How can you determine how seriously scientists believe in something? There are several ways. One way is to look for how much a particular thing is mentioned in articles and papers written by scientists. But that method may not be very reliable, because of sociological effects involving conformity. Within some scientific community, it may become a speech custom to assert the existence of something, even though scientists may not believe very strongly in such a thing.
Another way to try to judge how seriously scientists believe in something is to look for opinion polls taken of scientists. But scientists are very bad about reliably polling themselves about what they think. Opinion polls of what scientists believe are not very often done. When such polls are done, they are usually done poorly. Often the polls will be biased polls that do not offer a fair selection of choices, but offer a choice between some "orthodox" position and a negatively worded "straw man" version of an alternative position. For example, a scientist polled about evolution may be given a choice between believing in the least objectionable statement of evolution ("change over time") versus the least defensible contrarian position. So, for example, the question may ask:
Which do you believe
(A) That mankind evolved over time, or
(B) That mankind was created about 6000 years ago as described in the Bible?
A more fair way to ask such a question would be to pose the question like this:
Please choose one of these answers:
(1) The human species arose by unguided natural processes.
(2) The human species arose because some higher power wanted humanity to exist.
(3) I don't know how the human species originated.
Another problem with polls of scientists is that they are rarely secret ballot polls. If a poll is not a secret ballot poll, a scientist may be unlikely to answer it in any way that he thinks is against the majority opinion of scientists, for fear that he may "get into trouble" by answering in such a way.
Then there is an entirely different way to judge what scientists believe and how strongly they believe in it. That way is to search for what is being funded. Scientists largely control their own funding. Federal agencies such as the National Science Foundation are given budgets, and committees of scientists decide whether particular requests for research funding are approved. If scientists believe strongly in some thing that can be scientifically investigated, they will tend to approve funding to either prove or further investigate that thing. As a general rule, the more funding they approve, the more strongly they believe in such a thing.
The web page here allows you to search grants that have been approved by the National Science Foundation:
Now, let's try a different search. We will look for funded research projects relating to dark matter, a hypothetical type of matter that has never been directly observed. Below is what the search term "dark matter" produces:
Now, let's try a different search. We will look for funded research projects trying to look for proof or evidence that memories are stored in the human brain. The term scientists use to mean a hypothetical spot in the brain where a memory is stored (or some set of brain components believed to be storing a memory) is the term "engram." When that term is used in the NSF grant search tool, we get the result shown below.
There are only 11 results returned by the query, and they are all shown above. Unlike the query about research projects involving dark matter, which produced 59 pages of result, the query about research projects involving engrams produces only a single page of results, consisting of the 11 rows shown above.
Four of these projects are not actually neuroscience projects, but instead computer science projects. Four of the rows refer to different project grants for a project called "Understanding memory in neuronal networks through a brain-inspired spin-based artificial intelligence." One of the projects ("Ice Regime Shifts of Arctic Lakes Drive Interactions and Feedbacks with Permafrost and Climate") only appears in the search results because it mentions someone with a last name of "Engram." So in terms of neuroscience projects involving the brain and attempts to find evidence for engrams, there are only six funded projects.
This is a very low level of funding for the concept of engrams. We may reasonably suspect from such results that perhaps neuroscientists do not even strongly believe in the idea of engrams. Maybe when neuroscientists refer to engrams or claim that memories are stored in brains, they are mainly "paying lip service" to some old idea they do not very strongly believe in. Or maybe neuroscientists have very little confidence in the idea that there can ever occur any discovery of memories stored in brains.
Let's look at the six neuroscience projects that came up in this query.
- Project #2422939: Building a Conceptual Ecology of the Engram. This is a project allocated $208,090. The abstract of the project is laughable, because there are question marks spread all over it, in appropriate places, as if the writer was ridiculously careless. For example, we read this: "Finding the engram ? the neural mechanism of memory retention ? has been a guiding project for neuroscience since its earliest days. But while it has long been assumed that there was an engram, only recently with the development of new tools and technologies have specific engrams been identified and activated." That is not at all correct -- there is no robust evidence that engrams have been identified or activated. The project calls itself a "project in the philosophy of neuroscience." We can classify this as some kind of philosophy project rather than a real neuroscience research project.
