Exceptional Memory Performance: Innate, Learned, or Something Else? Yogesh Raut

Human Memory Seminar (Guynn) May 11, 2014

From Jorge Luis Borgess classic short story Funes the Memorious to Donald J.

Sobols Encylopedia Brown tales to the Oscar-winning movie Rain Man to contemporary

detective series Psych, Sherlock, and Unforgettable, stories of human beings with extraordinary

powers of recall and recognition have exerted a powerful pull on audiences imaginations.

Cognitive and clinical researchers are not immune to this pull. One of the case studies found in

virtually every introductory cognitive psychology textbook is that of S, the name given to

Soviet journalist and professional mnemonist Solomon Shereshevsky by psychologist Alexander

Luria. According to Lurias (1968/1987) classic book The Mind of a Mnemonist, Shereshevsky

displayed both effortless accurate autobiographical recall and extremely good performance on

artificial memory tasks.

Luria (1968/1987) diagnosed with Shereshevsky with fivefold synesthesia, suggesting

that he involuntarily generated vivid imagery in response to stimuli, and such imagery has been

shown to have a salutary effect on memory (Paivio, 1995). However, Shereshevsky also

describes to Luria (1968/1987) a conscious system for generating imagery to help him remember

numbers (p. 31). Somewhat surprisingly, Luria does not draw a clear distinction between

whatever natural gifts Shereshevsky may have possessed and the conscious, learned strategies

that he used in his career as a professional mnemonist.

This omission, and similar gaps in other case studies of extraordinary memory ability,

have led to the development of an opposing perspective best summarized by the title of Ericsson

(2003): Exceptional memorizers: made, not born. In contrast to the natural memory view, this

skilled memory perspective (Chase and Ericsson, 1981, 1982; Ericsson and Kintsch, 1995)

argues that extraordinary memory is, like many other forms of expertise (Ericsson, Krampe, and

Tesch-Rmer, 1993), a product of training and practice.

This paper will review a number of cases of exceptional memory that have been

advanced in service of the natural memory perspective. It will then describe the skilled memory

perspective and show how studies from the natural memory perspective have failed to take into

account skilled-memory explanations, sometimes in dramatic fashion.

Finally, the paper will describe and review a newly proposed syndrome related to

exceptional memory: hyperthymesia, or highly superior autobiographical memory (LePort et al.,

2012; Parker, Cahill, and McGaugh, 2006). Persons with this syndrome have unusually good

memories for autobiographical events, but are no better than average in other memory domains.

The paper will discuss whether hyperthymesia is best accounted for by natural memory, skilled

memory, or a third pathway to extraordinary memory performance that the author terms intense

engagement. Finally, the paper will offer suggestions as to how future researchers of

extraordinary memory can exercise care to differentiate between these three paths to

extraordinary memory.

Cases of extraordinary memory

A 1947 New York Times article quotes Luria describing Solomon Shereshevskys

memory abilities:

He can easily remember any number of words and digits; equally easily he memorizes whole pages from books on any subject and in any language and for quite a long time at that. Shereshevsky can accurately quote anything he was told ten or twelve years ago (qtd. in Mecacci, 2013, pp. 2260-2261).

Shereshevsky first became aware that he was out of the ordinary while working as a

journalist in his twenties. During a meeting, his editor berated him for not taking notes, at which

point Shereshevsky recited back to him everything that the editor had said. Shereshevsky

claimed that until this incident, he assumed that everyone possessed the same memory abilities

as him (Luria, 1968/1987). The clear implication is that Shereshevskys abilities are natural and

automatic; indeed, Luria (Ibid) even describes Shereshevsky as suffering from an inability to turn

them off.

Lurias public reports emphasize Shereshevskys synaesthesia; he told a reporter that

Shereshevsky reacts with all his senses to everything he hears or sees and thus to him every

sound or thing has its own color, temperature, weight, shape, and so on (qtd. in Mecacci, 2013,

p. 2261). It can be concluded that Luria attributes Shereshevskys powers to this neurological

abnormality.

