There are people out there who can remember almost every detail of what they did on a random day ten years ago. But is it possible to have an actual photographic memory, whether developed by nature or nurture? Here's the truth.
A case study of one -- or possibly none
The list of people claiming to have photographic memories is a long one, but when you look at the list of documented scientific studies, that list narrows quite considerably, to one: a single paper published in 1970 in Nature. And some scientists, suggest that the number might be whittled down even further, to zero.
Image: An example of a random dot stereogram, this one showing a shark. (Fred Hsu)
In Nature, Charles Stromeyer, a vision researcher at Harvard, detailed the case of a woman, Elizabeth, whose memory was so exceptional that she could view a 10,000 dot-image stereogram with one eye one day, view a second dot-image with the other eye the next day, and then layer those two dot-images over top of each other in her memory so accurately that she could see the full, 3-d image they would create. Other researchers started to become sceptical, however, when she didn't try to replicate the tests with any researchers besides Stromeyer -- and became even more sceptical later on when Elizabeth and Stromeyer eventually married.
Scientific literature is riddled with other instances of "superior rememberers," some with exceptional skills. But, the kind of total, instantaneous recall -- uniting visual, spatial, audio, and verbal memories -- that defines a photographic memory is noticeably absent. So, if real-life photographic memories (the strange case of Elizabeth notwithstanding) don't exist, what about those people who just seem to have really, really good memories? There, with these superior rememberers, the scientific ground gets much more solid.
'Like a movie that never stops.'
In 2000, Jill Price emailed scientists at the University of California, Los Angeles to describe the remarkable, and unusual, personal memory she had seemingly been born with. "Most have called it a gift but I call it a burden," she wrote. "I run my entire life through my head every day and it drives me crazy!!!"
At first, the researchers were sceptical, but over five years of tests that gradually became convinced that the woman who called herself a "human calendar" was for real, describing her memory in the paper they published in 2006 in Neurocase as "nonstop, uncontrollable, and automatic." What it also was was, though, was limited.
Price did, indeed, seem to have near perfect recall, at one point dazzling researchers by dashing off a complete list of her last 20 years of Easters in 10 minutes. But that recall was entirely focused on herself and the day-to-day moments that had made up her life. In contrast to other superior rememberers, she did not practice to develop her memory. In fact, if anything, she seems to have found it rather unpleasant. Here's how Price described her condition:
It's like a running movie that never stops. It's like a split screen. I'll be talking to someone and seeing something else ... Like we're sitting here talking and I'm talking to you and in my head I'm thinking about something that happened to me in December 1982, December 17, 1982, it was a Friday, I started to work at Gs (a store)... . It's all about dates... . I just know these things about dates...
In most tests of memory -- for instance memorising a long string of digits or recalling information read in a book -- she did no better than average. She also noted that her memory skills were no help to her in school, not even in history. Her knowledge of dates is limited purely to the days that she herself has experienced, and even then it was not infallible. Researchers point out that Price did, on occasion, either misremember a date or not recall a previously told story.
To call Price's command over her memory photographic, therefore, seems not quite accurate, instead researchers coined the term "hyperthymestic syndrome" as a way to describe Price and a handful of other people whose exceptional memories seem to be purely confined to their own experiences.
But, if a photographic memory isn't a gift that can be granted by nature, then perhaps it is instead a goal that can be attained by other methods -- as some other famous "superior remembers" tried.
Can you develop a super-memory?
Chao Lu currently holds the world record for reciting Pi to the most decimal places from memory. In 2005, Lu -- who was studying Chemistry at the time in China -- rattled off Pi to the 67,890th place. It took him more than 24 hours of continuous speech. Surely this seems on the surface to be an extraordinary act of memory -- and it absolutely was, but it was also just as much an act of creativity.
To get to the point where he was able to grab a world record, Lu spent more than 4 years memorising the digits comprising Pi. But he wasn't memorising the numbers, instead he was memorising a story. Lu explained that he had broken down pairs of digits into corresponding images, which he then used to compose a series of stories. In essence, Lu had spent those four years composing and memorising an epic novel, which he then recited for onlookers much in the same way that a travelling storyteller would memorise and then recite a favourite tale.
