, what is it about my brain that gives rise to consciousness and not for example my liver which is also complex. And it is also just pieces of the brain, we know that you can remove the cerebellum and you keep consciousness intact. Now that we have a theory, which I believe is Integrated Information Theory, we can begin to test it in rigorous ways to see if consciousness does extend far beyond the range that most people are comfortable with.

Do you believe there are higher realms of consciousness that humans can attain?

If we observe ourselves during the day we will notice that there are different levels of consciousness depending on how much sleep or coffee you have had. Also if you look at a human as it develops from a baby to an adult you can see that consciousness changes and becomes larger. You also go through all sorts of experiences and learn things that have an impact on your consciousness. Then as you get older and maybe you experience dementia the domain of your consciousness shrinks.

But I’m skeptical by the implication of ‘higher’. We have different forms of consciousness that are different from your day to day experience, like dreaming. If you take mescalin or LSD you can have these fantastic experiences where you have this sensation of time and you think you understand the universe but of course afterwards you have great difficulty explaining it. Is that higher or just a different form of consciousness? In the Tibetan Buddhist community they have what are called pure experiences where they can get into these meditative states where they are not conscious of anything in particular, they are not conscious of ego or self or memory or anything that makes them a person, but they are not asleep. For me this is just a state of consciousness without any content.

For me the fundamental distinction is that it feels like something to be conscious. If it is something you experience everyday then it feels familiar and it isn’t magical, we call higher consciousness those states which you experience rarely.

What impact do you see the coming advent of Artificial Intelligence having on our consciousness?

Well in the extreme case it could lead to the end of human consciousness, that’s the extinction scenario that some people are concerned about, which I think is not completely irrational.

It would be a momentous event in the history of our species if we can create artificial simulacrum of the human brain that will be increasingly more intelligent. But it is also important to distinguish artificial intelligence from artificial consciousness. There is no question that over time we will have machines like Siri that can carry on conversations like what you and I are having within the next 20 or 30 years.

The question is, will it feel like anything to be Siri and what influence will that have on us? I believe it will be profound. If it is true and it feels like something to be Siri than she has to have moral rights. That is how we define if something is an object or a subject. If I take a hammer to my Tesla my neighbor might think I am crazy, but it is a machine and I can destroy it if I want to. If I do the same thing with my dog the police will arrest me because we believe it feels like something to be a dog. If it is true that machines are not only intelligent but also conscious than that raises the question of rights for them. Sooner or later we will come to this point and have to face that question.

For more on the work of Christof Koch pick up a copy of Consciousness: Confessions of a Romantic Reductionist. You can also click here to go to his website, or here to read his writings for Scientific American. I would also highly recommend going to the Allen Brain Atlas website and playing around with some of the tools that he and his team are developing.


  1. (1) “But in general if you have a highly organized piece of active matter like the brain that gives rise to conscious experience,…” (2)“It is really to push the study of neuroscience and to understand who we are because we are what our brains are, and to better understand diseases.”

    It is clear that both of his statements have the same assumption that consciousness is created by the brain activities. There is no reason to believe that. It is a very common problem in all of science that does not know which one is the cause and which one is the effect. How do we know that consciousness does not create the brain activities? There are many results in nature that shows that consciousness, which is a property of a soul, and the soul is outside the brain.

Leave a Reply