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Our future, our universe, and other weighty topics


Monday, November 11, 2019

Near-Death Experiences Suggest the “Brain as Mainly a Valve” Idea

A near-death experience is when someone reports astonishing and mysterious hard-to-explain events occurring at a moment of physical danger, typically one in which he or she came close to death. A recent study on near-death experiences indicates that such experiences occur to a significant fraction of the population. The study by Kondziella, Dreier and Olsen used an online “crowdsourcing” platform called Prolific Academy. People from all over the world register with this online site, and are paid small sums to participate in research studies. Using the platform, Kondziella, Dreier and Olsen were able to question 1034 random subjects from 35 countries.

Previous studies had indicated that between 4% to 8% of the population have had near-death experiences. But the Kondziella, Dreier and Olsen study found that 289 out of 1034 subjects claimed to have had something like a near-death experience. The scientists applied something called the Greyson scale to quantify the strength of the reported experiences. 106 of the participants reported experiences that were scored 7 or higher on the Greyson scale, which is generally regarded as the cutoff level for a “full-blown” or “classic” near-death experience. So about 10% of the subjects reported a “full-blown” or “classic” near-death experience, and some 28% reported some type of near-death experience.

This is an astonishingly high number when we consider that the great majority of people never have any close brushes with death. A reasonable guess about what percentage of people have had a close brush with death would be something like 10% or 15%. So if you get 10% of about 1000 subjects reporting a full-blown near-death experience, that may suggest that most people who have close brushes with death have a full-blown near-death experience.

Making a questionable use of the word “symptoms,” the authors report the following:The most often reported symptoms were abnormal time perception (faster or slower than normal; reported by 252 participants; 87%); exceptional speed of thoughts (n=189; 65%); exceptional vivid senses (n=182; 63%); and feeling separated from one’s body, including out-of-body experiences (n =152; 53%).” These are extraordinarily high numbers, involving about 20% of the random sample of 1034 subjects. These numbers suggest that the actual level of near-death experiences may be as high as about 20% of the population. There seems to be no obvious reason why we should not say that anyone who reports either “exceptional speed of thoughts” or “exceptional vivid senses” or “feeling separated from one's body” (during a health emergency or close brush with death) as a person who has had a near-death experience.

We should ponder the extraordinary significance of such numbers. Our neuroscientists dogmatically maintain that the brain is the sole source of our thoughts and mind. Yet judging from the numbers above, a full 15% of the population have had experiences in which their mind was separated from their body. Such a result is entirely incompatible with the “brain makes your mind” dogma, and strongly suggest that your mind and consciousness do not at all come from your brain, and can exist apart from your brain. When we get into the specific accounts given by near-death experiences, we often find those who have such experiences claim to have observed their bodies from above their bodies, just as if their soul was floating above their bodies. Why do our neuroscientists ignore such massively occurring observational reports, which argue so strongly that the dogmas neuroscientists are teaching are dead wrong?

An interesting idea is that your mind is something that comes from some external metaphysical reality beyond the human body, and that far from being the source of your mind, the brain is mainly a kind of valve that restricts your mind. It may be that each of us has a mind that is something far beyond what we experience in day-to-day living, and that the only reason we seem to have minds so limited is that our brains limit our minds. We can imagine a reason why there might need to be such a valve effect or limiting effect. So we can concentrate on all the measly little challenges of day-to-living (such as staying warm, getting enough food, and avoiding various types of physical harm), it might be necessary for consciousness to be reduced and restricted, so that we can focus our thoughts on the crummy little details of the here and now, rather than being absorbed in the grand thoughts of a philosopher.

A possible relation of the brain and mind

Under such a theory, what would we expect if a mind or soul somehow moves temporarily beyond the body, such as in the out-of-body experiences often reported during near-death experiences? We might expect that the mind or thinking might be enhanced, for in such a case the “valve” effect of the brain might no longer be limiting our minds. It is just such a thing that is often reported during near-death experiences. The study by Kondziella, Dreier and Olsen found that 65% of 252 people reporting near-death experiences reported “exceptional speed of thoughts.” There is no way to account for such a thing under a “brain makes the mind” theory. But if the brain is like a valve that restricts and limits the human mind, we might expect that people might report much faster thinking when their brains shut down because of a close brush with death.

What we know about the brain is consistent with the idea of a brain mainly being a kind of valve. No one has ever discovered any effect by which neurons can produce a thought or an idea or an understanding of something, and no one has any coherent explanation of how such things can be produced by neurons. But we do know of a variety of signal-slowing factors in the brain (things such as synaptic delay, neural noise, synaptic fatigue and what is called tortuosity) which should have a very strong cumulative signal slowing effect. 

The study by Kondziella, Dreier and Olsen was trying to establish some kind of association between near-death experiences and  something called “REM intrusion,” but it failed to convincingly find any causal link between the two. “REM intrusion” is a kind of “dream a bit while you're awake” effect that people can experience either when they're on the verge of falling asleep, or have just woken up but are sleepy. The study asked five questions designed to search for signs of “REM intrusion” in people. The questions were worded in such as to get the maximum number of people who could be claimed as people who experienced “REM intrusion.” People were asked “have you ever” questions such as “Just before falling asleep or just after awakening, have you ever seen things, objects or people that others cannot see?” or “Just before falling asleep or just after awakening, have you ever heard sounds, music or voices that other people cannot hear?” Asking such “have you ever” questions is not a reliable way to judge whether people experience “REM intrusion” to a significant degree, just as asking, “Have you ever felt an unexplained pain in your stomach?” is not a reliable to test for whether people have a stomach disease. A sound way to judge the degree of “REM intrusion” experienced by people would be to have a question like the following:

Just before falling asleep or just after awakening, how often have you seen things, objects or people that others cannot see?

