Why Most Correlation-Fishing Experimental Neuroscience Is Worthless

At the Myths of Vision Science blog, written by a vision scientist, there is a post quoting quite a few juicy tidbits in which neuroscientists speak candidly about how they are stumbling about in the dark and following poor methods. We hear of neuroscientists calling their work BS that doesn't replicate. The author states, " As Mehler and Kording (2018) have discussed, despite the intrinsic inability of post hoc sample correlations to generalize due to massive confounding, neuroscience practitioners continue to employ language in their publications improperly implying causality."  In another post, the scientist author explains the situation more clearly, stating this: 

“Neuroscience, as it is practiced today, is a pseudoscience, largely because it relies on post hoc correlation-fishing....As previously detailed, practitioners simply record some neural activity within a particular time frame; describe some events going on in the lab during the same time frame; then fish around for correlations between the events and the 'data' collected. Correlations, of course, will always be found. Even if, instead of neural recordings and 'stimuli' or 'tasks' we simply used two sets of random numbers, we would find correlations, simply due to chance. What’s more, the bigger the dataset, the more chance correlations we’ll turn out (Calude & Longo (2016)). So this type of exercise will always yield 'results;' and since all we’re called on to do is count and correlate, there’s no way we can fail. Maybe some of our correlations are 'true,' i.e. represent reliable associations; but we have no way of knowing; and in the case of complex systems, it’s extremely unlikely. It’s akin to flipping a coin a number of times, recording the results, and making fancy algorithms linking e.g. the third throw with the sixth, and hundredth, or describing some involved pattern between odd and even throws, etc. The possible constructs, or 'models' we could concoct are endless. But if you repeat the flips, your results will certainly be different, and your algorithms invalid...As Konrad Kording has admitted, practitioners get around the non-replication problem simply by avoiding doing replications.”

Here is an example. Suppose neuroscientist Joe wants to show that some particular region of the brain is activated more strongly than normal when people recall an old memory. Joe has 10 people undergo brain scans, and at a particular point in time Joe asks them to recall some memory from their childhood. Later Joe scrutinizes the brain scans of the people. He is looking for some tiny hundredth or thousandth of the brain that shows a little more activity when the recall occurred. Since brain areas have random variations in activity from moment to moment, differing in activity by a hundredth or a two hundredth from one minute to the next, it will be rather easy for Joe to find some hundredth or thousandth of the brain that he can declare as showing greater activity when the subjects recalled their old memories. 

Joe is engaging in correlation fishing, what is sometimes called data mining. If Joe merely reports a difference in some brain area of a hundredth or a two-hundredth, he has provided no real evidence that this brain area is more active when memory recall occurs.  Purely by chance we would expect one such hundredth or thousandth of the brain to show a hundredth or a two-hundredth more activity at any particular moment, purely because of chance variations. 

There are several conventions or tendencies in the world of experimental neuroscience that aid and abet Joe in this particular piece of junk science he is producing. 

(1) A lack of pre-registration. Pre-registration is when a scientist commits himself to testing one exact hypothesis, and also spells out exactly how data will be gathered and analyzed, before any data is gathered. It is generally recognized that pre-registration greatly reduces the amount of junk science. If, for example, Joe had to pick some particular hundredth of the brain for analysis, and test the hypothesis that this particular hundredth of the brain is more active during memory recall, it would be much less likely that Joe would produce a false alarm result coming from mere correlation fishing.  But, sadly, pre-registration is rarely practiced in experimental neuroscience. Once some neuroscientist has gathered data, he is free to check for correlations in 1001 different places, using a hundred and one different analysis pipelines, each a different way of analyzing the data. It will therefore be easy for some spurious correlation to be found, one that is not a real sign of a causal relation. 

(2) Small study group sizes, and failing tests put in file drawers (no guaranteed publication). If you limit yourself to small study group sizes, it's always easier to find spurious correlations that do not involve causal relations. For example, let's suppose you are looking for a correlation between birth year and death year, or birth month and death month, or birth day of week and death day or week, or any of those correlations occurring between a father and a son or a mother and a son. You won't find any such thing examining data on the lives of 1000 children and their parents, but it wouldn't be too hard to find such a correlation if you merely need to show such a correlation within a group of ten people. You could try using data from 10 or 20 people, and if you don't find anything, you could just keep trying, using a different set of 10 or 20 people. Before long you would be able to report finding such a correlation, even though it involves no causal relation. 

Sadly, this state of affairs matches what goes on in experimental neuroscience. It is very, very common for neuroscientists to publish papers based on small study group sizes such as those involving only 10 or 15 subjects. Also, very few studies occur as "registered reports" in which there is guaranteed publication. Neuroscientists are aware of what is called publication bias, meaning the tendency of journals to not publish results that are negative. So suppose someone like neuroscientist Joe can find no correlation between brain activity and recall activity, after testing with 10 subjects. He can just "file drawer" his study, and start over using another 10 subjects.  He can keep doing this several times, until he has some marginal correlation to report, reporting on only the subjects in his most recent iteration of his experiment.

(3) Weak variations in brain activity regarded as adequate evidence.  Neuroscientist Joe couldn't get away with his shady correlation fishing if there were standards such as a standard of requiring a 1% difference in brain activity as evidence of correlation.  But there are no such standards or conventions.  Many a neuroscientist has published papers reporting correlations involving differences in brain activity of no more than 1 part in 200 or 1 part in 500. Such reports are almost all false alarms. 

(4) Easy-to-obtain ".05" statistical significance as a standard for publication.  Somehow there arose in experimental science a convention that if you could show something has a "statistical significance" of .05, then that's good enough for publication in a science paper.  This is a very loose and weak standard that is all too easy to reach. Roughly speaking, with such a standard, anything is regarded as "statistically significant" as long as you would expect it to show up by chance only 1 time in 20 or less.  But when neuroscientists have not committed themselves (by pre-registration) to testing one particular hypothesis in one particular way, they are free to try 101 different ways to analyze their data looking for correlations. It's all too easy to find something that can be reported as "statistically significant." Even if you fail after fifty or a hundred attempts, you can just "file drawer" your study, start over, and you'll probably be able to report some "statistically significant" correlation on Version 2 or Version 3 of your experiment. In his book "The Cult of Statistical Significance," economist Stephen Thomas Zilliac laments this habit of judging science papers as being acceptable if they reach .05 statistical significance.  He says that science took a giant wrong turn by adopting such a convention.  He says, "Statistical significance is neither necessary nor sufficient for a scientific result." 

