Conscious
Conscious: A Brief Guide to the Fundamental Mystery of the Mind
Annaka Harris
- The most basic definition of consciousness is that given by the philosopher Thomas Nagel in his famous essay “What Is It Like to Be a Bat?,” and it is how I use the word throughout this book. The essence of Nagel’s explanation runs as follows: An organism is conscious if there is something that it is like to be that organism.
- The philosopher Rebecca Goldstein paints a wonderfully clear and playful portrait of the mystery: Sure, consciousness is a matter of matter—what else could it be, since that’s what we are—but still, the fact that some hunks of matter have an inner life . . . is unlike any other properties of matter we have yet encountered, much less accounted for. The laws of matter in motion can produce this, all this? Suddenly, matter wakes up and takes in the world?
- Likewise, how does felt experience arise out of nonsentient matter? The Australian philosopher David Chalmers famously termed this the “hard problem” of consciousness.
- Why do certain configurations of matter cause that matter to light up with awareness?
- I like to begin this exploration with two questions that at first glance appear deceptively simple to answer. Note the responses that first occur to you, and keep them in mind as we explore some typical intuitions and illusions. In a system that we know has conscious experiences—the human brain—what evidence of consciousness can we detect from the outside? Is consciousness essential to our behavior?
- “People are conscious; plants are not conscious.” Most of us feel strongly that this statement is correct, and there are good scientific reasons for believing that it is. We assume that consciousness does not exist in the absence of a brain or a central nervous system.
- In his book, What a Plant Knows: A Field Guide to the Senses, Daniel Chamovitz describes in fascinating detail how the stimulation of a plant (by touch, light, heat, etc.) can cause reactions similar to those in animals under analogous conditions.
- If memory entails forming the memory (encoding information), retaining the memory (storing information), and recalling the memory (retrieving information), then plants definitely remember. For example a Venus Fly Trap needs to have two of the hairs on its leaves touched by a bug in order to shut, so it remembers that the first one has been touched. . . . Wheat seedlings remember that they’ve gone through winter before they start to flower and make seeds. And some stressed plants give rise to progeny that are more resistant to the same stress, a type of transgenerational memory that’s also been recently shown also in animals.
- Simard was studying the levels of carbon in two species of tree, the Douglas fir and the paper birch, when she discovered that the two species were engaged “in a lively two-way conversation.” In the summer months, when the fir needed more carbon, the birch sent more carbon to the fir; at other times when the fir was still growing but the birch needed more carbon because it was leafless, the fir sent more carbon to the birch—revealing that the two species were in fact interdependent. Equally
- Still, we can easily imagine plants exhibiting the behaviors described here without there being something it is like to be a plant, so complex behavior doesn’t necessarily shed light on whether a system is conscious or not.
- If we design an AI that one day begins saying things like, “Please stop—it hurts when you do that!” should we take this as evidence of consciousness, or simply of complex programming in which the lights are off?
- Suddenly, our reflexive answers to question 1—What constitutes evidence for consciousness?—are beginning to dissolve.
- And this leads us to question 2, regarding whether consciousness performs an essential function in—or has any effect at all on—the physical system that’s conscious.8 In theory, I could act in all the ways I do and say all the things I say without having a conscious experience of it, much as an advanced robot might
- Once we imagine human behavior around us existing without consciousness, that behavior begins to look more like many behaviors we see in the natural world that we’ve always assumed were nonconscious, such as the obstacle-avoiding behavior of a starfish, which has no central nervous system.
- In fact, one of the most startling findings in neuroscience has been that consciousness is often “the last to know.” Visual, auditory, and other kinds of sensory information move through the world (and our nervous system) at different rates. The light waves and sound waves emitted the moment the tennis ball makes contact with your racket, for example, do not arrive at your eyes and ears at the same time, and the impact felt by your hand holding the racket occurs at yet another interval.
