Subject MM Had a Stupendous Memory for Facts, But a Normal Brain

People with what is called Highly Superior Autobiographical Memory (HSAM) have the very rare ability to recall with astonishing detail things that happened almost every day throughout their adult 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 (discussed in my post here) 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. 

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 (HSAM). The 2024 paper here says, "Structural neuroanatomical differences do not appear to characterise HSAM."

In the paper "Remarkable Cases of Memory" by W.D. Henkle in The Journal of Speculative Philosophy, Vol. 5, No. 1 (January, 1871), we read many accounts of people with memories far greater than that of the average man. Here is one account:

"Casaubon thus speaks of Joseph Scaliger: 'There was no subject in which any one could desire instruction which he was not capable of giving. He had read nothing (and what had he not read?) which he did not forthwith remember; there was nothing so obscure or obsolete in any ancient author, Greek, Latin, or Hebrew, with regard to which, when interrogated, he could not at once give a reply. He was at home in the history of all nations and all ages, the successions of government, the affairs of the ancient church; the properties, differences, and names, whether ancient or modern, of animals, plants, metals, and all natural objects, he knew accurately. With the situations of places, the boundaries of provinces, and their division at different times, he was perfectly familiar. He had left untouched none of the severer studies or sciences. So extensive and accurate was his acquaintance with languages, that if, during his lifetime, he had made but this single acquirement, it would have appeared miraculous. He committed [to memory] Homer in twenty-one days, the other Greek writers inside of two years. Sir Wm. Hamilton says, 'taking him all in all, he was the most learned man the world has ever seen. ' "

Later in the same article Henkle states this:

"Seneca, the rhetorician, says that he could repeat in order two thousand names read to him, and that he repeated in reverse order two hundred unconnected verses that had been pronounced by the pupils of his preceptor. Muretus says that he discredited this story until he tested Molino, a young Corsican, residing at Padua as a student of civil law. In the presence of a considerable number of distinguished persons in a saloon, Muretus began to dictate words, Latin, Greek, barbarous, significant and non-significant, disjoined and connected, until he wearied himself, the young man who wrote them down, and the whole company, all becoming marvellously tired, Molino alone alert and fresh wanted more words. Muretus said that he would be satisfied if he repeated half of what had been taken down. Molino, after a brief pause, repeated the words in exact order and without the slightest hesitation, and then repeated them backwards. Next he gave the first, third, fifth, and so on. He repeated them exactly in any order asked. He declared that he could repeat in this way 36,000 words, and remember them a year. ...Dr. Leyden could repeat a long act of parliament, or any similar document, after having once read it; but he could not recollect a particular point without repeating the whole. "

The highlight of the paper is Henkle's discussion of the case of Daniel McCartney, a most astonishing triple-savant with the ability to recall events from his life on any random day, along with the day of the week and weather on any such date, along with a super-human seeming math calculation ability. Henkle documented the case very well by making transcripts of three interviews he had with McCartney. The case is summarized in my previous post here. 

The 2018 paper "Neuropsychological Investigation of 'The Amazing Memory Man' ” documents the case of a subject MM, a 63-year-old man with astonishing abilities of factual recall but only average intellect. We read this about the subject:

"He has a phenomenal memory for events and dates from his personal past, but only average performance on clinical tests and laboratory tasks of new learning capacity. He does not try to memorize material or employ specific mnemonic strategies. These features make MM and other HSAM subjects different from contestants in national and international memory competitions (Maguire et al., 2003; “U.S.A. Memory Championship,” 2016; “World Memory Championship,” 2016)....MM differs from other HSAM subjects in that his extraordinary memory applies to historical events that he did not personally experience (including those long before his birth) and to general world knowledge. Most HSAM subjects have little interest in thinking about events from dates before they were born (McGaugh & LePort, 2014). Thus, the range of material for which MM has exceptional memory appears to be much broader than that of HSAM subjects previously described (see Table 3). "

According to Table 2 of the paper, his autobiographical memory was very good, with him scoring 100% on most aspects of a test. We read the following:

