HSAM Memory Whiz Subjects Scored 25 Times Higher on a Random Dates Test

 In my previous post on this blog "The Rare 'Total Recall' Effect That Conflicts With Brain Dogmas," I discussed some fascinating cases of what is called hyperthymesia or Highly Superior Autobiographical Memory (HSAM). People with this rare ability have an extraordinary ability to recall things that happened in their lives -- an ability seemingly many times greater than that of the average person.  Some have suggested that HSAM cases can be explained as being merely the result of superior mnemonic techniques. Others have suggested that press reports about this topic are just exaggeration or sensationalism. But a scientific paper documents the dramatic reality of  Highly Superior Autobiographical Memory (HSAM). The paper documents that certain people have memory about past events that is literally dozens of times better than the average person has. 

The paper (which can be read here) is a 2022 paper entitled "Individuals with highly superior autobiographical memory do not show enhanced creative thinking." The paper gives us this description of the memory tests given to 14 subjects with  Highly Superior Autobiographical Memory (HSAM), and also twenty-eight normal control subjects:

"We assessed participants’ ability to recollect public and personal past events using the Public Event Quiz and the Random Dates Quiz (LePort et al., 2012). The Public Events Quiz consisted of thirty questions, based on public events selected from five categories: sporting events, political events, notable negative events, events concerning famous people and holidays. For fifteen of these questions, participants were asked to retrieve the date of a given significant public (national or international) event (e.g., 'Please give the day of the week and precise date with day, month and year of when Federica Pellegrini, the famous Italian swimmer, won the gold medal at the Olympic game in Beijing'); the remaining fifteen questions requested participants to associate a given date with a highly significant public event (e.g., 'What happened on the 25th of June 2009?'). All questions concerned events that took place when the participants were at least 8 years old. For each question, individuals were asked to name the day of the week on which the date fell. One point was awarded for each correct response (i.e., the event, the day of the week, the month, the date and the year); the maximum total score was 88 points. The Random Dates Quiz consisted of ten computer-generated random dates, ranging from the individuals’ age of fifteen to five years before the testing. Individuals were asked to provide three details for each date: (1) the day of the week; (2) a description of a verifiable event (i.e., any event that could be confirmed via a search engine) that occurred within a few days before and after the generated date; (3) a description of a personal autobiographical event. One point each was awarded for the correct day of the week, a correct public event, and unverified personal autobiographical memory. A maximum of three points per date could be achieved (30 points total)." 

The results were spectacular.  The 14 subjects with Highly Superior Autobiographical Memory (HSAM) scored more than 25 times higher on the Random Dates test, scoring an average of 68.57% of the maximum possible.  The control subjects scored an average of merely 2.62% of the maximum possible on the Random Dates test. On the Public Events test, the 14 subjects with Highly Superior Autobiographical Memory (HSAM) scored more than 5 times higher, scoring an average of 58.20% of the maximum possible. The control subjects scored an average of merely 10.39% of the maximum possible on the Public Events test. The best-performing of the 14 subjects with Highly Superior Autobiographical Memory (HSAM) scored 96.67% of the maximum possible, an almost perfect score. 

The diagram below (from the paper) shows the differences, with the HSAM subjects being the two tall bars, and the control subjects being the two short bars. The squares are the results for individual subjects. 

Conversely, tests on other abilities not related to memory (such as creativity) showed no big differences in performance between the two groups. 

We have in this paper proof of the claim that certain rare individuals have a dramatically superior ability to recall the past, an ability vastly better than the average person has.  Cases such as these are evidence against claims that memory is mostly a neural phenomenon.  If memory was mostly a neural phenomenon, we would expect that only vast differences in brains could produce vast differences in memory performance. But those with Highly Superior Autobiographical Memory have brains that do not substantially differ from those with ordinary memories.  Read my post here for a discussion of two studies that attempted to show differences in the brains of those with Highly Superior Autobiographical Memory, but actually failed to show any major differences. The same post has a very interesting discussion of numerous memory marvels with recollection abilities as impressive as those with Highly Superior Autobiographical Memory. 

The normal facts of human memory performance are sufficient to discredit claims that memory formation and memory recall are brain activities. There is not a neuroscientist who can credibly explain how a brain can store a detailed memory.  Nothing known to neuroscientists can explain how learned information or experiences could be translated into brain states or synapse states. Neuroscientists claim that memories are stored in synapses, but we know that the proteins in synapses have average lifetimes of only a few weeks, 1000 times shorter than the maximum length of time that humans can remember things (more than 50 years).  We know the kind of things  (in products that humans manufacture) that make possible an instant retrieval of stored information: things such as sorting, addressing, indexing, and read/write heads.  The human brain has no such things.  Humans such as actors playing the role of Hamlet can recall large bodies of text with 100% accuracy, but such recall should be impossible using a brain in which each chemical synapse can only transmit a signal with 50% accuracy or less.  Brains are too slow, too noisy and too unstable to be the source of human memory recall which can occur at blazing fast speeds with 100% accuracy. 