Choice 1: Never.
Choice 2: Once or twice in my life
Choice 3: Three to ten times in my life
Choice 4: Between ten and twenty times in my life
Choice 5: More than twenty times in my life

Of the people who claimed to have a near-death experience, 34% answered “yes” to three of more of the five questions related to “REM intrusion.” Of the people who did not claim to have had a near-death experience, 14% answered “yes” to three of more of the five questions related to “REM intrusion.” There's a reason why such a difference does not actually establish that those reporting near-death experiences more often experience such “REM intrusion.” The reason is that those who reported a near-death experience may simply have a higher degree of candor and openness about reporting out-of-the-ordinary experiences. Once someone has reported one type of out-of-the-ordinary experience, there may be a kind of “breaking the ice” effect that may make him 20% or 30% or 40% more likely to report a second out-of-the-ordinary experience that he might have otherwise never discussed. Such a thing can easily account for the difference in the percentage of people who answered “yes” to three or more of the questions about “REM intrusion.” Since people don't report things like near-death experiences when they are on the boundary of normal sleep, "REM intrusion" makes no sense as an explanation for near-death experiences. 

A second crowdsourced study was done by Kondziella, Dreier, Lemale and Olsen, using the same online survey platform of Prolific Academy, but using a different group of subjects. The results were almost the same as in the first survey. The differences are shown below:



Survey 1 Survey 2
Number of subjects 1034 1037
Number claiming a near-death experience 289 286
Number with a “full-blown” near-death experience (Greyson score >= 7) 106 81
Number reporting time moving slower or faster than normal 252 257
Number reporting extraordinary speed of thought 189 169
Number reporting exceptional vivid senses 182 165
Number reporting feeling separated from one's body, including out-of-body experiences 152 113


The second of these studies tries to draw a link between near-death experiences and “migraine aura” headaches, based on the claim that “Forty-eight (6.1%) of 783 subjects without migraine aura and 33 (13.0%) of 254 subjects with migraine aura had experienced” a near-death experience. Here the attempt at an explanation is even less convincing than in the previous survey, for we have a mere 13% of those reporting these “migraine aura” headaches reporting near-death experiences. X is not likely to be the cause of Y if only 13% of the people reporting Y also report X. Moreover, there has never been a tendency for people to report head pain during near-death experiences, making migraine headaches a particularly unlikely explanation. And people don't report they have near-death experiences after they merely had a bad headache.

The important takeaways from these two studies are:
  1. A significant fraction of people report near-death experiences, with about 25% of people reporting such experiences, and about 8% or 10% of people reporting “full blown” near-death experiences with 7 or more of the classic characteristics of near-death experiences.
  2. Most of those reporting near-death experiences report their mind operated exceptionally fast, with some 16% to 18% of the total population reporting such an effect. 
  3. Most of those reporting near-death experiences report having had extraordinary experiences in which they were separated from their body, with some 10% to 15% of the total population reporting such an effect. 
So what we have is a massive empirical reality that is very much inconsistent with prevailing dogmas about the brain and mind, that the brain is the source of the mind. But such an empirical reality is consistent with the idea that your mind is not the product of your brain or body, and that your brain is like a valve that serves mainly to limit your mind, rather than something that gives rise to your mind.

Thursday, November 7, 2019

He Gets "Victorians and the Paranormal" All Wrong

The Victorian Era was the era when Queen Victoria was queen of the British, between 1837 and 1901. The second half of the nineteenth century was an astonishing period in which inexplicable events repeatedly occurred before a host of witnesses, which included ordinary people and countless distinguished experts. When those skeptical of the paranormal write about such events, they sometimes produce travesties of history that are full of gigantic omissions and glaring distortions. An example is an article by Karl Bell that appeared online on October 31. The article was entitled “Victorian scientists thought they’d found an explanation for ghosts – but the public didn’t want to hear it.”

Distorting the historical reality, Bell tries to create in the reader's mind two ideas:
  1. That the Spiritualism movement (beginning in 1848) and the seances of the following decades were merely caused by people misidentifying furniture movements that occurred because of muscular movements when people put their hands on furniture such as tables.
  2. That the scientist Michael Faraday debunked such things by showing an “ideomotor effect” by which people can unconsciously move furniture that they are touching.
The Spiritualist movement that began in 1848 did not originate in any accounts of furniture moving when people touched furniture. The movement began with reports in Hydesville, New York of an abundance of mysterious unexplained noises, including mysterious rappings, and many other loud unexplained noises. Many witnesses claimed that the noises responded in a seemingly intelligent manner to human speech, as if they were caused by some invisible power. A very full account can be found on pages 284 to 299 of Robert Dale Owen's fascinating 1860 book Footfalls on the Boundary of Another World. You can read such an account here. Interestingly, on page 272 to page 283 of the same book we read about a similar case that occurred in 1850 in France, a case in which there were two solid months of inexplicable noises and inexplicable physical disturbances resembling poltergeist activity and an intelligent invisible force. Many witnesses attested to the phenomenon at a place that had not yet heard of the Hydesville incidents. Referring to this French phenomenon, Owen states on page 283, “It would be difficult to find a case more explicit or better authenticated than the foregoing.”

In the early 1850's many people engaged in what was called table turning. This involved a group of people placing their hands on a table. Very often the table would seem to make mysterious movements. The reported effects included the following:
  1. a simple tilting or turning of the table when people put their fingers on top of it;
  2. cases of a table rising up into the air when people put their fingers on top of it;
  3. cases in which a table would rise up into the air or move when no one touched the table.

Because items (2) and (3) were widely reported, it is clear that Faraday did not at all explain the better cases of the reported phenomena. There is no amount of manual force with the fingers that can cause a table to rise up into the air when people place their fingers on top of it, even if they are intentionally trying to do such a thing. Nor can any theory of unconscious force explain cases of tables moving or rising when no one touched them.