• Recalling previous addresses lived during his lifetime, subject MM could "confidently recall the address of all of his 15 homes, occasionally forgetting only zip codes."
• "He [was] able to recall all 44 presidents, in reverse order and without error, but he often sprinkled his reporting with amusing esoterica about them." The average college student will recall only about 19 of them. 
• "MM was given 30 random dates (e.g., February 20, November 12), and asked to describe the importance of that date in history. Well-known holidays and other dates of historic significance (e.g., July 4, September 11) were avoided. An informal survey of our colleagues produced zero correct responses. MM was successful for 27 of the 30 dates. He often produced more than one correct historical fact for each date, and he occasionally supplemented these with personal memories." 
• " Asked to provide one-word answers to 75 world knowledge questions," MM got 63% correct.  As shown in Figure 3, his performance was about twice as good as college students on the easy questions, ten times as good as the college students on the medium-hard questions, and 25 times as good as the college students on the hard questions. 
• "MM was asked to match the title of each year’s Academy Award-winning Best Picture with the year that it won the award," and answered perfectly for every year between the early 1940's and the early 1990's. 

Subject MM said that his parents had normal memory powers, which argues against any idea that memory abilities such as his have a genetic or neural basis. The authors had the subject undergo 2 MRI brain scans. The authors failed to find anything that might constitute a brain explanation of why MM had such superior memory. A few differences from average are reported here and there, but you will get a few differences from average here and there when you scan the brain of a randomly chosen person and compare it to each of a hundred structural averages in human brains.  We read this:

" Standard clinical evaluation of MM’s brain MRI images revealed no structural abnormalities. In addition, MM’s total brain and hippocampal subregion volumes were unremarkable. This is consistent with most of the previous literature. Although Maguire and colleagues (Chadwick, Bonnici, & Maguire, 2014) found that volume of hippocampal subregion CA3 was associated with degree of confusion about past memories in normal subjects, they also found that winners of international memory competitions had undistinguished brains on structural MRI scans (Maguire et al., 2003)." 

A report such as this is quite consistent with my claim that the brain is not any storage place of human memories, and that memory is not a brain activity. 

The page here tells us of a man who despite a severe intelligence defect (described as "high-grade amentia") had a very-far-above-normal ability to accurately remember biographical details:

"At the present time there are two such in Earlswood Asylum. One of them is a man, sixty-five years of age, suffering from high-grade amentia, whose penchant is biographical history. It is only necessary to mention to him the name of any prominent personage in early or ancient history, and out there flows in a steady, unhesitating stream a full and detailed account of his birth, life, and death. His knowledge has been acquired by poring over biographical details in such books as were available, and is, of course, simply a matter of memory. It is not, however, merely repetitive, for he stands cross-questioning in a manner which shows that he has some knowledge, although not full understanding, of the occurrences he is talking about."

HSAM Wonder Daniel McCartney Was a Math and Memory Marvel

The credibility of claims that memory recollections come from brains is inversely proportional to the speed and capacity and reliability at which things can be recalled. There are numerous signal slowing factors in the brain, such as the relatively slow speed of dendrites, and the cumulative effect of synaptic delays in which signals have to travel over relatively slow chemical synapses (by far the most common type of synapse in the brain). As explained in my post here, such physical factors should cause brain signals to move at a typical speed very many times slower than the often cited figure of 100 meters per second: a sluggish "snail's pace" speed of only about a centimeter per second (about half an inch per second).  Ordinary everyday evidence of very fast thinking and instant recall is therefore evidence against claims that memory recall occurs because of brain activity, particularly because the brain is totally lacking in the things humans add to constructed objects to allow fast recall (things such as sorting and addressing and indexes). Chemical synapses in the brain do not even reliably transmit signals. Scientific papers say that each time a signal is transmitted across a chemical synapse, it is transmitted with a reliability of 50% or less.  (A paper states, "Several recent studies have documented the unreliability of central nervous system synapses: typically, a postsynaptic response is produced less than half of the time when a presynaptic nerve impulse arrives at a synapse." Another scientific paper says, "In the cortex, individual synapses seem to be extremely unreliable: the probability of transmitter release in response to a single action potential can be as low as 0.1 or lower.")  The more evidence we have of very fast and very accurate and very capacious recall (what a computer expert might call high-speed high-throughput retrieval), the stronger is the evidence against the claim that memory recall occurs from brain activity. 

