[Paleopsych] Sigma Xi: Brain-Based Values

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Brain-Based Values 

    [26]Patricia S. Churchland

    The Ethical Brain. Michael S. Gazzaniga. xx + 201 pp. Dana Press,

    Envision this scene: Socrates sits in prison, calmly awaiting
    execution, passing the time in philosophical discussions with students
    and friends, taking the occasion to inquire into the fundamentals of
    ethics: Where do moral laws come from? What is the root of moral
    motivation? What is the relation between power and morality? What is
    good? What is just?

    Ever modest, Socrates confesses ignorance of the answers. The pattern
    of questioning strongly hints, however, that whatever it is that makes
    something good or just is rooted in the nature of humans and the
    society we make, not in the nature of the gods we invent. This does
    not make moral rules mere conventions, like using a fork or covering
    one's breasts. There is something about the facts concerning human
    needs that entails that some laws are better than others.

    From the time of Socrates to the present, people have sought to give a
    natural basis for morals--that is, to understand how a moral statement
    about what ought to be done can rest on hard facts, albeit facts about
    conditions for civility and peace in social groups. How can ethical
    claims be more than mere conventions? How can such claims be rooted in
    facts about human nature but have the logical force of a command?

    Developments in evolutionary biology have helped to explain the
    appearance of moral motivation in humans and in other eusocial
    animals--animals that display behavior involving cooperation, sharing,
    division of labor, reciprocation and deception. In these species,
    various forms of punishment (shunning, biting, banishing, scolding)
    are visited on those who threaten the social norms. Ethological
    studies help us appreciate that, at a basic level, human social
    behavior has much in common with that of other species.

    Developments in neuroscience hold out the promise of extending the
    naturalistic perspective to aid in the understanding of how the brain
    and its circuitry underlie the capacity to learn social norms and to
    behave in accordance with them. Many of us ponder the possibility that
    discoveries about brain function and organization will challenge the
    conventional wisdom on which our system of justice relies and will
    allow us to see more deeply into the biology of social behavior,
    including moral behavior. In his new book, The Ethical Brain, Michael
    S. Gazzaniga takes an unflinching look at the interface between
    neuroscience and ethics, and offers his own thoughtful perspective on
    some of the tough questions.

    As a graduate student at Caltech, Gazzaniga studied under one of the
    towering figures of neuroscience, Roger Sperry, whose lab pioneered
    research into the cognitive effects of cutting the fibers connecting
    the two cerebral hemispheres (a procedure used to treat intractable
    epilepsy). Ingenious testing of these so-called "split brain" patients
    revealed that their two brain hemispheres operated independently, each
    hemisphere acting almost like a distinct person. These were profoundly
    important results, both for philosophy and for neuroscience. Gazzaniga
    went on to explore the neurobiology of higher mental
    functions--attention, memory, choice, consciousness--more generally,
    always with a philosophical question biting his heels. He currently
    serves on the President's Council on Bioethics. Thus it is especially
    fitting that he should now pen his thoughts on neuroethics.

    The most fundamental neuroethical issue concerns free will and
    responsibility. The mind is what the brain does, and the brain is a
    causal machine. Consequently, deliberations, beliefs, decisions and
    ensuing behavior are the outcome of causal processes. Typically, the
    causal processes leading to awareness of a decision are nonconscious.
    The "user illusion," nevertheless, is that a decision is created
    independently of neuronal causes, by one's very own "act of will."
    Some philosophers--usually called libertarians--resolutely believe
    that voluntary decisions actually are created by the will, free of
    causal antecedents. Like flat-earthers and creationists, libertarians
    glorify their scientific naiveté by labeling it transcendental

    Gazzaniga, like many a philosopher, realizes that it would make a
    mockery of the criminal justice system if the accused could escape
    punishment simply by pleading that the brain is a causal machine and
    hence he or she lacked free will. So when and how ought we to hold
    people responsible for their behavior?

    Gazzaniga's answer has two components: First, he claims that we hold a
    person responsible, causality notwithstanding, so long as his or her
    behavior was unconstrained--so long as the person could have done
    otherwise. Second, Gazzaniga identifies responsibility as a social,
    not a neurobiological, property. His point is that our institutions
    for assigning responsibility derive from the need to maintain and
    protect civil society, which must figure out suitable criteria for
    when and how to punish those who violate the rules.

    Gazzaniga sums up his solution to the problem of free will by saying
    that "the brain is determined, but the person is free." The logic of
    this brain/person duality is not particularly compelling, or even
    coherent, yet as Gazzaniga's writing implies, it may be in our
    collective interest to live by this dualistic legal fiction.