- Only after all the relevant input has been received by the brain do the signals get synchronized and enter your conscious experience through a process called “binding”—whereby you see, hear, and feel the ball hit the racket all in the same instant.
- Your perception of reality is the end result of fancy editing tricks: the brain hides the difference in arrival times. How? What it serves up as reality is actually a delayed version. Your brain collects up all the information from the senses before it decides upon a story of what happens. . . . The strange consequence of all this is that you live in the past. By the time you think the moment occurs, it’s already long gone. To synchronize the incoming information from the senses, the cost is that our conscious awareness lags behind the physical world.
- We now have reason to believe that with access to certain activity inside your brain, another person can know what you’re going to do before you do.
- Our intuition that consciousness is behind certain behaviors is informed by our experience of freely making choices in the world, as our willed actions are inextricably linked to a sense of conscious control in the present moment.
- Consequently, findings about how decisions are made at the level of the brain—and the milliseconds of delay in our conscious awareness of sensory input and even of our own thoughts—have caused many neuroscientists, Gazzaniga included, to describe the feeling of conscious will as an illusion. Note that in such experiments, the subjects felt they were making a freely willed action that, in actuality, had already been set in motion before they felt they made the decision to move.
- So what role does consciousness play if it’s not creating the will to move but merely watching the movement play out, all the while under the illusion that it is involved?
- The brain, as a system, does have a type of free will, however—in that it makes decisions and choices on the basis of outside information, internal goals, and complex reasoning. But when I discuss the illusion of conscious will here, I’m speaking of the illusion that consciousness is the will itself.
- Many people, however, object on ethical grounds to the assertion that conscious will is an illusion, holding that people should be held responsible for their choices and behavior. But people can (and should) be held responsible for their actions, for a variety of reasons; the two beliefs are not necessarily contradictory. We can still acknowledge the difference between premeditated, lucid actions and the sort that are caused by mental illness or other disorders of the mind/brain.
- Even though we are talking about modifying a conscious experience, consciousness itself isn’t necessarily controlling the system; all we know is that consciousness is experiencing the system. It is no contradiction to say that consciousness is essential to ethical concerns, yet irrelevant when it comes to will.
- It seems clear that we can’t decide what to think or feel, any more than we can decide what to see or hear.
- A highly complicated convergence of factors and past events—including our genes, our personal life history, our immediate environment, and the state of our brain—is responsible for each next thought.
- There are also instances of bacterial infections causing behavioral changes in people, and scientists are continuing to discover links between infections and human psychological disorders.
- With so many behind-the-scenes forces at work—from the essential neurological processes we previously examined to bacterial infections and parasites—it’s hard to see how our behavior, preferences, and even choices could be under the control of our conscious will in any real sense. It seems much more accurate to say that consciousness is along for the ride—watching the show, rather than creating or controlling it. In theory, we can go as far as to say that few (if any) of our behaviors need consciousness in order to be carried out.
- This brings us back to our two questions. And, once again, it’s hard to see how conscious experience plays a role in behavior. That’s not to say it doesn’t, but it’s almost impossible to point to specific ways in which it does.
- When I contemplate “what it’s like” to be something, that experience of consciousness presumably affects the subsequent processing taking place in my brain. And almost nothing I think or say when contemplating consciousness would make any sense coming from a system without it. How could an unconscious robot (or a philosophical zombie) contemplate conscious experience itself without having it in the first place?
- we must reevaluate the assumptions we tend to make about the role consciousness plays in driving behavior, as these assumptions naturally lead to the conclusions we draw about what consciousness is and what causes it to arise in nature.
- When we talk about consciousness, we usually refer to a “self” that is the subject of everything we experience—all that we are aware of seems to be happening to or around this self. We have what feels like a unified experience, with events in the world unfolding to us in an integrated way. But, as we have seen, binding processes are partly responsible for this, presenting us with the illusion that physical occurrences are perfectly synchronized with our conscious experience of them in the present moment.