It is therefore very important to collect and study all cases of exceptional human memory performance. The more such cases we find, and the more dramatic such cases are, the stronger is the case against the claim that memory is a neural phenomenon. Or to put it another way, the credibility of claims that memory is a brain phenomenon is inversely proportional to the speed and reliability of the best cases of human mental performance.  The more cases that can be found of humans that seem to recall too quickly for a noisy address-free brain to do ever do, or humans that seem to recall too well for a noisy, index-free, signal-mangling brain to ever do,  the stronger is the case that memory is not a neural phenomenon but instead a spiritual or psychic or metaphysical phenomenon.  

In the paper "Remarkable Cases of Memory" by W.D. Henkle in The Journal of Speculative Philosophy, Vol. 5, No. 1 (January, 1871), we read many accounts of people with memories far greater than that of the average man. Here is one account:

"Casaubon thus speaks of Joseph Scaliger: 'There was no subject in which any one could desire instruction which he was not capable of giving. He had read nothing (and what had he not read?) which he did not forthwith remember; there was nothing so obscure or obsolete in any ancient author, Greek, Latin, or Hebrew, with regard to which, when interrogated, he could not at once give a reply. He was at home in the history of all nations and all ages, the successions of government, the affairs of the ancient church; the properties, differences, and names, whether ancient or modern, of animals, plants, metals, and all natural objects, he knew accurately. With the situations of places, the boundaries of provinces, and their division at different times, he was perfectly familiar. He had left untouched none of the severer studies or sciences. So extensive and accurate was his acquaintance with languages, that if, during his lifetime, he had made but this single acquirement, it would have appeared miraculous.' He committed [to memory] Homer in twenty-one days, the other Greek writers inside of two years. Sir Wm. Hamilton says, 'taking him all in all, he was the most learned man the world has ever seem. ' "

Henkle then documents in the greatest detail the extraordinary memory and calculation abilities of Daniel McCartney, born in Pennsylvania, USA on September 10, 1817. Henkle gives a transcript of the second interview he had with Daniel McCartney. In the interview Henkle would ask about random dates in the past Henkle had selected. The numbers in parentheses before the answers are how long a delay before the answer was given.  We may presume that Henkle knew stenography or had a stenographer with him. Before the advent of tape recording, stenography was a skill allowing you to write down exactly what someone was saying, even if he talked at a normal pace. 

Q. October 8,1828?

A. (2 seconds.) Wednesday. It was cloudy and drizzled rain. I carried dinner to my father where he was getting out coal.

Q. February 21, 1829 ?

A. (2 sec.) Saturday. It was cloudy in the morning, and clear in the afternoon ; there was a little snow on the ground. An uncle who lived near sold a horse-beast that day for $35.

Q. October 13,1851 ? 

A. (15 sec.) Monday. It was kinder [sic] pleasant-like weather. I stayed all night Sunday night at my brother's, and next day I went to the depot in Cardington to saw wood.

Q. July 1, 1863 ?

A. (1 sec.) Wednesday. Sultry and cloudy. I kept the baby of the family I lived with, while the man and his wife went to Tipton to buy goods. "

All of the days of the week were correct. Below is another section of the interview. 

"Q. March 5, 1849?'

A. (2 sec.) Monday. It was a disagreeable sloppy day. Gen. Taylor was inaugurated that day. I heard at the time, that the Bible Washington was sworn in on was carried from New York to Washington to use at Taylor's inauguration.

Q. April 15, 1861 ?

A. (3 sec.) Monday. It was bright and clear. Fort Sumter was taken the Friday before. I was cutting stove wood for a man.

Q. May 8,1846?

A. (2 sec.) Friday. It rained some. The Saturday before, I attended a quarterly meeting in Iberia. [He is a Methodist.]

Q. December 2,1859 ?

A. (2 sec.) Friday. It was very cold and raw. On the Tuesday before, it began to grow very cold, and continued cold until Saturday, when it began to moderate. John Brown was hanged on the 9th, a week later.

