If
we are to believe in the claim that brains store human memories, we
must have a credible account of four things: encoding, neural
storage of very old memories, the instantaneous formation of
memories, and the instantaneous retrieval of memories. The theory
that human memories are stored in the brain fails in regard to each
of these things.
There
exists no plausible theory as to how a brain could store memories
lasting for 50 years, but we know humans can remember many things for
that long. The most popular idea of brain memory storage claims that
memories are stored in synapses, but the proteins in synapses have an average lifetime of less than two weeks, meaning such a theory falls short by a factor of 1000 when it comes to explaining memories that persist for 50 years. As for memory retrieval, there is no theory explaining how humans could possibly recall instantly
things they learned many years ago, and haven't thought about in
years. You may hear the name of some obscure historical or cultural
figure you learned about decades ago, and haven't heard about or
thought about since that time. You may then instantly recall
something about that person. But if that memory was stored somewhere in your brain, how could you instantly find the exact
little location where that memory was? Doing that (for example,
instantly finding a memory in storage spot 834,220 out of 1,200,000)
would be like instantly finding a needle in a mountain-sized
haystack. If a brain had an indexing system, or a coordinate system,
or a neuron numbering system, there might be a faint hope for
explaining instantaneous memory retrieval; but the brain has no such
things. As for the instantaneous formation of memories, there is no
theory that can account for it in a brain. The prevailing theory that
memories are stored by synapse strengthening (which would involve
protein synthesis requiring minutes) fails to account for memories
that humans can form instantly.
When
we consider the issue of memory encoding, we find a difficulty as
great as the difficulties just discussed. Encoding is supposedly
some translation that occurs so that a memory can be physically
stored in a brain, so that it might last for years. The problem is
that human memories include incredibly diverse types of
things, and we have no idea how most of these things could be stored
as neural states. Consider only a few of the types of things that can
be stored in a human memory:
- Memories of daily experiences, such as what you were doing on some day
- Facts you learned in school, such as the fact that Lincoln was shot at Ford's Theater
- Sequences of numbers such as your social security number
- Sequences of words, such as the dialog an actor has to recite in a play
- Sequences of musical notes, such as the notes an opera singer has to sing
- Abstract concepts that you have learned
- Memories of particular non-visual sensations such as sounds, food tastes, smells, pain, and physical pleasure
- Memories of how to do physical things, such as how to ride a bicycle
- Memories of how you felt at emotional moments of your life
- Rules and principles, such as “look both ways before crossing the street”
- Memories of visual information, such as what a particular person's face looks like
How could all of these very different types of information ever be translated into neural states so that a brain could store them?
Our
neuroscientists have told us again and again that the brain does such
an encoding, but there is no real evidence that any such thing takes
place. What we have evidence for is merely evidence that humans
remember things. If you are someone who believes that memories are
physically stored in brains, then you may claim that memory encoding
occurred at such and such a rate whenever you observe people learning
something at such and such a rate. But merely observing evidence of
learning or memory is not acquiring any actual evidence that encoding
has occurred. There remains the possibility that our memories are
not stored as neural states, the possibility that our repository of
memory is some spiritual or psychic facility that is non-neural and
non-biological.
Such
a possibility should not seem remote when we consider that there
is no workable theory as to how learned knowledge and experiences could be encoded so that they might be stored in a brain. No matter what theory we may create to
account for the encoding of learned knowledge and episodic experience so that they can be stored in a
brain, such a theory will always end up sounding ridiculous after we
examine the theory in detail and consider its requirements and
shortcomings. Let's look at some possibilities, and why they fail.
Theory
#1: Direct writing of words and images
First,
let's consider the simplest theory of encoding we can imagine –
that a memory is stored in the brain so that it appears in a neural
form pretty much as we see it in our minds. Under this theory, when
you memorized some series of words, this would cause a sequence of
microscopic little letters to become stored in your brain; and when
you experienced some visual experience, this would get stored as some
tiny little image in your brain. So, for example, under this theory,
if someone memorized the sentence, “There may be green aliens in
the center of the galaxy,” then after the person died, some
scientist might examine that person's brain with an electron
microscope, and actually find some tiny little words in some neurons,
words that directly spelled out, “There may be green aliens in the
center of the galaxy.” And under this theory, if someone was given
a picture of a toy purple pony, and asked to memorize it, then after
the person died, a scientist might be able to examine the person's
brain under an electron microscope, and the scientist might say,
“Aha, I see in his neurons a tiny little image of a toy purple
pony.”