- Project # 2337788: A Molecular Pursuit for the Engram: Microfluidic temporal transcriptomics for single cell learning This is a project allocated $300,000. This project is a real neuroscience project, one that is trying to prove a hypothesis that has little support among neuroscientists -- the hypothesis that "RNA encodes memory and learning in single cells." The abstract claims that "studies have shown that RNA holds information that can transfer memories between organisms in multicellular species like C. elegans, Aplysia, flatworms, rats, and fish, challenging a purely synaptic view." We have no mention of specific scientific papers, and the claim is not well-established. It sounds like this project is not one that will involve human memory, and that the scientists will try to show some type of information transfer in animals, something that the scientists might describe as "memory transfer." The project was started in November, 2023, and it has an end date of October 31, 2025. A search for the recent papers of the principal investigator (Saad Bhamla) seems to show no hopeful signs that this project is producing important results.
- Project 2143910: Reward Learning Shapes the Fear Circuit. This is a project awarded about $504,000, with a "total intended award amount" of $1,250,939. The project started in 2022, and has an "estimated completion date" of mid-2024. The abstract starts out by claiming "neuroscience research tends to conceptualize particular brain regions as specialized to encode particular types of memories," but the truth is that neuroscientists lack any understanding of how any part of the brain could encode a memory. The project seemed to be something about challenging existing guesses about which part of the brain encodes a particular memory. The project seems to be finished, and failed to show any evidence for engrams. Unlike the next project mentioned below, the page for this project lists no publications that resulted from the project.
- Project 1845355: Opposing roles of cortical input to dorsal striatum. We have a project awarded $900,000, spread over 2019 to 2023. The project specification makes no mention of the word "engram." The only reason this project has shown up in the search results is that it is supposedly related to a paper "FosGFP expression does not capture a sensory learning-related engram in superficial layers of mouse barrel cortex." which apparently reports a failure to find an engram.
- Project 1743392: Dendritic spine mechano-biology and the process of memory formation. This project was awarded nearly a million dollars. It started in 2017 and ended in 2023. We read, "This research project quantitatively characterizes the relevant molecular processes involved in the dynamical 'tectonic' reorganization inside a dendritic spine involved in forming memories." There is no actual evidence that dendritic spines have anything to do with memory. Tiny bumps on dendrites, dendritic spines look nothing something that could store information. Also, dendritic spines are too unstable and short-lived to be a storage place for memories that can last for decades. We have a list of papers that resulted from the project. None of them sound like anything having much relevance to the topic of engrams or memory storage, except for the paper "Exploring the F-actin/CPEB3 interaction and its possible role in the molecular mechanism of long-term memory," which you can read here. Early on that paper states, "The growth and stabilization of dendritic spines is thought to be essential for maintaining long-term memory." No, the tiny stubs that are dendritic spines bear no resemblance to an information storage device, and dendritic spines are too short-lived and unstable to be something that can explain memories that can last for decades. The paper gives us no observations supporting the claim that dendritic spines have anything to do with memory. Instead it merely provides a " computational structural model of the F-actin/CPEB3-ABD complex." The million dollars spent on this project did nothing to show any neural basis for memory, and did nothing to establish the existence of engrams in the brain.
- "Project 8809208: Functional Dissociation Within the Hippocampal Formation: Learning and Memory." This is a project completed in 1992. It was granted $163,070. We have no mention of any publications that resulted from the research.
There is one other NSF-funded project I am aware of that is related to a search for engrams. $600,000 has been allocated for the project described on this page:
The project (NSF award # 2050850) is one entitled "Elucidation of RNA-Based Mechanisms of Long-Term Memory Storage." The idea of an RNA-based mechanism of long-term memory storage is an absurd one. RNA is a short-lived molecule. Referring to David Glanzman, the project incorrectly states, " the principal investigator has discovered that long-term memory (LTM) in the marine snail Aplysia appears to be stored in neurons by nuclear changes." No such thing has been discovered by Glanzman or anyone else. Glanzman's paper here received lots of press incorrectly talking about a "memory transfer" between marine snails. The paper provided no robust evidence for any such thing, and involved study group sizes of only 7, way too small for a reliable result. A search for David Glanzman's recent papers on Google scholar shows that the NSF award # 2050850 has failed to produce any interesting papers backing up claims of RNA-based mechanisms of long-term memory storage.
