Not too long ago, the New York Times "Opinionator" blog ran a piece titled “Can Neuroscience Challenge Roe v. Wade?”
by William Eggington, a professor of humanities at Johns Hopkins
University. Eggington argues that scientific information has no place in
the formulation of public policy on matters involving essential human
rights. In such matters, he claims, science is irrelevant because
rights "have nothing at all to do with the truths of science," and
therefore "should not be dependent on the changing opinions of
science."
Eggington's piece responds to several states’ recent efforts to
restrict abortion prior to viability based upon a fetus’s ability to
experience pain. The author dismisses the possibility that a fetus is
capable of “reflective” pain awareness and asserts that the "real
purpose" of such statutes is "to use potential evidence of pain
sentience in fetuses to indicate the presence of something far more
compelling—namely, personhood."
Eggington rejects this effort because neuroscience "has nothing to
say about the fundamental question of what counts as a full-fledged
person deserving of the rights afforded by a society." Moreover,
Eggington sees such incursions of science into issues of human rights as
both inappropriate and dangerous, concluding ominously, "When science
becomes the sole or even primary arbiter of such basic notions as
personhood, it ceases to be mankind’s most useful servant and threatens,
instead, to become its dictator."
"Humanizing" Humans
As a practicing research neuroscientist and bioethicist, I disagree
with Eggington's thesis on a number of grounds, most immediately with
his odd contention that because a fetus is unlikely to experience pain
in precisely the "reflective" manner of a mature human, fetal pain
statutes are nothing more than a covert attempt to advance a particular
view of personhood.
Imposing avoidable pain on any pain-capable organism is cruelty
and most modern societies have enacted laws against cruelty,
irrespective of the precise quality of pain involved. We do not need to
know if a human fetus is self-reflective or even self-aware to afford
it the same consideration we currently afford other pain-capable
species. I am pretty confident, for example, that a chicken does not
experience pain in the same manner I do, but I support legislation to
ensure that poultry are killed in a pain-free, humane manner. Certainly
a human fetus that is capable of experiencing pain in any manner deserves at least the same degree of consideration as a chicken that doesn't even have the regions of the brain responsible for "higher" functions, such as consciousness and self-reflection.
Eggington is clearly concerned about the psychological impact of
fetal pain legislation; that if society acknowledges a fetus is capable
of experiencing pain in any capacity, the fetus will assume greater
value in the minds of many, and therefore abortion may be subjected to
more stringent regulation.
Yet concern that laws designed to avoid fetal pain will serve to
"humanize" the fetus must be reconciled with a humane position on the
prevention of cruelty. Simple fear that "anthropomorphizing" the fetus,
to the same degree society currently anthropomorphizes pets and farm
animals, might result in a restriction of the abortion license cannot
justify the continued practice of cruelty. The knowledge that pets
experience pain in some capacity prevents us from "euthanizing" them in
the same manner that we currently destroy a fetus during an abortion.
Does anyone really consider animal anti-cruelty laws an inappropriate
restriction of the practice of animal euthanasia or an unwarranted
intervention of science into public policy?
Fetal "Personhood"
Eggington dismisses what he sees as a disingenuous attempt to use
neurobiological data to extend legal personhood to a fetus, because
"science does not and should not have the power to absolve individuals
and communities of the responsibility to choose." Yet this argument
clashes with historical fact. In the two landmark cases that have
determined current abortion policy, Roe v. Wade and Planned Parenthood v. Casey,
the courts used scientific knowledge to help determine the state's
interests in protecting the fetus after "viability." If this knowledge
has informed current policy, how can it legitimately be excluded as a
basis for revising this policy in light of new scientific evidence?
Moreover, it is absurd to claim that states are using neurobiological
information as a Trojan horse to extend legal rights to a fetus.
Subterfuge isn’t necessary when a concept is already well-accepted in a
large body of existing legislation and legal precedent. In virtually
every area of law outside the restricted domain of abortion, the courts
have both recognized and repeatedly upheld the rights of the fetus.
More than two-thirds of the states have statutes that define killing an unborn child in any context outside of abortion as criminal homicide,
and despite numerous court challenges, none of these statutes has been
struck down on any grounds.
A majority of the states that allow capital
punishment prohibit execution of a pregnant woman, in the interest of
protecting the life of the innocent unborn child. Similarly, most states
prohibit withholding or withdrawing life-sustaining medical treatment
from a pregnant woman under the authority of an advance medical
directive, in order to protect the rights of the fetus in such
situations. Multiple areas of tort law recognize the rights of the
fetus, with thirty states admitting fetuses as plaintiffs in cases of
prenatal injury or wrongful death. Finally, property law also recognizes
the rights of an unborn child to inheritance, and all states permit a
guardian ad litem to be appointed to represent the legal interests of the unborn child in such situations. 1
Clearly, in many areas of the law a fetus already is
recognized as a legal individual (i.e., the holder of rights, equally
protected under the law), independent of the “dictates” of neurobiology.