This
theory may immediately provoke giggles, and it is rather easy to
think of some reasons why it does not work. They are these:
- If memory worked in such a way, we would surely have already discovered such easily-recognizable memory traces. But no such things have been seen, even though a great deal of human neural tissue has been examined at very high magnification. When we look at brain tissue at the highest magnification, we see no tiny little letters or tiny little images of animals, cars, and persons.
- For a brain to be able to write words that we memorized in this type of direct manner, it would seem that the brain would need some very precise write mechanism, capable of forming the exact characters of the alphabet in brain tissue; but no such brain capability is known to exist.
- It seems that if such a theory were true, recalling some words would be like reading. But recalling words is almost never like reading, and we don't see in our mind's eye some stream of letters as we recall some words we memorized.
- For a brain to be able to read words that we memorized in this type of direct manner, it would seem that the brain would need some very precise reading mechanism, capable of reading the exact characters of the alphabet stored in very tiny letters written in brain tissue; but no such thing is known to exist. We don't have tiny little “micro-eyes” in our brains that might allow us to read tiny microscopic letters stored in our brains.
Theory
#2: Brain storage of words and images using some unknown non-binary
coding or translation protocol
Now,
let's consider a different theory of memory encoding – the idea
that instead of directly storing words and images (so that we could
directly read the words and directly see the images), the brain uses
some type of unknown coding or translation protocols. For example, it
could conceivably be that words that we learn are somehow translated
into proteins or chemicals or electrical states, using some as-of-yet
undiscovered translation scheme.
For
example, such a scheme might work a little like this:
Item | How the item might be represented |
Letter “A” | Some particular neural arrangement of atoms, chemicals or electricity |
Letter “B” | Some other neural arrangement of atoms, chemicals or electricity |
Letter “C” | Some other neural arrangement of atoms, chemicals or electricity |
Such
a scheme might work a little like the Morse code, in which particular
letters are translated into some sequence of dots, dashes, or dots
and dashes. Some particular arrangement of atoms, chemicals or
electricity might work like a dot in the Morse code, and some other
particular arrangement of atoms, chemicals or electricity might work
like a dash in the Morse code.
Or
there could be some higher-level translation system based on
particular words rather than letters. For example, we can imagine
something like this:
Item | How the item might be represented |
Word “sun” | Some particular neural arrangement of atoms, chemicals, proteins or electricity |
Word “man” | Some other neural arrangement of atoms, chemicals, proteins or electricity |
Word “move” | Some other neural arrangement of atoms, proteins chemicals or electricity |
There
is one giant problem with such a theory. All of the languages that we
use are fairly recent innovations, having been created in only the
last few percent of the time that humans have existed. For example,
back in the Roman Empire people used Latin, but the English we use
today has only been in use for less than 1200 years. The alphabet
used for English is less than 1000 years old, and its alphabetic
predecessor (the Latin alphabet) is only a few thousand years old. It
is generally acknowledged even by Darwinism enthusiasts that very
complex evolutionary innovations cannot arise in only a few centuries
of time or a few thousand years. So we could never explain how the
brain could naturally possess some elaborate translation system based
on such a relatively recent innovation as the English language and
the English alphabet.
Scientists
strain our credulity whenever they talk about novel functional genes accidentally appearing even over the course of a million years. Think, then, on
how much greater a problem there would be in explaining how hundreds
of novel functional genes could have appeared in less than 3000
years, to perform some translation operation involving characters and
words that have existed for less than 3000 years. To assume such a
thing would be to assume evolution working thousands of times faster
than the rate we would predict from known mutation rates.
There
is also no evidence that any such great burst of genetic novelty has
occurred. Although the half-life of DNA is 512 years, we have enough
samples of human DNA from ancient Rome and ancient Egypt to know that
there has been no big change in the DNA of humans during the past
3000 years. So it seems impossible that there could be any genetic
capability (arising in the past few thousand years) that would allow
humans to neurally store information using some encoding mechanism
specifically tailored to the letters and words of the English
language that have existed for less than 3000 years.
Another
difficulty with the theory of encoding just mentioned is that if it
existed, we would see big differences in the genes of people who
spoke different languages. According to such a theory, we would
expect that Chinese people would have one group of genes
corresponding to proteins or RNA molecules needed to translate Chinese words into neural states, and that English speaking people
would have some other quite different set of genes corresponding to
proteins or RNA molecules needed to translate English words into
neural states (particularly since the Chinese language and alphabet
is so different from the English language and alphabet). But there exists no such
difference in the genes of Chinese speaking people and English
speaking people.