The rituals called seances might involve table turning, but often involved many other types of seemingly paranormal activity. Reported events at seances included the mysterious levitation of furniture or chairs (sometimes when no one was touching them), the levitation of a human being, the arising of mysterious inexplicable noises, voices appearing from out of nowhere, musical instruments playing when no one touched them, the appearance of mysterious lights, curtains or other objects shaking or fluttering when no one was touching them, or objects seeming to appear from out of nowhere (what are called apports).

It is therefore a misleading distortion to suggest that the activity at seances was merely table turning. Clearly table turning was only a small fraction of the reported paranormal activity at seances.

This phenomenon of table turning (and related anomalous phenomena) were scientifically investigated by a distinguished scientist, Harvard chemistry professor emeritus Robert Hare. Hare started out completely believing in Faraday's idea that table turning was caused purely by muscular force. But his investigations led him to reject such an idea. In 1855 he published a long book reaching the conclusion that the phenomenon involved an inexplicable paranormal reality. For example, on page 46 he states, “I first saw a table continue in motion when every person had withdrawn to about the distance of a foot; so that no one touched it; and while thus agitated on our host saying, 'Move the table toward Dr. Hare,' it moved toward me and back again.” This is only one of countless paranormal incidents described in the book, which Hare mainly regarded as proof of some mysterious paranormal reality. He devised numerous scientific instruments to test paranormal effects, and frequently found them to give dramatic inexplicable results. 

This phenomenon of table turning was also scientifically investigated at length by Count Agenor de Gasparin, who published in 1857 a two-volume scientific book describing countless paranormal effects (such as table levitation and mysterious rappings) observed under controlled conditions. Gasparin's research is well-summarized in Chapter VI of the book Mysterious Psychic Forces by the astronomer Camille Flammarion.  For example, Gasparin described this happening on September 3, 1853:

Some one proposed the experiment which consists in causing a table to rotate and give raps while it has on it a man weighing say a hundred and ninety pounds. We accordingly placed such a man on the table, and the twelve experimenters, in chain, applied their fingers to it. The success was complete: the table turned, and rapped several strokes. Then it rose up entirely off the floor in such a way as to upset the person who was upon it.”

Such a result is inexplicable through any result of subconscious muscle movement. Gasparin reported the following occuring on October 7, 1853:

Let us turn again to the finest of all demonstrations, that of levitation without contact. We began by performing it three times. Then, since it was thought by some that the inspection of the witnesses could be carried on in a surer way in the case of a small table than in that of a large one, and with five operators more certainly than with ten, we had a plain deal centre-table brought which the chain, reduced by half, sufficed to put in rotation. Then the hands were lifted, and, contact with the table being entirely broken, it rose seven times into the air at our command.”

Since this was a report of levitation of a table without contact, it obviously cannot be explained through Faraday's “ideomotor effect” of subconscious muscle movement. Shockingly, the phenomenon of table turning had stood up well to rigorous scientific experiments, with the investigators finding it to be a mysterious paranormal reality rather than something they could debunk.

Something similar was reported in 1855 by Eliab Wilkinson Capron, who reported that a “table moved on the floor with nobody touching it – moved to the distance of a foot or more and back, in various directions.” In 1869 the London Dialectical Society (a rationalist organization) launched a major scientific investigation of phenomena such as table turning. It concluded that “movements of heavy bodies take place without mechanical contrivance of any kind or adequate exertion of muscular force by the persons present, and frequently without contact or connection with any person.” 

Excerpts of the report of the committee can be read here, and the entire report can be read here. Below are some quotes from the report (go to this link to see the place in the report from which I quote).

  1. "Thirteen witnesses state that they have seen heavy bodies-in some instances men—rise slowly in the air and remain there for some time without visible or tangible support.
  2. Fourteen witnesses testify to having seen hands or figures, not appertaining to any human being, but life-like in appearance and mobility, which they have sometimes touched or even grasped, and which they are therefore convinced were not the result of imposture or illusion.
  3. Five witnesses state that they have been touched, by some invisible agency, on various parts of the body, and often where requested, when the hands of all present were visible.
  4. Thirteen witnesses declare that they have heard musical pieces well played upon instruments not manipulated by an ascertainable agency.
  5. Five witnesses state that they have seen red-hot coals applied to the hands or heads of several persons without producing pain or scorching; and three witnesses state that they have had the same experiment made upon themselves with the like immunity.
  6. Eight witnesses state that they have received precise information through rappings, writings, and in other ways, the accuracy of which was unknown at the time to themselves or to any persons present, and which, on subsequent inquiry was found to be correct.
  7. One witness declares that he has received a precise and detailed statement which, nevertheless, proved to be entirely erroneous.
  8. Three witnesses state that they have been present when drawings, both in pencil and colours, were produced in so short a time, and under such conditions as to render human agency impossible.
  9. Six witnesses declare that they have received information of future events and that in some cases the hour and minute of their occurrence have been accurately foretold, days and even weeks before."

Flammarion states that the committee included "physicists, chemists, astronomers and naturalists, several of them members of the London Royal Society."  At this place in the report, the committee made the following general conclusions:

"These reports, hereto subjoined, substantially corroborate each other, and would appear to establish the following propositions:—
1. That sounds of a varied character, apparently proceeding from articles of furniture, the floor and walls of the room (the vibrations accompanying which sounds are often distinctly perceptible to the touch) occur, without [Pg 292]being produced by muscular action or mechanical contrivance.
2. That movements of heavy bodies take place without mechanical contrivance of any kind or adequate exertion of muscular force by the persons present, and frequently without contact or connection with any person.
3. That these sounds and movements often occur at the times and in the manner asked for by persons present, and, by means of a simple code of signals, answer questions and spell out coherent communications.
4. That the answers and communications thus obtained are, for the most part, of a commonplace character; but facts are sometimes correctly given which are only known to one of the persons present."