 Q. Are you certain?

A. I am not positive.

 Q. Do you remember anything in particular that occurred that day? 

A. Nothing particular. I remember it was pretty cold getting in wood.

Q.. April 12,1861?

A. (2 sec.) Friday. It was pleasant but cloudy. I went from Wilton to my brother's, ten miles away. 

Q. What else happened that day ? 

A. Fort Sumter was taken

Q. April 9,1865?

A. (5 sec.) Sunday. It was cloudy in the afternoon. Lee surrendered that morning.

The days of the week McCartney gave are all correct. His statements about the inauguration of  General Zachary Taylor and the capture of Fort Sumter are correct. The only mistake he made is that when given the date that John Brown was hung, he has mentioned the hanging of John Brown, but incorrectly stated that it was a week later. 

Below is another section of the interview:

Q. December 28,1835?

A. (2 sec.) Monday. Cool but pleasant. We were chopping in the clearing, and came near falling [felling] a tree on one of the boys.

Q. June 15,1836?

A. (2 sec.) Wednesday. It was very clear, hot weather. The folks that I lived with had a swarm of bees that day.

Q. December 25, 1837?

A. (2 sec.) Monday, Christmas day. It was raw, but not very cold. My father was buried that day.

Q. April 4,1841 ?

A. (3 sec.) Sunday. It was rainy and muddy. Gen. Harrison died that day.

Q. July 21,1861 ?

A. (2 sec.) Sunday. Very hot and sultry. It was the day of the Battle of Bull Run.

The days of the week given were all correct. April 4, 1841 was the date of the death of General Harrison (US president William Henry Harrison), and July 21, 1861 was the date of the Battle of Bull Run. 

Below is another section of the interview:

Q. What is 32 times 45?

A. (2 sec.) 1440. I multiplied by 5 and then by 9.

Q. What is 93 times 97?

A. (12 sec.) 9021. From 9300 I took away 3 times 93.

Q. What is 53 times 84?

A. (8 sec.) 4452. Twice 53 is 106 ; 10 times 106 is 1060 ;

adding 53 gives 1113; multiplying by 4, 4452.

Q. What is 123 times 456 ?

A. (35 sec.) 56,088. Multiply 456 by 100 ; then 23 by 400 ;

then add; multiply 23 by 56 and add.

Q. What is 3756 times 182 ?

A. (4.5 minutes. He became confused.) 683,592.

Q. What is the sum of 26, 67, 43, 38, 54, 62, 87, 65, 53, 44,

77, 33, 84, 56 and 14 ? (One minute occupied in calling the

numbers.)

A. (Instantly.) 803

The answers given are all correct. Later in the interview McCartney is asked "How do you bound Tennessee?"  He gives this completely correct answer: "It is bounded on the north by Kentucky and a small part of Virginia, on the east by North Carolina, on the southeast by Georgia, on the south by Alabama and Mississippi, and on the west by Arkansas and a small portion of Missouri." The answer suggests something like a photographic memory. 

We then have a transcript of McCartney being asked about many random dates during the past few decades, and in each case he correctly gives the day of the week, and recalls various things about what he was doing on that date. On page 21 we have some more math questions:

• He is asked what is the cube root of 59,319, and in 30 seconds gives the correct answer of 39. 
• He is asked the cube root of 76,507, and in 17 seconds gives the correct answer of 43.
• He is asked the cube root of 117,649, and in 5 seconds gives the correct answer of 49, saying that he knew that long ago. 
• He is asked the cube root of 571,787, and in 15 seconds gives the correct answer of 83.  
• He is asked the cube root of 357,911 and in 15 seconds gives the correct answer of 71.
• He is asked the cube root of 110,592 and in 2 seconds gives the correct answer of 48.
• He is asked the cube root of 389,017 and in 15 seconds gives the correct answer of 73.
• He is asked the cube root of 4,741,632 and in 3.5 minutes gives the correct answer of 265.  