There
is also the difficulty, discussed more fully in the conclusion of
this post, that there is no sign in the human genome that any such
genes exist for performing such an elaborate operation of encoding
human learned knowledge and episodic experience so that it can be
stored in neurons or synapses (and there would need to be many hundreds or
thousands of genes dedicated to performing such a task if it was done).
Theory
#3: Binary writing of words and images
Now,
let's consider a theory of memory encoding that perhaps the
words we memorize and the images we remember are stored in binary
format. We know that computers store information in binary format, so
when it is suggested that the brain may use a similar format, this
may sound reasonable to the average person (although it isn't, a
brain being radically different from an electronic computer).
This
possibility actually has all of the difficulties of the previous
possibility. What goes on when your computer stores words in binary
format is the following:
- First individual letters in the words are converted into decimal numbers (such as 13, 19, and 23) using a particular translation table called the ASCII code.
- Then, those numbers are converted from decimal to binary using a decimal-to-binary conversion routine.
So
if we are to believe that the brain does binary encoding like a
computer, we would need to believe that built into the brain on a
low level is some type of translation scheme like the one below, a
scheme in which letters are translated into decimal numbers.
ASCII table used by a computer to store encoded information
In
addition, we would also have to believe that the brain has some kind
of capability to translate the numbers in such a system into binary
numbers. Alternately, we could believe that the brain has a scheme
for directly translating characters into binary, but the overall
complexity of such a translation mechanism would be every bit as
great as a system in which characters are converted into decimal, and
then into binary.
We
have the following difficulties involved with such an idea:
- If memory worked in such a way, we would surely have already discovered such easily-recognizable memory traces. We would have discovered tiny little traces in the brain that resemble binary coding. But no such things have been seen, even though a great deal of neural tissue has been examined at very high magnification.
- For a brain to be able to write words that were memorized in this type of direct manner, it would seem that the brain would need some very precise write mechanism, capable of writing binary traces; but no such thing is known to exist.
- For a brain to be able to read words that we memorized in this type of direct manner, it would seem that the brain would need some very precise reading mechanism, capable of reading in binary; but no such thing is known to exist.
- Since the alphabets of human languages are only a few thousand years old, there would have been no time for the human body to have evolved some complex biological mechanism capable of converting specific alphabetic characters to binary.
- We can imagine no way in which a brain could achieve the translation effect in which words are translated into binary. As far as we know, there is nothing anything like an ASCII table in your brain, nor is there anything like a facility for translating English letters directly into binary, nor is there anything like a facility for translating English letters into decimal, and then translating decimal numbers into binary. There are no genes in the genome that perform such tasks.
Theory
#4: Storage of sensations occurring when something is learned or experienced
Now,
let's consider a whole different theory. It could be that instead of
storing words that you memorized, a brain might store the sensations
that occurred when you memorized something. So imagine I open up a
copy of Vogue magazine, and read an ad saying, “You'll feel fresher
than the morning dew.” If I memorize that slogan, it might be that
my brain is storing the electrical or chemical activity in my brain
when I saw that slogan. And if I hear on the radio some advertising
slogan of “We'll build your wealth sky-high,” and memorize that,
it could be that my brain is storing something corresponding to the
electrical and chemical activity in my brain when I heard such a
slogan.
One
reason for doubting this theory of memory encoding is that
perceptions involve large parts of the brain, and it is hard to
imagine that sensations involving large fractions of the brain could be stored in
a tiny part of the brain. Since our minds store many thousands or
millions of visual memories, if we are to believe that memories are
stored in brains, we would have to believe that each stored memory
uses only a tiny portion of the brain. But my current visual
sensations require the involvement of a large fraction of the
occipital lobes of the brain – probably many cubic centimeters. But
we cannot plausibly imagine that the brain simply dumps the chemical
or electrical contents of those cubic centimeters into some memory
that took up only a tiny space on my brain, a millionth or less. It
would seem, therefore, that if the brain simply dumped your visual
and auditory sensations into memory, that it would require a space
vastly bigger than itself to store all the memories we have of things
we have seen and heard.