Perhaps the most famous scientific investigations into the paranormal in the Victorian Era were the investigations of the eminent scientist William Crookes. Bell conveniently ignores making any mention of Crookes, and it is easy to figure out why. The case is one that is entirely inconsistent with what Bell tries to insinuate.

Crookes was the co-discover of the element thallium, and the inventor of the Crookes tube, a kind of vacuum tube that was the earliest ancestor of all television sets and computer monitors. Crookes made two important investigations into the paranormal. The first was to investigate the famous medium Daniel Dunglas Home. Many distinguished observers had reported the most astonishing paranormal phenomena in the presence of Home, such as levitations of furniture and levitations of Home himself. Home passed Crookes' scientific tests with flying colors. Crookes reported that when Home merely touched the top of an accordion that Crookes had recently bought, while the accordion was inside a cage, the musical instrument played by itself; and that when Home removed his hand entirely, so no one was touching the instrument, it also played by itself. "The instrument then continued to play, no person touching it, and no hand being near it," Crookes reported (Researches in the Phenomena of Spiritualism, page 13). 



 On page 10 Crookes writes the following:

"Among the remarkable phenomena which occur under Mr. Home's influence, the most striking, as well as the most easily tested with scientific accuracy, are –(1) the alteration in the weight of bodies, and (2) the playing of tunes upon musical instruments (generally an accordion, for purposes of portability) without direct human intervention, under conditions rendering contact or connection with the keys impossible. Not until I had witnessed these facts some half-dozen times, and scrutinised them with all the critical acumen that I possess, did I become convinced of their objective reality."

Crookes also investigated the medium Florence Cook. He reported the most astonishing phenomenon: that a ghostly “full form materialization” would repeatedly appear next to the body of Florence Cook. This could not have been Florence in disguise, for Crookes reported seeing both at the same time. A fuller discussion of Crookes'  account of these investigations (with quotations of his exact statements) can be found here.

Besides not saying a word about Crookes, and not saying a word about the investigation of the London Dialectical Society, Bell fails to say a word about perhaps the other most famous case of the Victorian era, the case of Leonora Piper. Unlike mediums such as Home and Cook, Piper was what is called a mental medium. Except for one time, she produced no anomalous physical phenomena. But upon going into a trance, Piper seemed to speak under the control of some external spirit. Very many times, in such trances Piper would seem to know things that were impossible for her to know, such as intimate details of the lives of the people in the same room.

For eighteen months, Piper was investigated by William James, a psychologist so eminent that he is sometimes called “the father of American psychology.” On page 268 of this link, in the article on Piper, we read that in the Proceedings of the Society for Psychical Research, James concluded the following: “And I repeat again what I said before, that, taking everything that I know of Mrs. Piper into account, the result is to make me feel as absolutely certain as I am of any personal fact in the world that she knows things in her trances which she cannot possibly have heard in her waking state, and that the definite philosophy of her trances is yet to be found.’’ An arch-skeptic (Richard Hodgson) was brought in to investigate, and even resorted to hiring private investigators to search for evidence of fraud. None was found, and Hodgson ended up avowing to the authenticity of Piper.

Bell also completely fails to mention the Society's work documenting reports of apparitions seen by credible witnesses. The culmination of that work was a 1000-page two-volume work by three members of the Society (psychologist Edmund Gurney, Frederic Myers and Frank Podmore), entitled Phantasms of the Living, which can be read online here and here

The very careful scholarly work Phantasms of the Living provided many hundreds of well-documented cases of people seeing apparitions or ghosts. You can read summaries of many of the accounts here and here and here and here  and here and here. A type of case very commonly reported was when someone would unexpectedly see an apparition of someone he did not know was dead, only to find out later that such a person had recently died. Very many such accounts can be read using the links I just gave.

Far from providing some natural explanation for ghosts, the massive scholarly work Phantasms of the Living failed to do any such thing, and made it look more likely than ever that there is no natural explanation for ghosts and apparitions. Again and again, the accounts in the book were just the type of thing we would expect if a human soul survives death and leaves the body after death.

What do we hear about Leonora Piper in Bell's account? Not a word, nor does he mention the equally dramatic Victorian case of Eusapia Palladino. What do we hear about Phantasms of the Living in Bell's account? Not a word. He mentions the physicist William Barrett, failing to tell us that Barrett authored the book Deathbed Visions giving many accounts of people seeing apparitions, without  offering any natural explanation for such sightings. Under a misleading heading “Debunking the bump in the night,” Bell merely says the following, trying to make it sound as if the Society for Psychical Research had somehow debunked the paranormal:

Various subcommittees investigated hypnotism, telepathy, seances and hauntings). Their work helped expose frauds and they were careful to apply scientific controls to their investigations.”

Not one word is mentioned by Bell about all the evidence for the paranormal gathered by the Society for Psychical Research. Bell ends by approvingly quoting some person in 1882 who made the stupid statement that scientists must engage in “careful abstention from dangerous trains of thought,” which sounds like something we would hear not from a scientist but from a dogmatic religionist. 

The title of Bell's article is very misleading. His title claims “Victorian scientists thought they'd found an explanation for ghosts,” but he mentions only one such scientist (who did not actually claim to have an explanation for ghosts, but only for turning tables). A more accurate title to describe a full discussion of Victorian scientists and the paranormal would be “Victorian scientists found good evidence for the paranormal all over the place.”