The Development of the Human Nervous System
Given the potentially significant social and legal impacts of fetal
pain, it is important to consider what neuroscience has to say about
fetal brain development and whether this information appropriately
informs our concept of "personhood." Consciousness and the kind of pain
perception it enables are complex. And the development of this capacity
is continuous from very early embryonic stages.
The earliest “rudiment” of the human nervous system forms by
twenty-eight days after sperm-egg fusion. At this stage, the primitive
brain is already "patterned," that is, cells in different regions are
specified to produce structures appropriate to their location in the
nervous system as a whole. Over the next several weeks, the brain will
grow enormously and generate many complex connections, but the overall
organization of the nervous system is established by twenty-eight days.
This is significant because it shows that even at this early stage, the
brain is not anything like a mere collection of cells or a “blank slate”
to be written upon by later developmental processes. Like all embryonic
organs, the structure of the early brain "anticipates" the organization
and function of the mature system.
In the region of the brain responsible for consciousness (the
neocortex), the earliest neurons are generated during the fourth week. 2 The earliest connections between neurons are detected by 37 days and are well established by 8-10 weeks. 3 This
indicates that the brain is “wiring” itself in the first trimester,
well before reaching the fetal stage of life. Early establishment of
connections between neurons further indicates that brain formation is an
active process of progressively building the structures and
relationships required for mature brain function.
There is good evidence that communication between neurons of the
brain is established in the seventh week. Synapses, or the molecular
structures required for brain cells to communicate with each other, are
detected in the cortex at this time. 4 In
animals, synapses are functional immediately and this is likely also
true of humans. Thus, the earliest function of the neocortex as a
network (not “consciousness” strictly speaking, but merely communication
among large groups of cortical neurons) is likely to commence in the
seventh week.
After this point, the communication between different regions of the
brain becomes progressively more complex. The long-range connections
within the cortex that are believed to be required for consciousness do
not arise until much later, around twenty-two to twenty-four weeks of
gestation. 5 And
these connections continue to develop for an exceptionally long time.
Indeed, recent studies indicate that the anatomy of the human brain, and
therefore the pattern of brain activity underlying all higher functions
(reason, memory, emotion, language, etc.) is not fully mature until approximately twenty-five years after birth. 6
Consciousness and Personhood
Structures capable of new functions are formed throughout
embryogenesis. For example, grasping becomes possible once hands have
formed. But the fundamental process of development proceeds
continuously, both prior to and after hand formation, and the onset of
this function reflects an ongoing developmental process. Given the continuous nature of development, to argue that embryos and fetuses become
humans once some anatomical or functional landmark such as
"consciousness" has been achieved is to assert some kind of magical
transformation; i.e., that at some ill-defined point, a non-human entity
spontaneously transmogrifies into a human being, without any change
whatsoever in its behavior, its molecular composition, or any other
observable feature.
I reject this argument. For something actually to transform into a
different kind of thing, a change must take place in its composition or
in its pattern of biological activity. For example, sperm and egg are
two specific human cell types that fuse to produce a distinct cell (the
zygote) with unique molecular composition and with a pattern of organismal
behavior that is distinct from the behavior of either sperm or egg. A
clear, non-magical, scientifically observable transformation from one
kind of entity (two human cells) to another kind of entity (a distinct
human organism) has occurred.
Similarly, a living person transforms into a corpse at death, and
this is also an observable event. Respiration stops. Heartbeat stops.
Brain activity stops. Eventually, all metabolic processes stop and
decomposition alters the molecular constitution of what was once a
living person. The precise "moment" in time at which death occurs may be
difficult to determine, but corpses are clearly distinguishable from
living persons based on a large number of observable traits.
Yet in the logic of those who want to assign personhood based on consciousness, no difference whatsoever can be observed between those who possess "personhood" and those who do not. The entity has acquired a new function,
based on the maturation of the underlying neuroanatomy, but the entity
itself is not distinguishable from the "non-human" entity that preceded
it. Such an arbitrary definition can hardly be the basis for determining
who is the subject of "essential human rights."
Building the complex architecture of the brain is a continuous
process that is initiated at sperm-egg fusion and proceeds through
orderly steps under the direction of a "builder," that is, a human
organism that is present from the beginning. The presence of an agent
capable of constructing the mature body, including the brain, is the
only sustainable definition of a human being. This agency should not be
misconstrued as some kind of mystical or spiritual element that is
merely attributed to an embryo or fetus based on personal or religious belief. The fact that the embryo acts as an agent is entirely a matter of empirical observation; embryos construct themselves.
As a scientist, I view the manifestation of this agency as a sequence
of biochemical processes that proceeds in a manner characteristic of
human embryos. Others may choose to see this agency in more spiritual or
poetical terms, but such a viewpoint does not alter the scientific
facts; embryos manifest a unique molecular composition and pattern of
behavior characteristic of an organism, and this conclusively
demonstrates a level of agency that is definitive of a human being.
