Computing the mind: a scientific approach to the philosophy of mind and brain.

For centuries, philosophers have puzzled over the mind-body problem -- the captivating enigma that asks how subjective mental states are connected to our objective physical biology. In this century, neuroscientists have made spectacular achievements in describing the cellular and molecular actions of the nervous system, while cognitive psychologists have indirectly observed and measured mental and psychological functions, sometimes with ingenious experimental methodology and often borrowing brain-imaging techniques from neuroscience.

The most recent contributors to the mind-body topic are computer network experts who study how individual elements interact in a systematic way, producing computational processes which give rise to information processing and artificial intelligence. Pioneers such as Alan Turing, John von Neumann, Warren McCulloch and Walter Pitts, and, more recently, Patricia Churchland an Terrence Sejnowski have provided an analysis of systems at a higher level than the typical biomedical approaches of neuroscience and at a lower level than the macro states and behaviors favored by psychologists. By examining neural networks, these researchers hope to uncover just how individual cells combine to create emergent phenomena which are more than the sum of their parts.

Of course, in each cast the attention is on the human brain as the locus of mental and psychological functions. Computer guru Marvin Minsky has called the brain a "meat machine" and a machine that "clanks softly." Viewing the brain as a soft computational machine allows an interesting commentary on the recent chess match lost by Garry Kasparov to the IBM computer sometimes called Deeper Blue (because it is an improved version of Deep Blue beaten by Kasparov the previous year). in this view, it was not man against machine as much as it was one type of machine -- or process, if you prefer -- against another. As was shown, one process happened to be better at chess than the other.

Critics complain that a digital computer lacks awareness or understanding, that it is just making unconscious computations. But a brain is a type of computer and it has awareness and understanding. A brain also just makes subconscious computations-by neurons creating electrical current and squirting transmitter chemicals. This, of course, is the essential mystery: how can these singularly objective cellular brain events transform into psychological states, moods, and behaviors? The consciousness we experience is apparently achieved via the interaction of billions of unconscious computational events, which in themselves have no awareness or understanding.

Certainly Deeper Blue was made and programmed by humans, but so was Kasparov! If we're giving credit to Deeper Blue's programmers, then let's give credit to the programmers of Kasparov: his parents, teachers, previous opponents, authors of books he read, and so forth. Also, some machines today are made by other machines, and someday computers will likely be made and programmed by other computers. So what? None of these truths diminishes human integrity, dignity, worth, goals, values, or self-actualization. There is no threat. Brains are better at some things, while silicon digital computers excel at others.

Analogies

Years ago we were told that a human brain functions like a telephone switchboard. I still remember the scratchy 16mm movie that illustrated brain activity as a sequence of switchboard plugs being methodically pulled from and inserted into an impressive array of holes. This analogy was readily embraced throughout society, in and out of schools, and it even sprouted in pedestrian places such as the silly 1972 Woody Allen movie Everything You Always Wanted to Know About Sex But Were Afraid to Ask. Allen depicts the brain as a command center for body actions (sex, in this case), which are initiated and regulated via telephone communication.

The days when a brain was likened to a telephone switchboard are thankfully long gone. In the modern zeitgeist, the idea seems humorously antiquated, belonging more properly to an era of bobby-soxers, air raid drills, and bomb shelters. But contemporary society need not go metaphorless because -- as is usually the case -- when one analogy grows passe, another elbows its way into our collective hearts. The au courant brain metaphor, which is both ubiquitous and appropriate for the "information age," is that a brain is like a computer.

Our popular culture absorbs and reflects this analogy regularly -- through such television characters as Commander Data of Star Trek: The Next Generation, who achieves consciousness with a "positronic" electronic matrix brain; through popular fiction like The Terminal Man, which features a man with epilepsy who has electrodes inserted into his brain; through newscasts which regularly report findings that certain traits are "hardwired" into the brain; and through movies such as Brainstorm (1983), Total Recall (1990), and Until the End of the World (1991), which envision machines that are able to interface with a living human brain and thereby access various mental functions, such as memories and dreams. Apparently, the brain-computer analogy is widespread and implicitly accepted throughout our culture. The brain has gone cyber.

Is a Brain Like a Computer?