This can be done when there's no pre-registration

Underpowered studies are those with a statistical power of under 50%. A scientific paper says this about the practice of accepting p=0.05 as a "good enough" mark for publication of science papers:

"If you use p=0.05 to suggest that you have made a discovery, you will be wrong at least 30% of the time. If, as is often the case, experiments are underpowered, you will be wrong most of the time....Button et al. [9] said, 'We optimistically estimate the median statistical power of studies in the neuroscience field to be between about 8% and about 31%' ".

(5) Phony visuals are allowed in correlation-fishing papers. It should be a standard in experimental neuroscience that any paper will be rejected if it misleadingly has a visual giving people the impression that a difference in brain activity was greater than it was. Unfortunately, no such standard exists. Correlation-fishing studies routinely include "lying with colors" visuals that dishonestly depict differences of only 1 part in 200 or 1 part in 500, making them look like much greater differences such as 1 part in 10. See here for how this type of visual deception occurs. 

At the end of the long quote above was the sentence, "As Konrad Kording has admitted, practitioners get around the non-replication problem simply by avoiding doing replications." That's right. As scientist Randall J. Ellis stated in 2022, "There are no completed large-scale replication projects focused on neuroscience."

Involving only very slight reported differences in brain activity, correlation-fishing experimental neuroscience studies do nothing to show that the brain is the source of the human mind or the storage place of human memories. Search for the phrase "percent signal change" and you will find that almost all of such studies are reporting changes of only about 1 part in 200 or smaller. In the rare case when a signal change of 1% is reported, it is usually because of head movements, which are a large source of false alarms in such studies. A person being brain scanned and not perfectly following instructions to keep his head motionless can cause a brain scan blip that is reported as a region activation.  A paper states, "The signal derived from functional MRI (fMRI) can also be greatly perturbed by motion; two detailed reports by Power and colleagues describe the complex and variable manner by which different types of motion can impact fMRI acquisitions and increase the proportion of spurious correlations across the brain." Another paper says this:

"A general relationship between head motion and changes in BOLD signal across the brain can be seen in every subject examined in this paper (N=119 in four cohorts)....Any and all movement tends to increase the amplitude of rs-fcMRI signal changes."

Scientists use a variety of types of "motion scrubbing" to try and get rid of the effects of head movements during brain scans, and there is no standard for such data massaging; it's "roll your own." The paper notes that "motion scrubbing tends to decrease many short-range correlations, and to increase many medium- to long-range correlations. " We can imagine how it is for some scientist fishing for correlations between mental activity and brain activity in brain scans. If he is dissatisfied with the size of the correlation reported, he can just tweak his "motion scrubbing" technique to easily get some more correlation that can be reported. 

10 Reasons Synapses Cannot Be a Storage Place for Human Memories

We can classify several different types of scientific truth claims, along with some tips on how to recognize the different types. 

Type of truth claim	How to recognize it
Citation of established fact	Typically occurs with a discussion of the observational facts that proved the claim.
Citation of a claim that is not yet established fact	Typically occurs with phrases such as “scientists believe” or “it is generally believed” or an appeal to a “scientific consensus.” The claim of a “scientific consensus” is often unfounded, and there may be many scientists who do not accept the claim.
Citation of a claim that has little basis in observations, and that there may be good reasons for doubting	Often occurs with a phrase such as “it is widely believed,” or maybe a more confident-sounding phrase like “it is becoming increasingly clear” or “there is growing evidence.”

Claims that memories are stored in synapses fall into the third of these categories.  Such claims often are made using the weak-sounding phrase "it is widely believed." To show that, I may cite some of the many times in which writers or scientists suggested that memories are stored in synapses, and merely used the weak phrase "it is widely believed" as their authority. 

• "It is widely believed that synaptic plasticity mediates learning and memory"  (link). 
• "It is widely believed that synapses in the forebrain undergo structural and functional changes, a phenomenon called synaptic plasticity, that underlies learning and memory processes" (link).
• "It is widely believed that synaptic modifications underlie learning and memory" (link).
• "As with other forms of synaptic plasticity, it is widely believed that it [spike-dependent synaptic plasticity] underlies learning and information storage in the brain" (link).
• "It is widely believed that memories are stored as changes in the number and strength of the connections between brain neurons, called synapses" (link).
• "It is widely believed that modifications to synaptic connections – synaptic plasticity – represent a fundamental mechanism for altering network function, giving rise to phenomena collectively referred to as learning and memory" (link).
• "It is widely believed that encoding and storing memories in the brain requires changes in the number, structure, or function of synapses"  (link).
• "It is widely believed that long-term changes in the strength of synaptic transmission underlie the formation of memories" (link).
• "It is widely believed that the brain's microcircuitry undergoes structural changes when a new behavior is learned" (link).
• "It is widely believed that long-lasting changes in synaptic function provide the cellular basis for learning and memory in both vertebrates and invertebrates (link).
• "It is widely believed that the brain stores memories as distributed changes in the strength of connections ('synaptic transmission') between neurons" (link).
• "It is widely believed that the long-lasting, activity-dependent changes in synaptic strength, including long-term potentiation and long-term depression, could be the molecular and cellular basis of experience-dependent plasticities, such as learning and memory" (link).
• "It is widely believed that a long-lasting change in synaptic function is the cellular basis of learning and memory" (link).
• "It is widely believed that the modification of these synaptic connections is what constitutes the physiological basis of learning" (link).
• "It is widely believed that memory traces can be stored through synaptic conductance modification" (link).
• "It is widely believed that memories are stored in the synaptic strengths and patterns between neurons" (link).
• "It is widely believed that long-term changes in the strength of synaptic connections underlie learning and memory" (link).
• "It is widely believed that long-term synaptic plasticity plays a critical role in the learning, memory and development of the nervous system" (link).
• "It is widely believed that learning is due, at least in part, to long-lasting modifications of the strengths of synapses in the brain" (link).
• "It is widely believed that long-term memories are stored as changes in the strengths of synaptic connections in the brain" (link). 
• "It is widely believed that activity-dependent modification of synapses is the brain's primary mechanism for learning and memory" (link).
• "It is widely believed that synaptic modifications are one of the factors underlying learning and memory" (link).
• "Learning, it is widely believed, is based on changes in the connections between nerve cells" (link).
• "It is widely believed that memories are stored as changes in the number and strength of the connections between brain cells (neurons)" (link).
• "It is widely believed that memories are stored as changes in the strength of synaptic connections between neurons" (link). 
• "It is widely believed that memory formation is based on changes in synapses" (link).

These examples by themselves prove that claims of a storage of human memory in synapses are not well-supported scientific claims. People do not tend to use the phrase "it is widely believed" when referring to well-established scientific claims. For example, you never hear someone say "it is widely believed that the sun produces energy through nuclear fusion" or "it is widely believed that people can get diseases from viruses." When you keep hearing people using the weak phrase "it is widely believed," you have a "red flag" sign that you are being referred to a claim that is not very well-supported by evidence. 

