Oops: Grand Lab Tries to Prove Brain Storage of Learning, But Then Pulls the Plug

Neuroscience within academia suffers from a social disease. That disease is the sick culture of academia, a culture suffering from many problems. They include the following:

(1) Neuroscientists are members of a belief community clinging to unwarranted and groundless dogmas such as the dogma that the brain is the source of the human mind and that memories are stored in human brains (a place where microscopic examination has never discovered memories or any trace of anything anyone learned). 

(2) This belief community exists within a hierarchical structure of authority having many resemblances to the hierarchical structure of authority within the Catholic Church. 

(3) There is a "publish or perish" culture within this belief community, in which scientists are judged by how many papers they publish and how many citations such papers get. This culture incentivizes the production of low-quality "quick and dirty" papers, papers often untruthfully making important-sounding claims that may cause such papers to be cited, driving up the citation counts of the paper authors. 

(4) There is a predominance of a variety of Questionable Research Practices such as the use of way-too-small study group sizes, a lack of the use of blinding protocols, and the use of unreliable methods such as trying to judge rodent recall by "freezing behavior" judgments. 

In the paper here we read a description of the Janelia Research Campus, which tried to do neuroscience in a different way. Part of the Howard Hughes Medical Institute, this campus was a very fancy set of labs set up on the Potomac River,  55 miles upstream of Washington D.C. The paper here describes this Janelia campus as "a state-of-the-art research campus and community of more than 350 scientists, split between individual research labs, project teams and shared scientific support groups." We read that "the new research campus would have organizational and reward structures very different from those found in academia." We read that one of its goals was to create an environment "insulating Janelia from the dominant academic culture through geographical separation." Wow, I guess the dominant academic culture must be in pretty bad shape if some giant lab would feel the need to insulate itself from that culture.

Below is a short video showing the palatial surroundings of the fancy Janelia Research Campus, which has a staff of 650, a budget of 300 million dollars, and a campus of 689 acres:

In the paper we read that after pondering what goals to pursue, it was decided that the big fancy new neuroscience research campus would undertake two grand goals: " i) understanding how information is stored and processed by neuronal circuits; and ii) developing novel imaging methods and computational tools for image analysis." The first of these research goals was quixotic folly. There has never been any good reason for thinking that learned information is stored in neuronal circuits. No one has ever come up with a decent theory as to how the very many types of things that humans learn could ever be stored in "neuronal circuits."

A recent article at The Transmitter site tells us that now this fancy Janelia Research Campus has decided to "pull the plug" on quite a few of its mouse researchers trying to find "how information is stored and processed by neuronal circuits." We read of a "major course correction." We read, "As part of the change, Janelia is also shuttering two programs and plans to phase out projects that use rodent models, The Transmitter has learned." We may presume that one of these program was the big goal of "understanding how information is stored and processed by neuronal circuits." 

Apparently the Janelia Research Campus was getting nowhere trying to back up claims that memory is stored by in neuronal circuits. Now the big fancy facility is switching gears, focusing on "whole-brain imaging of a transparent fish called Danionella."

The Janelia campus is offering a very comfy transition process for the floundering mouse researchers. The mouse researchers will be given  "roughly three years to wrap up their projects and find new positions, and Janelia plans to provide each researcher with an additional $1 million in transition funding," But despite getting these ridiculously generous terms, we read below that the mouse researchers are furious, and are screaming, "Betrayal!" 

In the Transmitter article we read this: 

 "The facility added the Mechanistic Cognitive Neuroscience program in 2019 and the 4D Cellular Physiology program in 2022. Janelia initially announced that it planned to fund each program for 15 years, but it now plans to close both to make way for the Danionella work".

No one should be surprised. "Mechanistic Cognitive Neuroscience" is a dead end that has produced no robust evidence that minds or memory could arise in any mechanistic or neural way. Those trying to produce such results have produced mainly dead-end misleading results guilty of Questionable Research Practices, results that fail to be reproduced in any convincing way. So we can hardly be surprised that some big lab would "pull the plug" on so failing a project. 

But the Janelia Research Campus has not learned any humility from the failure of its earlier grand plans. Now it announces a different research plan, a plan making mistakes similar to its previous plans. We read that it now has the grand goal of "understanding how the brain generates complex behavior." The brain does not do any such thing, so this goal will fail as badly as the previous goal of "understanding how information is stored and processed by neuronal circuits." Nature never told us that brains generate behavior or that brain store learned information in neuronal circuits. 

Janelia's press release announces this: "Janelia is betting on a decade-long scientific effort to understand how the brain generates behavior, pursuing a mechanistic account that links molecules, neurons, circuits, physiology, computation, and action in a living vertebrate." The vertebrate referred to is the transparent fish. They won't be able to understand how behavior arises from studying a fish.  

