[Paleopsych] Reason: Are We Just Really Smart Robots?

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Are We Just Really Smart Robots?: Two books on the mind put the
human back into human beings. 
http://www.reason.com/0504/cr.ks.are.shtml
5.4

by   [6]Kenneth Silber

    [7]On Intelligence, by Jeff Hawkins with Sandra Blakeslee, New York:
    Times Books, 261 pages, $25
    [8]Mind: A Brief Introduction, by John R. Searle, New York: Oxford
    University Press, 326 pages, $26

    Neurobiologys advances generate anxiety as well as joy and hope. On
    the joyful and hopeful side, there are the prospect and reality of
    improved treatments for brain diseases and debilities. But anxiety
    arises over what the science tells us, or will tell us, about
    ourselves. Thoughts and feelings may be reduced to brain structures
    and processes. Consciousness and free will may be proven unimportant
    or illusory. Much of what we value about ourselves, in short, may be
    explainedor, worse, explained away.

    The prevailing trends in the philosophy of mind reinforce such
    concerns. The field is dominated by schools of materialism that
    describe mental phenomena as types or side products of physical
    phenomena. Mind-body dualism, which posits a separate existence for
    the mind, has been effectively eclipsed (although it seems to receive
    continued implicit acceptance from many nonexperts). Some forms of
    materialism argue that the mental phenomena in question do not even
    exist.

    This turn toward the mechanistic could have baleful cultural and
    political consequences. It threatens to undermine peoples sense of
    responsibility and self-worth. There is the danger of what philosopher
    Daniel Dennett calls creeping exculpation, as more and more human
    behavior is attributed to material causes. Criminal violence, for
    example, might be excused as a consequence of low levels of serotonin
    or monoamine oxidase in the brain. Many philosophers, including
    Dennett, argue that humans should be regarded as responsible agents
    even if human behavior is fully determined. But the very fact that
    such arguments need to be made shows how the deterministic premise has
    altered the terms of debate.

    If humans are mechanistic beings, it becomes harder to understand why
    they should not be used as means to an end or why there should be much
    concern with what they are thinking or feeling. At a political level,
    such quandaries pose a threat to liberal democracy, which relies
    heavily on the assumption that we are autonomous beings with the
    capacity to make meaningful decisions. Mechanistic theories have
    enjoyed an authoritarian cachet in the past. Stalins regime embraced
    the work of Ivan Pavlov, famous for conditioning dogs to salivate at
    the ringing of a bell. In Walden Two (1948), the American psychologist
    B.F. Skinner described a society whose managers use operant
    conditioning to suppress competitiveness and other undesired
    behaviors.

    Alongside the conception of human beings as biological machines looms
    another specter: that human mental capacities will be equaled or
    exceeded by machines of our own creation. An influential doctrine in
    the philosophy of mind, congruent not only with neurobiology but with
    cognitive psychology and computer science, is computer functionalism.
    This view holds that the mind is fundamentally a computer program
    implemented in the brains hardware one which could be replicated in a
    different physical substrate. Notwithstanding the limited progress of
    artificial intelligence (A.I.), many experts expect it to achieve vast
    advances in coming decades. More important, the general public expects
    this too. The prospect arouses considerable anxiety, as reflected in
    the Terminators and Matrixes that populate science fiction.

    The scientific and philosophical quest to understand human beings as
    part of the natural world thus seems to come with a hefty price. It
    forces us to regard ourselves as mere machinesindeed, as potentially
    obsolescent machines, given advances in computing. Or does it?
    Technologist Jeff Hawkins and philosopher John Searle both approach
    matters of mind and brain from a naturalistic perspective, but their
    arguments veer sharply from the grim picture sketched above. Both
    provide valuable analysis and speculation about mental phenomena while
    taking issue with much current scientific and philosophical thinking
    about the subject.