There is no robust evidence that synapses store human memories. Evidence given to support such claims is merely the kind of evidence we would expect to get, given a large belief community of thousands of richly funded neuroscientists eager to provide evidence for some belief they hold. Similarly, if there was a large well-funded community of thousands of researchers believing that the ghosts of dead animals live in the clouds,  such researchers could occasionally produce superficially impressive photos showing cloud shapes that look like animals. Almost invariably, a close examination of papers produced by neuroscientists trying to show evidence for synaptic memory storage will reveal their research was guilty of multiple types of what are Questionable Research Practices. A list of 50 types of Questionable Research Practices is found here. A discussion of some of the misleading tricks used by neuroscientist memory researchers can be found here. 

Below I will give ten reasons why there is no credibility in claims that synapses store memories. 

Reason #1: One of the main hallmarks of stored information is the use of an alphabet, but there is no sign of any type of alphabet used by synapses. 

Although not all types of stored information uses an alphabet, most types of stored information do use an alphabet. Defining the term broadly, we can define an alphabet as a restricted set of symbols used for storing information. One type of alphabet we all know of is the set of characters used in writing a language such as English. To write English sentences, you use a restricted set of 26 letters and a small number of punctuation marks.  

There are other types of alphabets. When information is written in binary, we may regard that as using an alphabet consisting of only two symbols: 0 and 1. It is often said that genetic information in DNA is written in an alphabet consisting of only four letters. the chemicals guanine, cytosine, adenine and thymine,  Different triple combinations of such chemicals (called codons) stand for different types of amino acids, when such combinations are interpreted using the coding scheme known as the genetic code (depicted below). In the diagram below, A stands for adenine, C stands for cytosine, G stands for guanine, and T stands for thymine. 

A requirement for the effective use of an alphabet to store information is what we may sequencing. There must be some physical arrangement that allows for the symbols of the alphabet to appear in a sequence rather than merely in some disordered heap. A book meets such a requirement, by restricting characters to a sequence. DNA meets such a requirement, as it is a chain-like molecule containing long chains of guanine, cytosine, adenine and thymine chemicals in a sequence. A binary file contains such a sequence, as it consists of a sequence of 0's and 1's with a beginning and an end. 

There is no sign of any alphabet used by synapses. Synapses have a string-like structure, but there is no sign of any chemicals sequentially stored in such a structure in a way that might be a utilization of an alphabet. Synapses constantly transmit chemical signals passing along them, in a way that results in instability in the chemicals within synapses. Synapses have a presynaptic terminal that is kind of a bag of short-lived chemicals. Such a thing cannot be utilizing an alphabet, because of its disordered structure lacking a sequence.

Reason #2: One of the main hallmarks of stored information is the use of tokens, but there is no sign of any type of tokens used by synapses. 

Stored information requires what are called tokens, which can be defined as particular units that represent particular things or ideas or qualities. When stored information uses an alphabet, the tokens are some combination of the symbols of the alphabet, to make a particular word. Stored information that does not use any alphabet can use pictorial tokens to store information. 

Let me give an example of how information can be recognized as information even when its meaning has not been deciphered. Imagine someone gives you the image below:

How could you tell this is stored information, and not just random pixels of black and white? Your first step would be to look for an alphabet. In this case you would be able to find an alphabet being used. This would be a strong hint that you were dealing with stored information. 

Your second step would be to look for tokens. That could be done by looking for repeated sequences of the characters. A token analysis would show that many of the sequences are repeated. In the visual below, we see some of those repetitions:

Having detected both the use of an alphabet and the use of tokens, we would be justified in concluding that the image above contains stored information. The image is Abraham Lincoln's Gettysburg Address in Italian. A similar analysis looking for tokens in a DNA molecule would find very many tokens. Examining the DNA in detail, you would find not merely a use of a chemical alphabet (consisting of the "letters" of guanine, cytosine, adenine and thymine chemicals), but also a very abundant use of tokens. In DNA the tokens are combinations of the "letters" of guanine, cytosine, adenine and thymine chemicals to represent an amino acid. Just like a block of text will show many repeated words, a large block of DNA will contain many repetitions of tokens representing amino acids. 

Looking in synapses, can we find any tokens? None at all. There is no evidence of an alphabet used by synapses, and there is no evidence of tokens used by synapses. 
 

Reason #3: When stored information does not use either an alphabet or tokens, it will often use pictorial representations; but no such things can be found in synapses. 

The discussion above deals mainly with written information such as binary information, textual information or genetic information. But there is another way to produce stored information: by using pictorial representations.  A pictorial representation might be a drawing or photo or sketch or video. Is there any evidence that synapses use pictorial representations? None whatsoever. We can imagine no way in which pictures could ever be stored in synapses. 

Reason #4: Groups of synapses have no organized arrangement that might enable some information storage.

If there are organized groups of something which seems to have no capability of storing information, there might be some information storage occurring. For example, an individual toothpick seems to have no way of storing information. But if you arrange 100 toothpicks in just the right way, you might store some text.  Could it be that information storage arises from some special arrangement of large groups of synapses? 

 

Viewed through electron microscopes, groups of synapses seem to have no organized pattern. If you try to visualize a large vat of spaghetti boiling at the mess hall kitchen of a large army base, you might have a good idea of how disorganized is the arrangement of synapses in the brain. It is therefore not credible to maintain that there is something about the arrangement of synapses that allows them to store information.  Returning to the toothpick analogy, we might compare arrangement of synapses in the brain to the disorganized arrangement of a dump truck filled with toothpicks. You can't store information by so disordered an arrangement. 

Reason #5: The brain has no synapse pattern reader.

We may further rule out the idea of memories being stored by something in the large scale arrangement of synapses when we consider that the brain has no mechanism for reading the arrangement of synapses in the brain. There are no little eyes floating around in the brain that might allow a brain to retrieve information based on some arrangement of synapses. Nor is there any moving cellular part in the brain that might traverse some arrangement of synapses to figure out what was the particular arrangement of synapses in the brain. 

Reason #6: Like muscles in the arm, synapses in the brain do not have some discrete small set of possible strength levels, but have an analog range of strength levels ranging continuously from very weak to very strong.

As the quotes above indicate, it is sometimes suggested that memories are stored by changes of strength levels in synapses. This idea is as nonsensical as claims that your memories can be stored by changes in the strength levels of your arms or legs.  One reason that could never work is that the strength levels of your arms and legs do not have a limited set of discrete discontinuous values. Unlike a coin which can only have two discrete states on a table -- a state of "heads" or "tails" -- things such as synapses and arms can have a million different strength levels.  You can't store information by variations of an analog continuous variable such as "strength" that can have any number of values, particularly if there's no "strength reader" around to read such a variable.  