- Without binding processes, you might not even feel yourself to be a self at all. Your consciousness would be more like a flow of experiences in a particular location in space—which would be much closer to the truth.
- We can have a full awareness of the usual sights, sounds, feelings, and thoughts, absent the sense of being a self who is the receiver of the sounds and the thinker of the thoughts. This is not at all at odds with modern neuroscience: an area of the brain known as the default mode network, which scientists believe contributes to our sense of self, has been found to be suppressed during meditation.
- Interestingly, one of the reasons people who take psychedelics inhabit such altered states is that this class of drug can also interrupt binding processes. It seems likely that this, too, contributes to a suspension of the feeling of being a self, distinct and separate from the world. Pollan points out that “our sense of individuality and separateness hinges on a bounded self and a clear demarcation between subject and object. But all that may be a mental construction, a kind of illusion.”
- If the distinctness of the bodily self can be tampered with via such mechanical means [i.e., psychedelic drugs, a stroke, or a neurological disorder], then we must begin to accept that the bodily self—that feeling we are whole, inviolate beings—is not due to some special soul, or “I,” resident behind our eyes.
- The Buddhist scholar Andrew Olendzki describes the illusory nature of self that can be revealed through meditation: Like the flatness of the earth or the solidity of the table, it [the notion of self] has utility at a certain level of scale—socially, linguistically, legally—but thoroughly breaks down when examined with closer scrutiny.
- David Eagleman is involved in research that explores the possibilities of expanding our human umwelt to include information we don’t currently have access to through our five senses. He explains that the brain “doesn’t care how it gets the information, as long as it gets it.”11 At a 2015 TED conference, Eagleman described the potential future results of sensory substitution, whereby “new senses” are created for people: There’s really no end to the possibilities on the horizon for human expansion. Just imagine an astronaut being able to feel the overall health of the International Space Station, or, for that matter, having you feel the invisible states of your own health, like your blood sugar and the state of your microbiome, or having 360-degree vision or seeing in infrared or ultraviolet.
- The split-brain literature contains many examples suggesting that two conscious points of view can reside in a single brain. Most of them also topple the typical notion of free will, by exposing a phenomenon generated by the left hemisphere that Gazzaniga and his colleague Joseph LeDoux dubbed “the interpreter.”
- This phenomenon occurs when the right hemisphere takes action based on information it has access to that the left hemisphere doesn’t, and the left hemisphere then gives an instantaneous and false explanation for the split-brain subject’s behavior. For example, when the right hemisphere is given the instruction “Take a walk” in an experiment, the subject will stand up and begin walking. But when asked why he’s leaving the room, he will give an explanation such as, “Oh, I need to get a drink.”
- With the revelations brought to us through split-brain research and other advances in modern neuroscience, many have been led to the following question: Is there some version of split consciousness that occurs in brains that aren’t physically split? Are there other centers of consciousness, even what we might think of as other minds, residing closer to us than we think? Perhaps it’s not impossible to imagine that different “centers,” “configurations,” or “flows” of consciousness exist in close proximity to one another or overlap, even in a single human body.
- When we view our own experience of consciousness as being “along for the ride,” we suddenly find it easier to imagine that other systems are accompanied by consciousness as well. It’s at this point that we must consider the possibility that all matter is imbued with consciousness in some sense—a view referred to as panpsychism.1 If the various behaviors of animals can be accompanied by consciousness, why not the reaction of plants to light—or the spin of electrons, for that matter? Perhaps consciousness is embedded in matter itself, as a fundamental property of the universe.
- One branch of modern panpsychism proposes that consciousness is intrinsic to all forms of information processing, even inanimate forms such as technological devices; another goes so far as to suggest that consciousness stands alongside the other fundamental forces and fields that physics has revealed to us—like gravity, electromagnetism, and the strong and weak nuclear forces.
- Modern thinking about panpsychism is informed by the sciences and is fully aligned with physicalism and scientific reasoning.