Another case of extraordinary memory is that of Kim Peek, often described as the

inspiration for the character of Raymond Babbitt in Rain Man (Feltes, 2006; F. Peek, 1996),

although unlike Raymond, Peek was not autistic (Weber, 2009). Peek is perhaps the most

famous case of savant syndrome (Treffert, 2009), in which individuals with severe mental

disabilities display extraordinary abilities within specific narrow fields, fields that Treffert and

Wallace (2002) aptly termed their islands of genius.

According to Treffert and Christensen (2005), Peek was born with an enlarged head, a

malformed cerebellum, and a completely missing corpus callosum. They note that he walks

with a sidelong gait, cannot button his clothes, cannot manage the chores of daily life, and has

great difficulties with abstraction (p. 110). In spite (or because) of this, Peek has learned 9,000

books by heart so far and can provide Yahoo-like travel directions within any major city or

between any pair of them, in addition to being able to identify hundreds of classical

compositions, tell when and where each was composed and first performed, give the name of the

composer and many biographical details, and even discuss the formal and tonal components of

the music (Ibid).

Treffert and Christensen describe NASA as wanting to created a high-resolution 3-D

anatomical model of Kims brain architecture and add that his unusual brain is of particular

value (p. 113), implicitly taking for granted that his abilities are tied to abnormalities in his

brain structure. An unstated premise is that Peeks low IQ renders him unable to develop

memory skills through training and practice.

A case that has gained considerable recent attention is that of Daniel Tammet, described

in a popular documentary called The Boy with the Incredible Brain (also known as Brainman)

and in Tammets own best-selling memoirs Born on a Blue Day and Embracing the Wide Sky.

Tammet claims to have Aspergers syndrome and synesthesia, brought on by childhood epilepsy

(Tammet, 2006/2007), and he has recited over 22,000 digits of pi, speaks 10 languages plus one

of his own invention, and is capable of abnormally rapid mental mathematical calculations

(Lyall, 2007). Noted researcher Simon Baron-Cohen has argued that Tammet displays savant

syndrome as a result of neurological abnormalities related to his synesthesia (Baron-Cohen, Bor,

Billington, Asher, Wheelwright, and Ashwin, 2007; Bor, Billington, and Baron-Cohen, 2007).

Evolutionary psychologist Scott Barry Kaufman (2013), attempting to refute skepticism

about the existence of natural exceptional memory (e.g., Foer, 2011, 2012), cites the case of

Jacob Barnett, an autistic child prodigy and published astrophysicist (K. Barnett, 2013), as

conclusive proof. Kaufman (2013) states, When [psychologist Joanne] Ruthsatz asked

[Barnett] to memorize 28 states presented in random order, he could immediately recall them

forwards and backwards with ease, and could still do so when asked again three months later!

(para. 10). Though this anecdote does not appear in the published account of Ruthsatzs findings

(Ruthsatz and Urbach, 2012), there is no overt reason to doubt it. Kaufmans (2013) argument is

that if exceptional memory exists in a boy so young, it must be natural.

Reasons for skepticism and the skilled-memory account

The field of cognitive psychology has often been slow to display skepticism toward

claims of extraordinary memory. One of the most notorious examples is that of Charles

Stromeyer III. In a 1970 article in the top journal Nature, Stromeyer and a colleague claimed to

have found a woman who could pass an incredibly stringent test for long-term eidetic memory.

Specifically, they used a test in which she was presented with two dot-matrix stereograms that,

when combined, formed a single three-dimensional image. Incredibly, they reported that this

woman could describe the combined image even when the two stereograms were presented up to

24 hours apart (Stromeyer and Psotka, 1970)!

This sounds too good to be true, and indeed it proved too good to be replicated.

Although the initial subject was found quite by accident (Ibid, p. 347), exhaustive efforts by

one of Stromeyers colleagues to seek out other subjects with this ability proved fruitless

(Merritt, 1979). While it is often reported that the woman was never tested again after

Stromeyers initial study (e.g., Foer, 2006), this is not the case; Pollen and Trachtenberg (1972)

published, again in Nature, a study of alpha rhythms produced by Stromeyers subject during her

alleged eidetic imaging. However, despite the fact that skepticism about Stromeyer and Psotkas

(1970) finding was expressed, in the same highly visible journal where they published, less than

six months later (Blakemore, Braddick, and Gregory, 1970), Pollen and Trachtenberg (1972) do

not attempt to replicate the stereogram task. Rather, they had the subject picture a Marc Chagall

painting and text from a New Yorker article, both presented in the lab, as well a passage from

Goethes Faust that had supposedly been committed to her eidetic memory a number of years

ago (p. 110).