Reason #7: Chemical synapses (by far the most common type) do not reliably transmit information, so synapses cannot be the explanation for human memory recall which occurs so reliably. 

There are two types of synapses: chemical synapses and electrical synapses. The parts of the brain allegedly involved in thought and memory have almost entirely chemical synapses. (The sources here and here and here and here and here refer to electrical synapses as "rare."  The neurosurgeon Jeffrey Schweitzer refers here to electrical synapses as "rare."  The paper here tells us on page 401 that electrical synapses -- also called gap junctions -- have only "been described very rarely" in the neocortex of the brain. This paper says that electrical synapses are a "small minority of synapses in the brain.") 

The predominance of chemical synapses in the brain is a huge problem for all theorists of synaptic memory storage, because of the fact that chemical synapses do not reliably transmit signals. How reliably does a signal travel when it passes between two neurons? It has been repeatedly stated in neuroscience literature that brain signals travel across chemical synapses with a reliability of only .5 or smaller, and almost all synapses in the brain are chemical synapses.  In an interview, an expert on neuron noise states the following:

"There is, for example, unreliable synaptic transmission. This is something that an engineer would not normally build into a system. When one neuron is active, and a signal runs down the axon, that signal is not guaranteed to actually reach the next neuron. It makes it across the synapse with a probability like one half, or even less. This introduces a lot of noise into the system."

 A scientific paper tells us the same thing. It states, "Several recent studies have documented the unreliability of central nervous system synapses: typically, a postsynaptic response is produced less than half of the time when a presynaptic nerve impulse arrives at a synapse." Another 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."

A 2020 paper states this:

"Neurons communicate primarily through chemical synapses, and that communication is critical for proper brain function. However, chemical synaptic transmission appears unreliable: for most synapses, when an action potential arrives at an axon terminal, about half the time, no neurotransmitter is released and so no communication happens... Furthermore, when neurotransmitter is released at an individual synaptic release site, the size of the local postsynaptic membrane conductance change is also variable. Given the importance of synapses, the energetic cost of generating action potentials, and the evolutionary timescales over which the brain has been optimized, the high level of synaptic noise seems surprising."

Faced with such facts, the theorist of synaptic memory storage will try to insinuate that human memory is unreliable, citing a few anecdotes and maybe asking you to recall some embarrassing time you forgot something. But claims that humans cannot remember reliably can very easily be defeated, by citing examples such as these:

• Actors who play Hamlet recall with 100% accuracy more than 1400 lines with complete accuracy.
• Wagnerian tenors who sing the role of Seigfried recall with 100% accuracy not just a comparable number of lines, but also the musical notes corresponding to each of the syllables in the role. 
• It is a well established fact that some Muslims can recite with 100% accuracy all the verses in their holy book, a work with more 6000 verses, each consisting of several words. 
• Some even more impressive cases of human memory performance are listed in my post here. 

Humans can recall things with an accuracy that would never be possible if memory recall required accessing synapses that do not reliably transmit information. 

Reason #8: Chemical synapses (by far the most common type) do not transmit information with a speed that can account for instant human memory recall; and no type of synapses have any addresses, indexes or sorting that could explain fast recall. 

Besides reliability, a central fact of human memory is speed. Humans routinely recall obscure facts instantly. Any credible theory of memory would have to be one in which memory recall can occur instantly. But we know of an extremely strong reason for thinking that memory recall could never occur instantly if it was occurring by retrieving information stored in synapses. The reason is that traversing synapses would take quite a bit of time. Every jump across the gap of a chemical synapse requires a delay called the synaptic delay.  A single synaptic delay is only about 5 milliseconds. But for a signal to travel a decent distance in the brain, there would be very many such synaptic delays. These would add up to a severe slowing factor that would prevent the instantaneous recall that humans routinely experience. We know of things that enable fast retrieval of information in products that human create: things such as addresses, indexing and sorting. No such things exist in synapses or any other structures in the brain. Synapses actually act as kind of neuron anchors that exclude any type of sorting from occurring in the brain (you can't sort something that is anchored to a particular position). 

In the paper "Emission of Mitochondrial Biophotons and their Effect on Electrical Activity of Membrane via Microtubules" by 7 scientists, we read this.

"Synaptic transmission and axonal transfer of nerve impulses are too slow to organize coordinated activity in large areas of the central nervous system. Numerous observations confirm this view. The duration of a synaptic transmission is at least 0.5 m/s, thus the transmission across thousands of synapses takes about hundreds or even thousands of milliseconds. The transmission speed of action potentials varies between 0.5 m/s and 120 m/s along an axon. More than 50% of the nerves fibers in the corpus callosum are without myelin, thus their speed is reduced to 0.5 m/s."

The authors  then call these "low velocities," and ask how these "low velocities" can explain fast phenomena such as instant recall. 

Reason #9: The proteins that make up synapses have short lifetimes of only two weeks or less, causing synapses to be unstable structures unsuitable for explaining memories that can last for 50 years. 

Synapses are built from proteins. Research on the lifetime of synapse proteins is found in the June 2018 paper “Local and global influences on protein turnover in neurons and glia.” The paper starts out by noting that one earlier 2010 study found that the average half-life of brain proteins was about 9 days, and that a 2013 study found that the average half-life of brain proteins was about 5 days. The study then notes in Figure 3 that the average half-life of a synapse protein is only about 5 days, and that all of the main types of brain proteins (such as nucleus, mitochondrion, etc.) have half-lives of 15 days 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). 

A ratio every person should remember is that human memories can last for 1000 times longer than the average lifetime of synapse proteins. This is because synapse proteins have average lifetimes of less than two weeks, but humans can reliably remember things for more than 50 years; and 50 years is 1000 times greater than two weeks. 

Reason #10: Synapses are connected to other structures in the brain (dendritic spines) known to be unstable short-lived structures, causing synapses to be unstable structures unsuitable for explaining memories that can last for 50 years. 