- Once we realise that physics tells us nothing about the intrinsic nature of the entities it talks about, and indeed that the only thing we know for certain about the intrinsic nature of matter is that at least some material things have experience . . . the theoretical imperative to form as simple and unified a view as is consistent with the data leads us quite straightforwardly in the direction of panpsychism.
- Consider the Higgs field as an analogy: Physicists knew that the Higgs field had to exist—if it didn’t, the electrons and quarks that make up all of us would be massless and travel at the speed of light. For years before the discovery of its carrier, the Higgs boson, they posited a Higgs field. Although nothing about its confirmation supports (or provides any evidence for) theories about consciousness, it helps us understand the analogous proposition in panpsychism—that perhaps consciousness is another property of matter, or of the universe itself, that we have yet to discover.
- If consciousness were not present in matter, this would imply a theory of strong emergence that is fundamentally anti-scientific. Such emergence is “radically opposed to the spirit of science, which has always attempted to explain the complex in terms of the simple. . . . If the scientific point of view is correct, we shall ultimately find them [signs of consciousness in inert matter], at least in rudimentary form, all through the universe.”
- Additionally, when scientists assume they have bypassed the hard problem by describing consciousness as an emergent property—that is, a complex phenomenon not predicted by the constituent parts—they are changing the subject. All emergent phenomena—like ant colonies, snowflakes, and waves—are still descriptions of matter and how it behaves as witnessed from the outside.
- Calling consciousness an emergent phenomenon doesn’t actually explain anything, because to the observer, matter is behaving as it always does.
- Some philosophers go so far as to suggest that there isn’t a hard problem of consciousness at all, reducing consciousness to an illusion. But as others have pointed out, consciousness is the one thing that can’t be an illusion—by definition.
- Nevertheless, scientific considerations of panpsychism are still seen as controversial and are contrary to the conventional scientific view. While consciousness is notoriously difficult to study and even to define, most neuroscientists believe that it results from complex processes in the brain, and that we’ll eventually discover the ultimate cause of consciousness by studying its neural correlates.
- The neuroscientist V. S. Ramachandran, for example, has conceded that “qualia” (the experiential qualities of consciousness that we can label, such as what it’s like to see the color blue or feel something sharp) will remain a puzzle: Qualia are vexing to philosophers and scientists alike because even though they are palpably real and seem to lie at the very core of mental experience, physical and computational theories about brain function are utterly silent on the question of how they might arise or why they might exist.
- Neuroscientists who study consciousness are most interested in the differences at the level of the brain between seemingly conscious and unconscious functions of the body (you’re aware of reading the words on this page at this moment, but you’re not aware of the activities of your kidneys) and conscious and unconscious states (being awake versus being in deep sleep, for example).
- Francis Crick and Christof Koch among them, have even speculated that it is the frequency at which neurons fire that causes them to give rise to consciousness.
- They hoped to better understand which types of visual stimuli we process consciously (are aware of seeing), which stimuli the brain is responding to but we have no conscious awareness of (subliminal processing), and which areas of the brain are responsible for these different kinds of processing.
- While useful and interesting, this type of research is, once again, limited.
- Christof Koch is one neuroscientist who is willing to consider the panpsychic interpretation, telling an interviewer: If you take a more conceptual approach to consciousness, the evidence suggests there are many more systems that have consciousness—possibly all animals, all unicellular bacteria, and at some level maybe even individual cells that have an autonomous existence. We might be surrounded by consciousness everywhere and find it in places where we don’t expect it because our intuition says we’ll only see it in people and maybe monkeys and also dogs and cats. But we know our intuition is fallible, which is why we need science to tell us what the actual state of the universe is.