Image: A pi pie / Paul Smith
What's more, Lu, only got a little more than 3/4 of the way through that tale on the day that he broke the record -- he can actually, he says, make it all the way through 100,000 digits:
I've got 100,000 digits of pi, and I was going to recite 91,300 digits of them. But I made a mistake at the 67,891th digit. It was "0" but I said "5" in my recitation. Then after a few while the challenge stopped.
Inside the Mind Palace
Once a year, a carefully-curated group of some of the most exceptional memories in the world can be found all gathered together at the World Memory Championship. There, they compete at besting each other in tricks such as speed-recalling the order of cards in a deck, memorising strings of binary numbers, and matching faces with names. In 2002, Neuroscientist Eleanor Maguire decided to do a series of MRIs on the memory champions, for a study that she would eventually publish in Nature, to see what differences she could find in their brains that might explain their remarkable facility for memory.
What she found was nothing.
The memory champions showed no differences in brain structure, no unusual levels of cognitive activity, no exceptional skills in either verbal or non-verbal areas. The only difference Maguire was able to find was that, curiously, when the memory champions performed a feat of memory there was brain activity in areas that were usually associated with remembering physical locations or recalling directions.
In interviews with the memory champions, almost all of them told Maguire that they had been using what a memory technique popular in Ancient Greece, "the method-of-loci," what you may know better as the mind palace technique.
"It's based on navigation," Maguire explains, "they imagine going down a street they know well, place items at certain positions along the street, then mentally retrace their route to find the items."
A pharmaceutical solution?
So, it seems as though -- through a great deal of work and mental training -- it is possible to train your brain to become, if not photographic, then certainly still very good at recall. But what if there was a way to skip the hours of practice, the tricks, and the years of training? What if the problem of improving your memory was as simple as taking a pill? There's a number of researchers working on just that.
In a recent study published in Nature Neuroscience, researchers at Johns Hopkins University found that a caffeine pill could cause a temporary boost in memory performance over a 24 hour period. Unfortunately, they also found that either having caffeine regularly or having more than might be present in a single, small cup of coffee quickly negated all the benefits.
In the world of memory research, though, the most sought after prize is usually much longer than a 24-hour bump. The real goal is finding a way to boost recall to superior levels over the longterm -- and some researchers have done just that, with mice. In 2009, research published in Science showed that mice could be given a near perfect visual memory for a span of two months by boosting production of a protein found in their visual cortex. Later research published from Baylor College in Cell found that by surpressing levels PKR, a molecule involved in sensing viruses, researchers could boost spatial memory in mice to similar levels.
In both instances, researchers thought that the research could eventually lead to similar results in humans. But, though the studies might be good enough reason for mice to throw out their day planners and accumulated post it notes, no such pill exists for absent-minded humans -- not yet, anyway.
The wrong primate?
So, is the existence of an actual photographic memory just a myth? For humans it seems to be -- but maybe that means we've just been looking at the wrong primate. A study from Kyoto University pitted humans, adult chimps, and young chimps against each other in a test to see who could best recall the location of a remembered sequence of numbers on a touch screen. Adult chimps and humans performed roughly equally, but the results of the young chimps blew both out of the water. What's more, researchers noticed that the young chimps times were actually showing response times that were faster than their eye's ability to scan the screen -- making researchers believe that some young chimps might possess photographic memories.
It's not just chimpanzees that have the potential to possess what might be called a photographic memory, however. The humble fruit fly has also been targeted by researchers as the potential possessor of a photographic memory -- but only if it's mutated. A Current Biology study of fruit flies with the CREB gene boosted suggested that they were able to gain what researchers called a form of photographic memory over the course of their brief lives. In turns out that the CREB gene is one that humans also share with fruit flies, but the potential for a similar boost in humans hasn't yet been studied.