Antonio Damasio has been working to solve the conundrum of consciousness almost since modern neuroscience first began to tackle the problem over three decades ago. In the early 1990s, the Italian neuroscientist was among the first to publish research suggesting that feelings such as hunger and pain might provide the foundations for consciousness, that familiar experience of being alive, awake, and self-aware in the world.
Today, Damasio has plenty of scientific company in his empirical approach to consciousness. But among consciousness researchers there are many prominent and conflicting theories of what consciousness is and how it functions, which differ significantly. Damasio belongs to the camp that believes that consciousness requires a body. Other theorists argue that all you need is sophisticated information processing architecture, which could exist without any kind of fleshy home.
Read More: “What’s So Hard About Understanding Consciousness?”
Damasio has written many books about his work and ideas over the years, starting with Descartes Error: Emotion, Reason, and the Human Brain, published in 1994. Now he has published another volume: Natural intelligence & the Logic of Consciousness. I spoke with Damasio about why he has more confidence in his theory concerning the biological imperative for consciousness now than ever, whether a robot body could develop AI consciousness, and how natural intelligence could explain someone like Donald Trump.
Has your account of consciousness—how it arises and what it is—changed since 2022, when we last spoke? This was right after you published your previous book Feeling and Knowing: Making Minds Conscious.
Yes. It has changed in terms of the clarity that I have over the mechanism. My idea that consciousness is very closely related to feelings has been there for quite a while, as you know. That is something about which I am clearly different from a lot of my colleagues in this field. Most of those colleagues tend to think of consciousness as a product of high-end intelligence and high-end creativity and high-end regions of the brain. I think it’s exactly the opposite. I think consciousness comes out of feelings that have to do with our body, with our life. That’s something in which I have been more and more clear, and more and more certain.
One ought to be cautious when uttering statements that are very solid, because you can always be proven wrong. But I’ve gained confidence that this is in fact correct and that consciousness emerges out of the humble process of life in organisms that have a brain and a nervous system, out of homeostatic feelings. Other people had the idea that it was really coming out of the cerebral cortex. I had a great friend in Francis Crick, whom I adored as a person and as a scientist enormously. I remember him telling me over and over again, “Antonio, consciousness is the most distinguished part of our behavior, of our capabilities. It has to come out of the most distinguished part of biology, which is the cerebral cortex.” This is an interesting statement, but you see, it’s wrong. On the contrary, there’s no reason why something that develops from the humble part of our system, from homeostatic feelings, will not end up producing the most refined product that we can imagine, which is our thinking.
What gives you more confidence in your theory about consciousness now?
The fact that we have investigated numerous cases of patients that had complete loss of consciousness and what was wrong in every single one of the patients was that they had damage to the brainstem as opposed to the cerebral cortex. If you damage the cerebral cortex enough, if you have very large lesions or several lesions in different systems, you will impair consciousness, no question about it. But you will not impair consciousness in the way that damage to the brainstem does. Damage to the brainstem eradicates consciousness once and forever. You’re not able to formulate consciousness at all. You can have a mind, but that mind does not belong to one body, does not belong to oneself, does not belong to one person. The damage to the brainstem is one of the critical points in the theory.
The brainstem is essential because it processes signals from the rest of the body?
Exactly. It’s interesting because you have the fine anatomy of the visual system or auditory system. You and I are using it beautifully right now. We both see each other. We both hear each other. That’s incredible. We have this ability to map the sounds we hear. We have the ability to map what we see. We have the ability to map tastes and touches. That’s incredibly sophisticated, and it really arose with the development of the cortex. But with feelings and with consciousness, what you have to do is to map out the state of your organism in terms of its current operation. And that, rather than going at cortical level from the eyes or the ears into the cerebral cortex, goes from all over the body. It enters the central nervous system through many channels, in some cases via the spinal cord, and others through a very interesting nerve called the vagus nerve, that goes out to the viscera—the heart, the lungs, the gut—and carries information straight to the brainstem.
Would you call what you’re describing a theory of consciousness?
Yes. What I’m describing is actually the factual data that supports the theory. The theory is the idea that the cerebral cortex gives you access to images of the world, whereas the brainstem and the interoceptive system gives you access to images of our interior. Our consciousness comes out of that imagery of our interior.
Scientists today are building humanoid robots today with AI minds. You mention in the book that if AI had a certain amount of vulnerability that perhaps it could develop consciousness. Is it possible that giving AI a body will make it vulnerable enough to result in consciousness?
Yes, it could develop consciousness, but not like our consciousness. It’s going to be different. When you think about AI devices, even very complex AI devices, they are not living. They don’t have a life like you and me have. You and me are susceptible to lots of attacks that would make our life impossible, such as, for example, hunger and thirst. But all of these creatures that were invented and are in the form of a robot, they don’t have any of those things. They have a mind that is artificial, that is really based on what our mind is, but in a simple form, designed by a computer. That computer is not at risk of dying, provided it has electricity. It will be there operating always the same way.
Even if it has a body?
Well, it is vulnerable. You can go to it and disconnect it, or you can go take an ax and destroy it. But we have a different kind of vulnerability. Our body has a birth, a growth and a continuation of adult life, and finally, a decline in death. We have this incredibly complex curvature that happens from the time of birth to the time of death. In our case, we have to be quite old, hopefully, before we die. But in a robot, you have on and off switches that are always going to work the same way.
Could a vulnerability to decay be programmed into a humanoid robot? I don’t know enough about how these robots work.
You know, it could, but nobody knows enough about robots. There are very different kinds with very different complexities. And the more complex they are, the more they can do interesting things. But if you turn off the energy, they can’t. And if you destroy them, they can’t either.
What is natural intelligence and what does it have to do with consciousness?
