When Neuroscientists Doing Shoddy Studies Make Grandiose Boasts

Misleading statements are extremely abundant in neuroscience literature. One incredibly common type of misstatement is when neuroscientists produce scientific papers that claim in their titles and abstracts to have shown things that their research never showed.  You should never forget that you simply cannot take for granted the truth of achievement claims made in the titles or abstracts of biology papers, which often do not correspond to any achievements made in the paper. Then there are the huge number of misstatements made in university and college press releases announcing new science research. Such press releases often make grand achievement claims not matching any claims made by the scientific papers the press releases are promoting. 

In such cases a neuroscientist may be able to semi-credibly claim that it was not him who was deceiving people. Neuroscience papers typically have many different authors. So if you are one of seven authors of a neuroscience paper with a title claiming to have shown something the study did not actually show, you might be able to make a claim such as: "It was not me who wrote the title." If you are a co-author of a paper that is incorrectly described by a university press release making groundless boasts, then maybe you can semi-credibly say something like, "Well, you know how those PR guys are -- they are always making crumbs sound like castles." I don't find such excuses to be very credible. If you are a researcher at a university, and a press release is being written to announce your research, you should be able to review that press release for accuracy, and to make sure it does not make boastful misstatements about your research. 

In the case of a personal narrative in which one individual scientist makes untrue claims that something was done by him or his team of scientists, we have a case in which such excuses for misstatements cannot be used. If scientist Joe Smith says, "My colleagues and I have shown..." and makes a claim that is untrue, then we have very clear evidence that scientist Joe Smith has not told us the truth. In such a case Joe Smith cannot excuse his misstatement by using some "joint authorship" excuse or some excuse in which misstatements are blamed on overenthusiastic "hype everything" public relations writers. 

In the article here, we have an example of a neuroscientist personal narrative with some accuracy shortfalls. The article entitled "While do some memories stick while others fade" is written by neuroscientist Sadegh Nabavi.  Referring to a recently published study that he co-authored (a very bad example of poorly-designed junk science), Nabavi makes some grand boasts of achievement that are untrue. 

Nahavi starts out by stating a half-truth. He states this: "Research shows that emotionally impactful events strengthen the neural connections in the brain that store our memories." It is true that emotions help us remember things better and longer, but there is no scientific basis for the claim that it is "neural connections in the brain that store our memories." No memories have ever been found in a brain by microscopic examination. 

Nahavi then begins boasting, telling us this:

"My colleagues and I conducted a study using mouse models, whose brain functions are remarkably similar to humans. Our findings offer new insights into what happens in the brain during memory formation and help explain why some things are remembered while others are not."

Mice have brain functions remarkably similar to humans? This is not a story line that a "brains make minds" persons should feel comfortable making, given the gigantic difference between the intellectual capabilities of mice and humans. The paper referred to offers no such insights, because of defects in it I will soon list. 

Nahavi then makes this claim:

"Scientists agree that memories are formed (and lost) by changes in the strength of these synapses—a process known as synaptic plasticity. Synaptic plasticity can be increased or decreased in two ways: by altering the number of synapses or by making existing synapses larger or smaller."

The claim about scientists agreeing on this topic is untrue. The claim that memory is stored by changes in synapse strength is an utterly untenable theory, for a large number of reasons I explain in my post here, entitled "10 Reasons Synapses Cannot Be a Storage Place for Human Memories." Quite a few scientists have recognized that claims of memory storage by synapse strengthening are untenable or dubious, or recognized that scientists lack any well-established or credible theory of memory creation. I quote some of these scientists in the appendix of this post.

Nahavi makes this misleading claim: "At the same time, we observed that the synapses active during the event were strengthened – either by forming more channels or by expanding existing ones." Mice have billions of synapses, most of which are continually active at any given time, because neurons throughout the brain are constantly firing at random intervals, (between about 1 and 200 times a second), and that causes activity in synapses. It is utterly beyond today's technology to simultaneously study all the active synapses in the brain of a rodent, or even a hundredth of them, to tell whether they are strengthening.  And it is utterly untrue that when something is learned, particular synapses act in some distinctive way different from average synapses, some "standout" way that would allow a neuroscientist to credibly say, "Oh, I see, those are the synapses that are storing the memory just learned." 

