Neurologists
like to assume that all your memories are stored in your brain. But
there are actually quite a few reasons for doubting this unproven
assumption, including the research of scientists such as Karl Lashley
and John Lorber. Their research showed that minds can be
astonishing functional even when large parts of the brain are
destroyed, either through disease or deliberate surgical removal.
Lorber documented a case of a person who was doing well in his
college studies, even though the great majority of his brain had been
destroyed by disease. Some children with brain problems sometimes undergo an
operation called a hemispherectomy, in which half of their brain is
removed. An
article in Scientific American tells us, “Unbelievably, the surgery
has no apparent effect on personality or memory.”
Given
such anomalies, we should give serious consideration to all arguments
against the claim that your brain is storing all your memories. In my
previous post, I presented one such argument, based on the apparent
impossibility of the brain ever naturally developing all of the many
encoding protocols it would need to store the many types of things humans remember. In this post I will
present another argument against the claim that your brain stores all
your memories. This argument, which I call the navigation argument,
is simpler than the argument in my previous post.
The
navigation argument can be simply stated like this: a long-term
memory cannot be stored in some particular part of the brain, because
there could be no way in which your brain could ever instantly find
the location where such a memory was stored.
Let's
consider a simple case. You hear the name of a movie star. You then
instantly recall what that person looks like, and see a faint image
of that person in your “mind's eye.” But how could this ever
happen, if the memory of that person is stored in some particular
part of your brain? In such a case, you would need to know or find
the exact place in the brain where that memory was stored. But there
would be no way for your brain to do such a thing. It would be like
trying to find one particular needle in a skyscraper-sized stack of
needles.
Let's
try to imagine some ways of getting around this difficulty, and
consider whether they are viable. One possibility is that a memory
hypothetically created in the brain might have some type of unique
positional identifier, something rather than a GPS coordinate or a
longitude/latitude coordinate (although it might be something like a
3D coordinate). When a visual memory was created, the brain might
associate this coordinate with some memory cue (such as the person's
name). So, for example, when you hear the phrase “White House”
maybe your brain subconsciously retrieves some 3D coordinate allowing
you to find where you have stored in your memory an image of the
White House in Washington, D.C. The visual below illustrates the
idea.
But
there are three reasons why this doesn't work as an explanation. The
first is that there is no way that the brain could ever know what the
3D coordinate was for some particular spot where a new memory was
created. For example, if a brain is creating a new memory at a
location with an X coordinate of 23.23342, a Y coordinate of
45.34245, and a Z coordinate of 33.3293, the brain would have no way
of knowing that the memory was being created at that exact location.
A second reason is that even if there was some brain storage area
storing the location coordinates for particular memories, there would
still be the question of: how could the brain instantly find the
correct spot in such a cue storage area to find where these
coordinates were? Since your brain can store millions of different
memories, we must imagine that this cue storage area would also have
millions of items. There is no reason we can think of why you would
be instantly be able to find the exact part of this cue storage area
that would have the coordinate needed to locate the appropriate
memory. Third, there is the difficulty that even if the brain had
the physical coordinates at which the memory stored, it would have no
way of navigating to such a coordinate.
To
try to make things a little better, let's get rid of this idea of a
coordinate system. Let's imagine that there is some kind of cue
memory area with direct neural connections leading to the spots where
memories are formed. So then if you hear a particular name, your
brain merely finds that name in the cue storage area, and then
follows this little neural connection (rather like a wire or
telephone line) to where the memory is stored. The visual below
illustrates the idea.
But
this still does not give us a plausible answer as to how you could
recall a memory stored in a particular spot in your brain. For one
thing, there would be the difficulty of explaining how this wiring-up
was occurring. It doesn't seem plausible to maintain that each time
you memorize something, you are adding an entry in two different
storage areas of your brain, and also instantly creating a neural
wire or line connecting only these two. That seems like too much work
and coordination to be occurring so quickly. We have no evidence that
coordinated changes occur in two different areas of the brain when a
memory is stored. While we know that connections can gradually form
between neurons, this isn't something that can instantaneously occur
to link separate areas of the brain when a memory is created.