As you can imagine, this title for the book was very intentional. I wanted to make a very clear separation between human abilities, our enormous capacity to be intelligent about the world, to understand it and develop in it, and contrast that with artificial intelligence. There’s a very interesting relationship between what is natural and what is creative. We naturally intelligent individuals created artificial intelligence—and this is just to inject a little bit of sanity into the insanity of the attention given to artificial intelligence. No one seems to recognize that AI is a human invention.
You write that natural intelligence exists not just in humans but also in unicellular organisms like bacteria and in plants. But you argue that bacteria and plants don’t have consciousness because they really only sense, they don’t feel.
The process of life regulation is what we call homeostasis. It exists in any creature that is living, but the process of representing the state of your organism can only occur in organisms that have nervous systems. So at some point, very humble organisms became richer by having nervous systems that help regulate life. Bacteria are self-regulated without having a self. They don’t know what they’re doing. They’re just doing it. Everything humans do, we actually know that we are doing it, or we can know. Doesn’t mean that we do the right thing. That’s another story. But we know what we’re doing.
What is the simplest life form that can have consciousness?
I’m not going to name an animal, but the simplest life form is one that has a nervous system inside a body. Bacteria, for example, and tons of other unicellular organisms, don’t have nervous systems, and they don’t have consciousness. An organism that is devoid of a nervous system can operate in a satisfactory way, can survive, but it does not have information about its own body and that information is not relevant for what the organism is doing.
All mammals are conscious. All birds are conscious. Probably the majority of reptiles are conscious. Fish, yes. All of those creatures have very complicated nervous systems that are doing what our nervous systems are doing right now, which is informing us of our state of life. We also have a sense of our presence. We have a sense that we are living. We have a sense that our life animates one body instead of several. There’s that unity that consciousness gives us.
Why are unity, as well as what you call privacy, so important to consciousness?
We have one body as opposed to several, and that body is collecting information about itself and delivering information about itself to the brain. We get to know that we have a life because of the information that is coming from our organism into the central nervous system. For example, if right now you were deprived of oxygen, you would be in a state of great perturbation, and that would be due to the fact that your brainstem would have been detecting a lack of oxygen. That’s an alarm signal. That’s why, when you see people who are asphyxiated, they’re racing about and gasping for air. Because the lack of air, which is vital to the continuation of life, is detected by the brainstem, and the brainstem generates a response to agitate you in the hope that you find air.
Why do psychedelics seem to so easily dispel some of those feelings of unity and privacy and what can that tell us about the nature of consciousness? So many people seem to report feeling like they have more consciousness on psychedelics, when their sense of a united self dissolves, becoming plural.
That’s fine, but that’s not what we’re talking about. When you talk about psychedelics giving you a greater sense of consciousness, it can help illuminate some parts of your normal processing in relation to others that would otherwise not have been apparent to you. But that’s not consciousness, that’s just knowledge about the world. Consciousness is a very specific thing. Consciousness is about knowing that you are an individual.
One argument that you make in the book is that religion and politics and markets function as forms of homeostasis, but it seems so often that they do the opposite. The world is so divided right now. Why are these institutions and cultural forms failing at this homeostasis so spectacularly right now? Why is there so much hatred and chaos in the world?
I think what happens is that we have the possibility of creating very different interpretations of different kinds of behavior. I have a suspicion that you and I actually have very similar ways of interpreting the behavior of others. Depending on the maturity of our minds, we will regard some behaviors as admirable and other behaviors as not. And that has to do with our experience and with how we catalog the things that are around us as good or not. What’s very important here is the recognition that consciousness is what allows us to know who we are, where we are at a given moment. That’s consciousness. And it gives us this centrality. Consciousness is about being one individual, one person, good, bad, or indifferent. A conscious individual can be a very mean person or a very good person. Those are different things.
How does natural intelligence explain someone like Donald Trump?
I’m not quite sure that I understand what you mean. People have a certain set of values. I don’t think that we need biology to explain those people. They are organized mentally in a different way, and they have different goals.
Toward the end of the book, you say that understanding how consciousness works could help us find better ways of resolving our conflicts and maybe pull humanity back from the brink. How so?
You realize by having consciousness, not only of oneself, but of the others, that the things that are extremely similar in terms of suffering or in terms of the sense of triumph. It’s a way of discovering how others like us can think. That’s fundamental for our own salvation in the true sense of the term, because it allows us to understand other people. I understand right now what you are as a person within the limits of the fact that I’ve met you before, but you are the way you are, you’re smiling right now, you are very similar to me. And I can guess the way some of our mental processes are going. I know that those mental processes are different because you’re conscious and you’re not asleep, for example.
So the idea is that a better understanding of consciousness could make us more empathic towards others?
It certainly can. First of all, empathy is something natural in the individual, but how you cultivate it is up to you. We have all of this enormous rationality, this enormous ability to comprehend what we are and where we are. That’s how we know another person needs something. It’s how we determine that we care for that person and want to help. Or if you are a very different kind of person, you may say, “I don’t care for what people are.” But the caring or not caring can only happen and appear in your mind if you are conscious of who you are. If you’re not conscious, you won’t know if you are caring for others or if you are not caring for others. You know, consciousness is this ability to realize who we are in a given circumstance.
But it seems as though consciousness can lead to just as much destruction as empathy for others. If consciousness is about sensing yourself as an individual separate from others, that’s sort of the root of so much conflict as well, of tribalism, of hatreds.
Yeah, but it’s both. You realize who you are and if you are well educated and if you have been exposed to the right ideas and examples, you will try to behave in a way that’s compatible with those examples. But you would not be able to behave in a good way if you did not have consciousness of who you are and of who others are. You cannot say that it’s consciousness that leads you to behave badly towards people. You can say that consciousness empowers you to behave well or badly. It’s then up to you to have the moral choice. 
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