Saturday, August 11, 2018

The Brain Seems to Have No Mechanism for Reading or Writing Memories

Sometimes an idea may seem fairly believable when it is painted in broad brushstrokes, but we may recognize the idea as being untenable once we start to examine the idea in detail. One such idea is the theory of Santa Claus. When painted in broad brushstrokes, this idea doesn't seem too outrageous: there's a guy living in the North Pole, who has a big toy workshop; and every Christmas Eve he uses a big sled pulled by flying reindeer to deliver toys to all the little children around the world. It is when you start to examine this idea in detail that it breaks down. Suppose we calculate how many toys would need to be in a sled to give even one toy to half the world's children. We quickly find you would need a sled the size of a skyscraper tower. And suppose we calculate how quickly Santa would have to move to give one toy to every child in a single day. We quickly find Santa would have to move at a rate faster than one child per second. And suppose we consider that Santa is too fat to go down chimneys, and that most people don't live in houses with chimneys. So how could Santa get into houses with locked doors? And suppose we start asking: how is that reindeer can fly without wings? It would appear the Santa theory cannot hold up to adult intellectual scrutiny.

A theory taught to every adult is that our memories are stored in our brains. This unproven idea does not sound too unreasonable when painted in broad brushstrokes. You can very broadly imagine that sensory experience or knowledge is kind of like a fluid, and that the brain stores this kind of like a cup stores water you pour into it. That doesn't sound too unreasonable. But imagine we try to subject the theory of the brain storage of memories to a very close and detailed scrutiny. Then the theory breaks down again and again, just like the theory of Santa Claus when it is exposed to scrutiny.

One way the theory of a brain storage of memories breaks down upon scrutiny is when we consider: how long should memories last if they are stored in brains? The main theory of brain memory storage is that memories are stored in synapses. But we know that the constituents of synapses are short-lived proteins with an average lifetime of no greater than a few weeks. So based on the prevailing idea of brain memory storage, we should be unable to remember anything for more than a few weeks. But instead people can reliably remember things for 50 years.

Another way the theory of a brain storage of memories breaks down upon scrutiny is when we consider: how long should a brain take to store a memory? Our neuroscientists suggest the formation of a memory requires the synthesis of new proteins, but such proteins take minutes to synthesize, and we can form a memory instantaneously. It doesn't take you minutes to form a memory of when someone fires a gun at you.

Another way the theory of a brain storage of memories breaks down upon scrutiny is when we consider: how could a brain instantly find a memory stored in some exact spot? There are many, many thousands of memories you can recall. But when you hear the name of a person, you are able to instantly recall what you know about that person. There is no plausible theory as to how a brain can do that. Neurons don't have neuron numbers, the brain does not use physical sorting, indexing or grouping, and particular sections of the brain are not labeled by content. So retrieving a memory stored in a brain would seem to be like instantly finding a needle in a mountain-sized haystack. Retrieving a memory stored in a brain should be like instantly finding exactly the right information stored in one particular book in a library, when there are more than 100,000 volumes in the library, and none of the books have covers, and none of the aisles have signs indicating their content. This is the problem I call the navigation problem: how could a brain possibly instantly navigate to precisely the right tiny little millionth of the brain where some exact memory was stored? Materialists have no real answer to this difficulty.

We cannot overcome this difficulty by imagining that a brain scans through all of its stored memories like someone leafing through the pages of a book, until it finds the right answer. That would take days. Nor can we overcome the navigation difficulty by imagining that each memory is stored throughout the brain. Such an idea makes no more sense than imagining a textbook in which each of the thousands of sentences is stored on every line of the textbook.

Then there is the problem of encoding. For a brain to store memories physically, there would need to be some translation of mental experience into neuron states, which would require extensive translation known as encoding. We know that cells do one type of translation, translating the nucleotide base pairs in DNA into proteins. But to do that quite simple translation, the genome uses hundreds of special transfer RNA genes dedicated to such a translation task. It seems that to encode human mental experience into some kind of physical storage in the brain, the genome would need to have thousands of genes dedicated to such an incredibly hard task. But we've mapped the entire genome, and have found no such genes anywhere. As discussed at the end of this post, there's one paper claiming to find some scant evidence of some memory encoding genes, but the methodology of the paper is quite goofy, involving trying to find correlations between gene expression data in one set of people and brain wave data in an entirely different set of people, which makes no sense.

There is another difficulty that arises when we consider the issue of the retrieval of memories stored in a brain. This is a problem that I can call the position focus problem. This is the problem that an organ like the brain would seem to have no mechanism for focusing on some particular part of the brain, so that a memory could be read from some particular location.