When first proposed in the 1960s, the brain-computer analogy was widely criticized, quite unfairly, on the basis that brains do very different tasks from computers. For example, it was noted that a brain is exquisitely excellent at visually recognizing a face or an object, while a computer is clunky and exceedingly slow at pattern recognition. On the other hand, a computer can do complex mathematical calculations at extremely high speed, while a brain is stumped by such tasks. While these indeed were and still are accurate observations, what makes this criticism a red herring is that it isn't the particular content of a computation that determines if something is like a computer; rather, it is the process used. In other words, it isn't what is done but how it's done that matters.

A more valid complaint of the brain-computer analogy is regarding the word like. The brain is not like a computer; it is a computer. Certainly a brain does not compute the same information that a PC does, but in the method -- the manner in which it processes information -- the brain is computing. For better or worse, your brain is a computer. Greetings, Data.

Not surprisingly, the idea that a brain is a computer receives a good deal of resistance and scoffing. One reason for this is that the term computer is often wrongly interpreted to exclusively denote serial digital computers. But the PC, like the slide rule, is just one example of a device that makes computations. A brain also is a computational device.

A second reason for resistance is that most nonexperts and even a few experts believe that a brain is more than a mere computer; that brain functioning in some way -- perhaps at a sub-atomic or metaphysical level -- results in the creation of emergent mental and emotional properties that would not be possible simply through computational processes. When this idea is presented with a rationale, it, commonly is accompanied by quasiscientific jargon. References to chaos theory and particle physics are currently in vogue, as if brains were the only substances on Earth that involve principles of quantum physics.

Arcane and illogical philosophical arguments are also often given. These imply that brains are somehow different than other matter in the universe and only brains can experience metaphysical transformations. Although these contentions certainly stimulate entertaining discussions, they are grossly speculative, controversial -- even volatile when linked with religious beliefs -- and extremely unlikely to be resolved in the near future. So far, a materialist view is completely complementary to today's wide-ranging multidisciplinary empirical data.

What seems clear is that, whatever other qualities it may possess, a brain appears to be a kind of computer, a nature-made computer. Through a series of complex interactions, a brain takes incoming sensory signals, processes that information, and achieves a computational product, an output. Think of your senses as the keyboard or modem and your conscious mind as the monitor. The output of the brain includes regulation of body systems, emotions, behaviors, and thoughts, both conscious and unconscious. A brain does compute. Of course, exactly what it computes varies significantly from a PC or Macintosh.

This idea is typically a frightening one to people, although not to a majority of brain researchers and artificial intelligence experts who have calmly accepted it, at least at some fundamental level, despite disagreements over nuances. For our part, although we may have some trepidation, if we are willing to take an open-minded view, then it seems reasonable, even fun, to agree with the experts that a brain is a natural computer, the world's first computer, the best and brightest computer. There should be nothing threatening nor dehumanizing about this view. in fact, adopting this insight may help us to better understand and accept emotional, behavioral, and cognitive differences between people and the mental problems that beset us. However, even if we accept this framework, there are significant clarifications necessary, lest unwarranted conclusions be drawn.

What Kind of Computer Do You Have?

A brain may be a computer, but it is a distinctly different sort of computer than the silicon chip models on our desks. The complex networking that is characteristic of both a PC and a brain is achieved in each case through the use of entirely different substances and different systems of organization. The cells (neurons) which permit communication within a brain are alive; a brain is a living computer. Brain cells require oxygen and involve complex biological processes driven by genetic codes. They are subject to malformations, irregularities, and damage via biological mechanisms (consider, for example, Alzheimer's disease). This simple realization leads us to the most enlightening fact that, since brain cells are alive and therefore are malleable and dynamic, it becomes difficult, perhaps impossible, to distinguish between hardware and software within the brain.

In contrast, a semiconductor computer uses cells that are essentially static, unchanged by the signals they carry; in a PC or Mac, the hardware is not significantly altered by the software program it runs. When the software is removed, the hardware is unchanged, back to normal, ready for more software. Brains don't work like that. A brain's hardware is pivotally changed by its software -- a process that is at the heart of how a brain stores information (that is, remembers) and maintains continuity. As a brain takes in information through the senses, the cells which comprise the hardware are physically changed by the process.

