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How the Mind Works
In this William James Book Prize Lecture, presented to the Annual Meeting of the American Psychological Association, August 1999, Steven Pinker, Department of Brain and Cognitive Sciences, MIT, attempts to describe how the mind works, using three key ideas: computation, evolution, and specialization.
Originally presented as a lecture August 1999. Published on KurzweilAI.net February 22, 2001.
The human mind is a remarkable organ. It has allowed us to walk on the moon, to discover the physical basis of life and the universe, and to play chess almost as well as a computer. But the mind presents us with a paradox. On the one hand, many everyday tasks that we take for granted--walking around a room, picking up an object, recognizing a face, remembering information-are feats that scientists and engineers have been unable to duplicate in robots and computers. Nonetheless, these feats can be accomplished by any four-year-old, and we tend to be blasé about them.
On the other hand, for all its engineering excellence, the mind has many apparent quirks. For example, why is the thought of eating worms disgusting when worms are perfectly safe and nutritious? Why do men do insane things like challenge each other to duels and murder their ex-wives? Why do people believe in ghosts and spirits? Why do fools fall in love?
How the Mind Works is an attempt to answer those kinds of questions, using three key ideas: computation, evolution, and specialization.
The first idea, computation, is meant to explain how intelligence is possible in a physical system. But what is intelligence? Few people today are satisfied with the traditional psychologist's definition, "whatever it is that IQ tests measure." A better definition comes from William James himself, who tried to put his finger on the difference between intelligent behavior and superficially similar behavior that we would not ascribe to intelligence:
Romeo wants Juliet as the filings want the magnet; and if no obstacles intervene he moves toward her by as straight a line as they. But Romeo and Juliet, if a wall be built between them, do not remain idiotically pressing their faces against the opposite sides like the magnet and filings with the card. Romeo soon finds a circuitous way, by scaling the wall or otherwise, of touching Juliet's lips directly. With the filings the path is fixed; whether it reaches the end depends on accidents. With the lover it is the end which is fixed; the path may be modified indefinitely."
James identifies intelligence, then, with the pursuit of goals by means of inference, or the satisfaction of desires by beliefs about how the world works.
It is not just Romeo's behavior that we need to explain by invoking beliefs and desires, but virtually all human behavior. If I were to ask you, "Why did Bill just get on the bus?," to answer that question you wouldn't run a neural network simulation, and you wouldn't need to put Bill's head in a brain scanner. You could just ask him, and you might discover that the explanation for his behavior is that he wants to visit his grandmother, and he knows that the bus will take him to his grandmother's house. No science of the future is likely to provide an explanation with greater predictive power than that. If Bill hated the sight of his grand- mother, or if he knew the route had changed, his body would not be on that bus.
But this excellent theory raises a puzzle. The beliefs and desires that cause Romeo's behavior, or Bill's behavior, are colorless, odorless, tasteless, and weightless. Nevertheless, they are as potent a cause of action as any billiard ball clacking into another billiard ball.
How do we explain this seeming paradox? The solution, I believe, is that beliefs and desires are information. Information is another commodity that is colorless, odorless, tasteless, and weightless yet can have physical effects without resorting to any occult or mysterious process. Information consists of patterns in matter or energy, namely symbols, that correlate with states of the world. That's what we mean when we say that something carries information. A second part of the solution is that beliefs and desires have their effects in computation--where computation is defined, roughly, as a process that takes place when a device is arranged so that information (namely, patterns in matter or energy inside the device) causes changes in the patterns of other bits of matter or energy, and the process mirrors the laws of logic, probability, or cause and effect in the world. The result is that if the old patterns are accurate or true, or correlate with some aspect of reality, the new arrangements of matter or energy will as well. The cascade gives the device an ability to deduce new truths from old truths in pursuit of a goal, which comes pretty close to William James' characterization of intelligence.
This idea, the computational theory of mind, is the only theory that I know of that can explain how it is that patterns of physical change in a device--be it a computer or a brain, or, for that matter, some extraterrestrial intelligent life--might accomplish something we would dignify with the term "thinking." It's the only explanation we have for how physical changes actually do something we would be willing to call intelligent.
A few comments must be added to this claim. One is that the computational theory of mind is very different from the computer metaphor of the mind.. There are many ways in which commercially available computers are radically different from brains. Computers are serial; brains are parallel. Computers are fast; brains are slow. Computers have deterministic components; brains have noisy components. Computers are assembled by an external agent; brains have to assemble themselves. Computers display screen-savers with flying toasters; brains do not.
The claim is not that commercially available computers are a good model for the brain. Rather, the claim is that the answer to the question "What makes brains intelligent?" may overlap with the question "What makes computers intelligent?" The common feature, I suggest, is information-processing, or computation. An analogy is that when we want to understand how birds fly, we invoke principles of aerodynamics that also apply to airplanes. But that doesn't mean that we are committed to an airplane metaphor for birds and should ask whether birds have complimentary beverage service. It's a question of isolating the key component of the best explanation.
