The
main theory of a brain storage of memories is that people acquire new
memories through a strengthening of synapses. There are many reasons
for doubting this claim. One is that information is generally stored
through a writing process, not a strengthening process. It seems that
there has never been a verified case of any information being stored
through a process of strengthening.
If
it were true that memories were stored by a strengthening of
synapses, this would be a slow process. The only way in which a
synapse can be strengthened is if proteins are added to it. We know
that the synthesis of new proteins is a rather slow effect, requiring
minutes of time. In addition, there would have to be some very
complicated encoding going on if a memory was to be stored in
synapses. The reality of newly-learned knowledge and new experience
would somehow have to be encoded or translated into some brain state that
would store this information. When we add up the time needed for this
protein synthesis and the time needed for this encoding, we find that
the theory of memory storage in brain synapses predicts that the
acquisition of new memories should be a very slow affair, which can
occur at only a tiny bandwidth, a speed which is like a mere trickle.
But experiments show that we can actually acquire new memories at a
speed more than 1000 times greater than such a tiny trickle.
One
such experiment is the experiment described in the scientific paper “Visual
long-term memory has a massive storage capacity for object details.”
The experimenters showed some subjects 2500 images over the course of
five and a half hours, and the subjects viewed each image for only three seconds.
Then the subjects were tested in the following way described by the
paper:
Afterward,
they were shown pairs of images and indicated which
of the two they had seen. The previously viewed item could be
paired with either an object from a novel category, an object of the
same basic-level category, or the same object in a different state
or pose. Performance in each of these conditions was remarkably high (92%, 88%, and 87%, respectively), suggesting that participants
successfully maintained detailed representations of thousands
of images.
In this experiment, pairs like those shown below were used. A subject might be presented for 3 seconds with one of the two images in the pair, and then hours later be shown both images in the pair, and be asked which of the two was the one he saw.
Although
the authors probably did not intend for their experiment to be any
such thing, their experiment is a great experiment to disprove the
prevailing dogma about memory storage in the brain. Let us imagine
that memories were being stored in the brain by a process of synapse
strengthening. Each time a memory was stored, it would involve the
synthesis of new proteins (requiring minutes), and also the
additional time (presumably requiring additional minutes) for an
encoding effect in which knowledge or experienced was translated into
neural states. If the brain stored memories in such a way, it could
not possibly keep up with remembering images that appeared for only
three seconds each in a long series. It would be a state of affairs
like that depicted in what many regard as the funniest scene that
appeared in the “I Love Lucy” TV series, the scene in which Lucy
and her friend Ethel were working on a confection assembly line. In
that scene Lucy and Ethel were supposed to wrap chocolates that were
moving along a conveyor belt. But while the chocolates moved slowly
at first, the conveyor belt kept speeding up faster and faster,
totally exceeding Lucy and Ethel's ability to wrap the chocolates
(with ensuing hilarious results).
The
experiment described above in effect creates a kind of fast moving
conveyor belt in which images fly by at a speed so fast that it
should totally defeat a person's ability to memorize accurately – if
our memories were actually being created through the slow process
imagined by scientists, in which each memory requires a protein
synthesis requiring minutes, and an additional time (probably
additional minutes) needed for encoding. But nonetheless the subjects
did extraordinarily well in this test.
There
is only one conclusion we can draw from such an experiment. It is
that the bandwidth of human memory acquisition is vastly greatly than
anything that can be accounted for by neural theories of memory
storage. We do not remember at the speed of synapse strengthening,
which is a snail's speed similar to the speed of arm muscle
strengthening. We instead are able to form new memories in a manner
that is basically instantaneous. The authors of the scientific paper
state that their results “pose a challenge to neural models of
memory storage and retrieval.” That is an understatement, for we
could say that their results are shockingly inconsistent with
prevailing dogmas about how memories are stored.
There
are some people who are able to acquire new memories at an
astonishing rate. The autistic savant Kim Peek was able to recall
everything he had read in the more than 7000 books he had read. Here
we had a case in which memorization occurred at the speed of reading.
Stephen Wiltshire is an autistic savant who has produced incredibly
detailed and accurate artistic works depicting cities that he has
seen only from a brief helicopter ride or boat ride. Of Wiltshire, savant expert Darold Treffert says, "His extraordinary memory is illustrated in a documentary film clip, when, after a 12-minute helicopter ride over London, he completes, in 3 hours, an impeccably accurate sketch that encompasses 4 square miles, 12 major landmarks and 200 other buildings all drawn to scale and perspective." Again, we have a case in
which memories seem to be formed at an incredibly fast rate. Savant Daniel Tammet (who one time publicly recited accurately the value of pi to 22,514 digits) was able to learn the Icelandic language in only 7 days. Derek
Paravicini is a blind and brain-damaged autistic savant who has the
incredible ability to replay any piece of music he has heard for the
first time. In 2007 the Guardian reported the following:
Derek
is 27, blind, has severe learning difficulties, cannot dress or feed
himself - but play him a song once, and he will not only memorize it
instantly, but be able to reproduce it exactly on the piano. One part
of his brain is wrecked; another has a capacity most of us can only
dream of.
