Michael Egnor is a professor of neurosurgery and pediatrics whose writings often appear at the Evolution News site. Egnor has written some good posts at that site, often presenting the kind of evidence I discuss on this site. But in one post this year on that site, Egnor seems to indicate that he is still clinging to some of the moldy old dogmas of neuroscientists, including some dogmas I regard as untenable.
It is not that Egnor is afraid to believe in a human soul. In the post he says "we have spiritual souls and physical bodies." In fact, Egnor is the author of a new book entitled The Immortal Mind: A Neurosurgeon's Case for the Existence of the Soul. The problem is that the soul Egnor believes in seems to be only half of what we need to postulate to have a credible theory of human minds. Egnor seems to believe that you have a soul responsible for your selfhood and consciousness and thinking, but that such a soul does not involve human memory. He apparently thinks that memory is a product of the brain. Teaching an unfounded triumphal legend, he states, "The pioneering neuroscientists of the 20th and 21st centuries — Wilder Penfield, Roger Sperry, Justine Sergent, Yair Pinto, Benjamin Libet, and many others — have shown that the brain is the source of five of these kinds of activities—physiological control (of heartbeat, breathing, etc.), locomotion, perception, memory, and emotion."
No, such neuroscientists sure did not show that the brain is the source of perception or locomotion or memory or emotion. There are brain chemicals that can influence emotions such as fear and anger; and brains help you achieve visual perception through the eyes and locomotion through your legs. But no one has ever shown any neural basis for the more elevated human emotions such as romantic love or parental love or wonder or awe. No one has an explanation for how a brain could produce a locomotion decision such as when you decide to get up and go for a walk. There is no neuroscience basis for claiming that the brain is the source of instant human recall, which occurs despite the nonexistence in the brain of the things that make instant information retrieval possible in products humans manufacture (things such as addressing, indexing and sorting). And there are the strongest reasons for thinking that the brain cannot be the storage place of human memories, things such as the fact that human memories can last 1000 times longer than the average lifetime of brain proteins.
In that quote by Egnor, he has a link to other posts, one link for each of the people he mentions. Let me discuss those links.
The Wilder Penfield Link
The link Egnor gives regarding Penfield is a link to a post he wrote about Wilder Penfield. The post is guilty of propagating one of the "old wives' tales" of neuroscience lore, the claim that Wilder Penfield produced memory recall by zapping people's brains with electricity. Penfield did no such thing. He merely noted that sometimes people would recall things when their brain was being electrically zapped. Since memory recall occurs almost all the time, memory recall during brain zapping does nothing to show that brains store memories. Penfield failed to document any effect by which one particular memory would always be evoked when some particular brain region was zapped.
Strangely Egnor quotes Penfield as saying "none of the actions we attribute to the mind has been initiated by electrode stimulation or epileptic discharge." Such a claim contradicts the idea that he did anything to produce recall by zapping a brain, because memory recall is certainly one "of the actions we attribute to the mind."
At www.archive.org I was able to find and borrow a 1967 book by Wilder Penfield, the book "The Excitable Cortex in Conscious Man." In that book Penfield discusses his research electrically stimulating parts of human brains. He makes no claim that a specific memory could be reproduced multiple times by stimulating a particular part of the brain. Instead on page 23 he merely refers to "experiential hallucinations" being produced by such brain stimulation.
In a future post discussing pages 23 to 32 of this book, I will document cases of how Penfield described imprecise statements from electrically stimulated patients (statements lacking the precision of exact recollections of real events), and how Penfield jumped to conclusions by making unwarranted characterizations of such statements, claiming that they were based on things the patients had experienced, without ever verifying that this was the case, while at the same time calling such statements descriptions of "hallucinations."
So Egnor is wrong about Penfield. He did not do anything to show memories are stored in brains. In particular, he made no attempt to determine whether accounts he collected from people being brain-stimulated matched actual things they had experienced. We don't even know whether such accounts were actual memories.
In another post Egnor continues to suggest incorrect ideas about the research of Penfield. He claims that some reader said that 5 percent of Penfield's stimulation produced memories. As his only link to back up this claim, he gives a link to the paper quoted above, which does not support any such claim, but instead tells us that "This remains a rare phenomenon with from 0.3% to 0.59% EBS [electrical brain stimulation] inducing reminiscences.” So the actual rate is that when you stimulate someone's brain, maybe 1 out of 200 times they will remember something. This does nothing to show that memories are stored in brains, and you could probably get a similar rate of memory recollection by scratching someone's elbow, simply because normal speech is rich in memory recollection.
The Roger Sperry Link
The link Egnor gives when referring to Roger Sperry is a link to the post here. The post discusses patients that underwent a cutting of the fibers connecting their two hemispheres. Such patients retained a single unified self. Such evidence is important in establishing that the brain is not the source of the mind, as they showed people with essentially two severed brain halves retain a single self. But split-brain operations do nothing to substantiate Egnor's mostly incorrect claim that "The pioneering neuroscientists of the 20th and 21st centuries — Wilder Penfield, Roger Sperry, Justine Sergent, Yair Pinto, Benjamin Libet, and many others — have shown that the brain is the source of five of these kinds of activities—physiological control (of heartbeat, breathing, etc.), locomotion, perception, memory, and emotion."