    In On Intelligence, Hawkins portrays human intelligence as more subtle
    and flexible than anything computers do. His model suggests that while
    future artificial systems may possess remarkable intelligence, they
    will be neither human-like nor the malevolent superhuman entities of
    science fiction. In Mind: A Brief Introduction, Searle provides an
    iconoclastic overview of the philosophy of mind, arguing for a
    position that accepts that the mind is materially based without
    dismissing or downplaying mental phenomena. Searles discussion ranges
    across such topics as the limitations of computers, the nature of the
    unconscious, and free will as a possible feature of the brain.

    Hawkins, who wrote On Intelligence with science journalist Sandra
    Blakeslee, is a computer entrepreneur with a longstanding interest in
    how the brain works. He is the inventor of the original Palm Pilot and
    the founder of the Redwood Neuroscience Institute. In 1980, as an
    Intel employee, he proposed a project to develop memory chips that
    operate on brain-like principles. Intels chief scientist turned him
    down, reasoning (correctly, Hawkins now believes) that such an effort
    was premature. Hawkins then sought to do graduate work at the
    Massachusetts Institute of Technology, to study brains as a means
    toward developing intelligent machines. MIT, suffused with the idea
    that A.I. had little need for brain research, rejected his
    application. In the late 1980s, Hawkins viewed with interest but
    growing skepticism the rise of neural networks, programs that bore a
    resemblancebut only a very loose oneto brain operations. He found no
    use for neural networks in developing the handwriting recognition
    system later used in Palm Pilots.

    Such experiences fed Hawkins convictions that intelligent machines
    must be more genuinely brain-like, and that making them so requires a
    new theory of how the brain operates. Neurobiology, he argues, has
    amassed an impressive array of detail but lacks a compelling framework
    for understanding intelligence and brain function. On Intelligence is
    an attempt to provide such a framework.

    Hawkins focuses mainly on the cortex, the most evolutionarily recent
    part of the brain. The cortex, in his view, uses memory rather than
    computation to solve problems. Consider the problem of catching a
    ball. A robotic arm might be programmed for this task, but achieving
    it is extremely difficult and involves reams of calculations. The
    brain, by contrast, draws upon stored memories of how to catch a ball,
    modifying those memories to suit the particular conditions each time a
    ball is thrown.

    The cortex also uses memories to make predictions. It is engaged in
    constant, mostly unconscious prediction about everything we observe.
    When something happens that varies from predictionif you detect an
    unusual motion, say, or an odd textureit is passed up to a higher
    level in the cortexs hierarchy of neurons. The new memories are then
    parlayed into further predictions. Prediction, in Hawkins telling, is
    the sine qua non of intelligence. To understand something is to be
    able to make predictions about it.

    A key concept in this memory-prediction model is that of invariant
    representations. The cortex is presented with a flux of sensory data
    but manages to perceive objects as stable. The magazine youre now
    holding, or the computer screen youre looking at, sends constantly
    changing inputs to your eye and optic nerve, but the subsequent
    pattern of neurons firing in your visual cortex displays an underlying
    stability. This capacity to pick out unchanging relationships gives
    humans considerable cognitive flexibility. Imagine looking at a
    picture of a face formed by dots (like those drawings in The Wall
    Street Journal). Now imagine each dot is moved a few pixels to the
    left. A human, unlike a conventional A.I. program or neural net,
    easily will see it as the same face.

    Hawkins buttresses his memory-prediction model with a fair amount of
    neurobiological detail. Much of the model is speculative. There is,
    for instance, considerable evidence of invariant representations in
    the workings of the visual cortex, but it is not yet clear whether the
    concept applies broadly to other sensory areas and to motor regions of
    the cortex. Hawkins presents a list of neurobiological predictions to
    test his models validity. He posits, for example, that certain layers
    of the cortex contain neurons that become activated in anticipation of
    a sensory input. Such anticipatory activity is in keeping with the
    idea that perception involves prediction, as well as receipt, of
    sensory inputs. When you glance around your living room, your brain
    fills in some details based on what it has seen before.

