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Dan Pouzzner~~9.85~~16 Dec 92~~Major Disorders of Mind and Brain\\
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Perhaps the most disturbing mind to interact with is a broken one.
People who suffer from disorders such as schizophrenia, mania, Down's
Syndrome, William's Syndrome, or any of the other physiologically
detectable disorders, can easily shock those whose minds are normal.
What is obvious to a healthy mind is incomprehensible to a broken one,
and what is obvious to a sufferer of schizophrenia or mania is
ludicrous to a healthy mind. Progress in cognitive science,
neurophysiology, neurochemistry, and psychology, have all enlightened
these disorders to varying degrees. Nonetheless, many aspects of the
broken brain are just as mysterious as the operation of the healthy
brain. In fact, a better understanding of the healthy brain would
greatly assist an understanding of broken brains and vice versa.\\

Scientific American's September special issue, ``Mind and Brain,''
includes an article titled ``Major Disorders of Mind and Brain'' which
is essentially a rehashing of the present understanding of the
relationship between genetic factors, environmental factors, physical
abnormalities, and broken minds. It offers treatments of two
disorders, schizophrenia and depression/mania.\\

A pattern that starts to emerge is that, though the relationship is
very complex, virtually all disorders have a statistical correlation
with genetic factors to one degree or another. Incidence of
schizophrenia is profoundly influenced by pedigree. Bipolar disorder
has a similar link to genetics: ``Mood disorders also stem from the
interaction of genes with some aspect of the environment.''(p.129)
The issue I address in this essay is the nature of this interaction.\\

With genetically identical twins, the development of schizophrenia in
one of the pair is very tightly correlated to its incidence in the
other, but it is not automatic. Why is this? Schizophrenia has severe
consequences for the structure of the mind and brain, detectably
affecting the prefrontal lobe of the cerebrum, the ventricles, the
cortex, and the hippocampus. If a pair of individuals with identical
genetic endowments can diverge this dramatically, then perhaps the
significance of environmental factors is being underestimated.\\

Statistical phenomena like the rise in incidence of bipolar disorder
and schizophrenia in the developed world pose and answer questions at
the same time. The developed world in the last hundred years or so has
seen a radical increase in the intensity of typical sensory
experiences. Moreover, the introduction of film and television, and
especially of animation and special effects, has produced a vast array
of intense and highly inconsistent sensory experience that is ingested
by virtually everyone from a very early age. Films replete with sex
and violence are also archetypically psychopathic, in that they
instill in the viewer an emotional detachment from sensory experience.
A bullet or blade no longer means death but only means blood, and an
orgasm no longer means new life but becomes something more akin to
shooting heroin.\\

These environmental factors are very reminescent of the symptoms of
schizophrenia. The mood of a schizophrenic is often inappopriate for
the situation, and his reasoning is impaired by a dissociation from
reality, both in perception and in interpretation. Somewhat similarly,
a bipolar mind experiences wild swings of mood that have little or
nothing to do with what it experiences through its senses. In both
disorders, the state of the mind is not appropriate given its sensory
input (cognitively the closest a mind can get to reality).\\

Back to the identical twins: how is it that the experiences of
identical twins raised in the same household can be so dramatically
different as to lead to development of a catastrophic disorder in one
but not in the other? Detailed examination of the children's behavior
starting at birth would surely help in understanding this. Another
clue is that physiological differences between the twins have been
detected in utero. Somehow the development of the two genetically
identical fetuses is affected by environmental factors very early on
(which demonstrates just how sensitive developmental phases are). Is
it just chance?\\

One reason researchers are handicapped in their efforts to understand
the origins of a disorder is that it is entirely unclear what the core
symptom of a given disorder is. Is the hippocampus shrunken because a
neurotransmitter imbalance results in understimulation, or is the
understimulation or imbalance a result of a hippocampal anomoly? In
the case of schizophrenia, a strong case can be made for a
neurotransmitter imbalance leading to the cortical and cerebral
underdevelopment, but still the cause of the hippocampal
underdevelopment seems ambiguous.\\

Once again, the key to dramatic progress in understanding major
disorders is a unified theory of mind and brain. This is the holy
grail of cognitive science, and the field is inching toward this goal
steadily now. It is perhaps the most important project of the
nineties, the Decade of the Brain, a turning point in humans'
understanding of themselves.\\

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