Other savants such as Leslie Lemke and Ellen Boudreaux have the same extraordinary ability to replay perfectly a song heard for the first time.
Other savants such as Leslie Lemke and Ellen Boudreaux have the same extraordinary ability to replay perfectly a song heard for the first time.
Cases
such as these are inconsistent with prevailing theories of memory.
Are we to believe that such people (typically with substantial brain damage) can somehow synthesize proteins in
their brains ten times or thirty times faster than the average human,
so that their synapses can get bulked up ten times or thirty times
faster? That's hardly credible. But if memories are not actually
stored in brains, but stored in or added to a human psychic or spiritual
facility, something like a soul, then there would be no reason why the brain-damaged might
not have astonishing powers of memorization.
Some
people can form memories 1000 times faster than should be possible
under prevailing theories of brain memory storage, which involve
postulating protein synthesis and encoding operations that should take minutes. This
thousand-fold shortfall in only one of three thousand-fold shortfalls
of the prevailing theory of brain memory storage. The two other
shortfalls are: (1) humans can remember things for 50 years or more,
which is 1000 times longer than the synaptic theory of memory storage
can account for (synapses having average protein lifetimes of only a few weeks); (2) humans can recall things 1000 times faster than
should be possible if you stored something in some exact location of
the brain. If you stored a memory in your brain (an organ with no
numbering system or coordinate system), it would be like throwing a needle onto a mountain-sized heap of needles, in the sense that
finding that exact needle at some later point should take a very
long time.
The
imaginary conversation below illustrates some of the many ways in
which prevailing dogma about brain memory storage fails. It's the kind of conversation that might occur if memories were formed according to the "brain storage of memory" dogmas that currently prevail among neuroscientists.
Costello:
Alright, guy, I'm now going to teach you an important geographical
fact: which city is the capital city of Spain.
Abbott:
Go ahead, I'm all ears.
Costello:
Okay, here it is. The capital
city of Spain is Madrid.
Abbott:
Okay,
I'll try to remember that.
Costello:
So what is the capital city of Spain?
Abbott:
I haven't formed the memory of
that yet. It takes time. I'm still synthesizing the proteins I need
to strength my synapses, so I can remember that.
Costello:
So try hard. Remember, Madrid
is the capital city of Spain.
Abbott:
I'm working on forming the memory.
Costello:
So do you remember by now
what the capital city of Spain is?
Abbott:
Don't ask me too soon. It takes minutes to synthesize those proteins.
After
five additional minutes like this, the conversation continues.
Costello:
Okay, so it's been five
minutes since I first told you what the capital city of Spain is. You
should have had enough time to have formed your memory of this fact.
Abbott:
I'm sure by now I have formed that memory, because there has been
enough time for protein synthesis in my synapses.
Costello: So
what is the capital city of Spain?
Abbott:
I can't recall.
Costello: But you formed the memory by
now. Why can't you recall it?
Abbott:
The problem is that I don't know exactly where
in my brain the memory was stored. So I can't just instantly recall
the memory. The memory is like a tiny needle in a haystack. There's
no way I can find that quickly.
Costello: Can't
you just search through all the memories in your brain, looking for
this one?
Abbott:
I could try, but it would take hours or days to search through all
those memories.
Costello: Sheesh, this is driving me
crazy. How about
this? I can teach you that Madrid is the capital city of Spain, and
when you form the memory, you can tell me the exact tiny spot where
your memory was formed. So maybe you'll tell me, “Okay I stored
that memory at brain neuron number 273,835,235.” Then I'll just
say to you something like, “Please look in your brain at neuron
number 273,835,235, and retrieve the memory you stored of what is
the capital city of Spain.”
Abbott:
That's a brilliant idea!
Costello: Thanks.
Abbott:
On second thought, it will never work.
Costello: Why not?
Abbott:
Neurons aren't numbered, and the brain has no coordinate system. It's
like some vast city in which none of the streets are named, and none
of the houses have house numbers. So if I put a memory in one little
“house” in the huge brain city, I'll never be able to tell you
the exact address of that house.
Costello: So
how the hell am I supposed to teach you anything?
Abbott:
Beats me. And if I ever learn anything new, I'm sure I won't
remember it for more than a few weeks. That's because there's a big
problem with those proteins that I will synthesize to store those new
memories. They have average lifetimes of only a few weeks.
As
long as they cling to “brain storage of memory” dogmas, our
neuroscientists will never be able to overcome difficulties such as
those mentioned in this conversation.
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