Besides the reason just mentioned, there is a separate reason why synapses are unstable things unsuitable for explaining memories that last for decades: the fact that synapses are typically connected to unstable dendritic spines. Synapses typically protrude out of bump-like structures on dendrites called dendritic spines. But those spines have lifetimes of less than 2 years.  Dendritic spines last no more than about a month in the hippocampus, and less than two years in the cortex. This study found that dendritic spines in the hippocampus last for only about 30 days. This study found that dendritic spines in the hippocampus have a turnover of about 40% each 4 days. This 2002 study found that a subgroup of dendritic spines in the cortex of mice brains (the more long-lasting subgroup) have a half-life of only 120 days. A paper on dendritic spines in the neocortex says, "Spines that appear and persist are rare." While a 2009 paper tried to insinuate a link between dendritic spines and memory, its data showed how unstable dendritic spines are.  Speaking of dendritic spines in the cortex, the paper found that "most daily formed spines have an average lifetime of ~1.5 days and a small fraction have an average lifetime of ~1–2 months," and told us that the fraction of dendritic spines lasting for more than a year was less than 1 percent. 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). 

The Synaptic Memory Claimant Is Like This

Using the term "synaptic memory theorist" is probably too flattering a term to use, because it suggests that people claiming synaptic memory storage actually have a theory. They don't really have any theory at all. All they have is a slogan or sound bite that they keep muttering. When asked about how a brain could store a memory, such people mutter the empty sound bite of "synapse strengthening." If you press for more details, and ask how that could work, all you will get is hand waving. 

I can give an analogy for the synaptic memory claimant (a person claiming memories are stored in synapses). He is like an accuser in America who claims that some very old slow-moving widow living in a small cottage is one of the most important spies for the Russians. Let's imagine the old woman's cottage is thoroughly searched by the FBI and CIA, using their most advanced equipment, and no trace of any secret information is found, just as no trace of memories can be found from a microscopic examination of brain tissue, using the most advanced electron microscopes. Suppose observations of the old woman reveal her speech and writing and walking are weak, slow and unreliable, rather like chemical synapses that do not transmit information reliably or very quickly. 

We can imagine the desperate attempts the accuser might make to try to keep his story afloat. He might speculate that maybe the dust particles on the woman's floor are using some secret code storing top-secret information. He might claim that the birds chirping on the old woman's roof are specially trained birds which transmit information to hidden nearby Russian microphones. He might claim that maybe when the woman pays for her groceries, she writes secret information in invisible ink on the dollars she gives to the cashier. Making such groundless accusations claiming a woman who bears not the slightest resemblance to a spy is a spy capable of great marvels of espionage, such an accuser would be like the synaptic memory claimant who claims synapses (which bear not the slightest resemblance to a fast-retrieval system for permanently storing information) are the explanation for the astonishing wonders of life-long human memory preservation and instant recall.  To such an accuser, we should say: nonsense, nonsense, nonsense,  nonsense, NONSENSE.  And that is just what we should say to the person claiming that memories are read from synapses:  nonsense, nonsense, nonsense,  nonsense, NONSENSE.

Some People Our Neuroscientists Don't Want You to Know About

In this post I will discuss some subjects with dramatic case histories that tell you very important things about the human brain and the human mind. Neuroscientists fail to mention these subjects with such important case histories. So we can assume that today's neuroscientists don't want you to know about such cases, because the cases contradict the dogmas that neuroscientists like to teach, such as the dogma that your brain makes your mind, the dogma that your brain stores your memories, and the dogma that there cannot be mysterious psychic powers inexplicable through any type of brain activity. 