While the fact that the subject was able to produce a detailed description of the Chagall

painting within a mere 68 seconds (Ibid) is quite impressive, that particular painting is extremely

famous, and there are no doubt many art history students who could provide an equally rich and

accurate verbal report of its contents. (Also, there is no assurance that the subject did not study

the painting outside of the laboratory.) The passages from the New Yorker and Faust raise even

more of a figurative eyebrow; while the latter is in German, a language the subject claimed not to

speak, both it and the New Yorker passage consist entirely of verbal information, and thus there

is no way to be certain that recalling them reflects eidetic rather than semantic memory.

In light of this, certain inconsistencies start to loom larger. For example, Stromeyer

claims that his subject described eidetic imaging as ridiculously easy (qtd. in Stromeyer and

Psotka, 1970, p. 347), but based on her brain waves Pollen and Trachtenberg (1972) state that the

tasks required and received considerable concentration and mental effort (p. 112). At one

point the researchers noted an unexpected eye movement but accepted the subjects claim that

an eidetic page had slipped off to the lower left (Ibid), demonstrating a willingness to

rationalize away anomalous data.

Looking back at Stromeyers original report, it now seems odd to devote a portion of an

article an article required to be extremely concise, since space in Nature is at a premium to

anecdotal accounts of the subjects eidetic prowess, especially as those accounts sound weirdly

pedestrian: Her eidetic ability is remarkable, for she can hallucinate at will a beard on a

beardless man (Stromeyer and Psotka, 1970, p. 347). The article further elaborates how

amazing this is, for the chin on [the] beardless man may disappear beneath the hallucinated

beard (Ibid). Given all this rhapsodic waxing, it may come as no surprise that this subject who

metaphorically fell right into Stromeyers lap also fell literally into his lap; subsequent to the

study, she married him (Foer, 2011). Knowing this, Stromeyer and Psotkas (1970) bold

assertion that any implicit communication between the experimenter, who knew the nature of

the figures [!], and the observer probably did not bias the reports (p. 347) sounds fairly dubious.

Its hard to escape the conclusion that some other famed memory researchers have been,

if not subject to quite the same level of conflict of interest as Stromeyer, at the very least rather

gullible in accepting their subjects self-reports. Luria (1968/1987), for example, appears to take

Shereshevskys claim that he did not realize that his memory was unusual until he was in his

twenties at face value. Shereshevsky was already a professional performer when Luria met him,

and it is quite possible that when he spoke to Luria, the showmans instinct to build a legend won

out over the journalists instinct to be faithful to the truth.

What then of Jacob Barnett, Scott Barry Kaufmans (2013) smoking gun with regard to

the existence of natural exceptional memory? It turns out that a bit of detective work can reveal

what Kaufman did not. A memoir by Barnetts mother about raising him contains the

information that Barnett was mentored extensively by child psychologist Carl S. Hale (K.

Barnett, 2013). Hales (n.d.) personal website describes Hale as having an interest in improving

memory and learning, especially in children (para. 1) and notes that Hale has developed

several programs for children, including Mnemonic Detective, a memory enhancement program

(para. 4).

Daniel Tammets deceptions may very well run far deeper. A laudatory online profile

written by psychiatrist Darold Treffert (n.d.) quotes Tammets online business website

(http://www.optimnem.co.uk) as saying,

[Tammet] was invited to Londons Institute of Neurology to undergo tests for a landmark study of prodigious mental ability. The summarized data, cowritten by some of Britains leading brain scientists, appeared in the New Year 2003 edition of the highly prestigious Nature neuro-scientific magazine [sic] (para. 6).

However, both the current version of the Optimnem website and Tammets personal website

(http://www.danieltammet.net) omit any mention of this study. Why?