    As Hawkins notes, invariant representations can be viewed as a bug, as
    well as a feature, in human cognition; negative stereotyping and
    bigotry might have roots in such invariance. The strong element of
    prediction involved in perception also has a downside: It could
    underlie peoples tendency to see what they want to see. Overall,
    though, Hawkins model underscores the considerable capabilities of
    human intelligence. It provides a plausible explanation of how the
    speed and agility of human thought can exceed the capacities of
    computers, even though the latter have components that operate far
    faster than neurons.

    The model may also offer insight into creativity, which arguably
    arises from the brains propensity to make predictions. In Hawkins
    view, there is a continuum between everyday actions and perceptions
    and the production of great novels or symphonies. The cortex during
    normal waking moments combines its invariant memories with the details
    of what is happening now; it is constantly predicting things that are
    similar to, but at least slightly different from, what it has
    experienced in the past. Our brains are geared to come up with
    something new.

    Hawkins ventures that memory and prediction will be crucial to an
    understanding of consciousness, but he acknowledges that his model
    does not probe deeply into how and why consciousness exists. He draws
    a link between consciousness and memory through a thought experiment:
    If your memories of yesterdays activities were erased, so would be
    your sense that your behavior had been conscious. He speculates as to
    why vision, hearing, and other senses are (normally) experienced as
    qualitatively distinct, even though their inputs are all converted
    into patterns in the cortex. The answer, he suggests, might involve
    the diverse connections between the cortex and other parts of the
    brain.

    In his final chapter, Hawkins writes enthusiastically about the
    prospects for intelligent machines. He expects rapid progress in the
    development of brain-like systems in the next several decades, citing
    speech recognition, vision, and smart cars as promising near-term
    applications. He imagines super-intelligent systems that will predict
    the weather, foresee political unrest, and understand
    higher-dimensional spaces. Yet he emphasizes that intelligent machines
    will not be similar to us. They will have something like a cortex and
    senses, but not human-like bodies, emotions, or experiencesthings it
    would be very difficult, and generally pointless, to give them. They
    will not strive for power, wealth, status, or pleasure. They will not
    be angry at being enslaved.

    To illustrate the error of likening machines to human beings (and vice
    versa), Hawkins draws on a well-known thought experiment: A man who
    understands no Chinese is placed in a room with a wall slot through
    which he receives questions written in Chinese. Following a rule book,
    he replies to the questions with other Chinese symbols. To an outside
    observer, he seems to understand Chinese. But in fact, he has no idea
    what the questions or answers are about.

    For Hawkins, the story of the Chinese Room points to limitations of
    conventional A.I. and of the Turing Test, the standard that a computer
    is intelligent if a human inquirer cannot distinguish its replies from
    a persons. Hawkins adds, however, that the Chinese Room would display
    intelligence if it contained a memory system that could make
    predictions about the content of the Chinese messages passed through
    the slot. This is an interesting wrinkle but a debatable point. One
    can imagine the man in the room adeptly foreseeing which symbols will
    follow which others but still not knowing what they mean.

    The man who first asked us to imagine the Chinese Room was John
    Searle, a Berkeley philosopher who has written influentially about
    mind, language, and other subjects. His point was that a computer
    manipulates symbols but attaches no meaning to them; it understands
    nothing. Searle revisits the Chinese Room in Mind: A Brief
    Introduction. He rebuts the common counterargument that it is the
    overall systemman, room, rule bookthat understands Chinese. The point
    is the same, he contends, even if the man is in an open field and has
    memorized the rule book. Indeed, Searle believes his original argument
    did not go far enough in debunking computer intelligence; something is
    a computer, he elaborates, only if an intelligent observer interprets
    it as such.