Henkle had a third interview with McCartney, and asked him about the same dates that he had previously asked about. This was an excellent way to see whether the claimed recollection of things McCartney did on a day long ago were actual recollections and not confabulations.  McCartney passed this test well. Henkle states this:

"In this review Mr. McCartney reproduced his answers as to dates, kind of weather, and circumstances, with the exceptions given below. His description of the weather was in other words, but in every case essentially the same, thus showing that he remembered distinctly the facts but not the words that he had previously used. The same may be said as to his reproduction of circumstances. In some cases he expanded the accounts, and in others he shortened them. Some of the days of the week were given in a shorter time and others after a longer time than on his first examination."

Henkle then discusses some minor differences in the recollections about what the weather was on some particular day and what McCartney was doing, but they seem to be no more than what you would get from a minor narrative variation in what you get from someone with the same memory. 

Cases such as the case of Daniel McCartney intensify the explanatory shortfall of "brains make minds" explanation and "brains store memories" explanation. We have here a case of lightning-fast mathematical calculation ability and lightning-fast autobiographical recall stretching back decades. Given the high number of brain physical shortfalls, neural explanations cannot account for the mental abilities of ordinary people. When we look cases such as that of Daniel McCartney, the failure of neural explanations to credibly account for human mental abilities becomes all the more obvious. 

The paper discussed above (the paper "Remarkable Cases of Memory" by W.D. Henkle) may have been the first paper ever documenting the phenomenon of Highly Superior Autobiographical Memory (HSAM, also called hyperthymesia). In recent decades many other cases have been documented of HSAM subjects (such as Jill Price) with the ability to recall almost every day of their adult lives. You can read about some of the cases in my series of posts here. A scientific paper documented the ability of such HSAM subjects to score 25 times higher on a random dates test than control subjects. 

 In the 1972 book "Coding Processes in Human Memory" we have a  chapter entitled "How Good Can Human Memory Be?" written by Earl Hunt and Tom Love of Washington University.  Registered users at www.archive.org can read the whole chapter using the link here. The authors start telling us about a subject they studied who they call VP. We are told VP was born in Latvia in 1935, and that by the age of five he had memorized the street map of Riga, a city of 500,000.  We are told he could play up to 60 games of chess simultaneously by correspondence, without consulting written records. 

The authors did tests on VP. The most impressive result is the result shown below, in which VP manages to recall a short story almost verbatim an hour after reading it twice, and also six weeks later, even though he had not been told he would be tested on the story a second time. The story was one notable for being hard-to-remember.

At the end of the chapter, we are given the text of the story, VP's first recollection of it, and the recollection six weeks later. The story is about 350 words long. Here is one example of how good the recollection was. The story begins, "One night two young men from Eugulac went down to the river to hunt seals, and while they

were there it became foggy and calm." An hour later VP recalls all words of this sentence in correct order, missing only the "and." Six weeks later VP recalled the same sentence exactly as well as he did the first time. 

Newspaper Accounts of Memory Marvels (Part 3)

The credibility of claims that memory recollections come from brains is inversely proportional to the speed and capacity and reliability at which things can be recalled. There are numerous signal slowing factors in the brain, such as the relatively slow speed of dendrites, and the cumulative effect of synaptic delays in which signals have to travel over relatively slow chemical synapses (by far the most common type of synapse in the brain). As explained in my post here, such physical factors should cause brain signals to move at a typical speed very many times slower than the often cited figure of 100 meters per second: a sluggish "snail's pace" speed of only about a centimeter per second (about half an inch per second).  Ordinary everyday evidence of very fast thinking and instant recall is therefore evidence against claims that memory recall occurs because of brain activity, particularly because the brain is totally lacking in the things humans add to constructed objects to allow fast recall (things such as sorting and addressing and indexes). Chemical synapses in the brain do not even reliably transmit signals. Scientific papers say that each time a signal is transmitted across a chemical synapse, it is transmitted with a reliability of 50% or less.  (A paper states, "Several recent studies have documented the unreliability of central nervous system synapses: typically, a postsynaptic response is produced less than half of the time when a presynaptic nerve impulse arrives at a synapse." Another scientific paper says, "In the cortex, individual synapses seem to be extremely unreliable: the probability of transmitter release in response to a single action potential can be as low as 0.1 or lower.")  The more evidence we have of very fast and very accurate and very capacious recall (what a computer expert might call high-speed high-throughput retrieval), the stronger is the evidence against the claim that memory recall occurs from brain activity. 