Two possible reasons emerge. One is that the study (Maguire, Valentine, Wilding, and

Kapur, 2003) was of competitors in the World Memory Championships. Tammets past as a

competitive memory athlete is one he seems eager to conceal, to the point of making no mention

of it in his memoirs, and even changing his name! (Tammet is a pseudonym; at the time of his

memory-sports career he went by his birth name of Daniel Corney.) Memory athletes are

generally masters of skilled-memory techniques, and, consistent with this, Foer (2011) reports

that Tammet once sold an email course offering to teach memory skills. Moreover, during a

scene in the Brainman documentary in which he completes a mental calculation (Gooder and

Weitz, 2005), he can be seen moving his fingers in a manner consistent with well-known

strategies for doing mental math (Crawford, 2008; Foer, 2011).

A second reason for Tammet to conceal his participation in the study is that the

researchers concluded that none of their subjects had abnormal structural brain differences.

Rather, they noted that memorization in top memory athletes is correlated with increased spatial

processing (Maguire et al., 2003), suggesting that high-level memory performance is entirely

mediated by the use of spatial-imagery mnemonic techniques like the well-known method of loci

(said to have been developed by the ancient Greek poet Simonides and recently re-popularized

by the BBC detective series Sherlock), in which items to be memorized are placed in various

locations within a memory palace and then retrieved by walking through this mentally

constructed house.

The findings of Maguire and her colleagues would seem to be in conflict with those of

Simon Baron-Cohen and his colleagues, who see Tammet as having unusual abilities rooted in

unique qualities of his brain, such as synaesthesia (Baron-Cohen et al., 2007; Bor, Billington,

and Baron-Cohen, 2007). However, the revelation that Tammets abilities are trained raises the

question of whether Baron-Cohen and his colleagues have just seen what they want to see. For

example, when Bor, Billington, and Baron-Cohen (2007) found that DT did not activate extra-

striate regions normally associated with synaesthesia, they concluded that he has an unusual

and more abstract and conceptual form of synaesthesia (p. 311). Foer (2011) pointed out that

another reasonable conclusion might be that Daniel is not a synesthete at all (p. 230) and notes

that Tammet has refused to be tested by Anders Ericsson, a cognitive psychologist who has been

publicly skeptical of the existence of natural exceptional memory.1

All of this is not to suggest that every claimed superior memorizer is covertly employing

mnemonic techniques; for example, there is no evidence that Kim Peek has used such

techniques. (An alternative explanation for his accomplishments will be explored later in this

paper.) Indeed, two of the co-authors of the paper that concluded that Tammet and his fellow

memory athletes had normal brains have also argued that there is some evidence for naturally

superior memory in top memory athletes. Wilding and Valentine (1994) divided subjects into 1 The question of whether or not Tammet is a genuine savant is explored in greater depth in Chapter 10 of Foers (2011) book Moonwalking with Einstein, which includes reports of Tammets response when Foer challenged him on this issue to his face.

those who reported using mnemonic strategies2 and those who believed that their abilities were

natural (and reported noticing superior memory at a young age and having relatives with similar

abilities). Based on rank ordering, on average the natural subjects outperformed strategic

subjects on memory tasks that were not amenable to common mnemonic strategies and did worse

than strategic subjects on tasks that were. However, with a tiny sample size and results that

werent always consistent, the authors final conclusion was only that several different patterns

of strengths and weaknesses are apparent in subjects demonstrating unusual memory ability (p.

242).

Curiously, one of the subjects (G) classified as a strategist had the best performance of

any subject on a task designed to test natural ability (namely, recognition of snow crystals). One

might conclude from this that G is both a natural and a strategist, which should make him

unstoppable in memory competitions. However, as one commentator has pointed out, when G

competed in the World Memory Championships against subject C (classified only as a

strategist), G lost four out of five matchups (Tomasyi, 2013)! This points to a larger question,

which is whether a supposedly naturally gifted memorizer has ever been documented performing

feats that are beyond a mere strategist. If so, that would be strong evidence for the existence of

natural exceptional memory.

One potential candidate for this distinction who was strongly advanced in the 1990s (c.f.