Take language, for example. One brain may run an "English" program while another runs a "French" one. Each brain has been programmed through experience, and the software programs are now integral parts of the hardware of the brain. The hardware of each brain is importantly different from the other at the cellular level. They are different in a physical/chemical way that would be extremely difficult, if not impossible, to undo without doing damage to their structures; in a brain, the software is intricately intertwined with the hardware. The program (in this example, language) cannot be removed without altering the hardware. Even while asleep (and not dreaming), when one's conscious mind is "turned off," the nature of the software program is retained within the hardware so that, when one awakens, the same old memories, thoughts, and feelings are booted up and running.

Make Up Your Mind!

This insight may lead us to wonder what exactly it is about brains that allows them to create thoughts, memories, awareness, emotions -- that is, a mind. Where in the brain's biological processes are the key elements that give us consciousness? Are mental and emotional experiences a product of the brain's cellular interactions and therefore might be reproducible using inorganic networks that replicate brain networks? Or are conscious experiences dependent upon the biological characteristics of brain cells themselves? Does a mental experience -- such as seeing, hearing, or feeling -- depend on some particular quality of the individual cells of the brain, or is the computational interaction between the cells sufficient to produce awareness?

If it is the brain cells that are crucial for creating consciousness, then we may wonder which specific properties or characteristics of the cells are the necessary ones. Do other cells that have those properties then also have a mental fife? Could mental experiences be replicated in a laboratory by reproducing those special cellular characteristics?

On the other hand, if mental experiences are produced not by particular aspects of the cells but instead by their interacting networks doing some sort of computing, then it should be possible to build a machine that could generate mental phenomena. if a silicon chip computer were built to exactly simulate brain connections, would it not feel? If not, why? What would be missing?

Of course, it is entirely possible -- in fact, it is likely -- that the creation of mental and emotional experiences depends on a unique combination of cellular characteristics and their interactions -- that both biological cellular mechanisms and neural networks are necessary. In that event, it would take information about both neural nets and cell biology to understand and to artificially create a conscious mind.

When a brain creates a mind -- when thoughts and emotions are formed by brain properties, states, conditions, and actions -- then precisely what are the particular, distinctive elements involved? Are thinking, feeling, dreaming, and consciousness unique to humans or are these subjective experiences shared on some continuum with animals, insects, amoebae, perhaps even inorganic materials? In other words, are mental phenomena reproducible? Could a nonliving machine, if properly constructed, conceive a thought, feel, think, dream?

A Scientific Answer

When we ask how it is that a brain creates a mind, it is somewhat similar to asking how any observed quality is created by its physical constituents. For example, how is it that rocks are hard, iron is magnetic, ice is cold, or, for illustrative purposes, water creates wetness? Just as wetness is a property or quality of water, the mind is a property or quality of the brain. Wetness is a state or condition that is created by the physical nature of water, and similarly we can conceptualize mental experiences as states or conditions created by the physical nature of the brain. Although this is not a perfect comparison -- in fact, there are no perfect comparisons since a mind is the only thing we know to have subjectivity or awareness -- still, we can use this comparison to help us achieve a better conceptual paradigm of the mind-brain connection.

When we attempt to explain a certain phenomenon, a scientific answer is one that describes the physical/chemical properties and interactions underlying the quality to be explained. For example, wetness is a quality that is scientifically explained by reference to certain properties and interactions of hydrogen and oxygen atoms. Following this paradigm, mental experiences can similarly be scientifically explained by detailing the specific brain substances and activities which generate them. Since the mind is one of the things a brain does, a scientific explanation of the mind would thus consist of a detailed description of the physical/chemical brain states and networks associated with each mental experience.

Though most people find this form of answer acceptable for explaining other things, it is typically found unsatisfactory for the question of how a brain creates a mind, since people want an answer of a different sort: one invoking the metaphysical or supernatural. Although the scientific approach may seem inadequate, it is how we explain other phenomena, and in those cases it is accepted. We don't ask how it is that water creates wetness; the how doesn't make sense, other than explaining wetness with reference to its underlying physical features. Perhaps this is the best approach to understanding the mind: to reduce mental experiences to their underlying physical features and not ask how it is that these features produce the mind.