    The obvious test of the "let's pretend" solution is to see whether it
    can specify relevant criteria for distinguishing between those who
    could have done otherwise and those who could not have, and between
    those cases in which mens rea (literally, a guilty mind) obtains and
    those in which it does not. (Mens rea is a criminal law concept
    requiring proof that the mental state of the accused was such that he
    or she committed the crime purposely, knowingly, recklessly or
    negligently; strict liability, in which state of mind has no
    relevance, is fairly rare in criminal law.) Here, however, the wheels
    fall off Gazzaniga's solution.

    Worried that ever-cunning defense attorneys will try to extract more
    exculpatory mileage out of neuroscience than the facts can support,
    Gazzaniga magnifies the incompatibility of responsibility as applied
    to persons and the causality that governs functions of a person's
    brain. He says, "The issue of responsibility . . . is a social choice.
    In neuroscientific terms, no person is more or less responsible than
    any other for actions." This implies that there are no relevant
    factual differences between someone with, say, obsessive-compulsive
    disorder and someone who can resist impulses. Can this conclusion be
    right? As the British neuroscientist Steve Rose has pointed out,
    badness, just as much as madness, involves the brain.

    The flaw in Gazzaniga's argument is that although responsibility is
    assessed in a social context, the capacity to learn social norms and
    the capacity to act in accordance with them are matters of individual
    brain function. It is precisely because an important difference exists
    between a normal brain and the brain of someone who is seriously
    demented or unreachably deluded that such people are not considered
    responsible for crimes they might commit. Moreover, judicial
    institutions rely on threat of punishment to deter. The late
    maturation of the prefrontal cortex (with reference to neuronal
    density, synaptic density, dendritic length and myelination) means
    that the brains of mature adults are critically different from those
    of young children--which almost certainly accounts for the child's
    more modest ability to appreciate the consequences of his or her
    choices and to resist temptation.

    Satisfied that the brain/person duality is workable, Gazzaniga pushes
    the hypothesis further. He says that because assignment of
    responsibility is a social matter, not a matter of fact about the
    brain, neuroscience cannot possibly "settle" whether a person is
    responsible. Granted, determining legal responsibility is complicated,
    and neuroscientific knowledge cannot be substituted for knowledge of
    the law and of community standards. What kicks up sand, however, is
    the unfortunate choice of the word settle. Neuroscientific evidence
    can surely be relevant, even if the disposition of the case is settled
    by members of a jury whose brains follow some form of
    constraint-satisfaction algorithm. Yet Gazzaniga resolutely insists
    upon the stronger point: Neuroscientific data are not even relevant.

    Why not? His reasoning goes like this: As a group, schizophrenics, for
    example, are no more prone to violence than individuals in the general
    population. Ditto, he says, for people with prefrontal lesions. If a
    given schizophrenic, Mr. Jones, kills someone, it is mere theater to
    display his brain scans in court, picking out some abnormality or
    other as "the cause" of his homicidal behavior. There are no relevant
    differences that neuroscience knows about that can explain why Jones
    killed, but Smith (also schizophrenic) did not. Not everyone with low
    glucose levels engages in violence; not all citizens raised in an
    inner-city hell become drug dealers; not all premenstrual women beat
    their children. We can assume there are differences in the brain, but
    whatever these differences happen to be, they are not, he believes,
    relevant to determination of responsibility. Why? Because there is no
    "responsibility" area whose functionality can be examined through a
    scanner or with electrodes--not now, not ever. Responsibility is a
    social construct, not a brain function. This point, he believes, holds
    generally--for schizophrenics, for patients with prefrontal cortex
    lesions, and so forth. And for good measure, he suggests that the
    insanity defense itself is too imprecise and problematic to be of
    practical value.

    It is widely expected that neuroscience has, or soon will have,
    something to say about competence to stand trial, about whether the
    mens rea condition has been met and about appropriate sentencing. Thus
    Gazzaniga's bold thesis raises important concerns. I share his worry
    that defense attorneys and hired experts from neuroscience may get out
    in front of what current science can honestly say--it's bad enough
    that venal psychiatrists have sown wholesale distrust of their
    discipline by selling their "expertise" to the highest bidder. On the
    other hand, perhaps Gazzaniga overstates the case.

    Consider the Virginia man who at around age 40 became obsessed with
    child pornography and eventually molested his eight-year-old
    stepdaughter. He had no previous history of pedophilic inclinations,
    and his interest in child pornography completely disappeared with the
    surgical removal of a tumor of the frontolimbic system, which had
    invaded the hypothalamic area of his brain. Along with other
    appetites, sexual drive is regulated in the hypothalamus. Some months
    later, when the tumor grew back, his preoccupation with pornography
    returned, only to vanish again with repeat surgery. Because the waxing
    and waning of his sexual compulsions corresponded to the waxing and
    waning of the tumor, his was not a standard molestation case. So long
    as his limbic structures are tumor-free, it seems rather pointless to
    punish him for a pornographic pursuit that was alien to his character.
    Punishment would not make sense either as deterrence or as