Thompson, Frieman, and Cowan, 1993) was Rajan Mahadevan, a then-world record holder for

memorizing digits of pi. Advocates of Mahadevans natural abilities showed that he segmented

large spans of digits into smaller chunks of 10-15 digits. While the use of chunks is not itself

evidence of natural exceptional memory, what stood out was the size of the chunks; they were 2 These strategies included the method of loci, as well as other schemes for re-coding stimuli using pre-rehearsed associations and then linking together those associated items through a meaningful chain or story.

much larger than the chunks of 3-5 digits reported by subjects in other memory experiments.

Based on this, the researchers concluded that Mahadevans feats were rooted in a natural

superior innate working memory that was then augmented by learned and practiced skills

(Thompson, Cowan, Frieman, and Mahadevan, 1991).

Anders Ericsson, the leading proponent of the skilled memory perspective, challenged

this conclusion. Ericsson, Delaney, Weaver, and Mahadevan (2004) showed that Mahadevan

had better recognition and made fewer errors for the first and last items in each 10-digit chunk,

and when items within each chunk were made similar to one another, his performance decreased

(presumably due to interference). Thus, they concluded that Mahadevans memory for chunks

was a result of between-item processing rather than an expanded working memory with 10 or

more slots for items.

Their studies enabled Ericsson and his colleagues to explain Mahadevans performance

through the three basic tenets of skilled memory theory (Chase and Ericsson, 1981, 1982). This

theory states that expert performance in memory is attained through 1) the use of prior

systematized knowledge to store presented items as groups during encoding (the encoding

principle), 2) the association of encoded information with retrieval cues during study (the

retrieval structure principle), and 3) a practice effect whereby a set amount of time and effort

corresponds to the storage of greater and greater amounts of information over time; in other

words, processing becomes quicker (the speed-up principle). In an early, dramatic

demonstration, Ericsson and colleagues showed that an experimental subject could increase his

working digit span from 7 to 79 items (Ericsson, Chase, and Falloon, 1980)!3 Other researchers

have also trained novice subjects to perform mnemonic feats comparable to those of expert

3 The subject was a runner who was able to group items into 4-digit chunks, as though they were running times.

memorizers (e.g. Higbee, 1997; Kliegl, Smith, and Baltes, 1989; Kliegl, Smith, Heckhausen, and

Baltes, 1987), and Ericsson and colleagues have more recently shown that a Chinese master

mnemonist named Chao Lu who, at nearly 70,000 digits, more than doubled Mahadevans

erstwhile world record for pi-memorization has only a normal working digit span (Hu,

Ericsson, Yang, and Lu, 2009).

These studies are a reminder that there was once a time when ars memoriae, or the art of

memory, was considered a standard part of education (Bolzoni, 2001; Carruthers, 1990; Foer,

2011; Rossi, 2000; Yates, 1966). Perhaps extraordinary feats of memory appear inexplicable,

both to laypeople and to many researchers, because most of what we know about memory comes

from sampling a society that, by and large, has allowed its natural faculties to ossify and rust.

Hyperthymesia: The new case for natural exceptional memory

Just as the natural vs. skilled memory debate was beginning to recede within the

academic literature, a new syndrome arose to reinvigorate it. As written up in the journal

Neurocase by Parker, Cahill, and McGaugh (2006), neuroscientist James L. McGaugh was

contacted by a woman (given the pseudonym AJ) who reported that

I can take a date, between 1974 and today, and tell you what day it falls on4, what I was doing that day and if anything of great importance (i.e. [sic]: The Challenger Explosion, Tuesday, January 28, 1986) occurred on that day I can describe that to you as well . Most have called it a gift but I call it a burden. I run my entire life through my head every day and it drives me crazy!!! (p. 35)

4 While being a perpetual calendar is often held up an example of exceptional memory, its actually a fairly simple party trick that can be learned in an hour.