• Dandy's patients: The case of Dandy's patients are reported in the American Journal of Psychology, Vol. 46, No. 3 (Jul., 1934), pages 500-503. We read this: "Dandy has completely removed the right cerebral hemisphere from eight patients. He has performed total extirpations of one or more lobes much oftener... There are tabulated below certain generalizations on the effects of removing the right hemisphere.... The operation was the complete extirpation of the right frontal, temporal, parietal, and occipital lobes peripheral to the corpus striatum. The weight of the tissue re moved varies, with the pathological conditions involved, from 250 to 584 grm [grams].Coherent conversation began within twenty-four hours after operation, and in one case on the afternoon of the same day. Later examinations showed no observable mental changes. The patients were perfectly oriented in respect of time, place, and person; their memory was unimpaired for immediate and remote events; conversation was always coherent; ability to read, write, compute, and learn new material was unaltered. Current events were followed with normal interest. There were no personality changes apparent; the patients were emotionally stable, without fears, delusions, hallucinations, expansive ideas or obsessions, and with a good sense of humor; they joked frequently. They showed a natural interest in their condition and future. They cooperated intelligently at all times throughout post-operative care and subsequent testing of function." How could the memory of patients be "unimpaired for immediate and remote events" if memories are stored in brains?
• Patient P. G. Described in the 1966 paper "Long-term changes in intellect and behaviour after hemispherectomy," Patient   P.G. had an IQ of 128 before the right half of his brain was removed. After the right half of his brain was removed, he scored 142 on the same IQ test, improving his score by 14 points. The paper tells us that this man with half a brain “obtained a university diploma after operation” and “has a responsible administrative position with a local authority.” If your brain makes your mind, how could taking out half of someone's brain cause their IQ to increase by 14 points, with an end result so far above average?
• Patient D. W. Described in the 1966 paper "Long-term changes in intellect and behaviour after hemispherectomy," Patient D.W.  had an IQ of 97 before the left half of his brain was removed. After the left half of his brain was removed, he scored 100 on the same IQ test, improving his score by 3 points.
• The French civil servant. The case is discussed here in a Reuters story entitled “Man lives normal life with abnormal brain.” Inside a normal brain are tiny structures called lateral ventricles that hold brain fluid. In this man's case, the ventricles had swollen up like balloons, until they filled almost all of the man's brain. When the 44-year-old man was a child, doctor's had noticed the swelling, and had tried to treat it. Apparently the swelling had progressed since childhood. The man was left with what the Reuters story calls “little more than a sheet of actual brain tissue.”  But this same man, with almost no functioning brain, had been working as a French civil servant, and had his IQ tested to be 75, higher than that of a mentally retarded person. The Reuters story says: “A man with an unusually tiny brain managed to live an entirely normal life despite his condition, caused by a fluid buildup in his skull.” The case was written up in the British medical journal The Lancet in a paper entitled “Brain of a white-collar worker.” It is as if the authors tried to make these facts be noticed by as few as possible, by giving their story the dullest title they could. 
• Christina Santhouse. In an article in the New Yorker magazine, we are told of a Christina Santhouse who had the right half of her brain surgically removed: “When I met her, she had taken her S.A.T.s and just finished high school, coming in seventy-sixth in a class of two hundred and twenty-five.”
• Beth Usher. Beth was mentioned in an article in the LA Times, which stated this: "How is it that 8-year-old Beth Usher of Storrs, Conn., can lose her left hemisphere, yet retain her large repertoire of knock-knock jokes? Beth’s memories survived not just the loss of brain tissue, but also the 32 days that she spent in a coma, the result of some brain stem swelling that occurred in response to the trauma of surgery. Shortly after Beth regained consciousness, her father began quizzing her about people and places from her past. Brian Usher didn’t get very far. 'Dad,' Beth interrupted, with a trace of impatience. 'I remember everything.'" Of course, there's a very easy answer to the question asked: the answer that memories are not actually stored in the human brain. 
• Borgstein and Grootendorst's 7-Year-Old. In 2002 in The Lancet these two published a paper "Half a Brain." They reported this on the child who had the left half of her brain surgically removed: "Though the dominant hemisphere was removed, with its language centres and the motor control for the left side of her body, the child is fully bilingual in Turkish and Dutch, while even her hemiplegia has partially recovered and is only noticeable by a slight spasticity of her left arm and leg. She leads an otherwise normal life."
• The Johns Hopkins 58 hemispherectomy patients. In a scientific paper ("Why Would You Remove Half a Brain? The Outcome of 58 Children After Hemispherectomy −−The Johns Hopkins Experience: 1968 to 1996") we read about surgeons at Johns Hopkins Medical School who performed fifty-eight hemispherectomy operations on children over a thirty-year period. At least eleven had the left half of the brain removed; and more had the right half removed. The paper states this: 
  "Despite removal of one hemisphere [i.e. one half of the brain], the intellect of all but one of the children seems either unchanged or improved....It is tempting to speculate, that the continuous electrical activity of these severely dysfunctional hemispheres interferes with the function of the other, more normal hemisphere. This might explain why motor function improves after hemispherectomy and why language recovers after removal of the dysfunctional left hemisphere, but does not seem to fully transfer before surgery. Perhaps it also partially explains intellectual improvement in these children after removal of half of the cortex. We are awed by the apparent retention of memory after removal of half of the brain, either half, and by the retention of the child’s personality and sense of humor."  An appropriate response to such observations would be not mere awe, but the questioning or discarding of belief dogmas such as the dogma that brains store memories (which cannot be found by microscopically inspecting brain tissue). 
• Kim Peek.  Kim Peek suffered from a lack of a corpus callosum, the bundle of fibers that connect the two hemispheres of the brain. Instead of this resulting in two minds in a single body (as we would expect from the "brains make minds" dogma), the result was a single mind and personality with an exceptional memory and astonishing calculation abilities. A newspaper report said Peek could accurately tell the contents of 12,000 books he had read, and the wikipedia article on him says he could "remember almost everything he had read." He could quickly tell strangers which day of the week they were born when they merely told him their birthdays. 
• Martel's boy. In a scientific paper ("Discrepancy Between Cerebral Structure and Cognitive Functioning") we read of a case of a boy who was "mentally unimpaired" until death (despite progressive loss of the senses), and who was found in an autopsy to have almost no brain. We read this: "Martel (1823) described a boy who died at the age of 10. During the first years of his life, he seemed healthy, but eventually, his health deteriorated considerably. He had severe headaches, gradually lost all his senses except hearing, developed fits, and became confined to his bed, but he nevertheless seemed mentally unimpaired until his death. His head appeared enlarged, and upon autopsy, apart from 'residues of meninges,' 'no trace of a brain' was found inside the skull (Martel, 1823, p. 20)." 
• John Lorber's patients. Lorber was a physician who had patients who lost the great majority of their brain due to a disease that replaces brain tissue with a watery fluid. Lorber was astounded to find that many of the patients had above-average intelligence, including a patient that had almost no brain but still had an IQ of 144. His patients are discussed here. 
• Masdeu's 44-year old. In the paper "Ventricular Wall Granulations and Draining of Cerebrospinal Fluid in Chronic Giant Hydrocephalus," Joseph C. Masdeu MD and others report a case of a 44-year-old woman with a huge fluid-filled hole in her brain, one that seemed to have replaced most of the tissue in her brain (judging from the photos in the paper). The paper reports the woman had an IQ of 98, worked as an administrator for a government agency, and could speak seven languages. 
• Egnor's Katie. In an article Michael Egnor MD tells of a patient he had named Katie who only "had a third of the brain that her sister had," her fraternal twin. Egnor tells us that Katie "sat and talked and walked earlier than her sister," "made the honor roll," and "will soon graduate high school."
• The Birjand Cyst patient:  This patient's case is reported in the paper "Giant Brain Hydatid Cyst in an Adult: A New Case Report." We are shown a photo of a giant hole in the patient's brain. We are told "The patient only complained of headache in the last two weeks and had no symptoms of visual or speech impairment." We are told the patient had no psychological problems. Surgery removed a fist-sized brain cyst that was 90 millimeters long and 40 millimeters wide. No mention is made of any mental or memory problem. 
• The 500 gram cyst girl. This patient's case is reported in the paper "Primary Giant Cerebral Hydatid Cyst in an 8-year-old Girl." Doctor's discovered a giant brain cyst of 500 grams measuring 20 cm × 15 cm × 12 cm, and they said "in our search this is the largest brain hydrated cyst in the literature." This was probably more than half the size of her brain, since the average adult female brain is about 1200 grams, and since an 8-year-old female would have a brain of less than 1000 grams. Despite having so large a brain cyst there was "no history of neurological deficits" and "no changes in behavior." A month after the removal of the cyst, the patient is described as "vitally stable, thriving well, no complaints, no neurological deficits, and with the normal neurological examination." No mention is made of any mental or memory problem. 
  
