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No, this column is not about Isaac Asimov’s famous science fiction
novels concerning the interaction between robots and humans (and
even less about the recent movie by the same title, very loosely
based on said novels). Rather, this month’s essay has been inspired
by the reading of Antonio Damasio’s Looking for Spinoza, the third
in a series of books by this neurobiologist that attempts to unravel
the mysteries of consciousness (the other two are Descartes’ Error
and The Feeling of What Happens).
One of the most recurring instances of anti-naturalistic prejudice
is the refusal to admit that the mind is a result of the activity
of the body; no ectoplasm needed, as philosophers of mind put it.
Few today would reject the notion that the body itself is very much
like a machine. I was reminded of this rather obvious conclusion
during a recent trip to the dentist: listening to a mechanical tool
working its way through my teeth in order to fix the problem (I
was having a root canal operation) it occurred to me that there
was little difference between my predicament and a mechanic working
on my car. This is a rather novel conception of the human body:
before the work of philosopher-scientist Rene` Descartes in the
17th century it would have been inconceivable even for most scientists
to think of the body as a machine.
But the mind, still most people say today, is an entirely different
matter. After all, Descartes himself stopped short of extending
his reductionist analysis to human thought (though it isn’t at all
clear weather he did so out of genuine conviction or as an attempt
to avoid the fate of his contemporary Galileo). Yet, consider the
following instance, reported by Damasio in Looking for Spinoza.
A group of neurosurgeons at a hospital in Paris was conducting a
farly routine operation on a patient affected by Parkinson’s disease.
The idea was that, since the woman wasn’t responding to drug treatment
anymore, the medical equipe would go straight into her brain and
stimulate via electrodes specific regions of the brain stem. The
procedure usually yields stunning results, which completely erase
the symptoms of the disease, greatly improving the patient’s quality
of life, at least temporarily.
In this particular instance, however, something went wrong. When
one of the electrodes was activated, the patient suddenly stopped
talking, began looking very sad and started crying uncontrollably,
eventually explaining how her life was meaningless and she wished
to die. It is important to note that the individual in question
had never shown symptoms of depression before the implantation of
the electrode. Even more stunningly, the talk of suicide, the crying,
and the sad expression all decreased and then disappeared minutes
after the electrode was removed by the medical scientists! If this
doesn’t sound like a machine being turned on and off at will by
a simple electrical stimulation, I don’t know what will convince
you.
A crucial reason why Damasio is interested in cases like the one
of the French woman affected by Parkinson’s lies in the exact sequence
of events and what it tells us about the nature of human thought.
Notice that the facial signs of sadness appeared first, followed
by the crying, and only significantly later by the articulation
of the feeling of emptiness and despair. The same sequence has been
found in other experiments and it suggests that feelings are generated
by the brain’s thinking about, or perceiving, the body’s emotions.
That is, emotions are simpler physical phenomena, while feelings
are more complex, second-order, mental events.
Still not convinced that we are very sophisticated biological machines,
in both body and mind? Then consider another fascinating example
from Damasio’s book. One of his own patients was affected by a bizarre
and rather disturbing condition, which provides a stunning insight
into the mind-body connection. The man in question suffered occasional
episodes during which he would begin to loose the feeling of the
lower parts of his body, as if under local anesthesia. The loss
of feeling continued gradually upwards throughout the body, until
it reached the throat, at which point the man passed out. A similar
condition affecting a female patient did not cause her to loose
consciousness, despite the frightening experience of no longer feeling
her limbs and trunk. Tellingly, this second patient retained a sensation
of her internal organs. Damasio suggests the intriguing possibility,
based on these and similar cases, that we have a mind only until
we have a body sensation of some sort (even highly incomplete, as
in the case of the second patient). However, no body immediately
means no mind. What more compelling evidence could there be that
dualism is dead in its tracks?
Damasio goes further, and in his book he builds a convincing, if
circumstantial, case for the radical idea that the mind actually
is a monitoring system of the internal and external state of our
body. The mind, then, is not a thing, but a process (of the brain,
and hence the body) by which certain animals with complex brains
keep track of and control what their bodies are doing. We seem to
be well on our way to truly explain consciousness as a biological
phenomenon. All of this, of course, is no reason to think that we
are “just” robots in the demeaning sense of being “mere” machines
having no intrinsic value. There is nothing trivial or simple about
the working of the human body and mind. Moreover, human life has
value for other humans, and scientific evidence of the kind I discussed
here is meant to help us understand how we generate, literally,
our selves, not to tell us how much we should value those selves
from an ethical perspective.
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