Another comment is that the computational theory of mind, explicitly or not, has set the agenda for brain science for decades. An old example from introductory neuroscience classes describes the naive person who asks, "Since the image on the retina is upside-down but we see the world right-side up, is there some part of the brain that turns the image right-side up?" We all realize that this question rests on a fallacy, that there is no such process in the brain, and that there doesn't need to be any such process. Why is it a fallacy? Because the orientation of the image on the retina makes no difference to how the brain processes information. Since information-processing is the relevant aspect of what goes on in the brain, the orientation on the retina--and, for that matter, on the visual cortex--is irrelevant; that is why the above is a pseudoquestion.
Similarly, the search for the neural basis of psychological functions is guided, from beginning to end, by invoking information-processing. One of the great frontiers of science is the search for the molecular basis of learning and memory. Well, of the hundreds or thousands of metabolic processes in the brain, how will we know when we've identified the one that corresponds to memory? We will know we have it when the process meets the requirements of the storage and retrieval of information. So again, it is information that sets the interesting questions in neuroscience.
A third comment is that the computational theory of mind is a radical challenge to our everyday way of thinking about the mind, because the theory says that the life-blood of thought is information. That goes against our folk notion that the lifeblood of thought is energy or pressure. Why did the disgruntled postal worker shoot up the post office? Well, for many years, we say, pressure had been building up until he finally burst; if only he had had an alternative outlet to which to divert all of that energy, he could have released it in more constructive ways. The metaphor is that thought and emotion are animated by some superheated fluid or gas under pressure. Now, there is no doubt that this hydraulic metaphor captures something about our experience. But we know that it is not literally how the brain works: there is no container full of fluid and channels through which the fluid flows. And that raises an important scientific question: Why is the brain going to so much trouble to simulate energy and pressure, given that it doesn't literally work that way? I will return to that question later.
Let me continue with the second key idea: evolution. How do we understand a complex device? Imagine that you are rummaging through an antique store and you come across a contraption bristling with gears and springs and a handle and hinges and blades. You have no idea how to explain it until someone tells you what it's for--say, an olive--pitter. Once you realize what the device is for--what its function is--suddenly all the parts and their arrangements become clear in a satisfying rush of insight. This is an activity called "reverse engineering." In forward engineering, you start off with an idea for what you want a device to do and you go and build the device. In reverse engineering, you stumble across a device and try to figure out what it was designed to do. Reverse engineering is what the technicians at Panasonic do when Sony comes out with a new product. They go to the store, buy one, bring it back to the lab, take a screwdriver to it, and try to figure out what all the little widgets and gizmos are for.
For the last few hundred years, the science of physiology has been a kind of reverse engineering. Living bodies are complex devices and pose questions like "Why, in the eye, do we find the most transparent tissue in the body that just happens to be shaped like a lens, behind the lens an iris that expands and contracts in response to light, and a layer of light-sensitive tissue that happens to be at the focal plane of the lens?" Questions like these can be answered only by the idea that the eye was in some sense "designed" to form an image. We analyze it just as if it were a machine. For centuries, the complexity of the eye and other organs was taken as conclusive proof of the existence of God. If the eye shows signs of design, it must have a designer-namely, God. Darwin's great accomplishment was to explain signs of engineering in the natural world through a purely physical force, namely, the differential replication rates among replicators competing for resources in a finite environment, iterated over hundreds and thousands of generations.
Of course, the eye doesn't just sit by itself, isolated in the skull. Rather, the eye is connected to the brain. In fact, the eye can validly be considered to be an extension of the brain. And that naturally leads us to treat the mind as a complex natural device--in this case, a complex computational device--which makes the science of psychology a kind of reverse engineering. Just as in the case of the olive-pitter, we can understand the brain only once we have correctly identified its function. If we thought that the olive-pitter was a wrist-exerciser, we would have a very different explanation for what the parts are for. The crucial place to begin explaining the mind, therefore, is to understand its function. Since the mind is a product of natural selection, not of a conscious engineer, we have an answer to that question: the ultimate function of the mind is survival and reproduction in the environment in which the mind evolved--that is, the environment of hunting and gathering tribes in which we have spent more than 99% of our evolutionary history, before the recent invention of agriculture and civilizations only 10,000 years ago.
The third key idea is specialization. The mind is designed to solve many kinds of problems, such as seeing in three dimensions, moving arms and legs, understanding the physical world, finding and keeping mates, securing allies, and many others. These are very different kinds of problems, and the tools for solving them are bound to be different as well. We know that specialization is ubiquitous in biology. The body is not made of Spam, but is divided into systems and organs and tissues, each designed to perform a special function or functions. The heart has a different structure from the kidney because a device that pumps blood has to be different from a device that filters blood. This specialization continues all the way down: to the different tissues that the heart and the kidney ate made from, all the way down to differences in the molecules that they are made from. The mind, like the body is organized into mental systems, organs, and tissues. I doubt that the the mind will ever be explained in terms of some special essence or wonder tissue or almighty mathematical principle. Rather, the mind is a system of computational organs that allowed our ancestors to understand and outsmart objects, animals, plants, and each other.