Another
difficulty in the “memories are sensation dumps” idea is that
there is no evidence of any mechanism for copying information from
one part of the brain to another. Let's imagine that when a memory
forms, the state of your occipital lobes (involved in vision) is
copied to some point on the cortex where the memory is stored. That
would require some biological functionality for copying the state of one large part of the brain to another part of the brain; but we know of
no such functionality.
It
is easy to think of another big reason for doubting such a
theory. It is that if our brains were to be storing something
corresponding to sensations, we would expect that when we remembered
words, we would remember something visual, with a characteristic font
or color, or something auditory, with a characteristic sound. But
while that sometimes happens, in almost all cases it does not work
that way.
For
example, if I remember the words, “Here's looking at you, kid,” I
do remember a very specific audio sound, the distinctive sound of
Humphrey Bogart saying that in the movie Casablanca. And if I
remember the phrase “Men walk on moon,” I do remember a specific
font, the font used in the famous New York Times headline of the
Apollo 11 lunar mission. But a very large fraction of my memories do
not have specific visual or audio characteristics. For example, if
someone asks, “What is the lightest particle in an atom?” I may
reply, “The electron is the lightest particle in the atom.” But
that memory I have recalled does not have any specific sound or sight
associated with it. I don't hear the answer in someone's voice, and I
do not see the answer as words in any particular font or color. And
if someone asks me, “What is your birthday?” I will remember a
particular day. But I will not see in my mind's eye some date written
in a particular font and having some particular color, nor will I
hear in my mind's ear some particular type of voice stating the
answer.
For
almost all of my knowledge memories, the same thing is true: when I
recall the memory, I don't see something that appears with some
particular visual appearance, nor do I hear something that has some
particular sound. It seems this would not be the case if the brain
was storing my memories by storing visual and auditory sensations.
It
is also true that I can memorize something that does not correspond
to any particular visual or auditory sensation I had. For example, I
can visualize some imaginary thing such as a giant purple elephant.
If I think about this imaginary thing enough times, it will become a
permanent memory. But this imaginary thing I have memorized does not
correspond to any sensation I had. In this case I never saw a giant
purple elephant. So it cannot be that my memory of the giant purple
elephant was formed from sensations that I had of such a thing.
Similarly, a fiction writer can dream up on Tuesday an idea for a
short story, and then write that short story on Wednesday, using the
memory he formed on Tuesday. But the memory will not correspond to
any visual or auditory sensations he had.
It
seems that we therefore cannot explain memories as merely being a storage of
sensations that we had at some time when we learned something. You
learned many thousands of things in school, but when you remember
such knowledge, you virtually never remember the sight and sound of
your school teacher teaching you such things or the sight of you
reading a book telling you such things (as you would if your memory
of learned knowledge was just a dump of the sensations you had when
you learned such things).
Conclusion
I
have reviewed some of the theories that could be used to account for
the encoding of learned information as neural states. There are
strong reasons for rejecting each such theory. It seems it is
impossible to present a specific theory of memory encoding that
stands up to scrutiny as a reasonable possibility.
How
is it that neuroscientists sidestep this difficulty? They simply
avoid presenting specific theories of how a brain could translate
learned information into neural states. An example is the
wikipedia.org article on “Memory (encoding).” The article tells
us, “Encoding allows the perceived item of use or interest to be
converted into a construct that can be stored within the brain and
recalled later from short-term or long-term memory.”
But
the article fails to discuss any specific theory discussing how such
a conversion would work. The article has all kinds of digressions
and tangential information, but nowhere does it advance a single
specific idea of how learned information (such as a learned sequence of
words) could be translated into neural states when a memory was
stored in a brain. An article on a memory experiment states, "Press a scientist to tell you how memories are encoded and decoded in the brain, and you’ll soon find that the scientific community doesn’t have an answer."
Just
as it is impossible to advance a credible detailed theory as to how
Santa Claus could distribute a toy to every good little boy and girl
in the world in a single 24 hours, it is impossible to advance a
credible detailed theory of how learned knowledge and episodic experience could be
encoded and permanently stored as neural states. If memories were to
be encoded so that they could be stored in brains, there would be two
major “footprints” of such a thing, physical traces showing that
it was going on. They are the following:
High
repetition of representational building blocks. Whenever encoded
information is stored, there is a repetition of two or more things
we can call representational building blocks or
representational atoms. In binary encoding these
representational building blocks are the 1's and 0's or their
electromagnetic equivalent. In alphabetic encoding, the
representational building blocks are the letters of the alphabetic.