Here are some relevant quotes:

• "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). 
• "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).
• "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." 

Every additional piece of evidence establishing extraordinary human memory abilities is an additional nail in the coffin of the doctrine that brains store memories. Given a brain lacking any of the characteristics that would be required to allow the best examples of human memory performance, the credibility of the claim that brains store memories is inversely proportional to the highest observed speed, accuracy, duration and depth of human memory performance.  The longer humans can remember things and the more they can remember and the more quickly they can remember and the more quickly they can form new memories, the less credible are claims of brain memory creation and storage. 

Below is an account of the memory of Antonio Magliabechi, from page 8 of the periodical here:

 "Magliabechi was born at Florence in 1633. His parents were of mean rank and estate. Being taken into the service of a bookseller, a passion for reading took possession of him, and a prodigious memory ensued. He read every book that came into his hands with surprising quickness, and yet retained not only the sense, but often all the words. His extraordinary talent soon obtained for him an appointment under the great Duke’s librarian. A trial of his surprising powers was once made. A gentleman in Florence had written a piece which was to be played. He lent it to Magliabechi, and some time after it had been returned he came with a long face to Magliabechi, and, seeming almost inconsolable, asked if he would try to recollect as much as he could, and write it down. Magliabechi assured him he would, and on setting about it wrote out the entire play without missing a word. By treasuring up everything he read, his head at last became an universal index both of titles and matter. When a priest was going to compose anything about a favourite saint, Magliabechi could at once tell him what everybody had written about that saint, and refer to the authors. The Grand Duke Cosmo III made him his librarian. Here he had immense facilities for reading, but ultimately he was dissatisfied, for he had read almost everything ever written or printed, it being a custom for most authors to send him a copy. He not only knew the contents of books, but the very place on the very shelf where they stood in the great libraries of Europe. The grand duke asked if he could get a certain book that was particularly scarce : ' No, sir,'  answered Magliabechi, ' it is impossible, for there is but one in the world, and that is in the Grand Signor’s library at Constantinople, and is the seventh book on the second shelf, on the right hand as you go in.' " 

Another source says this of Magliabechi: "He not only knew all the volumes in the library, as well as every other possible work, but could also tell the page and paragraph in which any passage occurred."

According to a book, "The great thinker, Pascal, is said never to have forgotten anything he had ever known or read, and the same is told of Hugo, Grotius, Liebnitz, and Euler. All knew the whole of Virgil's 'Aeneid' by heart." The famous conductor Toscanini was able to keep conducting despite bad eyesight, because he had memorized the musical scores of a very large number of symphonies and operas. 

A book tells us this: 

"The geographer Maretus, narrates an instance of memory probably  unequalled. He actually witnessed the feat, and had it attested by four Venetian nobles. He met in Padua, a young Corsican who had so powerful a memory that he could repeat as many as 36,000 words read over to him only once. Maretus, desiring to test this extraordinary youth, in the presence of his friends, read over to him an almost interminable list of words strung together anyhow in every language, and some mere gibberish. The audience was exhausted before the list, which had been written down for the sake of accuracy, and at the end of it the young Corsican smilingly began and repeated the entire list without a break and without a mistake. Then to show his remarkable power, he went over it backward, then every alternate word, first and fifth, and so on until his hearers were thoroughly exhausted, and had no hesitation in certifying that the memory of this individual was without a rival in the world, ancient or modern." 

The scientific paper "Extremely long-term memory and familiarity after 12 years" documents an ability of some people to remember trivial sensory experiences after many years, experiences they should have forgotten under common ideas of human memory. In 2016 the study authors rounded up 25 subjects who had been briefly exposed to some very forgettable images in a scientific experiment done between eight and fourteen years earlier: thumbnail-sized images such as a little drawing of a coffee cup and a little drawing of a hen.  The subjects were tested with a set of images, half of which were the original images, and half of which were decoy images designed to be similar to the original images. The subjects were asked to guess whether or not they had seen the images before, when they were tested many years earlier. The authors expected the subjects to make guesses no more accurate than chance. But they found that the subjects were able to guess with about 55% accuracy.  We read this:

"In this study we found that our group of test participants was able to recognize simple colored pictures seen for a few seconds between eight and 14 years earlier. Our best performer, who had been exposed to the pictures at most three times, was able to identify 15 pictures more than the 84 pictures expected by chance. Note that no instruction to learn the stimuli was ever given to the subjects, even at initial encoding, which makes this performance even more remarkable."