I will try to give you a glimpse of how three of these organs of computation might be dissected, by presenting examples of seeing, thinking, and feeling.
Let's begin with seeing. The problem of vision can be made vivid by imagining what the world looks like from the brain's point of view. It is not what we whole, functioning human beings experience, namely, a showcase of three--dimensional objects arrayed in space. Rather, the brain "sees" a million activation levels corresponding to the brightnesses of tiny patches on the retina; the retinal image as a whole is a two-dimensional-projection of the three-dimensional world. The task for the visual system of the brain is to recover information about three-dimensional shapes and their arrangements from the pattern of intensities on the retinal image. The brain has evolved a number of tricks for solving this problem, and I am going to talk about one of them--sometimes called "shape-from-shading." Each of these tricks exploits a regularity of optics that is true by virtue of physical law, and the brain can, in a sense, run these laws "backward" to try to make intelligent guesses about what is out there in the world based on the information that is coming in from the retina.
One important bit of physics is (roughly) that the steeper the angle formed by a surface with respect to a light source, the less light the surface reflects. So as I shine a flashlight perpendicularly to a card, it projects a concentrated, bright spot of light. But when I rotate the card, the beam is smeared across a large area, and any particular part of the area must be dimmer. Now, the shape-from-shading algorithms bit of psychology--more or less runs the law backward and says that the dimmer a patch on the retina, the steeper the angle of the surface in the world. And with that algorithm, the brain can reconstruct the shape of an object by estimating the angles of the thousands of tiny facets or tangent planes that make up the surface.
This process works reasonably well, but it depends on a key assumption. Since it interprets differences in brightness as coming from differences in surface angle, it implicitly assumes a uniformly colored world, or at least a randomly colored world. That means that the process is vulnerable, because surfaces that are colored in clever ways should fool the shape-from-shading module and cause us to see things that aren't there. In fact, it does happen. One example is television. If alien anthropologists visited this planet, they would be puzzled by the fact that the average American spends four hours a day staring at a piece of glass on the front of a box. Why do we do this? Because the television set has been arranged to violate the assumption of uniform or random coloration. It has been engineered to display a highly nonrandom pattern that fools the shape-from-shading module of the brain into hallucinating a three-dimensional world behind the pane of glass.
Another example is makeup. A person who is skilled at applying makeup might put a little blush on the sides of the nose, because the eye of the beholder is attached to a shape-from-shading module that interprets darker surfaces as steeper angles, making the sides of the nose look more parallel and the nose smaller and more attractive. Conversely, if you put light powder on the upper lip, the brain says that lighter equals a flatter angle, which makes the lip took fuller, giving that desirable pouty look that models strive so hard to attain.
More generally, these examples offer an explanation for many of the seemingly inexplicable quirks of modern human thought and behavior. Many illusions, fallacies, and maladaptive behaviors may come not from some inherent defect or design flaw but from a mismatch: a mismatch between assumptions about an ancestral world that were built into our mental modules over millions of years and the structure of the current world (which we have tamed topsy-turvy by technology in our recent history). It has long been a puzzle for biologists why people do maladaptive things like eat junk food, use contraception (which, when you think of it, is a kind of Darwinian suicide), or gamble. But if you posit that our mental modules assume a world in which sweet foods are nutritious (namely, ripe fruit), in which sex leads to babies (as it tended to do until the invention of reliable contraceptives), and in which statistical patterns have underlying causes, then these activities no longer seem quite so mysterious.
Next, let me turn to the problem of thinking. There is an old puzzle that has worried philosophers and biologists ever since it was pointed out by Alfred Russel Wallace, the co-discoverer, with Darwin, of natural selection: What do illiterate, technologically primitive hunter-gatherers do with their capacity for abstract intelligence? In fact, this question might be more justly asked by hunter-gatherers about modem American couch potatoes. After all, life for hunters and gatherers was like a camping trip that never ended, but without Swiss army knives and tents and freeze-dried pasta. Our ancestors had to live by their wits and eke out a living from an eco-system in which most of the plants and animals whose bodies we consume as food would just as soon keep their bodies for themselves.