You
would also still have the previously mentioned problem of how your
brain could instantly find the correct spot in this cue storage area
where these cues are located. Since your brain can store millions of
different memories, we must imagine that this cue storage area would
also have millions of items. There is no reason we can think of why
you would be instantly able to find the exact part of this cue
storage area that would have the direct wire or neural connection
needed to locate the appropriate memory in the visual storage area.
So
we seem to be getting nowhere trying to imagine how the brain could
allow you to instantly recall memories. Let's try looking at how
computers are able to quickly retrieve data. Perhaps that
might offer some clue.
One
basic technique computers use to speed retrieval access is physical sorting.
The same technique is used by a simple file cabinet in which the
files are alphabetically sorted. But we cannot believe that the brain
uses physical sorting. A mass of microscopic neurons (rather like a
city-sized blob of tangled spaghetti that has been shrunk) is not
something in which physical sorting is possible. All the different
brain connections make physical sorting impossible, just like you
can't sort a giant ball of tangled string into different parts
(unless you disassemble and reassemble). A brain structured totally
different from the human brain might be able to use physical sorting,
but not the human brain. We have zero evidence that neurons are
physically sorted.
Neurons cannot be physically sorted or physically grouped
Another
basic technique computers use to speed retrieval access is physical grouping,
such as when different types of information are placed in different
computer files. The same technique is used by a simple file cabinet
in which different types of information are put into different manila
files. But we cannot believe that the brain uses physical grouping. A
mass of neurons filled with connections between neurons is not
something in which physical grouping is possible. A brain structured
totally different from the human brain might be able to use physical
grouping, but not the human brain. When we look at the brain, we see
no evidence that a physical grouping of neurons is occurring. Neurons
are not arranged into little clusters like stars are arranged into
galaxies.
In
short, it seems physically impossible that a brain structured such as
ours could ever instantly retrieve memories, if such memories were
stored in particular parts of the brain. There is no physical
mechanism that can explain how this could occur in the human brain.
One
way to try to resist such an argument is to claim that a particular
memory is not stored in a particular place in the brain, but
throughout
the brain. If that were true, there would be no problem of the brain
trying to find just one particular spot where a memory is stored.
But a human mind has many thousands or millions of memories. We can
hardly believe that each of these is stored throughout the brain. If
my memory of my first kiss was stored throughout my brain, that would
leave no space for the thousands or millions of other memories I
have. We may also note how absurd it is to imagine that, for
example, I have stored throughout all the neurons of my brain
some trivial image such as the image of SpongeBob Squarepants.
It
is sometimes maintained that a specific memory is stored not in one
little spot in the brain, or throughout the entire brain, but is
scattered across several different places. This does nothing to make
the retrieval of a memory from a brain more plausible. You do not
lessen the difficulty of “how could the brain know where to find
one specific spot where a particular memory is stored” if we assume
that the memory is read from five or ten different specific places,
because there is still the problem of how the brain could find those
specific locations. Similarly, there would be no way for someone to
find some information very quickly if it is in some book among many
thousands of books in a library that all had no title on their cover;
and it would be even harder to get such information quickly if the
information was scattered across five or ten such books in such a
library. Lacking any coordinate system or labeling system, a brain storing memories
would be like such a library.
In
a blog post, a neurologist has replied to the type of argument being
made here (after it had been made by another writer). The
neurologist writes: “You don’t have to know (nor does your brain)
where in your physical brain a memory is located, because you can
access that memory simply because it is integrated with so many other
memories.”
This
reasoning is fallacious. Using similar reasoning, I could argue that
I don't have to know the phone number of someone in California to
telephone that person, because all of the telephones are integrated
with each other in a telephone network. But that's erroneous. You do
have to know someone's phone number to instantly access that person's
phone. To instantly access a memory such as occurs when you recall a
face after seeing a name (or vice versa), the brain would absolutely
need to know where that memory is stored (or have some mechanism for
instantly locating that precise brain location), if the memory was
stored in one particular location in the brain. But no one can give
any explanation of how the brain could know such a thing, or how the
brain could instantly find the correct memory. I may note that when
you recall a face instantly after seeing it, it is not at all a case
of one memory leading you to find another. We absolutely cannot use
“integration of memories” to explain such a thing.