In DNA the representational building blocks are the four types of
nucleotide base pairs that are repeated over and again. In Morse
code, the representational building blocks are dots and dashes. Even
if you don't know the system of encoding that was used, it is easy to
detect that encoded information is present, by seeing a high
repetition of representational building blocks. If brains stored
memories encoded into neural states, we would see a gigantic degree
of repetition of some type of representational building blocks.
Genes
dedicated to memory encoding. If human brains were to actually be
translating thoughts and sensory experiences so that they can be
stored as memory traces, such a gigantic job would require a huge
number of genes – many times more than the 500 or so genes that are
used for the very simple encoding job of translating DNA nucleotide
base pairs into amino acids.
There
is no sign at all of either of these things in the brain. We
absolutely do not see anything like very highly repeated
representational building blocks in the brain that might be the
footprints of encoded memory information. And we see no sign of any
such memory encoding genes in the human genome.
There
is a study that claims to have found possible evidence of memory
encoding genes, but its methodology is ridiculous, and involved the absurd procedure of looking for weak correlations
between a set of data extracted from one group of people and another
set of data retrieved from an entirely different group of people. See the end of this post for reasons we can't take the study as good evidence of anything. There is not one single gene that a scientist can point to and say,
“I am sure this gene is involved in memory encoding, and I can
explain exactly how it works to help translate human knowledge or
experience into engrams or memory traces.” But if human memories were
actually stored in brains, there would have to be thousands of
such genes.
There
is an additional general difficulty involved in the idea that brains
encode our episodic experiences and learned knowledge as neural
states. It is that if the brain did such a thing, it would require a
translation facility so marvelous that it would be a “miracle of
design,” something that we would never expect to ever appear by
unguided evolution.
Yet another problem is that if brains encoded learned knowledge and episodic experiences into engrams or memory traces, then forming new memories would be slow, and retrieving memories would be slow -- for whenever we formed a new memory, all kinds of translation work and encoding would have to be done (which would take a while), and whenever we retrieved a stored memory, all kinds of decoding work would have to be done (which would take a while). But instead humans can form memories instantly and retrieve memories instantly, much faster than things would work if all this encoding and decoding work had to be done.
What has been discussed here is only a small fraction of the very large case for thinking that human cognition and memory must be some psychic or spiritual reality rather than a biological or neural reality.
Let's imagine a boy who thinks that his mother will give him a pony for Christmas. December 25th comes, and the boy searches everywhere around his house and yard; but there's no pony. On December 28th, having spent several more days looking for such a pony without success, the boy says, "There must be a pony around here somewhere." We may compare this boy to the modern neuroscientist who believes there are brain engrams that encode our learned knowledge, but who still hasn't found such things, despite decades of searching. He says to himself, "They must be somewhere in the brain." But if they existed, they would have been found long ago. There is microscopic encoded information in DNA (specifying the amino acids in proteins). Unmistakable evidence of that was discovered around 1950. Why would it possibly be that we would have failed to discover encoded memory information in a brain by the year 2018, if such information actually existed in brains? It would be as easy to find as the genetic information in DNA.
Yet another problem is that if brains encoded learned knowledge and episodic experiences into engrams or memory traces, then forming new memories would be slow, and retrieving memories would be slow -- for whenever we formed a new memory, all kinds of translation work and encoding would have to be done (which would take a while), and whenever we retrieved a stored memory, all kinds of decoding work would have to be done (which would take a while). But instead humans can form memories instantly and retrieve memories instantly, much faster than things would work if all this encoding and decoding work had to be done.
What has been discussed here is only a small fraction of the very large case for thinking that human cognition and memory must be some psychic or spiritual reality rather than a biological or neural reality.
Let's imagine a boy who thinks that his mother will give him a pony for Christmas. December 25th comes, and the boy searches everywhere around his house and yard; but there's no pony. On December 28th, having spent several more days looking for such a pony without success, the boy says, "There must be a pony around here somewhere." We may compare this boy to the modern neuroscientist who believes there are brain engrams that encode our learned knowledge, but who still hasn't found such things, despite decades of searching. He says to himself, "They must be somewhere in the brain." But if they existed, they would have been found long ago. There is microscopic encoded information in DNA (specifying the amino acids in proteins). Unmistakable evidence of that was discovered around 1950. Why would it possibly be that we would have failed to discover encoded memory information in a brain by the year 2018, if such information actually existed in brains? It would be as easy to find as the genetic information in DNA.
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