Our species succeeded by entering what a biologist might call the "cognitive niche": the ability to overtake the fixed defenses of other organisms by cause-and-effect reasoning. In all human societies, no matter how supposedly primitive, people use a variety of tools; traps; poisons; various ways of detoxifying plants by cooking, soaking, and leaching; methods of extracting medicines from plants to combat parasites and pathogens; and an ability to act cooperatively to accomplish what a single person acting alone could not achieve. These accomplishments show that the mind must be equipped with ways of grasping the causally significant parts of the world. The world is a heterogeneous place, and it is likely that we have several different intuitive theories or varieties of common sense that are adapted to figure out the causal structure of different aspects of the world. We can think of them as a kind of intuitive physics, intuitive biology, intuitive engineering, and intuitive psychology, each based on a core intuition.
The most basic is intuitive physics, an appreciation of how objects fall, roll, and bounce. The core intuition behind our intuitive physics is the existence of stable objects that obey some kind of physical laws. This is not a banal claim. William James said that the world of the infant is a "blooming, buzzing confusion'!--a kaleidoscope of shimmering pixels--and that knowledge of stable objects is an achievement only of late infancy. Yet one of the first things we learn in introductory courses in philosophy is that unless one has an assumption that the multitude of sensory impressions is caused by an underlying stable object, one could experience the blooming and buzzing confusion all of one's life. Indeed, the more we know about the world of the infant, the more we see that William James, at least in this case, didn't have it quite right. The youngest infants that can be tested (about three months old) already are expecting a world that contains stable objects, and they are surprised when an experimenter rigs up a display in which an object vanishes, passes through another object, flies apart, or moves without an external push. As the psychologist David Geary summed up the literature: A "blooming, buzzing confusion" is a better description of the world of the parents of an infant than of the world of the infant.
But there are many objects that we encounter that seem to violate our intuitive physics. As the biologist Richard Dawkins has pointed out, if you throw a dead bird in the air, it will describe a graceful parabola and come to rest on the ground, just like the physics books say it should. But if you throw a live bird in the air, it won't describe a graceful parabola, and it might not touch land this side of the county boundary. In other words, we interpret living things such as birds not through our intuitive physics but through an intuitive biology. We do not assume that birds are some kind of weird, springy object that violates the laws of physics; we assume, rather, that birds follow a different kind of law altogether--the laws of biology. The core intuition of folk biology is that plants and animals have an internal essence that contains a renewable supply of energy or oomph, that gives the animal or plant its form, that drives its growth, and that orchestrates its bodily functions.
This deep-rooted intuition is found in all peoples and explains why hunter-gatherers are such excellent amateur biologists. Botanists and zoologists who do field work with hunter-gatherers are often astonished to learn that hunter-gatherers have remarkably de- tailed knowledge about local plants and animals and that their names for these plants and animals usually match the Linnaean genus or species of the professional biologists. These categorizations often involve lumping animals that, from surface appearance, look very different--for example, a caterpillar and a butterfly, or a male and a female bird with different plumage. Hunter-gatherers, using their intuitions about the hidden essences in animals or plants, predict their future behavior. They may, from a set of tracks, deduce the kind of animal and where it is likely to be heading so that they can surprise it at a resting place; or they might notice a flower in the spring and return to it in the fall to dig out a hidden tuber that the flower portends. They extract juices and powders of living things and try them out as medicines, poisons, and food additives.
The third kind of intuition, different from the first two, is an intuitive engineering. Our species is famous for exploiting and using tools or artifacts, and the core intuition behind tools is their function. If I ask you to define a "chair," you might say it is a stable horizontal surface supported by four legs. But that will not work for bean-bags, cubes, severed elephant's feet, and other objects that we can call chairs. The only thing that chairs have in common is that someone intended them to hold up a human behind. The core intuition behind our faculty to appreciate tools involves their function, or the intention of a designer. Young children, before they've entered school, sharply distinguish artifacts from living things. For example, in one experiment, children were told that doctors took a raccoon, spray-painted it black with a white stripe down its back, and implanted into it a sack of smelly stuff. The children were then shown a picture of a skunk and asked what it was. Most of them said that it was still a raccoon. But if they were told that doctors took a coffee pot, sawed off its handle, cut a hole through it, and filled it with birdseed, and then are shown a picture of a bird feeder and asked what it is, they say it's a bird feeder. This experiment shows that even young children appreciate that an artifact such as a bird feeder is anything that feeds birds, but a natural object such as a raccoon has an internal constitution that cannot be changed by superficial manipulations.
And finally, people have an intuitive version of psychology. I mentioned earlier that all of us explained Bill's behavior in getting on the bus not by assuming there is some kind of magnetic force that pulls him aboard or that he is a kind of artifact like a windup doll, but that he acts out of beliefs and desires, a kind of entity we cannot help but posit even though it is not directly observable. Again, this ability is displayed early by young children, who can, for example, deduce what an adult knows and wants just from observing what the adult is looking at.