You might say "Fool's Errand #1 has been replaced with Fool's Errand #2," but it would probably be more polite to say that Quixotic Quest #1 has been replaced by Quixotic Quest #2.

Postscript: A professor of neuroscience recently boasted that experimental science "has a powerful, century-old tool kit for limiting false inferences," one that includes "preregistered analyses." But the professor confesses that "preregistration remains rare in neuroscience." Oops, it looks like our neuroscientists are not doing what they need to do to avoid false inferences. 

The LTP Zap Deceits Continue

 In the English language "lost in the woods" is a phrase meaning "to be confused, bewildered or helpless." Neuroscientists trying to explain how human beings create memories have always been very much lost in the woods. Such scientists have no credible tale to tell on this topic. The problem is that nothing in the brain bears the slightest resemblance to some apparatus or mechanism for storing learned information. Humans create various types of devices for writing information, things such as pens, pencils, paint brushes, typewriters, laser jet printers, offset printers, and the read/write heads used by a computer hard drive. Nothing in the brain bears any resemblance to such things. 

So what do you if you are a neuroscientist trying to fool people into thinking that neuroscientists like yourself have some kind of understanding of how a human could form a memory? What such people normally merely do is to senselessly repeat the same old clueless charade that neuroscientists have been doing for about fifty years: they zap a tiny bit of brain tissue, creating some tiny change that lasts about as long as a suntan or the morning dew, and they try and pass off that little change as something like information storage, even though no information was stored. This is the witless nonsense of LTP experiments. 

What is misleadingly called “long-term potentiation” or LTP is a not-very-long-lasting effect by which certain types of high-frequency stimulation performed by scientists (such as stimulation by electrodes) produces a fleeting increase in the strength of synapses. In 2007 a scientist said on page 120 of her PhD thesis, "While LTP is assumed to be the neural correlate of learning and memory, no conclusive evidence has been produced to substantiate that when an organism learns LTP occurs in that organism’s brain or brain correlate."

So-called long-term potentiation is actually a very short-term phenomenon. Speaking of long-term potentiation (LTP), and using the term “decays to baseline levels” (which means “disappears”), a scientific paper says, "potentiation almost always decays to baseline levels within a week," while noting that even after considering LTP "we would be at a loss for a brain mechanism for the storage of a long-term memory."

The visual below depicts the deceit that is going on in the less deceitful  (but still very deceitful) LTP experiments. In these in vivo experiments, scientists use artificial fiddling to zap the brains of living mice or living rats with electricity, and then wrongly claim or insinuate that this sheds light on what naturally occurs in the brain. The claims are bogus, because when people learn and recall, they do not have electrodes or wires attached to their heads. 

But there is a form of such LTP deceit even worse than the deceit depicted above: the in vitro form of LTP deceit. The phrase "in vitro" refers to observations or experiments involving only tissue outside of a living organism, such as tissue in a test tube or glass beaker.  The typical scientist doing the in vitro form of LTP deceit will zap some dead tissue extracted from the brain of a mouse or rat, and will then insinuate (or have his allies insinuate) that this tells us something about learning occurring in living humans who were not zapped. This kind of deceit is depicted below:

I can give the latest example of the LTP zap deceit. It is a recent press release published by the MedicalXPress site that is a frequent purveyor of misleading neuroscience press releases. We have a headline of "How the brain regulates learning on a cellular level: 3D maps reveal synapses reorganizing in real time." The headline is bogus, because the press release does not discuss a study that did anything to study natural learning in humans or natural learning in animals. All that went on was that tissue extracted from the brains of rats was artificially zapped, and a study was made of synapse changes after such artificial zapping. 

The paper being promoted is the recent paper "Transition of the presynaptic vesicle cluster from a compact to dispersed organization during long-term potentiation."  Contradicting itself, the paper tells us, "Long-term potentiation (LTP) is a lasting form of synaptic plasticity that can persist for hours or even days."  Of course, it makes no sense  to describe something as "lasting" if it only persists for "hours or even days." The long-standing use of the term "long-term potentiation" for this very short-lived effect produced by artificial electrode stimulation is one of the most dishonest speech customs of neuroscientists.  So-called "long-term potentiation" should be called something like "artificially-induced short-term potentiation." The paper incorrectly refers to this LTP as "a cellular mechanism of learning." The description contradicts the paper's previous claim describing LTP as something involving synapses (synapses are not cells). The description also contradicts what the same six authors say in the preprint I mention below, where the authors refer to LTP as a mere "cellular model of learning." A model is not a mechanism. 