• The asymptomatic man with a giant brain cyst. This patient's case is reported in the paper "Asymptomatic giant arachnoidal cyst." We read of "a 39-year-old right-handed man, with a high-school education, good social and job functioning, and good command of three foreign languages (English, Spanish, and, in part, Arabic), had a 3-year history of mild migraine without aura." We are told that "neurologic examination and standardized cognitive assessment revealed normal findings." The man was found to have a giant cyst "occupying the anterior two thirds of the left hemisphere." We see a photo showing a huge hole in the person's brain, so big that it took about one third of the person's brain mass. How could you lose one third of your brain and have no symptoms, if a person's brain makes his mind? 
• The 57-year-old who described doctor's efforts to resucitate him while his heart had stopped.  The original  AWARE study authored by Sam Parnia and others did not succeed in its attempt to get people to identify images that were placed out of their sight in hospitals. But the study did report a case of a 57-year-old patient who successfully described the efforts of medical personnel to revive him while his heart was stopped. We read this: "The other, a 57 year old man described the perception of observing events from the top corner of the room and continued to experience a sensation of looking down from above. He accurately described people, sounds, and activities from his resuscitation (Table 2 provides quotes from this interview). His medical records corroborated his accounts and specifically supported his descriptions and the use of an automated external defibrillator (AED). Based on current AED algorithms, this likely corresponded with up to 3 min of conscious awareness during CA [cardiac arrest] and CPR [cardiopulmonary resuscitation]." The man said that a woman appeared in a high corner of the room, beckoning him to come up to her. He said that despite thinking that was impossible, he found himself up in the high corner of the room, looking down on the medical team trying to revive him. The man described specific details of the revival efforts, including the presence of a bald fat man with a blue hat, a nurse saying, “Dial 444 cardiac arrest,” his blood pressure being taken, a nurse pumping on his chest, a doctor sticking something down his throat, and blood gases and blood sugar levels being taken. Here we have a man apparently floating out of his body and viewing the efforts of medical personnel to restart his heart, something that should have been impossible if the human mind is produced by the brain. It is known that brains become electrically inactive within about 10 or 20 seconds of a person's heart stopping, and that people become unconscious only a few seconds after their heart stops. 
• Pam Reynolds. The late Pam Reynolds was a 35-year old with a large brain aneurysm when she underwent a very complicated operation that involved pumping out her blood and chilling her body temperature to only 60 degrees. Some twenty medical personnel worked on the complex operation. After the successful operation was over, Reynolds reported having a near-death experience during the operation. She reported floating out of her body, and witnessing her operation. She accurately reported details of some medical equipment that was used to cut her skull open, describing it as a “saw thing...like an electric toothbrush,” with “interchangeable blades” that were stored in “what looked like a socket wrench case.” She reported someone complaining that her veins and arteries were too small. These details were later verified. This was despite the fact that during the operation Reynolds eyes were covered throughout the operation, and her ears were plugged with earplugs delivering noise of 40 decibels and 90 decibels (not to mention that her body was chilled to a level at which consciousness should have been impossible). Reynolds said that she then encountered a tunnel vortex, saw an incredibly bright light, heard her deceased grandmother calling her, and encountered several of her deceased relatives. Reynolds says she was told by her uncle to go back through the tunnel, and to return to her body. These details were originally reported in the 1998 book Light and Death by Michael Sabom MD. That book includes diagrams of the medical equipment used to cut open Reynold's skull. They match her descriptions very well.
• Buckley's test subjects. A nineteenth century work Letters to a Candid Inquirer, on Animal Magnetism by William Gregory (professor of Chemistry at one of England's oldest universities) gives some very specific numerical details relating to clairvoyance in hypnotic trances (referred to below as "mesmeric sleep"):  "Major Buckley has thus produced conscious clairvoyance in 89 persons, of whom 44 have been able to read mottoes contained in nut-shells, purchased by other parties for the experiment. The longest motto thus read, contained 98 words. Many subjects will read motto after motto without one mistake. In this way, the mottoes contained in 4860 nut-shells have been read, some of them, indeed, by persons in the mesmeric sleep, but most of them by persons in the conscious state, many of whom have never been put to sleep. In boxes, upwards of 86,000 words have been read; 'in one paper, 371 words. Including those who have read words contained in boxes when in the sleep, 148 persons have thus read. It is to be observed that, in a few cases, the words may have been read by thought-reading, as the persons who put them in the boxes were present; but in most cases, no one who knew the words has been present, and they must therefore have been read by direct clairvoyance. Every precaution has been taken. The nuts, inclosing mottoes, for example, have been purchased of 40 different confectioners, and have been sealed up until read. It may be added, that of the 44 persons who have read mottoes in nuts by waking or conscious clairvoyance, 42 belong to the higher class of society; and the experiments have been made in the presence of many other persons. These experiments appear to me admirably contrived, and I can perceive no reason whatever to doubt the entire accuracy of the facts." 
• Alex, who did not start speaking until the left half of his brain was removed. A scientific paper describing the case says that Alex “failed to develop speech throughout early boyhood.” He could apparently say only one word (“mumma”) before his operation to cure epilepsy seizures. But then following a hemispherectomy (also called a hemidecortication) in which half of his brain was removed at age 8.5, “and withdrawal of anticonvulsants when he was more than 9 years old, Alex suddenly began to acquire speech.” We are told, “His most recent scores on tests of receptive and expressive language place him at an age equivalent of 8–10 years,” and that by age 10 he could “converse with copious and appropriate speech, involving some fairly long words.” Astonishingly, the boy who could not speak with a full brain could speak well after half of his brain was removed. The half of the brain removed was the left half – the very half that scientists tell us is the half that has more to do with language than the right half. 
  