AJs case was markedly different from that of any other serial mnemonists in the psychology

literature (e.g. Hunt and Love, 1972; Luria, 1968/1987; Wilding and Valentine, 1997). Whether

claiming to have natural exceptional memory or not, those individuals all had more or less

average autobiographical memories. AJs prodigious abilities of recall, meanwhile, did not

extend to any of the tasks that Parker, Cahill, and McGaugh (2006) put in front of her, like

memorizing a story or a matrix of numbers. She was also no Kim Peek: Her semantic

knowledge was completely average. At the suggestion of McGaughs colleague Spiros

Koulouris, the authors termed AJs condition hyperthymesia, though it is also commonly referred

to as highly superior autobiographical memory (HSAM).

Unsurprisingly, Parker, Cahill, and McGaugh (2006) sought to explain AJs syndrome by

running a battery of neuropsychological tests on her. They diagnosed her with anomalous brain

lateralization (though AJ insisted that she was right-handed, the researchers argue that she is

actually ambidextrous) and with significant deficits in executive functions involving

abstraction, self-generated organization, and mental control (p. 47). Based on these two

symptoms, they conclude that she probably has a frontostriatal disorder, part of the same family

as autism, OCD, ADHD, and Tourettes. After consulting Endel Tulving, they speculated that

she had difficulty inhibiting episodic retrieval mode, a normal state of remembering in which

memory of one past incident triggers the memory of another, and so on. (They do acknowledge

that while this accounts for AJs chronic dwelling on the past, it doesnt explain her ability to

recall any and all past incidents at will, or her strong meta-memory.)

In December 2010, the CBS newsmagazine program 60 Minutes ran a program on

hyperthymesia, collecting together as many of the people who had the syndrome as they could

find.5 The growing public visibility of hyperthymesia allowed for a more extensive test, one that

included brain scans of 11 subjects, by LePort et al. (2012). These researchers found a total of

nine morphological structures that differ in the brains of hyperthymesics. While they stopped

short of making strong claims about the functions of those parts of the brain, McGaugh

summarized the findings to 60 Minutes as the different parts of the brain have greater access to

each other (qtd. in Stahl, 2014). Its worth nothing that other researchers of hyperthymesics

have claimed to find abnormalities in different sets of neuroanatomical structures, such as the

amygdala (Ally, Hussey, and Donahue, 2013).

The evidence that hyperthymesia results from a biological abnormality is suggestive but

inconclusive. The syndrome has to date been diagnosed in two pre-adolescent children (both

boys), suggesting that it occurs early in development and yet, oddly, one of those boys is an

identical twin whose brother is not hyperthymesic (Stahl, 2014)! Needless to say, many

unanswered puzzles about hyperthymesia remain to intrigue the next generation of memory

researchers.

Intense engagement: A third way

Hyperthymesia would seem to be proof positive that at least one form of natural

exceptional memory exists; there is consensus agreement that hyperthymesics do not use skilled

memory techniques. But is there a way to explain their performance on memory tests without

invoking exceptional memory abilities? I will argue that there is, and I term this perspective

intense engagement. 5 One of these was redheaded sitcom actress Marilu Henner, a friend of 60 Minutes host Lesley Stahl and now a consultant on Unforgettable, a CBS crime procedural about a beautiful redheaded female detective with hyperthymesia that debuted in 2011.

I begin by noting that when AJ was asked to memorize the War of the Ghosts story

introduced in the pioneering studies of Bartlett (1932) and employed by Hunt and Love (1972) to

quiz a memorization specialist known as VJ, she not only tested poorly on it, she called it the

stupidest story Ive ever read (Parker, Cahill, and McGaugh, 2006, p. 45). Separately, the

researchers point out that AJ displays phenomenal interest and delight in recalling her personal

past (pp. 45-46). The contrast speaks for itself.

Now, it is far from surprising that a person would find her own life more interesting than

a random story (particularly one designed to be confusing). So while there is what Kaufman

(2013) calls a general consensus among cognitive psychologists that the function of memory is

to make meaning (para. 2), from which it follows that information that is interesting and

meaningful is recalled better than information that is not, by itself this does not explain AJs far-

above-average autobiographical recall.6

But AJs engagement with her own past goes well beyond finding it interesting and

meaningful. In a journalistic account of his interview with AJ published in Wired magazine,

cognitive scientist Gary Marcus (2009) wrote:

[AJ] remembers so much about herself because she thinks about herself and her past almost constantly. She still has every stuffed animal she's ever gotten, enough (as she showed me in a photograph) to completely cover the surface of her childhood bed. She has 2,000 videotapes and countless audiotapes, not to mention more than 50,000 pages of diary entries in idiosyncratic handwriting so dense that its almost unreadable. Until recently she owned a copy of every TV Guide since summer 1989. Im not sure [AJ] wants to catalog her life like this, but she cant help herself (para. 22).