There is evidence, apart from developmental psychology, that our reasoning ability really is divided into these intuitive theories or ways of thinking. For example, functional neuroimaging has shown that different parts of the brain are active when people think about tools or about living things. Moreover the presumably genetic syndrome of autism can be pretty well characterized by saying that it impairs a person's intuitive psychology: Autistic children really do interpret humans as if they were windup dolls, and have no concept that other people have beliefs and desires.
Misapplications of the four forms of thinking, or a shift from one way of thinking to another, can also explain certain puzzling behaviors and beliefs. One example is slapstick humor. We laugh when someone slips on a banana peel because of the sudden shift from thinking of the person in the usual way (using our intuitive psychology and thinking of him as a locus of beliefs and desires) to thinking of him as an object ignominiously obeying the laws of physics. Belief in souls and ghosts consists of taking our intuitive psychology and divorcing it from our intuitive biology, so that we think of minds that have an existence independent of bodies. And animistic beliefs do the opposite: They marry our intuitive psychology to our intuitive biology, physics, or engineering and allow us to think of trees, mountains, or idols as having minds.
I will now proceed to my final example: emotions elicited by other people. The main puzzle about our feelings toward other people is why they are often so passionate and seemingly irrational. Why do people pursue vengeance past the point of any value to themselves? Why do people defend their honor in crazy ways such as challenging each other to duels? Why do people fall head over heels in love?
The most common theory, among both scientists and lay people, is the "romantic theory"--the idea that the emotions come from a vestigial force (part of our heritage from nature), and that they are maladaptive and dangerous unless they are channeled into art and creativity. I'm going to explain a very different alternative, the "strategic theory," which proposes that passion is a "paradoxical tactic" wired into us. The basic idea is that a sacrifice of freedom and rationality can actually give one a strategic advantage when one is interacting with others whose interests are partly competing and partly overlapping with one's own. The theory applies particularly well to instances of promises, threats, and bargains. Just to show how unromantic this theory is, I am going to illustrate it by reverse-engineering romantic love.
Cynical social scientists and veterans of the dating scene agree on one thing: that love is a marketplace. There is a certain rationality to love--smart shopping. All of us at some point in our lives have to search for the nicest, smartest, richest, stablest, funniest, best-looking person who will settle for us. But that person is a needle in a haystack, and we might die single if we held out indefinitely for him or her. So we trade off value against time, and after a certain period set up house with the best per- son we have found up to that point. Good evidence for this sequence of events is the phenomenon called "assortative mating" by mate value: the overall desirabilities of a husband and a wife or a boyfriend and a girlfriend are approximately equally matched, as if each was trying to get the best partner he or she could.
Needless to say, that does not explain all there is to falling in love. There is an irrational part of love, an involuntariness and caprice to it. You cannot will yourself to fall in love. Many people can recall being fixed up with a person who looked perfect on paper, but when they met, they just didn't hit it off. Cupid's arrow didn't strike; the earth didn't move. It isn't a list of desirable traits that steals the heart; it's often something capricious like the way a person walks, talks, or laughs.
Is this any way to design a rational organism? As a matter of fact, it might be. Entering a partnership through totally "rational" shopping poses a problem. If you have set up house with the best person you have found up to a certain point, then by the law of averages, sooner or later someone even better will come along. At that point a rational agent would be tempted to drop a wife or husband like a hot potato. But now think of it from the spouse's point of view. Entering a partnership requires sacrifices--forgone opportunities with other potential partners and the time and energy put into child-rearing, among many other things. Rational spouses could anticipate that their partner would drop them when someone better came along, and they would be foolish to enter the relationship in the first place. Thus we would have the paradoxical situation in which what is in the interest of both parties--that they stick with each other--cannot be effected because neither one can trust the other if the other is acting as a rational, smart shopper.
Here is one solution to the problem. If we are wired so that we don't fall in love for rational reasons, perhaps we are less likely to decide to fall out of love for rational reasons. When Cupid strikes, it makes one's promise credible in the eyes of the object of desire. Romantic love is a guarantor of the implicit promise one makes in starting a romantic relationship, in the face of the problem that it may be rational to break that promise in the future.
Romantic love is an example of a concept from game theory called "paradoxical tactics," in which a lack of freedom and rationality can be an advantage. An analogy from a nonpsychological domain is the rationale for laws and contracts. When we apply for a mortgage from a bank, the law states that if we default on our payments, the bank has the power to foreclose on the mortgage and seize our house. It is only this law that makes it worth the bank's while to lend us the money, and therefore the law, paradoxically, works to the advantage of the borrower as well as the lender. Likewise, leases work to both the tenant's and the landlord's advantage by constraining the freedom of each. In this sense, many passions, such as romantic love, could be viewed as the neural equivalents of laws and contracts.
