[escepticos] The Responsible Brain

[Pedro J HernÃndez GonzÃlez <pedroj.hernandezgonzalez@xxxxxxxxxxxxxxxxxxxxxx>]

DespuÃs de nuestro debate algo confuso (por no saber realmente a veces
lo que discutÃamos en el fondo) de hace unas semanas sobre valores,
genes, cerebro y cultura, me retirà a hacer los deberes y he descubierto
un tema ciertamente apasionante. Por ejemplo el siguiente libro y su reseÃa
*
The Responsible Brain

*Neuroscientist Michael Gazzaniga says âbrains are determined; people
are free.â But is our freedom independent of having a brain in good
working order?

http://www.naturalism.org/criminal.htm#brain

Gazzaniga's book is also reviewed by philosopher, Patricia S. Churchland:

*Brain-Based Values

*Patricia S. Churchland

The Ethical Brain. Michael S. Gazzaniga. xx + 201 pp. Dana Press, 2005.

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 moralsâthat 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
animalsâanimals 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
functionsâattention, memory, choice, consciousnessâmore 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
philosophersâusually called libertariansâresolutely believe that
voluntary decisions actually are created by the will, free of causal
antecedents. Like flat-earthers and creationists, libertarians glorify
their scientific naivetà by labeling it transcendental insight.

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 unconstrainedâso 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 childrenâwhich 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 electrodesânot now, not ever. Responsibility is a social
construct, not a brain function. This point, he believes, holds
generallyâfor 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 sayâit'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 retribution.

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
themâfair 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 fairnessâto young children, for exampleâsupport 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 achievement.
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).

http://www.americanscientist.org/template/BookReviewTypeDetail/assetid/44445;jsessionid=baa6S5z-1EUlg4