It is therefore very important to collect and study all cases of exceptional human memory performance. The more such cases we find, and the more dramatic such cases are, the stronger is the case against the claim that memory is a neural phenomenon. Or to put it another way, the credibility of claims that memory is a brain phenomenon is inversely proportional to the speed and reliability of the best cases of human mental performance.  The more cases that can be found of humans that seem to recall too quickly for a noisy address-free brain to do ever do, or humans that seem to recall too well for a noisy, index-free, signal-mangling brain to ever do,  the stronger is the case that memory is not a neural phenomenon but instead a spiritual or psychic or metaphysical phenomenon.  In part 1  and part 2 of this series, I gave many newspaper clips giving examples of such exceptional human memory performance. Let us now look at some more of such newspaper clips. 

In the newspaper account below from 1890, we seem to have an account of what is now called Highly Superior Autobiographical Memory, something that reportedly dozens of people around the world have.  We read this:

"Prof. Henkle makes mention of a remarkable character whom he  met at Salem, Mass., in I868, Daniel McCartney by name. McCartney was 51 years of age at that time, but proved to the satisfaction of Mr.  Henkle that he could remember where he had been, the state of the weather, etc., for each day and hour since he was 9 years old; dates covering a period of forty-two years! These remarkable feats were proved and verified by weather records and newspaper files kept in the city, and of the hundreds of tests resorted to to try his powers be never failed of proving himself a wonder of wonders in a single instance."

The account can be read here:

https://cdnc.ucr.edu/?a=d&d=PWA18901025.2.10&srpos=1&e=-------en--20--1--txt-txTI-memory+prodigy-------

I have found the original source for this claim, a paper that documents the case in the greatest detail.  It is the paper "Remarkable Cases of Memory" by W.D. Henkle in The Journal of Speculative Philosophy, Vol. 5, No. 1 (January, 1871). Henkle gives transcripts of several interviews he had with Daniel McCartney, and documents the most extraordinary ability of him to do "in his head" very quickly very hard math problems, as well as his ability to correctly tell the day of the week and weather of random dates long ago, and what he what was doing on such dates, and whether any important news event occurred on such dates. Henkle verified the correctness of the recollections of the weather and what McCartney was doing by asking McCartney on different days about the same dates, and checking whether the answers given were consistent. 

In the newspaper story here, we read of a 90-day scripture memorization contest. We read this about the winner:

"On the day of the award it was found that among the older competitors the winner was Miss Leste May Williams, a young woman 16 years of age. With these ninety days, during which she had an attack of measles, she committed to memory and recited to the committee 12,236 verses of Scripture, covering the entire New Testament ...and including liberal selections from Genesis, Psalms, Ecclesiastes and other parts of the Old Testament."

Aitken and JB  performed similar feats when they memorized epic poems of about 10,000 lines, as did George Vogan de Arrezo, who memorized the entire text of Virgil's Aeneid (consisting of 9,896 lines. The New Testament has about 180,000 words, so the feat of Leste May Williams would seem to be far more impressive than the memorization of Virgil's Aeneid, which has only 63,719 words.  At the link here, the claim is made that "Indian youths have more than once repeated the whole New Testament," a feat matching the feat attributed to Leste May Williams in the quote above. 

Below is a description in a newspaper account of memory marvels of ancient times:

You can read the account here:

https://chroniclingamerica.loc.gov/lccn/sn82016339/1904-01-15/ed-1/seq-7/

An 1895 newspaper account tells us this:

The same article tells us this about a man who must have known the meaning of at least a million words in many different languages:

You can read the full account below:

https://chroniclingamerica.loc.gov/lccn/sn82015104/1895-04-18/ed-1/seq-6/

Below is a newspaper account of a young girl with remarkable powers of memory:

"Miss Gussie Cottlow, of Chicago, gave an entertainment at the Presbyterian Church Tuesday evening, under the

auspices of the Y. P. S. C. E. She is called

the child pianist and is only twelve years

old. She played the  most difficult pieces from the great composers without a note before her, thus displaying in addition to

her wonderful execution a power of memorization that is in itself a marvel."