To assert that a human being is only present once a specific anatomic
landmark has been achieved is absurd. The argument is analogous to
pointing at a construction site where the foundation has been dug but no
concrete yet has been poured, and asserting, "Clearly there is no
building company involved in this, because there isn't yet a structure
sufficient to be called a ‘building.’ We must wait until at least six
stories have been completed." This argument confuses the product of construction with the existence of an agent capable of doing
the construction. If we must wait until a certain level of structure
exists before we conclude a builder/contractor is present, how do we
explain all of the many orderly events that occur prior to this point?
Does the organized assembly of concrete, girders, glass, wire, pipes,
and countless other components just happen spontaneously?
Analogously, does a collection of human cells just so happen
to put together eyes, fingers, internal organs, and countless other
structures in a coherent, integrated manner, and then wait for
"consciousness" to breathe life into this amalgam of random parts?
Clearly, this is an argument that cannot be rationally maintained in the
face of factual evidence.
Science and Public Policy
To conclude, we must return to Eggington's initial assertion: that science should not, and indeed cannot,
contribute to the formation of sound public policy on matters of human
rights, because human rights are based on some undefined factor that is
outside the realm of science. While I agree that the essential rights of
humans are not determined by science, what constitutes an infringement of essential human rights and who, in actuality, is the holder of such rights, can and should be informed by scientific facts.
For example, in the past, lead-based paints were not considered a
threat to human health. Once scientific studies provided evidence that
children's health could be harmed by accidental consumption of paint
dust containing lead, legislation banning the manufacture and sale of
lead-based paint was put in place to protect children's health. Science
did not "dictate" that protection of children's health was required or
desirable; this was already a component of our culture and our laws. But
science legitimately determined what constitutes a threat to children's
health.
In a similar manner, science does not dictate that citizens have a
right to equal protection under the law, but science establishes that
individuals with different levels of skin pigmentation are all members
of the species Homo sapiens. And this scientific understanding legitimately
“dictates” that all such individuals are the subjects of this essential
right. In the same way, science has clearly determined when human life
commences, and this determination legitimately dictates that equal
protection under the law must extend to human beings at embryonic and
fetal stages of development.
Dr. Maureen L. Condic is a tenured associate professor at the University of Utah School of Medicine, who studies the development and regeneration of the nervous system and teaches medical embryology.
Notes:
- Paul Benjamin Linton, “The Legal Status of the Unborn Child Under State Law,” 6 U. St. Thomas J. Law & Pub. Pol. (2012) ↩
- Tangential networks of precocious neurons and early axonal outgrowth in the embryonic human forebrain. Bystron I, Molnár Z, Otellin V, Blakemore C. J Neurosci. 2005 Mar 16;25(11):2781-92.; ApoER2 and VLDLR in the developing human telencephalon. Cheng L, Tian Z, Sun R, Wang Z, Shen J, Shan Z, Jin L, Lei L. Eur J Paediatr Neurol. 2011 Jul;15(4):361-7.; The first neurons of the human cerebral cortex. Bystron I, Rakic P, Molnár Z, Blakemore C. Nat Neurosci. 2006 Jul;9(7):880-6. Epub 2006 Jun 18.; Development of the human cerebral cortex: Boulder Committee revisited. Bystron I, Blakemore C, Rakic P. Nat Rev Neurosci. 2008 Feb;9(2):110-22. ↩
- Development of axonal pathways in the human fetal fronto-limbic brain: histochemical characterization and diffusion tensor imaging. Vasung L, Huang H, Jovanov-Milošević N, Pletikos M, Mori S, Kostović I. J Anat. 2010 Oct;217(4):400-17.; Insights from in vitro fetal magnetic resonance imaging of cerebral development. Kostovic I, Vasung L. Semin Perinatol. 2009 Aug;33(4):220-33. ↩
- Synaptogenesis in layer I of the human cerebral cortex in the first half of gestation. Zecevic N. Cereb Cortex. 1998 Apr-May;8(3):245-52. ↩
- Functional maturation of neocortex: a base of viability. Gatti MG, Becucci E, Fargnoli F, Fagioli M, Ådén U, Buonocore G. J Matern Fetal Neonatal Med. 2012 Apr;25 Suppl 1:101-3; 3D global and regional patterns of human fetal subplate growth determined in utero. Corbett-Detig J, Habas PA, Scott JA, Kim K, Rajagopalan V, McQuillen PS, Barkovich AJ, Glenn OA, Studholme C. Brain Struct Funct. 2011 Jan;215(3-4):255-63. Epub 2010 Oct 29. ↩
- Gogtay N et al. (2004) Dynamic mapping of human cortical development during childhood through early adulthood. Proc Natl Acad Sci USA 101(21):8174; Sowell ER et al (2003) Mapping cortical change across the human life span. Nat Neurosci 6(3):309. ↩