• Patient BL: The paper "When only the right hemisphere is left: Studies in language and communication" reports on the case of a patient BL of "above normal intelligence" who underwent a left hemispherectomy at age five. Despite lacking the left half of his brain, BL "attended regular elementary and high school and graduated from college with a Bachelor's degree with a double major in business and sociology," he "played the baritone horn in a band," and worked "several years as an accountant in international business." The paper reports BL scoring normally on most of the cognitive tests he took. 
• The honors student (IQ=126) with only 3% to 10% of a brain. in the scientific paper "Long-Term Memory: Scaling of Information to Brain Size" by Donald R. Forsdyke of Queens University in Canada, he quotes the physician John Lorber on an honors student with an IQ of 126: "Instead of the normal 4.5 centimetre thickness of brain tissue between the ventricles and the cortical surface, there was just a thin layer of mantle measuring a millimeter or so. The cranium is filled mainly with cerebrospinal fluid. … I can’t say whether the mathematics student has a brain weighing 50 grams or 150 grams, but it’s clear that it is nowhere near the normal 1.5 kilograms." Forsdyke notes two similar cases in more recent years, one from France and another from Brazil.  Forsdyke says, "Three independent studies agree that there are, among us, people leading normal lives with approximately 5 % of the quantity of brain tissue found in others."
• Stephan Ossowiecki. In the paper "An experiment with the Polish Medium Stephan Ossowiecki, which can be read here, E.J. Dingwall describes a very careful test of clairvoyance. Dingwall says that when alone by himself, he drew a crude picture of a bottle, writing on it, "The vineyards of the Rhine, Moselle and Burgundy produce excellent wine." He says he put the paper in an "opaque red paper envelope," which was "then inserted flap end first into an opaque dull black envelope, into which it fitted closely." He says, "This envelope, again unsealed, was then inserted flap end first into a brown paper envelope, into which it again fitted closely," and that "the flap of this envelope was then pasted down and a single seal affixed to the lowest part of the flap where it adhered to the envelope." He gave the envelope to another researcher, who took the sealed envelope to Stephan Ossowiecki, asking him to guess the contents before witnesses. The contents were correctly identified by Ossowiecki, without the package being opened. Dingwall (who was given back the package) states, "The envelopes appeared to be wholly intact and no evidence whatever was discernible that the packet had been opened. I had no doubt that the test was valid and that the knowledge of the contents had been ascertained by M. Ossowiecki through channels not generally recognised.... In discussing this case it is necessary to bear in mind that the result of the experiment showed, I think, quite definitely that coincidence can be wholly excluded." Similar feats were performed innumerable times in public exhibitions by the clairvoyant Alexis Didier, discussed here, who was often able to identify the contents hidden in locked or sealed boxes. 
• Mrs. Croad. The case of Mrs. Croad is told in my blog post here, which quotes at length from the original report here. Suffering from a variety of medical ailments, she was bedridden for 14 years, and reported as blind and deaf. But J. G. Davey M.D.  reported that the blind Mrs. Croad could read by touching ordinary text with her fingers, even after she had been heavily blindfolded with blindfolding including heavy cotton wadding. Davey also reported that Mrs. Croad could read the contents of letters inside sealed envelopes, and stated, "It is said also by those near and dear to her that such is Mrs. Croad's prevision that she has been known to have foretold my own visits to her ; what I mean is, that on my approach to the house she occupies and when at a distance from it, and unseen by anyone about her — in fact, not within sight— she has said, ' Dr. Davey is coming ; he will be here directly.' "  The case resembles the case of Mollie Fancher discussed next. 
• Mollie Fancher. Like Mrs. Croad, Mollie Fancher had a very bad vision problem. Fancher was described at various times as either blind or very nearly blind.  Mollie had suffered terrible injuries even worse than Mrs. Croad's, including a fall from a streetcar. Both Mrs. Croad and Mollie Fancher were bedridden, and Mollie stayed bedridden for decades. Witnesses very often reported that Mollie Fancher would announce who had arrived at her door, before she could even see who had entered (something also reported of Mrs. Croad).  Both Mollie Fancher and Mrs. Croad passed with flying colors the most stringent tests of clairvoyance while securely blindfolded. Both Mollie Fancher and Mrs. Croad went in and out of trances.  Both Mollie Fancher and Mrs. Croad had long periods of time in which they seemed to neither eat nor drink, with such an abstinence occurring for much longer periods with Mollie Fancher.  A newspaper called the Brooklyn Eagle published an account of Mollie Fancher which stated this: ""When in the quiet condition of rigidity, the patient is in a trance. Her eyes closed, the ears are dead to sound, the muscles cease to act, respiration is hardly perceptible, and once or twice a state of ecstacy indicative of mental unsteadiness has resulted. These seasons last for four days, or two hours each. When in this condition, she is powerfully clairvoyant in her faculties. She can tell the time by several watches variously set to deceive her, read unopened letters, decipher the contents of a slate, and repeat what 'Mrs. Grundy says,' by serving up the gossip of the neighborhood. She appears to possess the faculty of second sight to a remarkable degree." The Mollie Fancher case is described in my post here, and in the long book here.
• Mother Davis. The astonishing case of an old black woman named Mother Davis is told in B. F. Austin's extremely interesting book Glimpses of the Unseen, which has many very interesting similar accounts (the book can be read here).  Austin includes beginning on page 110 an account written by James L. Hughes, an inspector of public schools in Toronto, Canada. Hughes says that when he was twenty he met an old woman who looked strange, as if half-demented. The woman suddenly said, "Young man, I can tell anything you ever did or anything you want to know." Hughes started asking questions of this woman he had never before seen, and was astonished he got from her answers that were correct. The woman was able to correctly tell Hughes his last name, his father's name, his mother's name, how many sisters he had (seven), how many brothers he had (three), what he did before coming to Toronto (farming),  and what was the worst accident he had.  The old woman predicted that Hughes would become a teacher in the school he now attended, which turned out to be true, even though Hughes thought at the time that nothing could be more absurd. The woman predicted, "Before you take your tea to-night a gentleman will come to see you who will be a relation of yours by your marriage." The one man who came to Hughes before he took his tea turned out to be the cousin of the woman Hughes would marry. Hughes said that this Mother Davis "could read minds fluently," and that the accuracies of her prophecies about him were inexplicable, because "no foundation of even the most shadowy kind existed" by which she could logically base such prophecies. 
• Solomon Shereshevsky. Neuroscientists love to talk about people with a memory problem, but such neuroscientists almost never tell us about cases of exceptional memory. The reason is that such cases greatly worsen the explanatory shortfall of "brains store memories" claims, which cannot explain ordinary memory facts such as instant recall, instant learning and life-long preservations of memories, and which seem all the more "on the wrong track" when we consider exceptional memories. One such person with an exceptional memory was Solomon Shereshevsky, called "S" in the book The Mind of a Mnemonist by Alexander Romanovitch Luria. A scientific paper says this about Shereshevsky: "According to Luria, Shereshevsky could' 'easily remember any number of words and digits' and 'equally easily he memorizes whole pages from books on any subject and in any language.'  He could accurately quote information from a decade earlier, including tables of numbers and strings of nonsense words....What Luria learned was that Shereshevsky’s memory differed from that of the vast majority of individuals; time did not erode his memories. Neither did a new stimulus affect his memory of an earlier one." Similar cases of exceptional memory are described in my post here. 
• The patient of Smith and Sugar. In their paper "Development of above normal language and intelligence 21 years after left hemispherectomy," Smith and Sugar state that "Neuropsychologic follow-up studies of a 5-year-old boy who had left hemispherectomy for seizures showed that he had developed superior language and intellectual abilities." This was a boy who had the left half of his brain removed, but who ended up with "superior language and intellectual abilities."
• Patient B.M. Patient B.M. had the right half of her brain removed, in an operation called a right hemispherectomy. She  had difficulty recognizing faces, a problem called prosopagnosia. But according to a paper on her, her "intellectual and cognitive functions were otherwise normal or only slightly impaired," despite the loss of half of her brain. 
• Patient HS4. This patient is discussed in the paper "Intrinsic Functional Connectivity of the Brain in Adults with a Single Cerebral Hemisphere.'" The paper discusses attempts to measure brain connectivity in patients who had half of their brain removed to treat very frequent seizures. The half-brain patient with the highest intelligence was patient HS4, with an IQ of 99 (according to the Supplemental Information of the paper). But this very patient had the smallest brain of the six half-brain patients. This patient HS4 had an average brain connectivity score of only .30, which is the same as one of the group of controls with normal brains, and less than the brain connectivity of the other group of controls with normal brains.   So the smartest person with half a brain (who had an IQ of 99) did not at all have any greater brain connectivity that can explain his normal intelligence with only half a brain. How can this subject HS4 have had a normal intelligence with only half a brain?  In this case, favorable brain rewiring or greater brain connectivity cannot explain the result.  

The half brain of subject HS4, IQ of 99, average brain wiring