Monday, November 4, 2019

The Seven Sins of “Memory Engram” Experiments

There are some very good reasons for thinking that long-term memories cannot be stored in brains, which include:
  • the impossibility of credibly explaining how the instantaneous recall of some obscure and rarely accessed piece of information could occur as a neural effect, in a brain that is without any indexing system and subject to a variety of severe signal slowing effects;
  • the impossibility of explaining how reliable accurate recall could occur in a brain subject to many types of severe noise effects;
  • the short lifetimes of proteins in synapses, the place where scientists most often claim our memories are stored;
  • the lack of any credible theory explaining how memories could be translated into neural states;
  • the complete failure to ever find any brain cells containing any encoded information in neurons or synapses other than the genetic information in DNA;
  • the lack of any known read or write mechanism in a brain.
But scientists occasionally produce research papers trying to persuade us that memories are stored in a brain, in cells that are called "engram cells." In this post, I will discuss why such papers are not good examples of experimental science, and do not provide any real evidence that a memory was stored in a brain. I will discuss seven problems that we often see in such science papers. The "sins" I refer to are merely methodological sins rather than moral sins. 

Sin #1: assuming or acting as if a memory is stored in some exact speck-sized spot of a brain without any adequate basis for such a “shot in the dark” assumption.

Scientists never have a good basis for believing that a particular memory is stored in some exact tiny spot of the brain. But a memory experiment will often involve some assumption that a memory is stored in one exact spot of the brain (such as some exact spot of a cubic millimeter in width). For example, an experimental study may reach some conclusion (based on inadequate evidence) about a memory being stored in some exact tiny spot of the brain, and then attempt to reactivate that memory by electrically or optogenetically stimulating that exact tiny spot.

The type of reasoning that is used to justify such a “shot in the dark” assumption is invariably dubious. For example, an experiment may observe parts of a brain of an animal that is acquiring some memory, and look for some area that is “preferentially activated.” But such a technique is as unreliable as reading tea leaves. When brains are examined during learning activities, brain regions (outside of the visual cortex) do not actually show more than a half of 1% signal variation. There is never any strong signal allowing anyone to be able to say with even a 25% likelihood that some exact tiny part of the brain is where a memory is stored. If a scientist picks some tiny spot of the brain based on “preferential activation” criteria, it is very likely that he has not picked the correct location of a memory, even under the assumption that memories are stored in brains. Series of brains scans do not show that some particular tiny spot of the brain tends to repeatedly activate to a greater degree when some particular memory is recalled. 

Sin #2: Either a lack of a blinding protocol, or no detailed discussion of how an effective technique for blinding was achieved.

Randomization and blinding techniques are a very important scientific technique for avoiding experimenter bias. For example, what is called the “gold standard” in experimental drug studies is a type of study called a double-blind, randomized experiment. In such a study, both the doctors or scientific staff handing out pills and the subjects taking the pills do not know whether the pills are the medicine being tested or a placebo with no effect.

If similar randomization and blinding techniques are not used in a memory experiment, there will be a high chance of experimenter bias. For example, let's suppose a scientist looks for memory behavior effects in two groups of animals, the first being a control group having no stimulus designed to affect memory, and the second group having a stimulus designed to affect memory. If the scientist knows which group is which when analyzing the behavior of the animals, he will be more likely to judge the animal's behavior in a biased way, so that the desired result is recorded.

A memory experiment can be very carefully designed to achieve this blind randomization ideal that minimizes the chance of experimenter bias. But such a thing is usually not done in memory experiments purporting to show evidence of a brain storage of memories. Scientists working for drug trials are very good about carefully designing experiments to meet the ideal of blind randomization, because they know the FDA will review their work very carefully, rejecting the drug for approval if the best experimental techniques were not used. But neuroscientists have no such incentive for experimental rigor.

Even in studies where some mention is made of a blinding protocol, there is very rarely any discussion of how an effective protocol was achieved. When dealing with small groups of animals, it is all too easy for a blinding protocol to be ineffective and worthless. For example, let us suppose there is one group of 10 mice that have something done to their brains, and some other control group that has no such done thing. Both may be subjected to a stimulus, and their “freezing behavior” may be judged. The scientists judging such a thing may be supposedly “blind” to which experimental group is being tested. But if a scientist is able to recognize any physical characteristic of one of the mice, he may actually know which group the mouse belongs to. So it is very easy for a supposed blinding protocol to be ineffective and worthless. What is needed to have confidence in such studies is not a mere mention of a blinding protocol, but a detailed discussion of exactly how an effective blinding protocol was achieved. We almost never get such a thing in memory experiments. The minority of them that refer to a blinding protocol almost never discuss in detail how an effective blinding protocol was achieved, one that really prevented scientists from knowing something that might have biased their judgments. 

For an experiment that judges "freezing behavior" in rodents, an effective blinding protocol would be one in which such freezing was judged by a person who never previously saw the rodents being tested. Such a protocol would guarantee that there would be no recognition of whether the animals were in an experimental group or a control group. But in "memory engram" papers we never read that such a thing was done.  To achieve an effective blinding protocol, it is not enough to use automated software for judging freezing, for such software can achieve biased results if it is run by an experimenter who knows whether or not an animal was in a control group. 

Sin #3: inadequate sample sizes, and a failure to do a sample size calculation to determine how large a sample size to test with.

Under ideal practice, as part of designing an experiment a scientist is supposed to perform what is called a sample size calculation. This is a calculation that is supposed to show how many subjects to use per study group to provide adequate evidence for the hypothesis being tested. Sample size calculations are included in rigorous experiments such as experimental drug trials.

The PLOS paper here reported that only one of the 410 memory-related neuroscience papers it studied had such a calculation. The PLOS paper reported that in order to achieve a moderately convincing statistical power of .80, an experiment typically needs to have 15 animals per group; but only 12% of the experiments had that many animals per group. Referring to statistical power (a measure of how likely a result is to be real and not a false alarm), the PLOS paper states, “no correlation was observed between textual descriptions of results and power.” In plain English, that means that there's a whole lot of BS flying around when scientists describe their memory experiments, and that countless cases of very weak evidence have been described by scientists as if they were strong evidence.