6 Though see a recent paper by Ally, Hussey, and Donahue (2013) which posits that hyperactive activation of the amygdala in hyperthymesics charges otherwise ordinary events with emotional, social, and self-relevance, thus enhancing recall for them. However, this conclusion is based on evidence from only a single subject.

Marcus (2009) notes that whatever abnormalities underlie AJs condition, they appear to bear a

strong similarity to obsessive-compulsive disorder (OCD). After talking this over with AJ, he

eventually gets her to agree and declare, I have OCD for my memories (qtd. in para. 33).

Marcus concludes that, The truth is, most people could remember their lives in considerable

detail if they contemplated them with the same manic intensity (para. 34). Parker, Cahill,

McGaugh (2006) write that AJs hyperthymesia causes her to spend much of her time

recollecting the past (p. 48), but could they have the arrow of causation pointing in the wrong

direction?

As it turns out, obsessive-compulsive tendencies (though generally not the full-blown

disorder) are a commonality of virtually all known hyperthymesics. One of them, Taxi and

Evening Shade actress Marilu Henner, told 60 Minutes Lesley Stahl (2010):

I love organization. I like my shoes a certain way, right foot going this way, left foot going that way, so you can always see the toe and the heel on every pair. And you'll see that things are very color coordinated here, but in sections. And I always hang like with like. And I have the exact same hangers, because then everything slides more easily.

Parker, Cahill, and McGaughs (2006) initial report pointed out that AJ reports that from an

early age she was upset when order in her external environment was disturbed, a sign of early

obsessive-compulsive tendencies (p. 47). LePort et al. (2012) expand these findings to nearly

their entire sample, though with the caveat that

HSAM participants typically do not view their memories as excessively intrusive, persistent, and/or unwanted or as disruptive of their daily life. Their memory does not distract them from ongoing tasks, nor does it hinder their ability to plan future ones (p. 87)

That said, nine of the eleven participants

reported that they hoard items, need organization in their physical environment, and/or are germ-avoidant. These reported behaviors included a need to organize childhood toys, CD collections, movie collections, and/or articles of clothing in a precise and/or complicated order. They described their excessive collections of stuffed animals, newspapers, TV guides, CDs, mugs, and/or hats, along with an inability to discard these items. They expressed aversions to touching public doorknobs, restaurant utensils, items that are near or have touched the ground, and/or a need to wash their hands excessively (p. 84).

Nine HSAM participants also reported organizing their memories chronologically or in some

similar categorical order. Those nine

also reported habitually recalling their memories, a seemingly compulsive tendency. Every night before bed one participant recalls what occurred on that day X number of years ago. Another recalls, while stuck in traffic, as many days possible from a certain year. Another wakes up every morning and reviews whether there are any upcoming anniversaries or birthdates to be congratulated. Three (of these nine) HSAM participants reported intentionally documenting their memories as a means of coping with the vast number they can remember. One claimed to be obsessed with writing things down as a means of offloading memories/thoughts from his/her mind. Another voiced that writing allows him/her to process the memories better. The third feels an obsession/compulsion to keep it [the memories] fresh. The other six reported habitually recalling their memories as a way of lulling themselves to sleep, a pastime, or as a means of staying on top of important events (p. 87).

LePort et al. (2012) also note that one of the neuroanatomical structures in which they discovered

an abnormality, the caudate nucleus, is more known to be associated with OCD than with

autobiographical memory.

Thus, it appears possible that while hyperthymesic abilities are mediated by structural

differences in the brain, those differences may not augment memory per se. Rather, they may

create or enhance the motivation to elaborately reminisce about past experiences. Through

repeated exposure, hyperthymesics may become as familiar with their own lives as we are with

our houses, the faces of our family and friends, and the streets on which we drive to work. The

architecture of their actual memory systems may be no different from ours.