The
complete lack of any workable theory for how memory recall can occur
so quickly is admitted by neuroscientist David Eagleman, who states:
Memory retrieval
is even more mysterious than storage. When I ask if you know Alex
Ritchie, the answer is immediately obvious to you, and there is no
good theory to explain how memory retrieval can happen so quickly.
The reasoning above
suggests that our neurologists will never be able to solve the
problem of how the mind is able to recall things so quickly. The
human brain is simply not structured the way a physical system would
need to be structured in order for an instantaneous recall of
detailed complex memory information to occur from one particular
storage location in the brain. The impossibility of explaining how
instant memory recall occurs is a powerful reason for believing that
long-term memories are not stored in your brain. We must postulate
that the human mind is part of some reality that transcends the human
nervous system. Call it a soul reality, or call it a spiritual
reality – it is something that must go beyond the human brain.
As we will see in my
next post, there is another reason for drawing the same conclusion:
the fact that there is no viable mechanism that explains how the
brain can be storing very long-term memories. In my next post, I
will look at the most common mechanistic theory of how the brain
stores long-term memories, and explain why it is untenable (citing
neurologists themselves who have given powerful reasons why such a
theory is untenable). The theory in question is untenable because it
tries to explain long-term memories by appealing to a “shifting
sands” type of mechanism that is so impermanent and fast-decaying that
it is completely unsuitable for explaining human memories that can
last for 50 years (and cannot even explain human memories that last
for two years).
Postscript: Given the complete lack of any coordinate system in the brain by which the exact locations of neurons can be specified, the brain can be compared to these things:
(1) the US phone system if no one's phone number had ever been published;
(2) a vast post office with countless post office boxes, none of them numbered;
(3) a city in which none of the streets were named, none of the buildings had an outside identifier, none of the apartments had apartment numbers, and none of the houses had street numbers;
(4) a vast library containing thousands of books, none of which have any title on their cover, chapter titles, or page numbers.
Imagine how hard it would be in any of such things to navigate to a precise location -- a particular post office box, a particular phone, a particular apartment in the city, or a particular book in the library. That's the kind of situation that should exist in a brain storing abundant memories, because there is no coordinate system in a brain, and neurons don't have neuron numbers or something like a brain longitude and latitude. Instantaneous recall of obscure memories should be impossible if our memories are stored in brains. The fact that we routinely perform such instantaneous recalls is strong evidence our memories are not mainly stored in brains.
Postscript: Given the complete lack of any coordinate system in the brain by which the exact locations of neurons can be specified, the brain can be compared to these things:
(1) the US phone system if no one's phone number had ever been published;
(2) a vast post office with countless post office boxes, none of them numbered;
(3) a city in which none of the streets were named, none of the buildings had an outside identifier, none of the apartments had apartment numbers, and none of the houses had street numbers;
(4) a vast library containing thousands of books, none of which have any title on their cover, chapter titles, or page numbers.
Imagine how hard it would be in any of such things to navigate to a precise location -- a particular post office box, a particular phone, a particular apartment in the city, or a particular book in the library. That's the kind of situation that should exist in a brain storing abundant memories, because there is no coordinate system in a brain, and neurons don't have neuron numbers or something like a brain longitude and latitude. Instantaneous recall of obscure memories should be impossible if our memories are stored in brains. The fact that we routinely perform such instantaneous recalls is strong evidence our memories are not mainly stored in brains.
I was not convinced by your arguments. But this argument did it: "Memory retrieval is even more mysterious than storage. When I ask if you know Alex Ritchie, the answer is immediately obvious to you, and there is no good theory to explain how memory retrieval can happen so quickly."
ReplyDeleteAnd it seems to me that you actually didn't understand it. The power of the argument is that it is done on the negative. For positive arguments you can argue at any time that might be some special mechanisms in place for fast retrieval: i.e. since I walk everyday, there is a fast hardwired mechanism in the brain that fast retrieves walking specifically. But since that argument is on the negative, you need to search for the whole brain in order to know if you know any Alex Ritchie. And this would take whole minutes or hours. So since we know instantly that we don't know any Alex Ritchie, then it means that memories are not in the brain. It's an amazing argument. I will use it from now on in any debate about the place of memories.