The Justine Sergent Link
The link Egnor gives is to the post here, which also discusses split brain operations, and mentions how neuroscientist Justine Sergent did some work following up on the "split brain" research of Roger Sperry, showing that two disconnected halves of a split-brain patient do not form connections reconnecting them. The discussion does nothing to substantiate Egnor's mostly untrue claim that "The pioneering neuroscientists of the 20th and 21st centuries — Wilder Penfield, Roger Sperry, Justine Sergent, Yair Pinto, Benjamin Libet, and many others — have shown that the brain is the source of five of these kinds of activities—physiological control (of heartbeat, breathing, etc.), locomotion, perception, memory, and emotion."
The Yair Pinto Link
The link Egnor gives is to the post here, entitled "Split-Brain Research Confirms Unity of the Human Mind." We read about how neuroscientist Yair Pinto did research further showing that split-brain patients retain a single unified mind. The discussion does nothing to substantiate Egnor's mostly untrue claim that "The pioneering neuroscientists of the 20th and 21st centuries — Wilder Penfield, Roger Sperry, Justine Sergent, Yair Pinto, Benjamin Libet, and many others — have shown that the brain is the source of five of these kinds of activities—physiological control (of heartbeat, breathing, etc.), locomotion, perception, memory, and emotion."
The Benjamin Libet Link
The link Egnor gives is to the page here, which does nothing to back up the mostly untrue claim quoted above.
Egnor's Other Attempts to Show Brains Handle Memory
Egnor makes two other attempts to suggest brains handle memory. He mentions Alzheimer's patients, saying "Alzheimer’s patients are quite conscious; what they lack is memory." Under the more severe understanding of the word "lack," this is a very bad misstatement. Alzheimer's patients are properly described as people with memory problems. The average Alzheimer's patient does have memory of various types, but performs more poorly than average in recalling and remembering (see the end of this post where I describe how by one measure they perform about 80% as well on average as normal people). Alzheimer’s patients do not show that memory is a brain process, because of the low correlation between brain damage and dementia. As I discuss in my post here, there is no convincing evidence that the brains of Alzheimer’s patients are more damaged or shrunken than the brains of people with normal memory performance. And the brain plaques called a hallmark of Alzheimer’s are found abundantly in many millions of people with normal memory performance.
Here is a quote from a book on dementia (you can find the quote using the link here and going to page 35):
Egnor also makes this claim: "Similarly, bilateral hippocampal destruction by injury to the temporal lobes causes a catastrophic loss of ability to form new memories, but such patients are fully conscious." The claim is a myth of neuroscientists. The neuroscience literature documents no case of a person with "bilateral hippocampal destruction" by either surgery by injury who had a "catastrophic loss of ability to form new memories." Claims that patient H.M. had such an inability to form new memories are untrue, as I document in my post here, where I cite quite a few cases of that patient learning new things after his injury and surgery. In that post I cite much research showing that damage to the hippocampus has little effect on the ability to form new memories. One of the examples I quote in that post is that while the claim was made in the 1950's that patient H.M. could form no new memories, when patient H.M. was shown a Kennedy half-dollar in 1968, he stated that the man shown on it was President Kennedy, and that he had been assassinated (referring to the death of Kennedy that occurred in 1963). This is only one of many similar examples given in the paper here.
Why "Brains Do Memory" Is Untenable
In the post I have quoted Egnor seems to claim that memory is handled by the brain. There are many reasons why that cannot be correct.
As shown in the many examples given here, here, here, here and here, contrary to the predictions of "brains make minds" and "brains store memories" thinkers, human minds can operate very well despite tremendous damage to the brain, caused by injury, disease or surgery. For example, removing half of a person's brain in the operation known as hemispherectomy produces little change in memory or cognitive abilities. There have been quite a few cases of people (such as Lorber's patients) who were able to think and speak very well despite having lost more than 60% of their brain due to disease. Such cases argue powerfully that the human mind is not actually a product of the brain or an aspect of the brain, and is not a storage place of human memories.
Although it is claimed that memories are stored in the brain (specifically in synapses), there is no place in the brain that is a plausible storage site for human memories that can last for 50 years or longer. The proteins that make up both synapses and dendritic spines are quite short-lived, being subject to very high molecular turnover which gives them an average lifetime of only a few weeks or less. The 2018 study here precisely measured the lifetimes of more than 3000 brain proteins from all over the brain, and found not a single one with a lifetime of more than 75 days (figure 2 shows the average protein lifetime was only 11 days). Both synapses and dendritic spines are a “shifting sands” substrate absolutely unsuitable for storing memories that last reliably for decades. Synapses are connected to dendritic spines, which have short lifetimes. A 2018 paper has a graph showing a 5-day "survival fraction" of only about 30% for dendritic spines in the cortex. A 2014 paper found that only 3% of new spines in the cortex persist for more than 22 days. Speaking of dendritic spines, a 2007 paper says, "Most spines that appear in adult animals are transient, and the addition of stable spines and synapses is rare." A 2016 paper found a dendritic spine turnover rate in the neocortex of 4% every 2 days. A 2018 paper found only about 30% of new and existing dendritic spines in the cortex remaining after 16 days (Figure 4 in the paper).