- In The Conscious Mind, David Chalmers suggests that consciousness could be manifested in the functioning of something as basic as a simple technological device: As we move along the scale from fish and slugs through simple neural networks all the way to thermostats, where should consciousness wink out? . . . The thermostat seems to realize the sort of information processing in a fish or a slug stripped down to its simplest form, so perhaps it might also have the corresponding sort of phenomenology in its most stripped-down form. It makes one or two relevant distinctions on which action depends; to me, at least, it does not seem unreasonable that there might be associated distinctions in experience.
- How can consciousness increase the likelihood of survival if it doesn’t affect our behavior in the typical sense?
- But while I’m not convinced that panpsychism offers the correct answer, I am convinced that it is a valid category of possible solutions that cannot be as easily dismissed as many people seem to think. Unfortunately, it remains difficult for scientists to join the conversation without fear of jeopardizing their credibility.
- implausible,” with its adherents likened to “religious fanatics.”21 Those of us who want to push this conversation forward have an important obligation to clearly distinguish panpsychic views from the false conclusions people tend to draw from them—namely, that panpsychism somehow justifies or explains a variety of psychic phenomena—following from the incorrect assumption that consciousness must entail a mind with a single point of view and complex thoughts.
- Ascribing some level of consciousness to plants or inanimate matter is not the same as ascribing to them human minds with wishes and intentions like our own.
- Bacteria with some minimal level of consciousness streaming through their atoms would still be bacteria. They would still lack brains and complex minds, much less human ones.
- In actuality, if a version of panpsychism is correct, everything will still appear to us and behave exactly as it already does.
- Most people who have had sufficient training in meditation realize that an experience of consciousness needn’t be accompanied by thoughts—or any input to the senses, for that matter. It seems possible to be acutely aware of one’s subjective experience in the absence of thought, sights, sounds, or any other perception.
- Rebecca Goldstein makes the case that we in fact already know that consciousness is integral to matter because we are made of matter ourselves, and it is the one property we have direct access to: Consciousness is an intrinsic property of matter; indeed, it’s the only intrinsic property of matter that we know, for we know it directly, by ourselves being material conscious things. All of the other properties of matter have been discovered by way of mathematical physics, and this mathematical method of getting at the properties of matter means that only relational properties of matter are known, not intrinsic properties.
- Though many people wonder: If the most basic constituents of matter have some level of conscious experience, how could it be that when they form a more complex physical object or system, those smaller points of consciousness combine to create a new, more complex sphere of consciousness? For instance, if all the individual atoms and cells in my brain are conscious, how do those separate spheres of consciousness merge to form the consciousness “I’m” experiencing? What’s more, do all the smaller, individual points of consciousness cease to exist after giving birth to an entirely new point of consciousness? This is referred to as “the combination problem,”
- For many scientists and philosophers, the combination problem presents the biggest obstacle to accepting any description of reality that includes consciousness as a widespread feature. However, the obstacle we face here once again seems to be a case of confusing consciousness with the concept of a self, as philosophers and scientists tend to speak in terms of a “subject” of consciousness.
- But perhaps it’s wrong to talk about a subject of consciousness, and it’s more accurate to instead talk about the content available to conscious experience at any given location in space-time, determined by the matter present there—umwelts applied not just to organisms, but to all matter, in every configuration and at every point in space-time.
- Since it seems as though the mind and the contents of consciousness can be divided in a split-brain patient, would two brains wired together produce a new, integrated mind? If Christof and I had our brains wired together, for instance, would it create a new Christof-Annaka consciousness—a new single point of view? Would a new mind be produced, with access to all the content that had previously been experienced separately by our brains—all our thoughts, memories, fears, abilities, and so forth—constituting a new “person”?
- In the instance of connecting two brains, we might simply have an example of consciousness changing its content or character—in the same way that the content of your consciousness changes when you close and open your eyes: the trees and sky are available to your field of view and then they’re not. When you dream, you experience environments quite different from your actual surroundings, maybe even feeling yourself to be a different person altogether.