And by symmetrical logic, if passionate love and loyalty are guarantors that our promises are not double-crosses, so passionate vengeance and honor serve as guarantors that our threats are not bluffs. The problem with issuing a threat, such as "If you steal my goats, I will beat you up," is that carrying out a threat can be dangerous: you could get hurt beating someone up. The only value of the threat is as a deterrent; once it has to be carried out, it serves no one's purposes. Since the target of the threat is aware of that fact, he can threaten the threatener right back by calling his bluff and daring him to go through with the vengeance. How does one prevent one's bluff from being called? By being forced to carry out the threat. If we are wired to interpret defiance or trespass as an intolerable insult for which we demand vengeance regardless of the cost to ourselves, that emotion serves as a credible deterrent. One gets the reputation of being someone that people don't want to mess with.
Let me conclude. Is this a cynical view? Granted, most people don't like to think of themselves as a system of computers "designed" by natural selection to promote survival and reproduction. On the other hand, the view is based on facts that I think can no longer be denied by any scientifically literate person. It is becoming increasingly clear, in particular, that the mind is a product of the brain; that the brain is a product of evolution, and that evolution is not guaranteed to produce niceness.
On the other hand, I personally do not think of it as a cynical view. Indeed, it may offer more grounds for optimism than some of the traditional ways of seeing man's place in nature. Recall the three key ideas of computation, evolution, and specialization. The idea of computation suggests that the mind is not a bundle of crude drives and reflexes, but is composed of intricate, ingenious, powerful software. The idea of evolution suggests that our legacy from natural selection is not just the nasty brutish emotions--greed, aggression, lust, a thirst for blood, a territorial imperative, and so on--but the kinder, gentler emotions as well, such as but love, friendship, sense of justice. Finally the idea of specialization--that the mind is a complex system composed of many parts--holds out the hope that some parts of the mind, those with the longest view of the future, can figure out ways to outsmart the other parts.
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Mind·X Discussion About This Article:
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will machines become conscious?
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I'm from Holland so I'll try to be as clear as possible in expressing the english language, but we try to approach the human consciousness in a tecnical way. First of all our reality is based on our perceptive abilities causing by five sensory systems. We are aware of our reality which seems to be manufactured by the magnetic difference between the sensors and the cerebral cortex. Our awareness is restricted because of the boundaries in wavelenghts and our restricted way of interpretating this 'reality'. We could ask ourselves what organs are responsible for our consciousness or is our consciousness responsible for it's reality? Our consciousness is part physical and part non-physical. The non-physical aspect is an magnetic/electric quantum principle in a balance situation when the brain 'interpretates'. The brain is nothing but a processor and because of the five sensory input systems it has a ressemblence to a pentium processor. Only the processor can process all sensory input but that's not the beginning of intelligence. Intelligence is relating certain topics to 'judge' them for individual purpose, something which can't be manufactured by the 'free' will of any technical cybernetics, these can only make a choice but never judge for individual purpose. This judging isn't because of our processing, the brain can process any reality but this reality is due to the choices a human being made after processing. So in my opinion our consciousness isn't only because of the reality based on the sensory cortical projection, we can interpretate things which can't be processed with our restricted brain. That's the bigger part of our consciousness. As long as we don't understand our brain, we honestly know very less about the human brain, we only can develop artificial intelligence by making a processor which can only make choices, but it never will be aware of the consequences forindividual purpose. It follows a basic structure of choices and sensory feed-back to develop itself in a pattern we have configured in this artificial system.
A computer isn't an intelligent lifeform because it makes a choice because we want to, intelligence is making a choice by itself for individual purposes. This choice is always due to things which can't be caused by the brain, the brain isn't the cause of anything, it's a processor for sensory input. Our awareness is much more complicated and isn't based on 'digital' choices.
Technically we may seem very much developed and it will be much more if we look on the situation in five years. But our brain is the same mystery as it was before the 'machine' was invented, we only know more about relativity. One thing in relation to another but the interpretation of the reality is based on concepts we can't approach technically because of linear thinking. When we reproduce A.I. this individual has no free will and will be a copy of the physical human being, the smallest part of our consciousness. The rest can't be approached by analytical choices or examination because of it's duality. Being and not being. Our awareness is build because of both, materia and non-materia. Consciousness is the combination of awareness and non-awareness. This is the reason why we don't understand the human processing of consciousness, it's not only due to the brain.
Silas |
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Re: The precent of the physical brain
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To know more about the human brain is to know our selves better. This is the first condition to know more about artificial reproducing of more advanced lifeforms.
Science is searching for limits to know more about the limitation it's self. Ofcourse you won't use the complete power of your automobile gear, but the process can be controlled better when one knows the limits.
When we would develop our brainprocesses we would know more about our restricted way of experience facts and therefor we would know more about ourselves and about the reality we are not aware of. The only problem that occurs is the fact that many facts cannot be related in a scientific way.
This doesn't mean we don't learn from it on the contrary, we learn a lot about ourselves by trying to develop a cybernetic organism. If we never find a way to let this happen, something I believe, we will know a great deal more about ourselves. That's maybe the biggest invention ever invented in human scientific technology. But we will probably never develop A.I. before knowing ourselves.