The paper above seems to suggest that 15 animals per study group is needed.  But In her post “Why Most Published Neuroscience Findings Are False,” Kelly Zalocusky PhD calculates (using Ioannidis’s data) that the median effect size of neuroscience studies is about .51. She then states the following, talking about statistical power:

"To get a power of 0.2, with an effect size of 0.51, the sample size needs to be 12 per group. This fits well with my intuition of sample sizes in (behavioral) neuroscience, and might actually be a little generous. To bump our power up to 0.5, we would need an n of 31 per group. A power of 0.8 would require 60 per group."

So the number of animals per study group for a moderately convincing result (one with a statistical power of .80) is more than 15 (according to one source), and something like 60, according to another source.  But the vast majority of "memory engram" papers do not even use 15 animals per study group.

Sin #4: a high occurrence of low statistical significance near the minimum of .05, along with a frequent hiding of such unimpressive results, burying them outside of the main text of a paper rather than placing them in the abstract of the paper.

Another measure of how robust a research finding is the statistical significance reported in the paper. Memory research papers often have marginal statistical significance close to .05.

Nowadays you can publish a science paper claiming a discovery if you are able to report a statistical significance of only .05. But it has been argued by 72 experts that such a standard is way too loose, and that things should be changed so that a discovery can only be claimed if a statistical significance of .005 is reached, which is a level ten times harder to achieve.

It should be noted that it is a big misconception that when you have a result with a statistical significance (or P-value) of .05, this means there is a probability of only .05 that the result was a false alarm and that the null hypothesis is true. This paper calls such an idea “the most pervasive and pernicious of the many misconceptions about the P value.” 

When memory-related scientific papers report unimpressive results having a statistical significance such as only .03, they often make it hard for people to see this unimpressive number. An example is the recent paper “Arti´Čücially Enhancing and Suppressing Hippocampus-Mediated Memories.”  Three of the four statistical significance levels reported were only .03, but this was not reported in the summary of the paper, and was buried in hard-to-find places in the text.

Sin #5: using presumptuous or loaded language in the paper, such as referring in the paper to the non-movement of an animal as “freezing” and referring to some supposedly "preferentially activated" cell as an "engram cell." 

Papers claiming to find evidence of memory engrams are often guilty of using presumptuous language that presupposes what they are attempting to prove. For example,  the non-movement of a rodent in an experiment is referred to by the loaded term "freezing," which suggests an animal freezing in fear, even though we have no idea whether the non-movement actually corresponds to fear.  Also, some cell that is guessed to be a site of memory storage (because of some alleged "preferential activation" that is typically no more than a fraction of 1 percent) is referred to repeatedly in the papers as an "engram cell,"  which means a memory-storage cell, even though nothing has been done to establish that the cell actually stores a memory. 

We can imagine a psychology study using similar loaded language.  The study might make hidden camera observations of people waiting at a bus stop.  Whenever the people made unpleasant expressions, such expressions would be labeled in the study as "homicidal thoughts."  The people who had slightly more of these unpleasant expressions would be categorized as "murderers."   The study might say, "We identified two murderers at the bus stop from their increased display of homicidal expressions." Of course, such ridiculously loaded, presumptuous language has no place in a scientific paper.  It is almost as bad for "memory engram" papers to be referring so casually to "engram cells" and "freezing" when neither fear nor memory storage at a specific cell has been demonstrated.  We can only wonder whether the authors of such papers were thinking something like, "If we use the phrase engram cells as much as we can, maybe people will believe we found some evidence for engram cells." 

Sin #6: failing to mention or test alternate explanations for the non-movement of an animal (called “freezing”), explanations that have nothing to do with memory recall.

A large fraction of all "memory engram" papers hinge on judgments that some rodent engaged in increased "freezing behavior,"  perhaps while some imagined "engram cells" were electrically or optogenetically stimulated. A science paper says that it is possible to induce freezing in rodents by stimulating a wide variety of regions. It says, "It is possible to induce freezing by activating a variety of brain areas and projections, including the hippocampus (Liu et al., 2012), lateral, basal and central amygdala (Ciocchi et al., 2010); Johansen et al., 2010; Gore et al., 2015a), periaqueductal gray (Tovote et al., 2016), motor and primary sensory cortices (Kass et al., 2013), prefrontal projections (Rajasethupathy et al., 2015) and retrosplenial cortex (Cowansage et al., 2014).” 

But we are not informed of such a reality in quite a few papers claiming to supply evidence for an engram. In such studies typically a rodent will be trained to fear some stimulus. Then some part of the rodent's brain will be stimulated when the stimulus is not present. If the rodent is nonmoving (described as "freezing") more often than a rodent whose brain is not being stimulated, this is hailed as evidence that the fearful memory is being recalled by stimulating some part of the brain.  But it is no such thing. For we have no idea whether the increased freezing or non-movement is being produced merely by the brain stimulation, without any fear memory, as so often occurs when different parts of the brain are stimulated.

If a scientist thinks that some tiny part of a brain stores a memory, there is an easy way to test whether there is something special about that part of the brain. The scientists could do the "stimulate cells and test fear" kind of test on multiple parts of the brain, only one of which was the area where the scientist thought the memory was stored. The results could then be compared, to see whether stimulating the imagined "engram cells" produced a higher level of freezing than stimulating other random cells in the brain. Such a test is rarely done. 

Sin #7: a dependency on arbitrarily analyzed brain scans or an uncorroborated judgment of "freezing behavior" which is not a reliable way of measuring fear.

A crucial element of a typical "memory engram" science paper is a judgment of what degree of "freezing behavior" a rodent displayed.  The papers typically equate non-movement with fear coming from recall of a painful stimulus. This doesn't make much sense. Many times in my life I saw a house mouse that caused me or someone else to shreik, and I never once saw a mouse freeze. Instead, they seem invariably to flee rather than to freeze. So what sense does it make to assume that the degree of non-movement ("freezing") of a rodent should be interpreted as a measurement of fear?  Moreover, judgments of the degree of "freezing behavior" in mice are too subjective and unreliable. 