It is claimed that memories are stored in brains, but humans are able to instantly recall accurately very obscure items of knowledge and memories learned or experienced decades ago; and the brain seems to have none of the characteristics that would allow such a thing. The recall of an obscure memory from a brain would require some ability to access the exact location in the brain where such a memory was stored (such as the neurons near neuron# 8,124,412,242). But given the lack of any neuron coordinate system or any neuron position notation system or anything like an indexing system or addressing system in the brain, it would seem impossible for a brain to perform anything like such an instantaneous lookup of stored information from some exact spot in the brain.
If humans were storing their memories in brains, there would have to be a fantastically complex translation system (almost infinitely more complicated than the ASCII code or the genetic code) by which mental concepts, words and images are translated into neural states. But no trace of any such system has ever been found, no one has given a credible detailed theory of how it could work, and if it existed it would be a “miracle of design” that would be naturally inexplicable.
If human brains actually stored conceptual and experiential memories, the human brain would have to have both a write mechanism by which exact information can be precisely written, and a read mechanism by which exact information can be precisely read. The brain seems to have neither of these things. There is nothing in the brain similar to the “read-write” heads found in computers.
We know from our experience with computers the type of things that an information storage and retrieval system uses and requires. The human brain seems to have nothing like any of these things.
As discussed here, humans can form new memories instantly, at a speed much faster than would be possible if we were using our brains to store such memories. It is typically claimed that memories are stored by “synapse strengthening” and protein synthesis, but such things do not work fast enough to explain the formation of memories that can occur instantly.
Contrary to the idea that human memories are stored in synapses, the density of synapses sharply decreases between childhood and early adulthood. We see no neural effect matching the growth of learned memories in human.
There are many humans with either exceptional memory abilities (such as those with hyperthymesia who can recall every day of their adulthood) or exceptional thinking abilities (such as savants with blazing-fast calculation abilities). But such cases do not involve larger brains, very often involve completely ordinary brains, and quite often involve damaged brains, quite to the contrary of what we would expect from the “brains make minds” assumption and the "brains store memories" assumption.
For decades microscopes have been powerful enough to detect memories in brains, if memories existed in brains. Very much brain tissue has been studied by the most powerful microscopes: both brain tissue extracting from living patients, and brain tissue extracted from someone very soon after he died. Very many thousands of brains have been examined soon after death. Microscopes now allow us to see very clearly what is in the tiniest brain structures such as dendritic spines and synapse heads. But microscopic examination of brain tissue has failed to reveal any trace whatsoever of learned information in a brain. No one has found a single letter of the alphabet stored in a brain; no has found a single number stored in a brain; and no one has ever found even a single pixel of something someone saw a day or more before. If memories were stored in human brains, microscopes would have revealed decisive evidence of such a thing decades ago. But no such evidence has appeared.
- There is nothing in the brain that looks like learned information stored according to some systematic format that humans understand or do not understand. Even when scientists cannot figure out a code used to store information, they often can detect hallmarks of encoded information. For example, long before Europeans were able to decipher how hieroglyphics worked, they were able to see a repetition of symbolic tokens that persuaded them that some type of coding system was being used. Nothing like that can be seen in the brain. We see zero signs that synapses or dendritic spines are any such things as encoded information.
- Many humans can remember with perfect accuracy very long bodies of text, such as hundreds of pages; but synapses in the brain do not reliably transmit information. An individual chemical synapse transmits an action potential with a reliability of only 50% or less, as little as 10%. A recall of long bodies of text would require a traversal of very many chemical synapses. A scientific paper says, "In the cortex, individual synapses seem to be extremely unreliable: the probability of transmitter release in response to a single action potential can be as low as 0.1 or lower." Moreover, the brain lacks any physical structure consistent with an ability to store very long sequences of information, as I discuss here.
- Humans often form vivid new memories while humans are having near-death experiences taking place during cardiac arrest, when the brain has shut down, showing only flatlines of electrical activity. That brain state is called asystole, and it occurs within about 10 to 20 seconds after the heart stops. If memories are created by the brain, the formation of new memories should be impossible while the brain is electrically inactive. But we know that very vivid and detailed memories can form during such states of brain electrical inactivity. That would not be possible if memory formation is a brain activity. Moreover, during near-death experiences occurring asystole, people do not find themselves as minds without memories. They find themselves as the same selves with the same memories. There are endless accounts along the lines of this: "Suddenly I was floating outside of my body, and could see it beneath me. Later I saw my deceased mother." No such experiences would occur if a soul lacking memory powers were to persist after the heart stopped and brain waves stopped. In that case there would be no memory recall, and no memory formation.
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