When we consider all of the different ways in which information is retrieved from a physical location, we find there is a common characteristic. In each such way there is always some mechanism of position focus. Position focus occurs when some particular part of the information is highlighted as kind of “the current position” within that information.

I can some give examples of this kind of “current position” effect:

  1. A book can be opened to only one pair of pages. When a reader reads that book, his eyes can focus on only one line at a time. When the reader focuses on a particular line, position focus is achieved.
  2. When a film is run through a film projector, only one frame at a time can be in front of the light that passes through the film. In such a way, position focus is achieved.
  3. In the disk of a computer hard-drive, there is a read-write head that moves around to read particular parts of the disk. At any time, the head is above one particular spot of the disk, and position focus is achieved.
  4. The needle of a 33 rpm phonograph record can only be resting on on one little spot on the phonograph record. Whenever that needle rests on one particular spot on the record, position focus is achieved.
  5. The current tab of a web browser will always be on one particular web page, with a URL displayed at the top of that tab. With such a rule, position focus is achieved, with the URL being a particular position within the vastness of the Internet.

Position focus mechanisms in a record player and computer hard drive

Now let us imagine that when you remember some specific memory, your brain is reading some particular tiny spot in the brain where the memory is stored. Ignoring for the moment the navigation problem of how the brain could instantly find that specific part, which would be like instantly finding a needle in a haystack, let us consider: how could any reading effect possibly occur? The brain has nothing like the needle of a phonograph player, something that restricts position focus to one particular spot. The brain has nothing like the read-write head of a computer hard drive, something that restricts position focus to one particular spot. It seems that there is no mechanism at all in the brain by which position focus could be achieved.

Position focus requires moving parts. For example, the pages of a book move, the eyes move as you read, a phonograph record spins, a movie projector moves the film continuously, and a read-write head moves about on a hard disk. But there is no macroscopic part of the brain that moves about when you retrieve a memory. Other than chemicals and electricity and blood, which are constantly flowing about in the brain, there is no movement that goes on in the brain when you retrieve a memory. It would seem, therefore, that there is no possible way in which a brain could achieve any type of position focus that would be necessary for it read from one particular spot to retrieve one and only one memory.

Answering the question “Are there any moving parts in the brain?” the “expert answer” site gives us two answers that both claim that there is lots of movement in the brain, but merely mention things like blood flow and neurotransmitter movement. There is, in fact, no type of movement at all in the brain when a memory is retrieved, other than the normal flow of fluid and chemicals that is constantly occurring in the brain. Other than fluid and chemicals in the brain, every single part of the brain stays exactly where it is. This should come as no surprise when we consider that there are no muscles at all in the brain. The brain is a static organ on everything except the microscopic level.

So on a macroscopic scale, there would seem to be no possible way in which a brain could ever achieve anything like the position focus that would be needed to read a memory from one particular spot. If we were to open up someone's skull, and ask him quiz questions, we would see no sign of anything moving in the brain to retrieve a memory from some particular spot. Could it be that there is some type of “chemical focus” or “electrical focus” that occurs in a particular spot of the brain when a memory is retrieved? Could it be that chemicals or electricity kind of “swarm” to some particular part of the brain to achieve some kind of memory retrieval effect? There is no evidence that this occurs. Nor can we imagine how any mere swarming of chemicals or electricity would cause something like a brain to be reading one and only one of countless thousands of memories stored in it.

I submit that the activity that we observe in the brain when someone retrieves a memory is 100% compatible with the claim that the brain does not at all retrieve memories stored inside it. When a human mind retrieves a memory, we see nothing special happening in the brain, no macroscopic sign of movement, and nothing at all that happens only when a memory is recalled. There is no “smoking gun” of memory retrieval that we can detect in the brain. Far more logical than the idea that memories are stored in brains is the idea that memory involves some non-physical faculty that is spiritual or psychic, some faculty that is far beyond our understanding. A host of difficulties arise when we scrutinize the idea that memories are stored and retrieved in brains, and all such difficulties can be avoided by believing that your memories are in your soul instead of your brain.

We have incredibly powerful electron microscopes that can see things as small as 50 picometers, which is about 1000 times smaller than 50 nanometers, the approximate size of a synapse. But our electron microscopes have revealed nothing at all to suggest that encoded memory information is stored in the brain. If such encoded memory information existed in the brain, it almost certainly would have been detected by now.  

A 2010 book by two neuroscientists confesses that neuroscientists have no understanding of anything like a mechanism that could read stored memories. It states the following:

How could that encoded information be retrieved and transcribed from the enduring structure into the transient signals that carry that same information to the computational machinery that acts on the information?....In the voluminous contemporary literature on the neurobiology of memory, there is no discussion of these questions. 