It not correct to call the idea of LTP or effects produced by LTP zapping a "model of learning," for the simple reason that in science a model is a detailed theory explaining how something happens, and LTP involves no such detailed theory, but merely the vague idea of "synapse strengthening" or its artificial elicitation, which is something vastly different from having an account of how human experiences and human learned knowledge could be naturally encoded into brain states or synapse states. Scientists have no credible detailed theories explaining how there could occur either memory encoding in brains or memory storage in brains. 

The paper is behind a paywall, but we can assume that the research corresponds to that described in a preprint with a very similar title, the title of "The presynaptic vesicle cluster transitions from a compact to loose organization during long-term potentiation," particularly since that preprint has exactly the same six authors, and mentions exactly the same very narrow topic, and also because I see the preprint repeats (using some nearly identical language) some of the language in the abstract of the published study.  Looking at that preprint, we get the details of what was going on. 

We read of "theta-burst stimulation (TBS) to produce long-term potentiation (LTP)." This is brain tissue zapping. Later we read of "2 hours of theta-burst stimulation (TBS) to produce LTP." So it wasn't just a single brain zap that was delivered, but two hours of brain zapping.  

And the experiment did not involve brain zaps of living rats. The experiment involved the in vitro zapping of brain tissue extracted from rat brains. We read this in the preprint:

"Brain slices from the middle of the rat hippocampus were prepared as previously described. Two concentric bipolar electrodes were lowered into the middle of stratum radiatum in area CA1 separated by 500 µm, stimulating independent axons. Control stimulation (one pulse every two minutes for 40 minutes) was delivered to one of the electrodes and TBS to the other one (8 trains of 10 bursts at 5 Hz of four pulses at 100 Hz delivered 30 sec apart). 2 hours following TBS, the slices were fixed, processed, and imaged."

So the scientists electrically zapped for two hours some dead tissue extracted from the brains of rats, rats who were not even trained to learn anything or remember anything. Can we learn from such an effort anything at all about how learning or memory occurs in living humans who were not electrically zapped?  Of course not. 

But how does the press release discuss this study having no relevance to learning or memory? With a bogus headline of "How the brain regulates learning on a cellular level: 3D maps reveal synapses reorganizing in real time." An honest headline would have been "What happened after they spent 2 hours zapping dead cells taken from rat brains."

LTP research is a cesspool of misleading junk science, and in vitro LTP experiments are the lowest nadir of that cesspool. An honest description of these experiments in news articles and science paper abstracts would have these characteristics:

(1) It would be made clear that artificial electrical stimulation was occurring, unlike anything that occurs in learning humans. 

(2) It would be made clear that the experiments involved rodents, not humans. 

(3) Whenever the experiments involved extracted brain tissue, it would be made clear that the experiments involved only zapping dead tissue stored in something like a test tube.  

(4) It would be made clear that no information storage resulted from this zapping, and that the zapped tissue did not end up storing any data or information  or knowledge transmitted by the electrical zapping. 

Just as sun-tanning from a tanning machine never results in information storage in skin, LTP experiments never produce data or information or knowledge stored in brains or brain tissue.

Part of the deceit involving the terms LTP and "long-term potentiation" involves using such terms to refer both to artificial zapping manipulations and also to natural variations in synapse strengths.  Through this technique writers try to create the impression of LTP as being something that naturally occurs. Erroneously claiming that LTP originally referred to a long-lasting increase, a science paper describes how the term LTP became fuzzy:

"Originally, LTP referred to a long-lasting increase in the synaptic response (potentiation) resulting from stimulation at high frequency (Bliss and Lomo, 1973). Over the years this term became fuzzy as it has been applied to pretty much any increase in synaptic strength regardless of the specific induction procedure."

Real science (as opposed to junk science) involves the precise communication of truth. When writers confuse things so badly that artificial electrical zapping is conflated and confused with natural events going on in brains, then we are in a realm of deceit or confusion much different from well-functioning truthful science. I don't know whether what I describe above as deceit is willful deceit or simply very bad misrepresentation by those who are confused or self-deceived or very careless or very clumsy. But since the first definition Merriam-Webster gives of deceit is "the act of causing someone to accept as true or valid what is false or invalid," I consider it fair to use the word "deceit" in describing these misrepresentations. 

Exhibit C That Neuroscientists Have No Understanding of How a Memory Could Form or Last in a Brain

 In 2020 on this site I published a post entitled "Exhibit A Suggesting Scientists Don't Understand How a Brain Could Store a Memory." In 2023 I published on this site a post entitled "Exhibit B That Scientists Have No Understanding of a Physical Basis of Human Memory." Now it is time for Exhibit C on this topic. 

I recently discovered a web site called The Transmitter (www.thetransmitter.org) that mainly covers neuroscience research and neuroscience theory. When read in a critical manner, an article on the last site serves to powerfully remind us that neuroscientists lack any such thing as either a real theory of memory storage or a real theory of life-long memory persistence. When scientists speak on these topics, they offer only the flimsiest catchphrases, soundbites that have the weight of soap bubbles. 