    Consider a more complicated discovery. In a landmark longitudinal
    study in New Zealand that followed the lives of about 500 men from
    infancy to about age 26, a significant subpopulation showed a strong
    and unmodifiable disposition to engage in antisocial behavior,
    including irrational and self-destructive violence. Genetic analysis
    revealed that most of the men in that subpopulation carried a mutation
    for a particular enzyme, monoamine oxydase A (MAOA). The enzyme
    metabolizes three neuromodulators (serotonin, norepinephrine and
    dopamine, all of which are relatively concentrated in prefrontal areas
    of cortex), thereby inactivating them. Environment was also a factor:
    In the group with the MAOA mutation, the criteria for adolescent
    conduct disorder (a measure of antisocial behavior) were met in about
    85 percent of those who had been severely maltreated as children, in
    about 38 percent of those who had probably been maltreated and in only
    about 22 percent of those who had not been maltreated. Among those who
    did not carry the MAOA mutation but had been severely maltreated, only
    about 42 percent had the conduct disorder.

    These findings are preliminary, and further research is needed on the
    exact nature of the effect of early maltreatment on the circuitry
    affected by low MAOA levels. Still, on the face of it, the capacity of
    maltreated children with the MAOA mutation to acquire and act on
    social norms appears to be diminished. If Gazzaniga is right, however,
    these data are irrelevant to determining responsibility. The fact that
    the men are irrationally violent means that society needs protection
    from them--fair enough. Even so, it is important to distinguish
    between custody and punishment. Why? For the sake of the integrity of
    the institution of justice, because as a social institution, the
    criminal sanction depends on broad social support to keep functioning
    properly. When the criminal sanction is applied to cases that violate
    common beliefs about fairness--to young children, for example--support
    is replaced by resistance and reform. In order to be broadly accepted,
    the legal fiction that the brain is determined but the person is free
    will have to make peace with the widespread conviction that because of
    brain abnormalities, we are not all equally masters of our fate.

    On other bioethical issues, Gazzaniga is just as forthright. The book
    begins with a discussion of the medical use of embryonic tissue and
    the debate over whether a blastocyst (which is a ball of a few hundred
    cells) is a person. This section is thoughtful, clearheaded and
    informed by developmental neuroscience. One fallacy Gazzaniga exposes
    depends on the common idea that graded differences block principled
    legal distinctions. In the version referred to as the fallacy of the
    beard, the logic goes like this: If we cannot say how long a man's
    whiskers must be to qualify as a beard, we cannot distinguish between
    a bearded man and a clean-shaven one. Although this form of argument
    fools nobody on the topic of beards, it has been seductively employed
    elsewhere, especially regarding embryos. Criticizing the
    blastocyst-as-baby argument, Gazzaniga sensibly points out that we can
    draw a reasonable, if imperfect, line. When a distinction is needed,
    we devise laws that draw one, typically erring on the side of caution,
    given prevailing community attitudes. There is no precise moment at
    which a child becomes an adult, or a blastocyst becomes a sentient
    person, but reasonable humans unencumbered by superstition can
    nonetheless come together to "draw a line," and we can redraw the line
    when the facts merit a revision. Eighteen as the age of majority is
    not the perfect line for all adolescents, but on the whole it works
    well enough.

    Gazzaniga also presents an eloquent defense of personal choice in
    end-of-life matters, while recognizing that there are bound to be
    fundamental differences across people regarding euthanasia. Most
    people understand the concept of brain death and see the wisdom in
    equating death with brain death. In large part, this acceptability may
    be owed to personal experiences concerning the remarkable benefits
    conferred by organ harvesting.

    Other topics covered, if not fully, then sufficiently well to provoke
    thought, concern the neurobiological and evolutionary explanations of
    religious beliefs, in all their amazing variety and conflicting
    manifestations. Gazzaniga discusses also the remarkable nature of
    autobiographical memory, and the susceptibility of memory to
    suggestions, reconstruction, invention and wholesale confabulation.
    Because it is brief, compelling and free of technical jargon, the
    whole book can be easily read during a transcontinental flight.

    At a time when intellectuals may feel cowed by the heavy hand of the
    fervently religious, it is a relief to see that Gazzaniga neither
    shies away from controversial opinions nor waters them down so as to
    offend nobody. At the same time, he is respectful of moral convictions
    that do not line up with his own. His opinions are delivered not as
    dogma but as part of an ongoing reflection and conversation, in which
    seeing all sides of a moral problem is itself regarded as a moral

Reviewer Information

    Patricia Smith Churchland is University of California President's
    Professor of Philosophy and chair of the Department of Philosophy at
    the University of California, San Diego. She is the author most
    recently of Brain-Wise: Studies in Neurophilosophy (2002).

    [32]A letter on Patricia Churchland's use of the term "libertarian" in
    a review of The Ethical Brain, and a reply from Churchland



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