You can read the account here:

https://chroniclingamerica.loc.gov/lccn/sn82015679/1891-05-31/ed-1/seq-14/#

The 1948 newspaper story below discusses a 10-year-old boy (Pierino Gamba) who had apparently memorized dozens of long orchestral works, well enough to conduct them from memory. We are told he knew "33 complete works by memory."

You can read the account of Gamba here:

https://chroniclingamerica.loc.gov/lccn/sn86075258/1948-09-22/ed-1/seq-6/

In the 1947 newspaper account here, we have another mention of Pierino Gamba. We see the young boy conducting an orchestra, and we see no musical score in front of him:

 It is known that the great Italian conductor Arturo Toscanini had a similar ability. According to the 1920 newspaper article here, he had so well-memorized 150 opera scores that he "never even glances at a score when conducting." During his later conducting years Toscanini's eyesight was too bad for him to read a musical score in front of him. He was able to continue conducting many symphonies and operas, because he had memorized their musical scores. The Encyclopedia Britannica article on Toscanini says, "His phenomenal memory stood him in good stead when, suffering from poor eyesight, he was obliged always to conduct from memory." At the site here, we read this about Toscanini: "It is believed that he conducted 117 operas and 480 concert pieces by memory, both during rehearsals and concerts." An average opera is hours in length. The newspaper account here claims Toscanini memorized one opera score in a single night. 

According to the page here, Pericles Diamandi was able to memorize 50 random digits in 7 minutes, 100 random digits in 25 minutes, and 200 random digits in 2 hours and 15 minutes. On that page, we are told Diamandi repeated a sequence of 200 random digits without any error. Below are 200 random digits. I don't think 1 in 100 people could memorize a sequence that long, even if he had all day:

2 0 9 6 9 1 9 1 8 5 2 2 3 3 1 8 4 7 4 8 5 2 5 7 5 4 9 2 5 7 8 7 5 4 2 7 4 5 1 4 8 6 4 9 3 1 5 1 8 7 0 5 1 9 2 0 9 5 8 9 4 8 4 1 1 9 2 2 5 7 6 2 7 2 5 1 8 1 0 7 9 8 4 1 9 1 3 8 3 8 2 1 3 5 4 5 4 9 0 2 9 5 7 0 1 2 4 9 4 7 3 5 4 1 2 9 1 9 1 4 5 2 0 3 2 0 1 8 5 5 0 3 3 5 7 7 4 2 0 3 7 1 3 9 1 0 8 8 2 1 8 9 0 8 7 0 0 8 5 0 3 5 2 7 6 5 9 3 5 4 3 4 1 2 9 8 6 5 6 4 4 0 3 0 6 2 2 0 8 0 0 6 4 7 9 8 5 9 1 3

The described feat above was far surpassed by the digits memorizations feats mentioned in my post here, discussing results from the World Memory Championships. 

According to the page here, a young man named Terry working at Harvard had an exceptional memory:

The account says Terry could recognize 10,000 faces. This ability is twice as good face recognition as the average person, since according to an article in the journal Science, the average person can recognize about 5,000 faces. The paper here tested 25 random subjects, and estimated that the face recognition per person varied between 1000 and 10,000, the latter matching the face recognition ability attributed above to Terry. 

In the 1955 newspaper account here, we read this about someone's remarkable memorization ability:

Back then papers typically had multiple columns and small print, meaning that memorizing 40 pages of a newspaper would be a stunning feat. 

In the newspaper account here, we read of a 4-year-old memory marvel named Gertie Cochran:

"Little Gertie Cochran, aged 4 years and 7 months, who has more facts and figures in her head than a college professor would contain will come to Lincoln ...Little Miss Cochran will give an exhibition from the stage of her marvelous powers of memory. Her mental store has been acquired from remembering what she has heard others repeat, as she has never been to school a day, nor does she know her letters. Her wonderful powers of readily appropriating everything that she hears were discovered shortly after they began to develop themselves when she was less than a year old. She began to talk at 7 months of age and rapidly acquired a vocabulary which attracted the attention of all who happened to come within the circle of neighbors known to her bumble home in Mount Vernon, ...The little one can recite the facts contained in the Bible from beginning to end, which, although a wonderful mental feat, is only a drop in the bucket to the oceans of mathematical statistics which she has at her tongue's end and which she recites as soon as asked without a minute's hesitation. These figures she has committed to memory by having them repeated to her, and in no case, no matter how long the string of figures, does she require that they be repeated more than twice before she has them fixed in her little head, never to be forgotten for so much ss a second when to repeat them."