The title of the article is "What makes memories last—dynamic ensembles or static synapses?" The reference to "static synapses" is a very misleading one. Everything we know about synapses tells us that a synapse is an unstable thing that cannot last for years.

We read a neuroscientist (Jason Shepherd) making these claims:

"The debate over how information is stored in the brain is often represented as one between two extremes. One viewpoint posits that learning induces changes in gene expression that ultimately alter the structure and function of specific synapses within the physical memory circuit, or engram. These molecular changes at the synapses can remain stable for the lifetime of the memory. The other viewpoint claims that information is represented not in a specific set of cells or synapses but rather across a loose set of cells and circuits that 'drift' over time."

The narrative of two rival theories is a false one. The situation is really "no theory at all" but merely empty, vacuous sound bites and slogans such as "synapse strengthening," which may differ from one speaker to the next. The claim above that "molecular changes at the synapses can remain stable for the lifetime of the memory" is something entirely contrary to fact. We know that human memories can persist for more than 50 years. Synapses, on the other hand, are "shifting sands" type of things that are dramatically unstable. The proteins that make up synapses have an average lifetime of less than 3 weeks.  Synapses are connected to dendritic spines, which are known to have short lifetimes, not lasting for years. Remarkably synapses are built of proteins which have an average lifetime about 1000 times shorter than the maximum length of time that humans can remember things. This discrepancy is one of very many reasons why the idea that memories are stored in synapses is one of the most nonsensical ideas that scientists have ever advanced. 

Notice well the utter emptiness of what is discussed as an alternative to the utterly-vacuous-by-itself idea that memories are formed by "synapse strengthening." The alternative is presented as the idea that " information is represented not in a specific set of cells or synapses but rather across a loose set of cells and circuits that 'drift' over time." That's an utterly vague, vacuous, empty sound bite that is as much  of an empty soap bubble as the equally empty notion of "synapse strengthening." Not the slightest bit of weight is added by the next two sentences:

"In this view, the cells that initially encoded an experience are not the same set of cells that actually store the information. Indeed, the precise set of cells do not matter in this framework—the information for a specific memory is instead decoded from the computational space of firing patterns across a set of cells."

As some type of attempt to explain stable memories that can last for 50 years, this idea is as supremely goofy as the idea that memories that last for 50 years are stored in the "shifting sands" of synapses. The "firing patterns" in the brain are ever-changing. Trying to claim that stable memories are stored in "firing patterns" is as goofy as the claim that your tax records and childhood photos are stored in the wind patterns around your house. 

Shepherd gives us some "rival cases" paragraphs. Under a heading of "The case for memory engrams," he makes some untrue statements. He states this:

" In experiments that used this approach, light-sensitive receptors were expressed only in the cells active during learning. Shining a light to activate these cells days or even weeks after training resulted in the recall of a memory without any external experience or cue. This remarkable observation set the stage for the idea that 'engram' neurons that encode learning are sufficient to store and recall a memory."

No robust research of any such type ever occurred.  Shepherd is simply repeating a groundless achievement legend of neuroscientists. When you read the papers that claim to have done such things, you will always find that they were junk-science studies guilty of multiple types of Questionable Research Practices such as the use of way-too-small study group sizes, and the use of unreliable techniques for attempting to judge recall in rodents, such as the unreliable method of trying to judge "freezing behavior."

Under the heading of "the representational drift perspective," Shepherd presents nothing in the way of any evidence. We get only the most roundabout hand-waving. 

Shepherd then asks eight neuroscientists for their opinions on the topic of memory storage by a brain. Shepherd follows a senseless procedure.  A good open question to ask would be something like this:

"Do you have a good, credible theory of how a brain could store memories, and how memories could persist a lifetime? If so, describe the best evidence for such a theory, and tell us how confident you are that such a theory is true."

And a good follow-up question would be questions like this:

• "Are there any physical factors in the brain that argue against such a theory? Explain how such a theory could really allow 50-year memory storage despite all the molecular and structural turnover in the brain."
• "Trying to be precise, and avoiding vague language, can you explain exactly how a detailed memory could be stored under such a theory? For example, exactly how could a brain store a page of text that someone had memorized, so that the person could retrieve that whole page?"
• "Under such a theory, how would it be possible for someone to instantly recall lots of relevant detailed information after seeing a single face or hearing a single name? For example, how could someone ever recite a paragraph describing the life of Abraham Lincoln after merely hearing his name? How could information about Lincoln stored in a brain ever be found quickly enough to allow instant recall?"

