The failure of scientists to find any memories by the microscopic examination of brain tissue is one of the strongest reasons for rejecting claims that the human brain stores memories. There is encoded genetic information in the nucleus of most cells, information which is pretty much the same in every cell, and is not memory information. That information was discovered around 1953. Since 1953 our technology has grown enormously. But there is still not a single case of anyone ever reading a memory from any brain (human or animal) outside of his own body. Scientists have never been able to read a memory by scanning with a microscope a living person's brain, or scanning some brain tissue. Do not be fooled by press accounts that sometimes grossly exaggerate scientific experiments, and give us headlines such as “Scientists invent mind-reading device.” Such experiments (typically trying to read neural correlates of visual perception) do not actually involve thought reading, and do not at all involve a reading of stored information in the brain.
When reminded of the non-existence of claims to have read memory information from human tissue by microscopic methods, someone might respond like this:
"Well, the problem is that scientists don't have time to study a brain after someone dies, because the body is buried or cremated. If scientists were able to spend lots of time studying the brains of people who had just died, they would probably be able to find memories in the brains of dead people."
But this claim is not correct. There actually exists an institute of scientists devoted to studying the brains of dead people. And they have had over 4000 brains to study, mostly cases of brains that were donated very soon after someone died, and quickly preserved.
The institute is called the Lieber Institute, and its web site is here. The site says that the Lieber Institute has 48,000 square feet of laboratory space at Johns Hopkins University. The Lieber Institute claims to have a repository of about 4000 brains. On another page of the institute, we are told, "Each brain is donated by a bereaved family just hours after the loss of their loved one." A Washington Post article describes a guy working for that institute who has the job of calling the families of people who just died (often from suicide), asking them for the brain of the dead person to be donated. We are told such requests must occur very quickly. The article says this guy "has a small window of time in which to get that consent — just one to three hours." The Post story says, "Researchers try to obtain brains within 24 to 36 hours." We are told the brains are "flash frozen."
So we have a modern institute with 4000 brains frozen within about a day after death. The Lieber Institute has been studying such brains for about a decade, mainly for the purpose for trying to find links between brain states and mental illness. The work of the Lieber Institute has involved a huge amount of studying brains frozen in the state they were put in within a day after death. You would think that if human brains stored memories, that by now such an institute would have been able to find abundant evidence of stored memories in brain. But no such evidence has been found. Nowhere in the 10-year progress report of the Lieber Institute is there any mention of finding any memories in the brains of dead people.
Could it be that one of the 100 or so publications on the institute's Publications page is one mentioning the finding of a memory stored in the brain? It seems not. Below is a list of all the papers on that page that use the word "memory":
" Countless shelves line the walls of a basement at Denmark's University of Odense, holding what is thought to be the world's largest collection of brains. There are 9,479 of the organs, all removed from the corpses of mental health patients over the course of four decades until the 1980s. Preserved in formalin in large white buckets labeled with numbers, the collection was the life's work of prominent Danish psychiatrist Erik Stromgren...The brains were collected after autopsies had been conducted on the bodies of people committed to psychiatric institutes across Denmark. Neither the deceased nor their families were ever asked permission."
We hear not one word about any discovery that came from studying these brains. A web page of the University of Odense describes the collection of brains, but fails to mention any progress that has come from studying the brains. There is no link to any papers that were produced using such brains.
There is another brain collection called the Human Brain Collection Core (HBCC). The collection is described here. The collection seems to consist of about 1000 brains, 700 from people who were diagnosed with mental illness. 300 of the brains are from normal people. We seem to have the same kind of method as used by the Lieber Institute. The families of people who recently died are asked to donate the brain of a family members, with a time pressure element of "we must act fast."
Related to this collection is a "Selected Publications" page, apparently listing the best results obtained from studying these brains. None of the 46 papers reports anything like a discovery of memories by analyzing brain tissue. None of the papers has a title referring to either memory or engrams.
Despite microscopically studying more than 14,000 brains (a large fraction of which were cryogenically preserved within a day after death), scientists are unable to read any memory from any of these brains, and are also unable to find any evidence of some neural code that could be used to translate learned information into brain states. The brains are saying "storing memories is not something brains do," but our scientists refuse to listen to what the brains are telling them.
Below is a diagram from the paper "Materials Advances Through Aberration-Corrected Electron Microscopy." We see that since the time the genetic code was discovered about 1953, microscopes have grown very many times more powerful. The A on the left stands for an angstrom, a tenth of a nanometer (that is, a ten-billionth of a meter).
Currently the most powerful microscopes can see things about 1 angstrom in width, which is a tenth of a nanometer. How does this compare to the sizes of the smallest units in brains? Those sizes are below:
Width of a neuron body (soma): about 100 microns (micrometers), which is about 1,000,000 angstroms.
Width of a synapse: about 20-30 nanometers, about 200-300 angstroms.
Width of a dendritic spine: about 50 to 200 nanometers, about 500 to 2000 angstroms.
Clearly the resolution of the most powerful microscopes is powerful enough to read memories stored in neurons or synapses, if such memories existed. And more than 10,000 brains have been microscopically studied in recent years. The failure to microscopically read any memories from human brain tissue is a major reason for thinking that brains do not store human memories.
Besides failing to find specific memories and items of learned knowledge by microscopically examining brains (such as the information that the New York Yankees belong to the American League of US baseball), scientists can find no evidence of a mechanism for storing learned information in brains. If such a mechanism existed, its fingerprints would be all over the place. Since humans can learn and remember so many different types of things (sights, sounds, feelings, facts, beliefs, opinions, numbers, smells, tastes, physical pains, physical pleasures, music, quotations, and so forth), any brain mechanism for storing all of these things would have a massive footprint in the brain and in the genome. No sign of any such thing can be found. The workhorses that get things done in the body are proteins, and humans have more than 20,000 types of proteins. No one has ever identified a protein that helps to write a memory of experiences or numbers or words to the brain or neural tissue, in any kind of way that helps explain how memories or knowledge could be stored in brains. Of course, you can find studies maybe showing that protein XYZ was used when someone learned something, but that does nothing to show a mechanism of memory storage.
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