But when we do, we will know a lot more about ourselves, we will know our limits and our capacities to use it for further development of science and we will discover that the analytical reality is a small part of the human thinking.
Our advanced technology will be the beginning of new scientific investigation.
If you never use the full capacity of your brain you'll never know what it's capable of.
We need to ask ourselves what could develop our own brain. If we know a littlebit of the complete capacity, I'm curious about the effect that science would have on it. I think we are frustrated by evolution by nature and try to speed things up with science. But as long as science is based on analytical thinking we are ignoring neglected structures that are inside our minds. As long as we view things ONLY scientific, the role of the human being in this universe will be the biggest question remaining for mankind.
Science is an instrument itself for further investigation. It will never answer the biggest questions, it will only be a relatively small part of reality.
Science has to develop, not just technically.
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Re: Silicon and neurons
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I went back to the Post, searched on 'neuron', and got the article. Here it is.
Scientists for the first time have linked multiple brain cells with silicon chips to create a part-mechanical, part-living electronic circuit.
To construct the partially living electronic circuit, scientists at the Max Planck Institute for Biochemistry in Germany managed to affix multiple snail neurons onto tiny transistor chips and demonstrated that the cells communicated with each other and with the chips.
The advance is an important step toward a goal that is still more science fiction than science: to develop artificial retinas or prosthetic limbs that are extensions of the human nervous system. The idea is to combine the mechanical abilities of electronic circuits with the extraordinary complexity and intelligence of the human brain.
Such combinations of biology and technology may not only one day help the blind to see and the paralyzed to move objects with their thoughts, but also help to build computers that are as inventive and adaptable as our own nervous systems and a generation of robots that might truly deserve to be called intelligent.
Meshing nerve cells with electronics has become a hot new field in science -- and has long been a staple of science fiction. But what "Star Trek" accomplished in a stroke of the pen has proved harder to achieve in real life.
"The nervous system is quite different than a computer," said Eve Marder, a professor of neuroscience at Brandeis University who studies how the brain adapts to change. "Many functions that are physically separate in a computer are carried out by the same piece of tissue" in the brain and nervous system.
The greatest challenge has been in building the interface between biology and technology. Nerve cells in the brain find each other, strengthen connections and build patterns through complex chemical signaling that is driven in part by the environment. Slice away some neurons, for example, and others will leap in to replace their function. No one understands how the brain learns to adapt to change, but it is a process that is as sophisticated as it is messy.
Silicon chips, on the other hand, can perform specific functions with great reliability and speed, but have limited responsiveness to the environment and almost no ability to alter themselves according to need.
"Things are constantly changing . . . processes are growing, there are substances called neuromodulators that change the properties of nerve cells and the strength of connections," said Marder. "That's the challenge of making a silicon-brain interface -- the rules of computation are not the same."
The German researchers used micropipettes to lift individual cells from the snail brain and then puff them out onto silicon chips that were layered with a kind of glue. The snail neurons, according to biophysicist Peter Fromherz, are a little larger than human or rat neurons and were therefore easier to work with.
"They suck them out and then blow them onto the structure," said Astrid Prinz, a post-doctoral researcher at Brandeis University, who used to work with the German group. "It's a matter of practice to learn to handle individual cells. You have them in a little pipette with fluid. You blow them out and you can maneuver them. One guy in the lab made a little movie on how to blow cells."
Each cell was positioned over a Field Effect Transistor, a device that is capable of amplifying tiny voltages, and a stimulator to prod the cell into activity.
The process was repeated with some 20 cells over multiple transistors and stimulators. By using polymers, the German scientists built tiny picket fences around the neurons to keep them in place over the transistors -- one of the great difficulties in building such circuits is that nerve cells tend to wander around, as they do in the brain.
Neurons on this silicon base developed a connection between each other known as a synapse. When researchers stimulated one neuron, it released an electrical signal. That signal was detected by the transistor that the neuron sat on as well as the transistor beneath a second neuron -- showing that the electrical signal had passed from the chip to the first neuron, through a synapse to the second neuron and then converted back into electricity and the second transistor.
"It's very primitive, but it's the first time that a neural network was directly interfaced with a silicon chip," said Fromherz, who published the results in today's issue of the Proceedings of the National Academy of Science. "It's a proof of principle experiment."
The group, he said, was already working on linking greater numbers of neurons with more transistors. The real challenge, he said, lay in figuring out where exactly the neuron's synapse was relative to the transistor, and in developing techniques that could reliably construct larger circuits.
Fromherz said plans were underway to build a system with 15,000 neuron-transistor sites.
When the number gets large enough, researchers hope they will begin to see the early glimmers of what actually happens in the brain: neurons forming complex connections that transmute electrical activity into computation, thoughts and maybe consciousness itself.