But Shepherd asks no such challenging questions to his eight neuroscientists. Instead he asks each of them the softest of softball questions. Each neuroscientist is asked these questions:

• "Is information stored in the brain at the level of cells (or circuits) or at the level of synapses?"
• "Can we reconcile observations that show distinct engram circuits seem to store memories versus observations that show the neuronal activity of these memory engram drifts?"
• "What experimental data would be helpful to reconcile these observations to help bring these theories together?"

The first question is a classic example of a stupid "either/or" question in which someone is asked to choose between two alternatives, neither of which is credible. The question is as stupid as asking, "Are UFOs spaceships from the planet Mars or spaceships from the planet Venus?" The second question is one with a false premise embedded within it. It is not true that there are "observations that show distinct engram circuits seem to store memories." Microscopic examination of brain tissue has never shown the slightest trace of anything anyone has learned or experienced. The third question is the type of question you might ask neuroscientists when they don't have any good evidence to back up their dogmas. Rather than asking them to tell about what evidence backs up their claims, you might ask them to fantasize about what type of future observations they might make that might back up their theories. 

None of the eight questioned neuroscientists has anything of any substance to offer in response to the questions. The first question at least offers an invitation for someone to start expounding about any theory he may have of neural memory storage. We get no impressive quotes in response to such a question. We get only the wobbliest hand-waving that makes the people giving the answers sound very empty-handed. 

• Andre Fenton of New York University has nothing of any substance to say. He says "information is not stored in any single element," and "it may not be practically possible to separate the process of storage from the access," both of which suggest that he has no understanding of how a brain could store a memory. People who understand how some type of information is stored do not say such things. 
• Loren Frank of the University of California gives us no impression that he understands how a brain could store a memory. He says, "It might be that changes in gene expression lead to changes in activity levels, although at the moment we really don’t understand the scope of these changes." He offers only the vaguest hand-waving, with a mention of the hippocampus. We have an example of the vaguest and most conceptually empty hand-waving in this statement by Frank: "Focusing on memories for the events of daily life, our current conception is that the events themselves drive activity across the brain, engaging specific neurons whose activity represents the various sights, sounds, smells and feelings that are part of the experience." 
• Kari Hoffman of Vanderbilt University also offers only the vaguest handwaving, an example being this statement: "I would submit that much of the heavy lifting is done at both the synaptic and circuit/ensemble level. Which levels dominate depends on factors such as memory type, when information was acquired and how it is integrated with the existing structures, themselves reflecting changes from earlier experiences. " Another statement by her indicates she has no real understanding on this topic: "That said, we may need to be careful in using the term 'these memories' or 'these memory engrams.'  Such terms suggest that experience creates biological bins to hold discrete memories, that memories exist as entities that are created 'de novo,' and that neural modifications must reside at only one level, all of which are positions that are not or may not be true." 
• Yingxi Lin of the University of Texas says, "It is, however, too early to say that those cells and synapses are sites of stored memory per se, as they may simply function to gain access to the memory."  She also says, " It is also possible that there aren’t specific sites for memory storage; cells and synapses may be part of a brain-wide code for memory expression." She seems to have no understanding of how a brain could store a memory. 
• Cian O'Donnell of Ulster University sounds like a weak scholar of neuroscience when he states, "The field has held synaptic plasticity up as the main mechanism for information storage in the brain for several decades now, and I haven’t heard any good reasons to start doubting it yet." There are very many such reasons, such as the fact that synapses are composed of proteins with very short lifetimes, the fact that synapses bear no resemblance to any system for writing or reading information, the fact that synapses do not reliably transmit information, and that synapses are connected to dendritic spines that are unstable and do not last for years. Nothing O'Donnell says makes him sound like anyone with an understanding of how a brain could store memories. 
• Timothy O'Leary of Cambridge University (not to be confused with the late Timothy Leary of Harvard) says nothing to inspire any confidence that he has any understanding of how a brain could store a memory. All he does is to reveal that he fell "hook, line and sinker" for bad neuroscience experiments using way-too-small study group sizes and the utterly unreliable technique of trying to judge recall by judging "freezing behavior." 
• Tomas Ryan of Trinity College also says  says nothing to inspire any confidence that he has any understanding of how a brain could store a memory. He engages in the emptiest of hand-waving when he says this: "It seems to me that the plausible level for the storage of long-term memories is in the topography of the connectome. So, the information is engraved through stable changes in the brain’s microanatomical circuit." The "connectome" he refers to is the collection of all synapses. But synapses are not stable, but the opposite of stable. So his claim makes no sense. 
• The last of the eight neuroscientists is Evan Schaffer of the School of Medicine at Mount Sinai. He states this: "As a consequence, I don’t think information can be stored in cells or synapses in the hippocampus in a way that is stable over a lifetime. In other parts of the brain, this may not be the case." No, actually, there is no credible storage place for memories in the brain, either in the hippocampus or anywhere else. Not sounding like anyone who understands how a brain could store memories, Schaffer also sounds like a poor student of human mental performance. Most misleadingly, he tries to suggest that humans may not be able to remember things well for weeks. He says, "On a timescale of a few days, memories seem pretty stable. On a timescale of a few weeks, there’s less evidence for stability." To the contrary, there is abundant evidence that humans can very well remember things for decades. To give one of endless examples I could cite, every opera fan knows that various opera stars are able to perfectly remember over many years the very many notes and words that make up particular opera roles. Placido Domingo, for example, performed more than 150 opera roles, many of which required singing for hours on the stage, from memory. 

