I
often hear inaccurate claims about what neuroscience states or what
neuroscience knows or what neuroscience has proven. These type of
misstatements take several forms. One very common type of
misstatement is when people confuse the opinions of neuroscientists
with neuroscience itself. The two are not identical. Neuroscience
consists of the observations and experiments that have been published
in neuroscience journals. Neuroscientists may hold quite a few
opinions that are not justified by such observations and experiments,
largely because such opinions are expected within their particular
intellectual set. Such opinions should not be classified as
neuroscience, but as the typical opinions of neuroscientists.
Another
common type of misstatement is when someone glibly claims that
neuroscience has proven some particular claim, when in fact
neuroscience may have merely hinted at such a thing as a possibility.
One example may be claims that memories are stored in synapses that
link together brain cells. In fact, we have no real understanding of
how memories are stored.
A synapse is shown in blue
A
recent article in the online version of Scientific American seems to
highlight how little neuroscientists really know about this matter.
The article starts out by telling us that the standard doctrine has
been that memories are stored in the synapses that connect brain
cells. The article puts it his way: “The
idea that synapses store memories has dominated neuroscience for more
than a century, but a new study by scientists at the University of
California, Los Angeles, may fundamentally upend it: instead memories
may reside inside
brain cells “
Neurobiologist
David Glanzman at U.C.L.A is quoted as saying this work “implies to
me that the memory wasn't stored in the synapse.” The article then
suggests that perhaps memories are really stored inside a brain cell
itself.
Such
a development should cause us to have little confidence in either the
claim that memories are stored in synapses or the claim that memories
are stored in brain cells. Similarly, if scientists one day suddenly
announced that the sun gets its power not through thermonuclear
fusion but through some process called photon transduplication, then
we should doubt very much that either explanation is valid. In
general, when someone changes his story to some different
explanation, it is best to be skeptical about the new explanation for
quite a while.
Rather
than claiming we have some clear understanding of the relation
between the brain and memories or consciousness, it would be more
candid and honest for us to admit our profound ignorance about the
topic. There are many facts and findings that conflict with the
simplest assumptions one can make about the brain, that it is some
kind of machine that is the sole cause of your consciousness and the
sole storehouse of your memories. I have written two previous blog
posts (here and here) discussing some of those facts and findings.
Rather
than repeating any of these items in this post, I will discuss
additional things not listed in those posts. The first is the strange
case of Phineas Gage. Gage was a railway worker who in 1848 had a
three feet long javelin-like piece of iron (one and a quarter inches
or 3.2 cm. in diameter) accidentally spear through his skull, passing
right through his brain, and producing a 2-inch exit wound. His brain
suffered about the same onslaught a brain would suffer if you held
two 45 caliber pistols barrel to barrel, one in your left hand and
one in your right,and then fired them into someone's skull. The path
of entry was entirely through the brain, not merely on the edges of
his brain.
But
Gage did not die, and apparently did not even lose consciousness (or
perhaps suffered only a short loss of consciousness). A medical
report in 1850 reported that Gage was “quite recovered in faculties
of body and mind.” It's true that after the injury people reported
that he became rude, profane, and capricious, but such problems are
rather trivial compared to the results we would expect from such an injury:
death, loss of all memory, or a great loss of intellect.
How
is it that we can reconcile the case of Phineas Gage with the
assumption that your brain is the sole source of your consciousness?
It is not at all clear.
Here
is another very strange fact to consider. According to scientists,
the male human brain has 6.5 times more grey matter than the female
brain. But the female brain has 9.5 times more white matter.
Scientists say that grey matter is a lot more involved in thinking.
So the theory that your brain is the sole producer of your
consciousness would seem to predict that there should be the most
radical difference between the male intellect and the female
intellect – like the difference between two species on two
different planets, or perhaps the difference between a man and a
squirrel. But there is no such difference. The differences are
instead relatively trivial. We see males doing about 10% better on
the SAT Math tests, but according to the difference in grey matter,
we might expect that to be a 600% difference.
This is a huge paradox, and
there are many other paradoxes involved with the brain. The
Paradoxical Brain is
a 466-page book published by the Cambridge University Press.
According to the summary on www.goodreads.com,
“The Paradoxical
Brain focuses on the
phenomenon whereby damage to the brain can actually result in
enhancement of function, questioning the traditional belief that
lesions or other negative effects on the brain will result in loss of
function.” How are such paradoxes compatible with the simplistic
assumption that your consciousness is nothing but a by-product of
your brain?
If
you give such paradoxes and anomalies some careful consideration,
then the next time you hear some dogmatic neurologist claiming to
understand your consciousness or your prospects of survival after
death, you can ask yourself: does this person really understand these
profound mysteries, or is he merely a pretentious “knowledge
poseur” who is claiming to understand matters far beyond the ken of
any human?
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