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Re: How the Mind Works
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>>The most common theory, among both scientists and lay people, is the "romantic theory"--the idea that the emotions come from a vestigial force (part of our heritage from nature), and that they are maladaptive and dangerous unless they are channeled into art and creativity<<
It is not clear to me what is meant here by "romantic theory", but whatever it is, it seems that Mr. Pinker, at least in this case, didn't have it quite right. Let me quote from Bertrand Russell's History of Western philosophy:
>>The romantic movement is characterized, as a whole, by the substitution of aesthetic for utilitarian standards. The earth-worm is useful, but not beautiful; the tiger is beautiful, but not useful. Darwin (who was not a romantic) praised the earth-worm; Blake praised the tiger. The morals of the romantics have primarily aesthetic motives. ...
It is not the psychology of the romantics that is at fault: it is their standard of values. They admire strong passions, of no matter what kind, and whatever may be their social consequences. Romantic love, especially when unfortunate, is strong enough to win their approval, but most of the strongest passions are destructive - hate and resentment and jelousy, remorse and despair, outraged pride and the fury of the unjustly opressed, martial ardour and contempt for slaves and cowards. Hence the type of man encouraged by romanticism, especially of the Byronic variety, is violent and anti-social, an anarchic rebel or a conquering tyrant.<<
It seems that Mr. Pinker assesses romanticism from the viewpoint of utilitarian tradition, and then calls this assessment "the most common theory" aka the "romantic theory".
>>Cynical social scientists and veterans of the dating scene agree on one thing: that love is a marketplace. There is a certain rationality to love--smart shopping. All of us at some point in our lives have to search for the nicest, smartest, richest, stablest, funniest, best-looking person who will settle for us.<<
I don't know about love, but social science community sure is a marketplace, and Mr. Pinker does a good job of selfpromoting. It probably helps that he is a narcisisstic egomaniac whose office is filled with his own books and awards, and that he is able to sell theories from the XIX century as something new and original. Let me put another quote here before discussing his theory of love, the Nietzsche's very first passage of "The Gay Science"
>>Whether I contemplate men with benevolence or with an evil eye, I always find them concerned with a single task, all of them and everyone of them in particular: to do what is good for the preservation of the human race. Not from any feeling of love for the race, but merely because nothing in them is older, stronger, more inexorable and unconquerable than this instinct'because this instinct constitutes the essence of our species, our herd. It is easy enough to divide our neighbors quickly, with the usual myopia, from a mere five paces away, into useful and harmful, good and evil men; but in any large-scale accounting, when we reflect on the whole a little longer, we become suspicious of this neat division and finally abandon it. Even the most harmful man may really be the most useful when it comes to the preservation of the species; for he nurtures either in himself or in others, through his effects, instincts without which humanity would long have become feeble or rotten. Hatred, the mischievous delight in the misfortunes of others, the lust to rob and dominate, and whatever else is called evil belongs to the most amazing economy of the preservation of the species. To be sure, this economy is not afraid of high prices, or squandering, and it is on the whole extremely foolish. Still it is proven that it has preserved our race so far.<<
The "love theory" of our very great Mr. Pinker seems to be influenced too much by the society he lives in, the fast-paced, liberal, utalitarian America, where shallowness of every sort prevails and where promiscuosity is a convinient way to fill the vacuous lives of its spoiled subjects. Pleasures of the dating market, so dear to great thinkers enjoyiong valuable status, did not exist until very recently and do not exist in the parts of the world less blessed by alienation and popcorn. In fact, arranged marriages are quite common even today, and females do not have that much choice or freedom. And they never did. Orientals view females as a property, and polygamy is common in Africa. It is not only that people of high status are more desirable, but they have more power and can own larger and better harems. The marriage was business affair, against which courtly love rebelled. It is power which enabled him to choose, and he choose against the wishes of competing men. And it is like that in most of the animal kingdom, at least for mammials. Like baboons, like man. It is absurd that thinking or calculaing would have anything to do with reproduction, since animals don't calculate and those fundamental mechanisms certaily predate thinking. Of course, there is sexual selection, as was noted by a certain British naturalist by the name of Darwin, but it is certainly not a rational affair. Market analogy has its place, but it was women who had to sell themselves and make themself desirable by applying all sorts of devices, hoping that they will marry well. Once they did, there was little they could do. And one could argue that in the more egalitarian society of hunter gatherers couples needed to stay together simply to survive, bonded in a family which was more important for survival in harsh conditions than getting a better mate who appears at random.
This wasn't an issue at all, it is only an issue in this age of conformism when survival is ensured even for the most brain impaired obese cretins. The instability of relationships does not come from the rationale of getting a better mate, it comes from superficiality and shalowness, greed and inherit instability of those who are not meant to choose, the excessive freedoms of liberal society which favours petty utilitarianism against human nature.
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