Can intense engagement explain other instances of exceptional memory besides

hyperthymesia? One of the earliest accounts of exceptional memory in the psychological

literature is of the Shass Pollak, a community of Jewish scholars supposedly so well-versed in

the Talmud that if one placed a pin through a given word on a given page of their standard text

which consisted of over 5,000 pages they could state what word the pin would penetrate on any

other given page (Stratton, 1917)! While it is possible that every single one of the Shas Pollak

possessed the same biological abnormalities, intense engagement seems a far more plausible

mechanism.

Or take the case of Kim Peek. Free from having to hold down a job, pay bills, maintain a

love life, or deal with the thousand other burdens of day-to-day life, he has vastly more time and

attention to devote to his interests than a non-disabled person would, not to mention fewer

distractions. A skeptic may claim that while autobiographical memories are by definition

relevant and meaningful, the geographical, historical, literary, cinematic, and musical trivia

accumulated by Peek is just that: trivial.7 But one might counter-claim that Peeks stored

semantic knowledge is in fact more meaningful than just about anything else in his life. Peeks

friends call him the Kim-puter (Treffert and Christensen, 2005, p. 108), and it is not hard to

suppose that his memory is at the center of his identity. The information stored in Peeks head

has earned him fame, attention, social bonds (with peers and with movie stars), a father whos a

published author, and even an Oscar (!), gifted to him by Rain Man screenwriter Barry Morrow 7 Then again, much of our lives is boring, and history, literature, cinema, and music are chock full of emotionally rich and moving stories. Even dry, dusty maps have been known to powerfully stimulate certain imaginations.

(Weber, 2009). If you or I had only one thing that mattered in our lives, wed get pretty good at

it too.

Conclusion: How do you know?

Of course, it is very difficult to imagine that all of the feats attributed to Peek could be

accomplished by a non-savant, even one given a lifetime to do nothing but learn how to

memorize. Then again, it is also impossible to know how many of the feats attributed to Peek

were actually performed by Peek. When it comes to reporting on superior memory, far too many

writers and filmmakers seem to subscribe to the philosophy of the newspaper editor in John

Fords (1962) film The Man Who Shot Liberty Valance, who said (slightly paraphrased), When

the truth becomes legend, print the legend!8

Superior memory is a rare enough phenomenon that it is usually examined through case

studies, and where there are case studies there are apocryphal anecdotes crowding out data. Any

researcher wishing to establish the existence of natural superior memory must follow certain

guidelines to minimize potential objections from proponents of the skilled-memory and intense-

engagement perspectives.

Treat all self-reports with skepticism and all secondhand reports with even greater

skepticism. The feats of memory that are hardest to explain through the skilled-memory or

intense-engagement perspectives also tend to be the ones that are hardest to verify.

Always be alert that a subject (or their handler, if the subject is disabled) might be trying

to con you. Ideally, behavioral scientists should always do this, but a scientist envisioning a

8 The actual quote is, When the legend becomes fact, print the legend.

major publication isnt always an ideal scientist. Of course, even subjects who are being

completely honest have no direct window into their mental processes, and thus may provide

reports of mental processing that are non-veridical (Nisbett and Wilson, 1977).

Whenever possible, independently verify all claims regarding what happened to a subject

at a young age, and do your best to independently verify that subjects are not using mnemonic

techniques. It may seem undignified to snoop into someones life, but fact-checking isnt just for

journalists.

Apply the same standard to a claim of natural memory as you would to a claim for

evolutionary origins. Its impossible to specify a priori exactly what a true natural memory

would look like, but certain kinds of performance are less open to skilled-memory and intense-

engagement explanations than others. To a skeptic who was still reasonably open-minded, the

most convincing displays of natural memory would a) begin at a very young age, b) apply across

a wide number of domains, including those that arent mnemonic-friendly, c) occur in

individuals who are close genetic relatives but didnt share an environment (to rule out social

influence, modeling, and learning explanations), and d) appear in the absence of social or other

incentives to either study specific material or to have a good memory in general.

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