Searching for Gertie Cochran's name on the Chronicling America site, I get many matches. On the page here we read this: "She can tell without a moment's hesitation the population of every city in the world, of over 100,000 inhabitants, and can answer most any other question that can be answered. "  The newspaper account here gives this description of Gertie's abilities:

The newspaper article here also mentions Gertie's abilities, hailing her as the girl who "never forgets anything she sees or hears":

Newspaper Accounts of Memory Marvels (Part 1)

The normal facts of human memory performance are sufficient to discredit claims that memory formation and memory recall are brain activities, given what we know about the brain's physical shortfalls. 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, often involving recall of things learned 50 years ago or earlier. 

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 better 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.  

Let us look at some clips from newspaper accounts of marvels of human memory.  Below is a 1921 account of a memory marvel:

The account can be read below:

https://chroniclingamerica.loc.gov/lccn/sn92070146/1921-07-27/ed-1/seq-2/                  

The account below is from 1931:

The account can be read here:

https://chroniclingamerica.loc.gov/lccn/sn82014085/1931-10-31/ed-1/seq-5/

The account below (from 1921) is part of an article entitled "An Elevator Dispatcher Who Never Forgets":

Yu can read the account below:

https://chroniclingamerica.loc.gov/lccn/sn89060136/1921-01-21/ed-1/seq-7/

The 1918 news article below claims that a man knew everyone in Chester, Pennsylvania and where he was born. Chester now has a population of about 33,000, and in 1918 probably had a population of at least 10,000.

The article can be read here:

https://chroniclingamerica.loc.gov/lccn/sn83045211/1918-06-15/ed-1/seq-15/

Below is a news story from 1922:

You can read the story here:

https://chroniclingamerica.loc.gov/lccn/sn84029386/1922-03-16/ed-1/seq-4/

The account below describes a multitasking ability I have never heard before of anyone doing:

You can read the story here:

https://chroniclingamerica.loc.gov/lccn/sn85038485/1923-01-14/ed-1/seq-53/

I was rather surprised to find that I can do two-thirds of the feat mentioned in red, because I am able to simultaneously sing a few lines in German while writing an English sentence.  But I could never write in two languages with two different hands at the same time. 

Below we have an account of an infant with an unusually good memory:

You can read the story here:

https://chroniclingamerica.loc.gov/lccn/sn84020422/1935-02-21/ed-1/seq-3/

Below is a news story from 1903:

You can read the story here:

https://chroniclingamerica.loc.gov/lccn/sn85033139/1903-07-16/ed-1/seq-2/

The newspaper article below comes from 1890:

The story can be read using the link below:

https://chroniclingamerica.loc.gov/lccn/sn84020355/1890-03-26/ed-1/seq-2/

George Vogan de Arrezo memorized the entire text of Virgil's Aeneid (consisting of 9,896 lines). Aitken and JB  performed similar feats when they memorized epic poems of about 10,000 lines. According to an old newspaper account, Leste May Williams memorized 12,000 verses of the Bible, including the entire New Testament. The New Testament has about 180,000 words, so the feat of Leste May Williams would seem to be far more impressive than the memorization of Virgil's Aeneid, which has only 63,719 words. The same feat of memorizing the New Testament was achieved by a male minister (Henry M. Halley). 

Neuroscientists give us nothing but the most vacuous hand-waving when they try to explain such marvels of memory by an action of brains.  Today I saw a recent paper that offered us the diagram below. We have only the flimsiest cobweb of an attempted explanation, something a million times too flimsy to explain marvels of human memory like the ones discussed above. Strengthening is not storage.