What happens in studies like this is that scientists will arbitrarily pick some tiny fraction of a rodent's synapses to study, some miniscule fraction like .000001 of the total synapses.  It is misleading to identify some tiny fraction of these synapses (chosen for study by neuroscientists) as "synapses active during the event," when 99.99% of the synapses that were active are not being studied.  Synapses throughout a brain are continually undergoing random changes that may be interpreted as strengthening or weakening. We know this because synapses are connected to dendritic spines that have short lifetimes, and also because synapses are built from proteins that have an average lifetime of only a few weeks or less. There is no way to convincingly correlate the strengthening of some little group of synapses with an experience event of an organism. What goes on in studies such as this is that some tiny group of synapses will be chosen for study, and neuroscientists will act as if they luckily happened to have chosen some group of synapses that are being affected by something a mouse recently experienced. Such an assumption is never warranted. 

What goes on is cases like this is like what might go on if someone had the theory that his memories are stored in flowers. Such a person might choose for study a few of the flowers in Central Park, and observe that the flowers were growing stronger as he got more memories by taking a school course. This would be nonsense, because flowers getting stronger is something happening continuously and massively, and there would be no sound basis for correlating the observed strengthening of a few flowers and your memory formation. Similarly, because in every brain there are always countless synapses strengthening and countless synapses weakening, you never validate some theory of synapse memory storage by showing that some synapses strengthened when something was learned. 

Nahavi then begins to make grandiose boasts. He claims to have found a memory in a mouse brain, and to have "activated" such neurons. He claims to have observed that there was synapse strengthening that had something to do with memory. He claims to have affected memory recall in a mouse by artificially strengthening synapses. 

"We strongly activated the neurons encoding the weak memory....In this case, the mice were able to recall the aversive memory even the following day. At the same time, we observed that the synapses active during the event were strengthened ...In our experiment, we artificially strengthened certain synapses, even though they weren’t directly linked to the trivial experience. The result? The mice could recall the 'trivial' event the next day. Even more interestingly, the synapses encoding the trivial experience also became stronger."

The claims are mostly false. The claim about "neurons encoding the weak memory" does not even agree with Navavi's earlier claim that synapses store memories. Neurons are not synapses.  Nahavi and his guys did not actually find any "neurons encoding the weak memory"; they did not actually find any good evidence that memory creation strengthens synapses; and they did not actually show that memory recall in a mouse can be changed by artificially strengthening certain synapses. The main reason none of these was done is that  Nahavi's paper is a very poorly-designed piece of junk science, guilty of very bad examples of Questionable Research Practices and an unreliable measurement technique (attempting to judge freezing behavior). 

Some of the defects of the paper are these:

(1) The study group sizes were way too small for any decent statistical power to be claimed. The study group sizes were way-too-small sizes such as only 4 mice or only 6 mice or only 9 mice, and never more than 11. As a general rule, no experimental neuroscience paper should be taken seriously unless it uses at least 15 or 20 subjects per study group; and usually a higher study group size is needed to produce a decent statistical power. 

The authors would have found out that the study group sizes they used were grossly inadequate if they had done a sample size calculation, like good experimental scientists; but they failed to do such a calculation. 

(2) No blinding protocol was used, and no study of this type should be taken seriously unless a rigorous and through blinding protocol was used. 

(3) The study was totally dependent upon a very unreliable method for judging whether mice recalled, the technique of trying to judge "freezing behavior." All studies using such a technique are junk science, for reasons explained at length in my post here. 

When this utterly unreliable technique is used, observers will look at mice, and attempt to judge whether they recalled a fearful stimulus, purely based on the percentage of time that is mouse is immobile, during some arbitrary time length (which can vary between 30 seconds and 180 seconds, based on the arbitrary whim of a researcher).  Such a technique does not reliably measure fear recall in mice. Mice afraid of something are just as likely or more likely to flee as to "freeze" or become immobile. So you cannot reliably tell whether a mouse is recalling something by trying to judge their immobility during some time span, and calling that "freezing behavior." Living a decade in an apartment where mice would appear an average of maybe 5 or 10 times a year, I never once saw a mouse "freeze in fear" when suddenly seeing a human who shrieked at the sight of the mouse. Instead, the behavior would inevitably be a fleeing behavior. 

