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Are Brains Smarter Than Us?

Rugrat johnhkm at logicworld.com.au
Wed Jul 22 21:14:05 EST 1998


    22/07/98 23:31

Help.

Over recent years there have been many significant advances in the
neurosciences but it seems to me that there still must be drawn a sharp
distinction between the findings of neuroscience, presently at least, and
the nature of human consciousness. No surprise there, but it irritates me.

Many years ago I saw a BBC special in which they interviewed a number of
adults (ages 18 -25) who had developed hydrocephalus as children and had a
shunt installed. Performing CAT scans (I think) the researchers established
that a few of these individuals had suffered significant tissue loss due to
shunt failure. One of the students, a 21 year old honours math student at
Birmingham University (I think, it was over 7 years ago), had less than half
or third of the typical neocortex; although he did have a very rich blood
supply to the remaining regions(signficant).

The CAT scans were fascinating as the tissue loss was obvious. I mentioned
this to a psychologist once who tepidly replied, "Well, the brain is 50%
fat." The tissue loss involves both grey and white matter. Mylineation,
important stuff, irrelevant. The issue is that there must have been a major
disruption of the internal pathways, although I doubt the corpus callosum
was damaged too much. Another consideration here is that 3 significant (two
specialised) pathways only on the left hemi, the superior longitudinal
fasciculus, the arcuate fasciculus, and the angular gryus, were also
probably spared, but many thalamic connections and nuclei were involved, and
also the frontal lobe-limbic (mesocortical?) connections were probably
damaged. Given this and the likely limbic disruptions
(hippocampus\amgydala?) I thought emotional anomalies would be prevalent
amongst such patients.

The damage is gradual, and experiments have confirmed that a number of small
lesions is much less damaging than a single large lesion, the hypothesis
being that the brain can cope with the little disasters but is overwhelmed
by the quick big one. There is evidence of stem and glial cell migration to
damaged areas. The problem in the above and other individuals is that
sometimes the entire structure is gone, or at least incapable of being
identified in these 'reconstituted' brains.

Interesting I thought but it was a TV progam after all. Norman Cook, "The
Brain Code: Mechanisms of Information Transfer Across the Corpus Callosum",
makes mention of such anomalies and makes reference to their disturbing
implications. Over the last few months more evidence, postings by doctors
(Anthro L, good archived discussion on it) who have witnessed similiar and
expressed some astonishment. I accept the reality that there are some normal
people who by most current understandings should be dithering emotionally
unpredictable unconscious automatons.

Given that in hominid evolution a great deal is made about the slowly
increasing cerebral volume I find such examples frustrating. It does seem
that we are developing a reasonable grasp on how normal brains develop but
when there is early childhood pathology the brain undertakes novel
strategies to achieve its goals. In some cases it does this exceptionally
well.

It is as if the human brain, at a cellular level, or by some internally
driven organisational level (hox genes? timeframes out?, modular, surviving
neurons [cf possible blindsight explanation],
stimulus\topographical\symbolic processing,) is destined to achieve
consciousness by whatever means. How's that for metaphysical. The early
childhood is very significant though, that's when real recovery can occur. I
have noted some studies indicating that children who suffered from cerebral
injury leading to asphasia, while often demonstrating an apparent full
recovery, do display subtle signs of the old injury. And many people with
seemingly normal brains just aint that.

A possible escape ...

In one of the above examples I made reference to the rich blood supply to
the remaining tissue. In hydrocephalics the damage, I believe, is inside
out, the arterial network may remain relatively intact, and given the
incredible plasticity of brain blood supply, it is conceivable that the
remaining tissues receive a larger blood dose and so are are able to operate
at an optimium level. It would be interesting to know if the current blood
supply arrangements for the normal human brain are 'stretched to the limit'.
Not meaning to sound sinister, but I wonder if these cerebrally deprived
individuals will be more likely to develop dementia through redundancy loss,
or at earlier ages. Do they suffer any volume shrinkage with age as the
normal brain does?

The problem for human brains may be that of supply and demand, even though
it already consumes 20% of everything @ 2% bodyweight it wants more or at
least could work a whole lot better if it had more. Intravenous glucose
injection provides an immediate IQ boost. Brain cell genes are also the most
expressive in the human body, neurones are metabolically manic. Recent
treatments for dementia etc have focussed on increasing oxygen supply to the
brain. In one study many years ago oxygen enhancement was shown to
significantly increase performance, but then lots of things seem to do that.
This supports an ongoing mild nutrient deprivation idea.

Our cortices may have outgrown our heart, which has to work so hard to pump
the blood up there. Bipedalism aint that old and we possess relatively huge
brains. How would a giraffe manage with a similiar brain\bodyweight? The
existing system suggests that evolution has already gone to a great deal of
trouble to feed this hungry organ; an organ capable of generating its own
hunger. The brain is vulnerable to malnutrition, especially during early
childhood.

This is one way out of the problem, but it does suggest that the
evolutionary mechanisms governing our cerebral construction are somewhat out
of step. This explains human history. It also allows the possibility that
significant increases in brain function are possible; although only through
some physical and\or genetic re-arrangement of bloody supply mechanisms at a
young age, an unpleasant prospect.

The above argument is also applicable to the question of brain cooling. "The
Radiator Hypothesis" is a possible explanation for the rapid encephalization
of the hominid line. Its basic premise is that the intricate bloody supply
system also serves as a brain cooling system and walking on those hot
African savannas made brains hot. Some larger African predators will not
hunt in the heat of the day; their metabolism isn't up to it. Maybe it just
gets too hot up there sometimes.

To steal Restak's title, The brain does have a mind of its own, even before
it has what we recognize as a mind it is heading towards creating one by
hook or by crook. If something gets in the way it seems capable of invoking
a set of hidden (?) strategies to find novel ways to achieve its goal.
Brains aren't following our rules, they create the rules. I wonder if
Neuroscience is faced with the unfortunate prospect of delineating how
brains work by the history of each brain(or categories of), which implies
that no single theoretic construction will be sufficient to fully explain
how all brains do what they do.

An 'information processing' model may avoid this problem, but I perceive
this as a type of dualism unless the model's units are neuroanatomical,
which is a problem with the hydrocephalics. The other thought here is that
each 'type' of brain may have its own type of basic information unit. (I
don't think so though. Epistemologically terrifying.) The firings may be the
same, but individuals may report different experiences for the same neural
events. I believe studies have been conducted demonstrating such anomalies
in self-reporting.

Neurosurgeons report that each brain is unique, each constructed slightly
and not so slightly differently. (Which may explain above anomaly re self
report.) Consciousness is very old, not requiring a massive neocortex at
all, just a well fed one, particularly if you're on four legs and
horizontal; or a sea mammal. There have been some animal studies lately
which have strongly suggested (satisfactorily in my opinion) that a
signficant number of mammals possess a style of consciousness, that while
different from our own, is nonetheless probably conscious at the
experiential level. Now, where are those crystals ... . Someone please take
these dreams away. I'll stop because I need help.

Any assistance appreciated.


Rugrat
johnhkm at logicworld.com.au












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