Then there is NIH Project # 1DP2MH129985-01 discussed on this page. Having funding of $1,434,188, the project had a title of "The Epigenetic Encoding of Learning and Memory." The project had an end date in 2024, but it did not produce any papers backing up the idea of memory storage in the epigenome, or anywhere else in the brain..
On the same official project page, there is a Publications section that lists 7 publications that resulted from this project (there is a double-listing for one of them). None of them do anything to establish the "epigenetic encoding of learning and memory" mentioned in the project title. The papers are these:
These are all the papers I am able to find searching for research on "engrams" funded by the National Science Foundation (I have added a couple of other projects I knew of that could have appeared in such a search if the word "engram" had appeared in their abstracts). Although adding up to a total funding of several million dollars, the funding is relatively little, compared to the money spent on other things scientists believe in, such as dark matter. The number of projects looking for proof of engrams is small, with only a tiny number of scientists doing such research. - "Control of striatal circuit development by the chromatin regulator Zswim6" (link). This paper makes no mention of memory or learning.
- "Histone variant H2BE enhances chromatin accessibility in neurons to promote synaptic gene expression and long-term memory" (link). The study provided no good evidence to back up its claim that H2BE has any relation to memory. To test the claim, the study produced "H2BE knockout" mice, whose performance was compared to normal test mice. The first test used was a "novel object recognition" test that is not an effective way of judging animal memory when a blinding protocol is not followed. In the test scientists attempted to judge how much time a mouse spends exploring a type of object it has already been exposed to, using manual scoring -- we are told "Time spent interacting with each object was manually analyzed." Such a test is not a reliable way of judging memory in rodents whenever there is a failure to follow a blinding protocol, and no mention is made that a blinding protocol was followed. The second test used was a test requiring a judgment of "freezing behavior," and such tests are utterly reliable in judging whether an animal recalled, for reasons discussed at length here.
- "A nociceptive amygdala-striatal pathway for chronic pain aversion" (link). No mention is made of learning or memory in this paper.
- "Loss of DOT1L function disrupts neuronal transcription, animal behavior, and leads to a novel neurodevelopmental disorder" (link). The authors first discuss 11 humans who had variations in something called DOT1L The paper claims that 2 of these 11 had "intellectual disability" without giving us any specifics. This does not constitute any evidence of a relation between this DOT1L and memory. The paper also claims that DOT1L modification in zebrafish had some effect on their cognitive performance. But the claim has no clear reference to memory, and the claim is not demonstrated, because the number of zebrafish tested is way too small, being only 3 zebrafish. There is then a claim that DOT1L modifications have some effect on mice. But no clear claim is made of an effect on memory performance.
- "Histone variant H2BE controls activity-dependent gene expression and homeostatic scaling" (link). The research discussed does not involve learning or memory.
- "SARS-CoV-2 disrupts host epigenetic regulation via histone mimicry" (link). The research discussed does not involve learning or memory.
- "Identification of a transcriptional signature found in multiple models of ASD and related disorders" (link). The research discussed does not involve learning or memory. It merely makes a passing reference to memory, claiming (without providing any specifics) that a "histone code" plays a role in memory.
It's rather as if deep down inside, neuroscientists scarcely even believe in engrams, or as if deep down inside, neuroscientists know that any project looking for proof of engrams will be extremely unlikely to succeed. Maybe some part of their minds have figured out that if it was really true that brains stored memories, microscopes would have discovered proof of that decades ago.
The decisions scientists make about what to fund is a factor speaking in a louder voice than what scientists claim about what scientists believe. The weak funding scientists have given to searches for proof of engrams may suggest that neuroscientists do not really have high confidence in the idea that memories are stored in brains. The weak results of the small number of projects related to claims of brain storage of memories (engrams) suggest that research into this area is futile in terms of substantiating claims of a brain storage of memories.
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