Finally in the article we have a summing up by Shepherd, who sounds just as empty-handed and theory-lacking as the eight experts he has interviewed. He says this:

"Finally, neuroscientists must do a better job of defining their terms. What is 'information,' and how is it 'represented' in the brain? What is an engram?"

The title of the article was "What makes memories last—dynamic ensembles or static synapses?" I re-read all of the answers to see whether anyone addressed the issue of how memories could last in a brain long enough to persist for decades. Not one of the eight neuroscientists even addressed the issue. Not one of them advanced any theory as to how memories could persist for decades. Not one of them advanced even a hypothesis about such a topic.  The issue of how memories could last for decades was simply ignored by the eight neuroscientists, none of whom had either a real theory of memory storage to advance, nor any theory of the life-long preservation of memory.  We certainly did not get any such thing when we got this piece of fantasy by Tomas Ryan:

"It seems to me that the plausible level for the storage of long-term memories is in the topography of the connectome. So, the information is engraved through stable changes in the brain’s microanatomical circuit." 

Engraved? No such engraving occurs in the brain. Nothing in a brain bears any resemblance to a system or component for writing learned information. There is zero evidence that anything bearing the slightest resemblance to engraving occurs in the brain. We see no "engraved" neurons, no "engraved" synapses, and no "engraved" dendritic spines.  Everything that has been learned about synapses shouts that a synapse cannot have any such thing as stable changes, in the sense of changes that last permanently for decades. The proteins that make up synapses have average lifetimes of less than a few weeks. And synapses are attached to dendritic spines that are known to have short lifetimes, dendritic spines that do not last for years. 

A 2019 paper documents a 16-day examination of synapses, finding "the dataset contained n = 320 stable synapses, n = 163 eliminated synapses and n = 134 formed synapses."  That's about a 33% disappearance rate over a course of 16 days. The same paper refers to another paper that "reported rates of [dendritic] spine eliminations in the order of 40% over an observation period of 4 days."  A paper studying the lifetimes of dendritic spines in the cortex states, "Under our experimental conditions, most spines that appear survive for at most a few days. Spines that appear and persist are rare." The rare persistence referred to was only a persistence of a few months. 

The 2023 paper here gives the graph below showing the decay rate of the volume of dendritic spines. It is obvious from the graph that they do not last for years, and mostly do not even last for six months. 

Page 278 of the same paper says, "Two-photon imaging in the Gan and Svoboda labs revealed that spines can be stable over extended periods of time in vivo but also display genesis (generation) and elimination (pruning) at a frequency of 1–4% per week." Something vanishing at a rate of 2% per week will be gone within a year. 

Below are some quotes by scientists and doctors who spoke candidly about brains and memory storage, rather than engaging in the kind of bluffing that went on from the people mentioned above:

