I recently mentioned in this blog how awed I am when I see a
baby becoming aware of its unique
self. Yet, what is the Self? That question has been examined for
millennia. Historically, the
answers have been all over the map.
Christianity identifies the self with a
God-given soul, separate from the body and surviving it. Buddhism denies the existence of a
distinct, permanent self, positing only an ever-changing consciousness, which
on death can be reincarnated into another body. Aristotle argued that the soul does not have an existence
independent of the body. Descartes viewed the soul as immaterial and distinct
from the material body, though oddly regarded the brain's pineal gland as the
place where they interact. Hume saw
the self not as a discrete entity, but as a bundle of sensations, perceptions
and thoughts, perhaps even rejecting the concept of the self altogether. Modern neuroscience may have a more
coherent story to tell … then again, it may not.
Our brain has about 100 billion
neurons, almost all present at birth.
They are not directly responsible for the functioning of the brain; that
role is assumed by the staggering number of synaptic interconnections that are
formed among them. Under genetic
control, the embryo's and infant's brain makes tens of millions of interconnections per minute, forming primitive neuronal networks that await
further sculpting.
In early life that sculpting is mostly
under the influence of sights and sounds.
For example, during a critical period for activating one primitive
network, optical data from the eyes drive the development of the visual cortex,
the site where those data are increasingly translated into recognizable
geometric and chromatic patterns.
In another critical period, the sounds of one's native language are
learned and categorized, leading to the formation of a language cortex. In a word, the neurons in our brain are
driven to form very specialized networks by a constant barrage of sensory
information arriving from the outside world.
More than influences from raw sensory
data are involved. We are social
creatures, so most of the behavior of our Self is impressed on our neural
system by interacting with others.
As babies, we realize early that smiling elicits attention. As we mature, we mimic others' behavior
as a way of becoming part of the social networks of home, school, workplace,
etc. We learn what is expected of
us and discover what is considered offensive or immoral. We share emotions. We respond to others' opinions of
us. We find out what others have
thought by reading and listening.
We acquire skills that are necessary for our lives and jobs. As this interaction with the outside
world proceeds from infancy throughout our life, the neuronal network in our
brain reformats itself constantly.
So what in fact is the Self? In The Self Illusion: How the Social Brain
Creates Identity, experimental psychologist Bruce Hood argues a
viewpoint close to Hume's. Self,
he contends, is no more than a mirroring of all the external influences we have
experienced throughout our lives, as filtered by and instantiated into the mass
of increasingly networked neurons in the brain. He doesn't deny the nature side of the nature-nurture dichotomy,
just asserting that our intrinsic properties
express themselves in interactions with the social world that defines us. It is an illusion, he says, for
us to try to distinguish anything about the Self that is independent of the
mirroring of the outside world reflected in the neuronal network.
To get a fuller understanding of Hood's reasoning, it's
worth while reading an interview
with him by Jonah Lehrer, the author of the book Imagine that I discussed in my posting Neurons
and Creativity.
Hood's representation of the Self may
seem compelling until one notices a big fly in the ointment: If the Self is illusory, so free will
must be. Hood claims that even
now, as I type this very sentence, I am not exercising free will. Any choices I think I have made, he
says, "must be the culmination of the interaction of many hidden factors
ranging from genetic inheritance, life experiences, current circumstances and
planned goals … play[ing] out as patterns of neuronal activity in the brain. …
We are not aware of these influences because they are unconscious and so we
feel that the decision has been arrived at independently." Hood is not at all alone among
contemporary neuroscientists in holding this doctrine. Sam Harris has just
published a short tractate Free
Will that makes the
same case, as do others. They
paint a disconcerting picture of humans as self-programming automata that develop only under the influence of the social matrix in which they are embedded, with no vestige of
free will.
In short, Hood and Harris come down
firmly on the side of Spinoza, who said, "Men are mistaken in thinking
themselves free; their opinion is made up of consciousness of their own
actions, and ignorance of the causes by which they are determined." But, if Hood and Harris are
wrong, if there is free will, their model of Self lacks an extremely important
component.
In supporting their position on free
will, both writers cite a few EEG and fMRI experiments that purport to show
that the motor cortex of a subject's brain exhibits activity a half-second
or more before the subject senses a decision to move. Hood, however, points out that such results are prone to
misinterpretation. The subject is
both the observed and an observer, passively awaiting an urge to act while simultaneously actively trying to detect consciousness of a decision to act,
both in the same neuronal network.
Interaction of these activities may distort the results.
Aside from these scant and questionable
neurophysiological results, Hood's and Harris' main case against free will is
based on proof by fiat: it's so because I say it's so. Their very definition of Self—i.e., no more than a mirroring of our
lifelong interaction with the outside world, instantiated in a neuronal network
that runs autonomously—is taken as an axiom. They then conclude that the Self ipso
facto cannot contain an
independent free will, since free will is not part of the axiom. As Harris says, "Thoughts and
intentions simply arise in the mind.
What else could they do?"
This seems to me to be a classic case of circularity, of begging the
question. It doesn't pass the
smell test. Dare I say that it is illusory?
Despite their insistence that there is
no free will, both authors are pragmatic.
Hood points to data showing that believing in free will leads to
better performance in, and enjoyment of, life. Harris says that "for most purposes, it makes sense to
ignore the deep causes of desires and intentions—genes, synaptic potentials,
etc.— … when thinking about our own choices and behaviors." I agree, and more than just as a way of
avoiding the issue. Until
neuroscience can provide a much more complete understanding of the subject,
I believe that free will will remain in the domain of philosophy and religion.
Meanwhile, I will continue to believe that I wrote this posting because
I intended to do so of my own free will, not because of the firings of autonomous
and anonymous neurons.