There are reliable techniques for measuring fear recall in mice. You can measure heart rate, which has a very strong spike when mice are afraid. Or you can use a simple "fear stimulus avoidance" technique like the one shown below. With such a setup, if a mouse recalls a fearful stimulus, it will take the harder path to a food reward; it if does not recall, it will take the easier path. 

Why do neuroscientists continue to use the utterly unreliable method of trying to measure fear recall in rodents by trying to judge "freezing behavior"? Because such a technique is a "see whatever you want to see" type of thing allowing a neuroscientist to report whatever he wants to report. All papers using "freezing behavior" judgments are junk science, including Nahavi's paper. 

(4) We have in the paper claims such as "Mice showed significantly increased freezing response during optical stimulation." The optical stimulation was optogenetic brain-zapping. Mice were brain-zapped, and a claim made that this was producing memory recall of a fearful stimulus, because a mouse was inactive, interpreted as "freezing behavior." But zapping a mouse's brain can itself produce freezing behavior, even when no recall is involved. A science paper says that it is possible to induce freezing in rodents by stimulating a wide variety of regions. It says, "It is possible to induce freezing by activating a variety of brain areas and projections, including the hippocampus (Liu et al., 2012), lateral, basal and central amygdala (Ciocchi et al., 2010); Johansen et al., 2010; Gore et al., 2015a), periaqueductal gray (Tovote et al., 2016), motor and primary sensory cortices (Kass et al., 2013), prefrontal projections (Rajasethupathy et al., 2015) and retrosplenial cortex (Cowansage et al., 2014).”

So any experiment trying to judge recall during brain-zapping (as judged by "freezing behavior") is guilty of doing things in a doubly-unreliable way. Trying to judge recall by judging "freezing behavior" is unreliable by itself; and doing such a thing while zapping a mouse's brain (which can produce freezing behavior by itself) is doubly-unreliable. 

Nahavi's method here seems as silly as that of some scientist who claims that memories are stored in a human's cheek, and who tries to test this claim by giving someone an embarrassing memory and then slapping him hard five times on the cheek, with the scientist claiming that the person's resulting red cheek is caused by stimulation of the memory cells in the person's cheek, which caused a blush after the embarrassing memory was recalled. This would be nonsense. The red cheek could be explained as merely a response to the slapping, without assuming any memory recall. And if mice engage in more "freezing behavior" when brain-zapped, that's just more evidence that brain-zapping tends to cause non-movement or "freezing behavior," not evidence of memory recall.  

What these kind of "memory experiments" mainly tell us about is the rather bad memory of some neuroscientists. 

Another recent example of a neuroscientist making groundless boasts of having done grand things is to be found in the article here. A neuroscientist makes these boasts:

"We wanted to know if there are cells that organise the knowledge of our behaviour, rather than the outside world, and how they work. Specifically, what are the algorithms that underlie the activity of brain cells as we generalise from past experience? How do we rustle up that new pasta dish?

And we did find such cells. There are neurons that tell us 'where we are' in a sequence of behaviour (we haven’t named the cells)."

The neuroscientist is referring to his paper "A cellular basis for mapping behavioural structure," which is an example of a junk science study because of its use of way-too-small study group sizes, and its lack of any blinding protocol.  The study group sizes were merely sizes such as 7 mice, 9 mice and 13 mice, way too small for any decent statistical power. We have in the paper the typical confession that occurs when authors fail to do a sample size calculation. We read, "No statistical methods were used to pre-determine sample sizes but our sample sizes are similar to those reported in previous publications (for example, in ref. 12)."  This is like someone saying "I cheated on my income tax, but it's okay because my friends also cheat on their income taxes."  The use of way-too-small study group sizes is a deplorable epidemic in today's neuroscience research. You do nothing to show that your study group sizes were large enough by claiming that other researchers are also using similar study group sizes. 

Appendix: The statements below show that Nahavi was not correct when he claimed "scientists agree that memories are formed (and lost) by changes in the strength of these synapses—a process known as synaptic plasticity."  There is no such agreement, and in the statements below, scientists express skepticism about such a claim or the claim that scientists know how memories are created. 

• "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). 
• "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). "