*** Warning: creationists are liable to be offended by this post, so they
may wish to avert their eyes now. ;-) ***
Channel 4 television broadcast a very interesting documentary programme last
night, called "Phantoms in the Brain", about the work of neuropsychologist
Dr V S Ramachandran.
Dr Ramachandran explores the workings of the brain by studying patients with
a variety of neurological conditions, such as phantom limb pain. One of the
less well known conditions covered was a mysterious one called
"anosognosia". Typically this results from damage to the right parietal lobe
of the brain. We were shown a patient suffering from this condition. He was
paralyzed in the left side of his body, but was convinced that that side of
his body was functioning normally. When asked to clap his hands together, he
waved his right hand against empty air or clapped it against his chest, yet
was still convinced that his left hand was working too!
Dr Ramachandran has developed a theory to explain how such patients come to
believe things which are so obviously untrue. See below for some info that I
found on the web. The theory may give some insights into how it is that
intelligent, well-educated people can fail to see their logical errors even
when those errors are obvious. Of course, I'm thinking specifically about
creationists here, but we see it also with other groups of people who hold
powerful dogmatic beliefs. And, to a lesser degree, the phenomenon affects
all of us.
I find this subject fascinating, and I'm impatiently awaiting next week's
program (Sunday 8.00pm, for any other Brits out there). Dr Ramachandran has
also written a book on the subject
(http://www.amazon.com/exec/obidos/ASIN/0688172172/neurosoftinccomp/103-2995
682-3675829).
Richard Wein (Tich)
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Coherencing of consciousness: lessons from anosognosia, supernumerary
phantom limbs, multiple personalities, and freudian defense mechanisms
V.S. Ramachandran (UCSD, La Jolla, CA 92093 0109, USA)
We present a new theory of human nature based on our experiments on
anosognosia and phantom limbs. Some right hemisphere stroke patients will
vehemently deny that their left arm or leg is paralyzed (`Anosognosia') even
though they are mentally lucid and intelligent. We present several new
experiments and a new theory to account for the syndrome. Specifically, we
suggest that in normal individuals the left hemisphere orchestrates a
coherent and internally consistent `belief system' and folds new experiences
into this pre-existing belief system. When a discrepancy threatens the
belief system, one option would be to ignore it, i.e. preserve the status
quo by engaging in denial, repression, reaction-formation, rationalization
and other Freudian `defense mechanisms'. The purpose of this is to ensure
stability and avoid indecisive vacillation. When the discrepancy, or
`anomaly', becomes too large, however, a devil's advocate in the right
hemisphere, performs a global consistency check and steps in to force a
complete revision of the internal, i.e. a Kuhnian paradigm shift. In
anosognosia, this devil's advocate is non-functional, and without it there
is no limit to the delusions that the left hemisphere will engage in. As an
analogy consider a military general in the heat of battle. Based on the
information provided by several scouts (e.g., `We have 600 tanks but the
enemy has only 500 tanks'), he decides to launch battle at dawn, at 6 am. A
single scout then shows up at 5:59 am with the information that he had
spotted 700 enemy tanks. Obviously, the general has no time to completely
revise the battle plan and he may decide to ignore the scout instead
(`denial'). But if the scout claims that the enemy had nuclear weapons the
general would be foolish to adhere to the original plan. Instead of a single
anomaly, if there are several anomalies inconsistent with the original
belief system (A), but consistent with each other, they may coalesce -- like
soap bubbles -- into a new belief system (B) that is insulated from (A);
creating multiple personalities. A phantom limb usually arises from multiple
sources (Ramachandran, PNAS, 1993, Nov.), e.g., stump neuromas, reafference
from motor commands, `memory' of the original limb and activity of
`remapped' sensory zones. These ordinarily convey mutually consistent
information but if the information from one source is inconsistent, the
dominant source prevails (`winner-take-all'). But if the inconsistent
information is too salient to ignore, another option would be to hallucinate
a non-existent limb -- a supernumerary phantom. The phenomenon is seen in
brachial plexus avulsion, as an illusion (Ramachandran, 1995 in press) in
that the patient recognizes its illusory nature. But in right hemisphere
stroke, even though the source of the illusion is the same (i.e., multiple
mutually inconsistent sensory inputs); the patient becomes convinced of its
reality since he has no `devil's advocate' to check global consistency. Many
enigmatic aspects of human nature such as caprice, innovation and creativity
may be manifestations of `complexity at the edge of chaos emerging at the
transitional zone between stability and deterministic chaos. Furthermore,
our theory is a viable alternative to Triver's `concealed lie' theory of
self deception and it also provides a Darwinian framework (Ramachandran,
Int. Rev. of Neurobiol., vol. 37, 1994) for interpreting a wide range of
seemingly unrelated clinical oddities such as anosognosia, supernumerary
phantoms, multiple personalities, Freudian defense mechanisms and the
creative surges of manic-depressives. It may even account for otherwise
inexplicable phenomena such as `misoplegia' (hatred for one's own left arm)
and the evolutionary origins of laughter and humor.
(http://www.maurer.demon.co.uk/SPECIAL/02_05.html#121)
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