    At the core of Mind: A Brief Introduction is Searles effort to situate
    mental activity in the physical world. Consciousness, he argues, is a
    biological phenomenon; it is a process of the brain, much as digestion
    is a process of the stomach. He emphasizes, however, that
    consciousness cannot be dismissed as an illusion or defined in terms
    of lower-level neurobiological processes. Conscious states exist
    insofar as someone experiences themthey have a first-person
    ontologyand in this regard they are distinct from physical phenomena
    that have a third-person ontology. The pain of banging into a coffee
    table (unlike the table itself) is real only because you feel it.
    Searle terms his position biological naturalism and contrasts it with
    the conventional categories of materialism and dualism.

    Searles picture leaves open the possibility of free will, defined here
    in contradistinction to determinism. In this view, quantum mechanical
    indeterminism at the micro-level may produce free will as a
    higher-level feature of the brain. In making decisions, the brain
    would draw upon the unpredictable behavior of its constituent
    particles. But wouldnt such freedom consist of mere randomness? Searle
    argues that this objection involves a fallacy of composition,
    confusing the properties of a system with those of its parts. Our
    pervasive experience of free will, he acknowledges, may be an
    illusion. But if so, it is a strange illusion, one that requires vast
    biological resources to maintain yet somehow survived evolutions
    travails.

    Searle ranges broadly across the subject of mental phenomena, poking
    holes in much received philosophical and scientific wisdom. A key
    feature of conscious experience, he notes, is its unified structure;
    one normally encounters sights, sounds, and so on as part of ones
    overall environment. Neurobiology, he ventures, will ultimately
    benefit more from a unified-field approach to consciousness than from
    the currently favored building-block emphasis. Searle also takes issue
    with philosophical arguments that humans perceive not the real world
    but merely sense data. Such claims, he contends, rely on slippery
    language and dubious assumptions.

    The concept of the unconscious, Searle argues, is indispensable for
    explaining some forms of human behavior, but it is sometimes pushed
    beyond its applicability. Unconscious mental states, in his telling,
    are states that could in principle become conscious. It is possible,
    for instance, to believe that George W. Bush is president even when
    you are sound asleep. In Searles view, however, cognitive scientists
    are incorrect to say, for example, that people see by performing
    unconscious computations on visual stimuli. The brain processes
    involved, much like the workings of the liver, are not the sort of
    thing that could be conscious; hence they are nonconscious rather than
    unconscious.

    Searle closes with a discussion of the elusive concept of the self. A
    longstanding philosophical tradition, initiated by David Hume, regards
    the self as a bundle of perceptions; we have a series of experiences
    but not an inner essence. Searle argues, to the contrary, that
    consciousness, a capacity to initiate action, and an ability to act on
    the basis of reasons do amount to a selfa non-Humean self that is more
    than just a set of experiences. Having such a self provides continuity
    between ones past, present, and future; it is what enables a person to
    take responsibility and make plans.

    Mind: A Brief Introduction and On Intelligence are thought-provoking
    and, no less important, anxiety-reducing. By dispelling overstated
    mechanistic claims arising from recent trends in neurobiology and
    philosophy, these books serve to combat public fears and forestall a
    possible backlash against science and technology. Humans can be part
    of the natural world without being mere machines, and without being
    outdone by our own machines.

    These books cast light on how it is possible to have a rich mental
    life while living in a physical universe. In so doing, they throw up
    roadblocks against any push for political authoritarianism or social
    engineering that might arise from increased knowledge of how brains
    work. Far from advancing tyranny, neurobiology may be starting to
    provide a deeper understanding of what human freedom is all about.

    -------------------------------------

    Kenneth Silber writes about science, technology, and economics for
    Mental Floss and Tech Central Station, among other publications.

References

    6. mailto:kensilber at yahoo.com
    7. http://www.amazon.com/exec/obidos/ISBN=0805074562/ref=nosim/reasonmagazineA/
    8. http://www.amazon.com/exec/obidos/ISBN=0195157338/ref=nosim/reasonmagazineA/