But some may argue that information could be read from any part of the brain, simply because neurons are all connected, allowing any neurons to be “electrically read.” I can imagine a conversation that illustrates the absurdity of such an idea.

John: I wrote some interesting stuff about my wife. Very private stuff.
Dave: Yeah, that was interesting. I read it myself.
John: What are you talking about? Did you break into my house?
Dave: No, not at all.
John: So you couldn't have read what I wrote. I didn't post it online. I only wrote it using an old computer I have, one that isn't even connected to the Internet.
Dave: But I read it electrically, by using the electrical system.
John: What are you talking about?
Dave: It works like this. All computers connect to the same electrical grid. So when you plug in your computer to power it, that means I can reach out and read what you wrote, because we're all connected to the same electrical grid. So I can “reach out electrically” and read stuff from your computer.

Dave here is just pulling John's leg, and John should be able to realize that Dave is talking hogwash. Just because two machines are connected to the same electrical grid, that would not be enough for one machine to read from another machine. And similarly, just because all neurons are electrically connected, that's no reason why a brain should be able to instantly find and read information from just the right spot in a brain where some particular memory is stored.  All known, verified cases of information reading from physical objects involve some kind of position focus mechanism, and there doesn't seem to be any such thing in the brain. This is another reason for thinking that when you remember, your brain is not reading a memory stored in the brain.

Let us imagine some religious cult which taught that 50,000 feet above us there floats a giant castle in the clouds populated by 500-year-old men who control the destiny of the world. Suppose we were to ask the members of such a cult, “How does the castle avoid falling to the ground?” or “How come these men don't die from the low air pressure at that altitude?” or “How can these men live for 500 years when the radiation at that altitude should give them cancer in a few decades?” or "How come none of our astronomers have detected this castle in the sky?"  Such cult members would probably say something like, “Do not ask such impertinent questions.” Similarly, suppose we were to ask a neuroscientist, “How can a brain find a memory instantly among thousands of stored memories?” or “How could a brain read a memory when it has no read mechanism?” or “How could memories be stored in synapses for decades when the proteins of such synapses are replaced every few weeks?” or “How could a brain encode memories when there are no genes for such a task?” or “How could a brain memory storage require protein synthesis, taking minutes, when you can instantly form a memory?” or "How could our electron microscopes have failed to detect positive signs of memories in the brain if they existed?" We would expect to get a reply that was essentially the equivalent of “Do not ask such impertinent questions.”

Besides lacking any mechanism for reading memories, the brain lacks any mechanism for writing memories.  Scientists have never specified any plausible mechanism by which a brain could write a memory as stored information. It is often claimed that an effect called LTP is some kind of memory writing mechanism, achieving memory storage through a gradual strengthening of synapses occurring over multiple repetitions of sensory experience. But such an idea is inconsistent with the fact that we can form a memory from a single sensory experience, as you demonstrate whenever you discuss with someone else a TV show or movie you saw only one time recently.  LTP (which stands for long-term potentiation) is actually a short-lived effect.  A scientific paper states the following:

LTP always decays and usually does so rapidly. Its rate of decay is measured in hours or days (for review, see Abraham 2003). Even with extended “training,” a decay to baseline levels is observed within days to a week.

LTP is so weak an effect it is hard to even detect it. A scientific paper asks the following:

Why is it so difficult to see learning-associated synaptic changes?And does their absence in numerous experiments favor the null hypothesis?

Such things would not be true if LTP was actually a write mechanism for memories that can last for decades. Referring to this scientific paper, another paper suggests that "LTP as a memory mechanism" is more of a dogma than something well established by observations:

Shors and Matzel,,.concluded that LTP did not meet the criteria for providing a causal mechanism of memory. To make a long argument very short, they documented instances where changes in memory occur without LTP and where LTP occurs without changes in memory.....They report that between 1974 and 1997, more than 1300 articles occurred with “LTP” in the title. Of these, fewer than 80 described any behavioral manipulation relevant to assessing changes in memory. Furthermore, the articles that contained behavioral manipulations tended to provide evidence against the hypothesis that LTP is a memory mechanism. Thus, the claim that LTP is a molecular mechanism for learning and memory may be more of a dogma of neuroscientific memory research than a hypothesis that is being rigorously tested.  

A 2014 book stated, "Although LTP is considered to be the primary model for how learning and memory storage occur at the synapse level, the evidence supporting this claim is still inconclusive and speculative." A 1995 scientific paper found. "There is a striking negative correlation of spatial learning ability with LTP." This is the exact opposite of what we should expect if LTP was some type of memory mechanism. 

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