• "Direct evidence that synaptic plasticity is the actual cellular mechanism for human learning and memory is lacking." -- 3 scientists, "Synaptic plasticity in human cortical circuits: cellular mechanisms of learning and memory in the human brain?" 
• "The fundamental problem is that we don't really know where or how thoughts are stored in the brain. We can't read thoughts if we don't understand the neuroscience behind them." -- Juan Alvaro Gallego, neuroscientist. 
• "The search for the neuroanatomical locus of semantic memory has simultaneously led us nowhere and everywhere. There is no compelling evidence that any one brain region plays a dedicated and privileged role in the representation or retrieval of all sorts of semantic knowledge."  Psychologist Sharon L. Thompson-Schill, "Neuroimaging studies of semantic memory: inferring 'how' from 'where' ".
• "How the brain stores and retrieves memories is an important unsolved problem in neuroscience." --Achint Kumar, "A Model For Hierarchical Memory Storage in Piriform Cortex." 
• "We are still far from identifying the 'double helix' of memory—if one even exists. We do not have a clear idea of how long-term, specific information may be stored in the brain, into separate engrams that can be reactivated when relevant."  -- Two scientists, "Understanding the physical basis of memory: Molecular mechanisms of the engram."
• "There is no chain of reasonable inferences by means of which our present, albeit highly imperfect, view of the functional organization of the brain can be reconciled with the possibility of its acquiring, storing and retrieving nervous information by encoding such information in molecules of nucleic acid or protein." -- Molecular geneticist G. S. Stent, quoted in the paper here. 
• "Up to this point, we still don’t understand how we maintain memories in our brains for up to our entire lifetimes.”  --neuroscientist Sakina Palida.
• "The available evidence makes it extremely unlikely that synapses are the site of long-term memory storage for representational content (i.e., memory for 'facts'’ about quantities like space, time, and number)." --Samuel J. Gershman,  "The molecular memory code and synaptic plasticity: A synthesis."
• "Synapses are signal conductors, not symbols. They do not stand for anything. They convey information bearing signals between neurons, but they do not themselves convey information forward in time, as does, for example, a gene or a register in computer memory. No specifiable fact about the animal’s experience can be read off from the synapses that have been altered by that experience.” -- Two scientists, "Locating the engram: Should we look for plastic synapses or information- storing molecules?
• " If I wanted to transfer my memories into a machine, I would need to know what my memories are made of. But nobody knows." -- neuroscientist Guillaume Thierry (link). 
• "While a lot of studies have focused on memory processes such as memory consolidation and retrieval, very little is known about memory storage" -- scientific paper (link).
• "While LTP is assumed to be the neural correlate of learning and memory, no conclusive evidence has been produced to substantiate that when an organism learns LTP occurs in that organism’s brain or brain correlate."  -- PhD thesis of a scientist, 2007 (link). 
• "Memory retrieval is even more mysterious than storage. When I ask if you know Alex Ritchie, the answer is immediately obvious to you, and there is no good theory to explain how memory retrieval can happen so quickly." -- Neuroscientist David Eagleman.
• "How could that encoded information be retrieved and transcribed from the enduring structure into the transient signals that carry that same information to the computational machinery that acts on the information?....In the voluminous contemporary literature on the neurobiology of memory, there is no discussion of these questions."  ---  Neuroscientists C. R. Gallistel and Adam Philip King, "Memory and the Computational Brain: Why Cognitive Science Will Transform Neuroscience,"  preface. 
• "The very first thing that any computer scientist would want to know about a computer is how it writes to memory and reads from memory....Yet we do not really know how this most foundational element of computation is implemented in the brain."  -- Noam Chomsky and Robert C. Berwick, "Why Only Us? Language and Evolution," page 50. 
• "When we are looking for a mechanism that implements a read/write memory in the nervous system, looking at synaptic strength and connectivity patterns might be misleading for many reasons...Tentative evidence for the (classical) cognitive scientists' reservations toward the synapse as the locus of memory in the brain has accumulated....Changes in synaptic strength are not directly related to storage of new information in memory....The rate of synaptic turnover in absence of learning is actually so high that the newly formed connections (which supposedly encode the new memory) will have vanished in due time. It is worth noticing that these findings actually are to be expected when considering that synapses are made of proteins which are generally known to have a short lifetime...Synapses have been found to be constantly turning over in all parts of cortex that have been examined using two-photon microscopy so far...The synapse is probably an ill fit when looking for a basic memory mechanism in the nervous system." -- Scientist Patrick C. Trettenbrein, "The Demise of the Synapse As the Locus of Memory: A Looming Paradigm Shift? (link).
• "Most neuroscientists believe that memories are encoded by changing the strength of synaptic connections between neurons....Nevertheless, the question of whether memories are stored locally at synapses remains a point of contention. Some cognitive neuroscientists have argued that for the brain to work as a computational device, it must have the equivalent of a read/write memory and the synapse is far too complex to serve this purpose (Gaallistel and King, 2009; Trettenbrein, 2016). While it is conceptually simple for computers to store synaptic weights digitally using their read/write capabilities during deep learning, for biological systems no realistic biological mechanism has yet been proposed, or in my opinion could be envisioned, that would decode symbolic information in a series of molecular switches (Gaallistel and King, 2009) and then transform this information into specific synaptic weights." -- Neuroscientist Wayne S. Sossin (link).