It is disconcerting to hear critics reject a scientific approach to the mind because it doesn't include nonscientific ideas, such as the metaphysical, paranormal, or spiritual. But in any way that the mind can be examined empirically, a scientific approach is appropriate. This does not dehumanize us or diminish the value of the arts, emotions, self-discovery, and so on. Other valid approaches to understanding human experiences are, of course, welcomed. But science can provide one powerful piece of the puzzle.

It is likewise disconcerting to hear quasi-scientific explanations of the mind, which often are seductive enough to gain the favor of listeners. For example, Deepak Chopra often says that "a thought is a quantum event." Because of his use of scientific terminology, the hypothesis seems plausible. However, this is a confused idea. A thought is a personal, subjective experience produced by the brain, while quantum events are activities occurring at a subatomic level (for example, the interaction between an electron and a photon) which occur regularly in all physical matter in the universe, in and outside of our bodies. A thought is no more or less a quantum event than is wetness. The subjective experience of thinking is produced by actions of brain cells, which naturally include quantum events as do all physical acts.

We need to get over the idea that humans -- and, in particular, the human mind -- are somehow mysteriously or miraculously outside of nature. How a brain creates a mind is no more or less a mystery or a miracle than how rocks are hard, how magnets create fields, how electrons produce current, how light is both particle and wave, or how water is wet. Those who study the mind scientifically are interested in this area because it is one way of examining the human equation. It is a very practical approach that offers hope for people who have mental problems, such as Alzheimer's, Parkinson's, depression, or schizophrenia.

Basics of Brain and Mind

The brain is a physical thing within the natural world, not a supernatural or metaphysical entity. Minds are not supernatural entities but personal experiences produced when brains are in a state of awareness of their own functioning, most probably a state created through the complex intercommunication between and among brain subcomputers for vision, hearing, language, attention, and other cognitive and perceptual functions. Minds are not substances; they are subjective experiences which the brain creates as a window into certain aspects of its own functioning. A brain, or a particular subdivision of the brain, is able to create an awareness of certain of its own states or functions -- a kind of self-monitoring.

This concept of the mind may help us in speculating about why the mind exists. Why didn't a brain evolve without consciousness? What was the evolutionary impetus for the development of awareness? Viewing mental experiences as self-monitoring events helps us initiate some hypotheses about why consciousness would have evolutionary survival advantages over a nonconscious brain.

Although some experts have proposed that minds and brains are the same thing (in fact, some writers have recently begun to use the term brain-mind), minds, of course, are not brains any more than wetness is water. Minds are a quality or product of certain brain activity -- one of the many things that a brain does, along with control of muscles, organs, and body housekeeping functions. While asleep, for example, a brain can be performing many functions, although consciousness (the mind) is temporarily turned off.

A brain has many tasks. One of the most interesting is the creation of thoughts, feelings, dreams, choices, personal identity, and awareness of the environment and the self -- in other words, a conscious mind. The specific details of how the mind is created by the brain are yet to be unraveled and are likely to be complex and difficult to uncover and elucidate. Still, there is no reason to believe that these details are conceptually any more inaccessible to scientific investigation and scrutiny than any other complex phenomena. Nor is there any reason to feel threatened or dehumanized by such studies. In fact, people who scientifically study the mind are demonstrating a central focus of humanism: a high regard for understanding human nature and experience without supernatural biases. One thing on which it is easy to agree is that how the brain creates the mind is one of the most fascinating and exhilarating of all questions.

As you read these final words, consider for a moment the idea that an abundance of intricate electrical and chemical signals surging through your brain at this very moment is responsible right now for your awareness and attention; your seeing and understanding; your memories and emotions; your questions, concerns, and doubts; your creative impulses, curiosity, and emerging ideas; and any excitement you may now feel as the computer in your head invites you to explore its cyberspace. Happy computing!

Bruce Hinrichs, a Phi Beta Kappa graduate of the University of Minnesota, is a professor of psychology and humanities at Century College in White Bear Lake, Minnesota. He is a recent recipient of a Unit One teacher-in-residence fellowship at the University of Illinois. During a previous honorary fellowship at the University of Wisconsin-Madison, Hinrichs began writing a book on cognitive neuroscience entitled Mind As Mosaic: The Robot in the Machine, from which this article is adapted.