Fear causes a sudden increase in heart rate in rodents, so measuring a rodent's heart rate is a simple and reliable way of corroborating a manual judgment that a rodent has engaged in increased "freezing behavior." A scientific study showed that heart rates of rodents dramatically shoot up instantly from 500 beats per minute to 700 beats per minute when the rodent is subjected to the fear-inducing stimuli of an air puff or a platform shaking. But rodent heart rate measurements seem to be never used in "memory engram" experiments. Why are the researchers relying on unreliable judgments of "freezing behavior" rather than a far-more-reliable measurement of heart rate, when determining whether fear is produced by recall? In this sense, it's as if the researchers wanted to follow a technique that would give them the highest chance of getting their papers published, rather than using a technique that would give them the most reliable answer as to whether a mouse is feeling fear. 


animal freezing

Another crucial element of many "memory engram" science papers is analysis of brain scans.  But there are 1001 ways to analyze the data from a particular brain scan.  Such flexibility almost allows a researcher to find whatever "preferential activation" result he is hoping to find.  

Page 68 of this paper discusses how brain scan analysis involves all kinds of arbitrary steps:

"The time series of voxel changes may be motion-corrected, coregistered, transformed to match a prototypical brain, resampled, detrended, normalized, smoothed, trimmed (temporally or spatially)...Furthermore, each of these steps can be done in a number of ways, each with many free parameters that experimenters set, often arbitrarily....The wholebrain analysis is often the first step in defining a region of interest in which the analyses may include exploration of time courses, voxelwise correlations, classification using support vector machines or other machine learning methods, across-subject correlations, and so on. Any one of these analyses requires making crucial decisions that determine the soundness of the conclusions."

The problem is that there is no standard way of doing such things. Each study arbitrarily uses some particular technique, and it is usually true that the results would have been much different if some other brain scan analysis technique had been used. 

Examples of Such Shortcomings

Let us look at a recent paper that claimed evidence for memory engrams. The paper stated, “Several studies have identified engram cells for different memories in many brain regions including the hippocampus (Liu et al., 2012; Ohkawa et al., 2015; Roy et al., 2016), amygdala (Han et al., 2009; Redondo et al., 2014), retrosplenial cortex (Cowansage et al., 2014), and prefrontal cortex (Kitamura et al., 2017).” But the close examination below will show that none of these studies are robust evidence for memory engrams in the brain. 

Let's take a look at some of these studies. The Kitamura study claimed to have “identified engram cells” in the prefrontal cortex is the study “Engrams and circuits crucial for systems consolidation of a memory.”  In Figure 1 (containing multiple graphs), we learn that the number of animals used in different study groups or experimental activities were 10, 10, 8, 10, 10, 12, 8, and 8, for an average of 9.5. In Figure 3 (also containing multiple subgraphs), we have even smaller numbers. The numbers of animals mentioned in that figure are 4, 4, 5, 5, 5, 10, 8, 5, 6, 5 and 5. None of these numbers are anything like what would be needed for a moderately convincing result, which would be a minimum of 15 animals per study group. So the study is very guilty of Sin #3. The study is also guilty of Sin #2, because no detailed description is given of an effective blinding protocol. The study is also guilty of Sin #4, because Figure 3 lists two statistical significance values of “< 0.05” which is the least impressive result you can get published nowadays. Studies reaching a statistical significance of less than 0.01 will always report such a result as “< 0.01” rather than “<0.05.”  The study is also guilty of Sin #7, because it relies on judgments of freezing behavior of rodents, which were not corroborated by something such as heart rate measurements. 

The Liu study claimed to have “identified engram cells” in the hippocampus of the brain is the study “Optogenetic stimulation of a hippocampal engram activates fear memory recall.” We see in Figure 3 that inadequate sample sizes were used. The number of animals listed in that figure (during different parts of the experiments) are 12, 12, 12, 5, and 6, for an average of 9.4. That is not anything like what would be needed for a moderately convincing result, which would be a minimum of 15 animals per study group. So the study is  guilty of Sin #3. The study is also guilty of Sin #7. The experiment relied crucially on judgments of fear produced by manual assessments of freezing behavior, which were not corroborated by any other technique such as heart-rate measurement. The study does not describe in detail any effective blinding protocol, so it is also guilty of Sin #2. The study is also guilty of Sin #6. The study involved stimulating certain cells in the brains of mice, with something called optogenetic stimulation. The authors have assumed that when mice freeze after stimulation, that this is a sign that they are recalling some fear memory stored in the part of the brain being stimulated. What the authors neglect to tell us is that stimulation of quite a few regions of a rodent brain will produce freezing behavior. So there is actually no reason for assuming that a fear memory is being recalled when the stimulation occurs. 

The Ohkawa study claimed to have “ identified engram cells” in the hippocampus of the brain is the study “Artificial Association of Pre-stored Information to Generate a Qualitatively New Memory.” In Figure 3 we learn that the animal study groups had a size of about 10 or 12, and in Figure 4 we learn that the animal study groups used were as small as 6 or 8 animals. So the study is guilty of Sin #3. Because the paper used a “zap their brains and look for freezing” approach, without discussing or testing alternate explanations for freezing behavior having nothing to do with memory, the Ohkawa study is also guilty of Sin #6. Judgment of fear is crucial to the experimental results, and it was done purely by judging "freezing behavior," without measurement of heart rate.  So the study is also guilty of Sin #7. This particular study has a few skimpy phrases which claims to have used a blinding protocol: “Freezing counting experiments were conducted double blind to experimental group.” But no detailed discussion is made of how an effective blinding protocol was achieved, so the study is also guilty of Sin #2.