• "We take up the question that will have been pressing on the minds of many readers ever since it became clear that we are profoundly skeptical about the hypothesis that the physical basis of memory is some form of synaptic plasticity, the only hypothesis that has ever been seriously considered by the neuroscience community. The obvious question is: Well, if it’s not synaptic plasticity, what is it? Here, we refuse to be drawn. We do not think we know what the mechanism of an addressable read/write memory is, and we have no faith in our ability to conjecture a correct answer."  -- Neuroscientists C. R. Gallistel and Adam Philip King, "Memory and the Computational Brain Why Cognitive Science Will Transform Neuroscience."  page Xvi (preface). 
• "Current theories of synaptic plasticity and network activity cannot explain learning, memory, and cognition."  -- Neuroscientist Hessameddin Akhlaghpourƚ (link). 
• "It remains unclear where and how prior knowledge is represented in the brain." -- A large team of scientists, 2025 (link). 
• "How memory is stored in the brain is unknown." -- Research proposal abstract written by scientists, 2025 (link). 
• "We don’t know how the brain stores anything, let alone words." -- Scientists David Poeppel and, William Idsardi, 2022 (link).
• "If we believe that memories are made of patterns of synaptic connections sculpted by experience, and if we know, behaviorally, that motor memories last a lifetime, then how can we explain the fact that individual synaptic spines are constantly turning over and that aggregate synaptic strengths are constantly fluctuating? How can the memories outlast their putative constitutive components?" --Neuroscientists Emilio Bizzi and Robert Ajemian (link).
• "After more than 70 years of research efforts by cognitive psychologists and neuroscientists, the question of where memory information is stored in the brain remains unresolved." -- Psychologist James Tee and engineering expert Desmond P. Taylor, "Where Is Memory Information Stored in the Brain?"
• "There is no such thing as encoding a perception...There is no such thing as a neural code...Nothing that one might find in the brain could possibly be a representation of the fact that one was told that Hastings was fought in 1066." -- M. R.  Bennett, Professor of Physiology at the University of Sydney (link).
• "No sense has been given to the idea of encoding or representing factual information in the neurons and synapses of the brain." -- M. R. Bennett, Professor of Physiology at the University of Sydney (link).
• ""Despite over a hundred years of research, the cellular/molecular mechanisms underlying learning and memory are still not completely understood. Many hypotheses have been proposed, but there is no consensus for any of these."  -- Two scientists in a 2024 paper (link). 
• "We have still not discovered the physical basis of memory, despite more than a century of efforts by many leading figures. Researchers searching for the physical basis of memory are looking for the wrong thing (the associative bond) in the wrong place (the synaptic junction), guided by an erroneous conception of what memory is and the role it plays in computation." --Neuroscientist C.R. Gallistel, "The Physical Basis of Memory," 2021.
• "To name but a few examples, the formation of memories and the basis of conscious  perception, crossing  the threshold  of  awareness, the  interplay  of  electrical  and  molecular-biochemical mechanisms of signal transduction at synapses, the role of glial cells in signal transduction and metabolism, the role of different brain states in the life-long reorganization of the synaptic structure or  the mechanism of how  cell  assemblies  generate a  concrete  cognitive  function are  all important processes that remain to be characterized." -- "The coming decade of digital brain research, a 2023 paper co-authored by more than 100 neuroscientists, one confessing scientists don't understand how a brain could store memories. 
• "The human brain isn’t really empty, of course. But it does not contain most of the things people think it does – not even simple things such as ‘memories’....We don’t create representations of visual stimuli, store them in a short-term memory buffer, and then transfer the representation into a long-term memory device. We don’t retrieve information or images or words from memory registers. Computers do all of these things, but organisms do not." -- Robert Epstein,  senior research psychologist, "The Empty Brain." 
• "Despite recent advancements in identifying engram cells, our understanding of their regulatory and functional mechanisms remains in its infancy." -- Scientists claiming erroneously in 2024 that there have been recent advancements in identifying engram cells, but confessing there is no understanding of how they work (link).
• "Study of the genetics of human memory is in its infancy though many genes have been investigated for their association to memory in humans and non-human animals."  -- Scientists in 2022 (link).
• "The neurobiology of memory is still in its infancy." -- Scientist in 2020 (link). 
• "The investigation of the neuroanatomical bases of semantic memory is in its infancy." -- 3 scientists, 2007 (link). 
• "Currently, our knowledge pertaining to the neural construct of intelligence and memory is in its infancy." -- Scientists, 2011 (link). 
•  "Very little is known about the underlying mechanisms for visual recognition memory."  -- two scientists (link). 
• "Conclusive evidence that specific long-term memory formation relies on dendritic growth and structural synaptic changes has proven elusive. Connectionist models of memory based on this hypothesis are confronted with the so-called plasticity stability dilemma or catastrophic interference. Other fundamental limitations of these models are the feature binding problem, the speed of learning, the capacity of the memory, the localisation in time of an event and the problem of spatio-temporal pattern generation."  -- Two scientists in 2022 (link). 
• "The mechanisms governing successful episodic memory formation, consolidation and retrieval remain elusive,"  - Bogdan Draganski, cogntive neuroscientist (link). 
• " The mechanisms underlying the formation and management of the memory traces are still poorly understood." -- Three scientists in 2023 (link). 
• "The underlying electrophysiological processes underlying memory formation and retrieval in humans remains very poorly understood." --  A scientist in 2021 (link). 
• "As for the explicit types of memory, the biological underpinning of this very long-lasting memory storage is not yet understood." -- Neuroscientist Cristina M. Alberini in a year 2025 paper (link).