- But we know that the idea of the self, as a concrete entity, is an illusion. It’s admittedly a very tough illusion to relinquish, but I think the solution to the combination problem is that there is really no “combining” going on at all with respect to consciousness itself.
- Maybe content is sometimes shared across large, intricately connected regions and sometimes confined to very small ones, perhaps even overlapping.
- That’s what molecules do in that configuration, and this is what they do in this configuration. Likewise, that’s what molecules feel like in that configuration, and this is what they feel like in this configuration.” We are again led back to a view of primary concepts: consciousness and content.
- First, although I’m defending panpsychism as a legitimate category of theories about consciousness based on what we currently know, I am not closed to the possibility that we might discover, by some future scientific method, that consciousness does in fact exist only in brains.
- Nor am I discounting the possibility that consciousness is something we will never fully grasp. Rebecca Goldstein is likely right when she suggests that the mystery of consciousness is impervious to scientific methods: It is somewhat depressing to think of an absolute limit on our science: to know that there are things we can never know. . . . Mathematical physics has yielded knowledge of so many of the properties of matter. However, the fact that we material objects have experiences should convince us that it cannot, alas, yield knowledge of them all. Unless a new Galileo appears, who offers us a way of getting at properties of matter that need not be mathematically expressible, we will never make any scientific progress on the hard problem of consciousness.
- Understanding whether or not advanced AI is conscious is as important as any other moral question. You have an ethical obligation to call an ambulance if you find your neighbor critically injured, and you would suddenly have similar obligations toward artificially intelligent beings if you knew they were conscious.
- Additionally, it seems probable that only complex minds are capable of great happiness and great suffering. In that case, even if a version of panpsychism were true, not all islands of consciousness would be equal, or equally important to understand.
- Many neuroscientists have considered the possibility that the feeling we have of being in the present moment, with time continuously moving in one direction, is an illusion. In his book Your Brain Is a Time Machine, Dean Buonomano, a UCLA neuroscientist, explains that whether the flow of time is an illusion or a true insight into the nature of reality depends in part on which of these two opposing views in physics turns out to be correct: Presentism: Time is in fact flowing and only the present moment is “real”; or Eternalism: We live in a “block universe,” where time is more like space—just because you are in one location (or moment) doesn’t mean the others don’t exist simultaneously.
- Wheeler also proposed a related thought experiment in which he imagined measuring a single photon from the light emitted by a quasar billions of light-years away passing by a black hole on its way to a telescope on Earth. Just as in the double-slit experiment, the light would be split by the gravitational effect of the black hole, causing the phenomenon known as gravitational lensing—an optical illusion in which we see multiple images of a single source, such as a quasar. In an interview with the author Rob Reid, Donald Hoffman, a cognitive scientist at the University of California, Irvine, explains what would happen if we measured a single photon in Wheeler’s cosmological thought experiment: You can now ask, for each photon that comes to me, whether it came from the left [or the right] side of the gravitational lens. [Let’s say] I decide to measure which side it came from, and I find out that it went on the left side. That means I can say that for the last ten billion years, that photon has been on a path that started from the quasar and went around the left side of the gravitational lens. But if, instead, I had chosen not to make that measurement and just measure the interference pattern, it would not be true that for the last ten billion years that photon had gone [down a path] around the left side. So the choice I make today determines the ten-billion-year-history of that photon.
- In addition to the already incomprehensible facts that Wheeler’s experiment reveals about light, if consciousness is in fact somehow intrinsic to matter, his experiment also suggests a very strange and counterintuitive relationship between consciousness and time.
- We have seen that through different processes the brain binds information that arrives at our sense receptors at different times and delivers it to us as a neat, present-moment package.
- From our current vantage point, it seems unlikely that we will ever arrive at a true understanding of consciousness. However, we may well be wrong about the absolute boundaries of knowledge. Humanity is young, and we’ve barely begun to understand our place in the cosmos. As we continue to look out from our planet and contemplate the nature of reality, we should remember that there is a mystery right here where we stand.