The Roy study claimed to have “identified engram cells” in the hippocampus of the brain is the study "Memory retrieval by activating engram cells in mouse models of early Alzheimer’s disease."  Looking at Figure 1, we see that the study groups used sometimes consisted of only 3 or 4 animals, which is a joke from any kind of statistical power standpoint. Looking at Figure 3, we see the same type of problem. The text mentions study groups of only "3 mice per group," "4 mice per group," and "9 mice per group,"  and "10 mice per group."   So the study is guilty of Sin #3. Although a blinding protocol is mentioned in the skimpiest language,  no detailed discussion is made of how an effective blinding protocol was achieved, so the study is also guilty of Sin #2.  Some of the results reported have a statistical significance of only "<.05," so the study is guilty of Sin #4. 

The Han study (also available here) claimed to have “identified engram cells” in the amygdala is the study "Selective Erasure of a Fear Memory." In Figure 1 we see a larger-than average sample size was used for two groups (17 and 24), but that a way-too-small sample size of only 4 was used for the corresponding control group. You need a sufficiently high number of animals in all study groups, including the control group, for a reliable result.  The same figure tells us that in another experiment the number of animals in the study group were only 5 or 6, which is way too small. Figure 3 tells us that in other experiments only 8 or 9 mice were used, and Figure 4 tells us that in other experiments only 5 or 6 mice were used. So this paper is guilty of Sin #3. No mention is made in the paper of any blinding protocol, so this paper is guilty of Sin #2. Figure 4 refers to two results with a borderline statistical significance of only "< 0.05," so this paper is also guilty of Sin #4.  The paper relies heavily on judgments of fear in rodents, but these were uncorroborated judgments based on "freezing behavior," without any measure of heart rate to corroborate such judgments. So the paper is also guilty of Sin #7. 

The Redondo study claimed to have “identified engram cells” in the amygdala is the study "Bidirectional switch of the valence associated with a hippocampal contextual memory engram."  We see 5 or 6 results reported with a borderline statistical significance of only "< 0.05," so this paper is  guilty of Sin #4. No detailed description is given of how an effective blinding protocol was achieved, and only the skimpiest mention is made of blinding, so this paper is guilty of Sin #2.  The study used only "freezing behavior" to try to measure fear, without corroborating such a thing by measuring heart rates.  So the paper was guilty of Sin #7.  The study involved stimulating certain cells in the brains of mice, with something called optogenetic stimulation. The authors have assumed that when mice freeze after stimulation, that this is a sign that they are recalling some fear memory stored in the part the brain being stimulated. What the authors neglect to tell us is that stimulation of quite a few regions of a rodent brain will produce freezing behavior. So there is actually no reason for assuming that a fear memory is being recalled when the stimulation occurs.  So the study is also guilty of Sin #6. 

The Cowansage study claimed to have “identified engram cells” in the retrosplinial cortex of the brain is the study "Direct Reactivation of a Coherent Neocortical Memory of Context." Figure 2 tells us that only 12 mice were used for one experiment. Figure 4 tells us that only 3 and 5 animals were used for other experiments. So this paper is guilty of Sin #3. No detailed description is given of how an effective blinding protocol was achieved, and only the skimpiest mention is made of blinding, so this paper is guilty of Sin #2.    It's a paper using the same old "zap rodent brains and look for some freezing behavior" methodology, without explaining why such results can occur for reasons having nothing to do with memory recall. So the study is guilty of Sin #6. Some of the results reported have a statistical significance of only "<.05," so the study is guilty of Sin #4. 

So I have examined each of the papers that were claimed as evidence for memory traces or engrams in the brain. Serious problems have been found in every one of them.  Not a single one of the studies made a detailed description of how an effective blinding protocol was executed. All of the studies were guilty of Sin #7.  Not a single one of the studies makes a claim to have followed some standardized method of brain scan analysis. Whenever there are brain scans we can say that the experiments merely chose one of 101 possible ways to analyze brain scan data. Not a single one of the studies has corroborated "freezing behavior" judgments by measuring heart rates of rodents to determine whether the animals suddenly became afraid. But all of the studies had a depenency on either brain scanning, uncorroborated freezing behavior judgments, or both. The studies all used sample sizes far too low to get a reliable result (although one of them used a decent sample size to get part of its results). 

The papers I have discussed are full of problems, and do not provide robust evidence for any storage of memories in animal brains. There is no robust evidence that memories are stored in the brains of any animal, and no robust evidence that any such thing as an "engram cell" exists. 

The latest press report of a "memory wonder" produced by scientists is a claim that scientists implanted memories in the brains of songbirds. For example, the Scientist magazine has an article entitled, "Researchers Implant Memories in Zebra Finch Brains." The relevant scientific study is hidden behind a paywall of Science magazine. But by reading the article, we can get enough information to have the strongest suspicion that the headline is a bogus brag. 

Of course, the scientists didn't actually implant musical notes into the brains of birds.  Nothing of the sort could ever occur, because no one has the slightest idea of how learned or episodic information could ever be represented as neural states. The scientists merely gave little bursts of energy into the brains of some birds. The scientists claimed that the birds who got shorter bursts of energy tended to sing shorter songs. "When these finches grew up, they sang adult courtship songs that corresponded to the duration of light they’d received," the story tells us.  Of course, it would be not very improbable that such a mere "duration similarity" would occur by chance.  

It is very absurd to be describing such a mere "duration similarity" as a memory implant.  It was not at all true that the birds sung some melody that had been artifically implanted in their heads.  The scientists in question have produced zero evidence that memories can be artificially implanted in animals.  From an example like this, we get the impression that our science journalists will uncritically parrot any claim of success in brain experiments with memory, no matter how glaring are the shortcomings of the relevant study.