Is Photographic Memory Real? What Science Says

Photographic memory, in the sense of taking a mental snapshot of a page and reading it back later without error, has never been confirmed in an adult by repeated, independent testing. So is photographic memory real? Not in that form. Writing for BrainFacts, the Society for Neuroscience’s public site, the memory researcher Larry Squire concluded in 2013 that photographic memory does not exist in the sense of error-free mental snapshots.¹

Several things that get called photographic memory are real, though, and they are worth keeping apart. Eidetic imagery, a vivid picture that lingers briefly after something is gone, turns up in a small share of children and is almost never found in adults. Memory athletes perform astonishing feats with techniques they practiced. A few people recall almost every day of their own lives, and some savants hold large stores of narrow information. Each is a different ability with its own evidence, and none is a camera.

Is photographic memory real? The reverse-reading test says no

Larry Squire’s BrainFacts answer gives a simple test: ask someone who believes they have a photographic memory to read two or three lines of text, then report the text in reverse order. If memory stored a photo, they could quickly read the image backwards. People cannot.¹

The test works because a photograph has no direction: every word sits on the page at once, so reading it right to left would cost nothing extra. Squire’s point is that memory holds no such picture to read from. The words have to be rebuilt from what you stored, and rebuilding them backwards is something people cannot do quickly (the steps from encoding to retrieval are set out in how memory works).

Squire compares memory to the pieces of a jigsaw puzzle rather than a photograph. When you recall a meeting, you assemble remembered elements and lose others, such as the color of the wall or the exact words someone used. He argues that this is useful, because what usually matters is the meaning of what happened.¹ The same rebuilding is why vivid, confident memories can still be wrong, a theme covered in the guide to why people remember events that never happened.

Squire’s test needs nothing more than a printed page, so you can run it on yourself.

If you catch yourself replaying the sentence forwards and picking words off the end, that effort is the jigsaw at work. It is the normal way human memory runs.

Eidetic memory is a brief childhood image that fades

Eidetic memory is the scientific term closest to the popular idea: a vivid visual image that persists for a short time after the picture has been removed. People often treat the two terms as interchangeable, but when they are kept apart, “eidetic” means this lingering image and “photographic” means recalling whole pages of text or numbers in detail.²

Alan Searleman, a psychologist at St. Lawrence University in the US, wrote in Scientific American in 2007 that prevalence estimates among preadolescent children range from about 2 to 10 percent, that eidetic images last from about half a minute to several minutes, and that virtually no adults seem able to form them.³ The images are also far from perfect. Searleman notes that people who have them often alter details and even invent some that were never in the picture.

A 1979 review by the psychologist Ralph Haber drew on his ten-year study of elementary-school children. He set criteria to tell an eidetic image from an afterimage or an ordinary memory: the child reports seeing the image projected on a surface, describes it in the present tense, and can move their eyes across it without the image moving. Haber found eidetic imagery in a small percentage of children aged 6 to 12, virtually none in adults, and no consistent link to intelligence, reading or any other measure.⁴

A child who describes a picture book page in vivid detail after it closes may be showing exactly this. The image is real for them, and it is temporary. It does not predict that the child will be a better student, and nothing suggests it can be kept or trained into adulthood.

Myth

Some children are born with a photographic memory that makes them gifted learners.

Fact

Eidetic images occur in a small share of children, fade within minutes, contain errors and show no consistent link to intelligence or reading.

The Elizabeth case: one strong claim, never repeated

The most famous evidence ever published for adult photographic memory is a single case studycase study: A detailed look at one organization, group, project or event, often with interviews and documents. It can show how something happened in context, but with no comparison group it cannot show that a change caused the result or that it would work elsewhere.Full entry in the glossary: a 1970 paper in Nature by Charles Stromeyer and Joseph Psotka about a Harvard student called Elizabeth. It is also a case some psychologists doubt, partly because it was never repeated with her or anyone else.⁵

The study

Limited evidence

One viewer, two dot patterns, a day apart: Elizabeth in Nature, 1970

Random-dot stereograms are two patterns of dots that look meaningless alone but show a hidden shape when each eye sees one. Stromeyer showed Elizabeth’s right eye a pattern of 10,000 random dots and, a day later, her left eye the second pattern. She mentally fused the two patterns and saw a three-dimensional image float above the surface. Foer notes that she seemed to offer the first conclusive proof that photographic memory is possible.⁶

If the result held, it would be the proof skeptics ask for. The journalist Joshua Foer, writing in Slate in 2006, lists why it is doubted: Stromeyer went on to marry Elizabeth, she was never tested again, and nobody else has matched her. In 1979 another researcher, John Merritt, reported on a photographic memory test he had placed in newspapers and magazines; he estimated that about a million people tried it. Thirty sent in the right answer; when he visited 15 of them at home, none could repeat the feat. Stromeyer told Foer he had no doubt about the data, but that his one-woman study is not strong evidence that other people have photographic memory.⁶

The same reasoning applies well beyond Elizabeth. One striking result from one person with one tester is a reason to look again, and the lack of any reported replicationreplication: Running a study again with fresh data and the same method, to see whether the original result comes back. A finding that fails to replicate is not automatically wrong, but it stops being something you can lean on.Full entry in the glossary since 1970 is a reason to hold the claim loosely. When someone offers a famous case as proof, the first question is whether anyone has repeated it.

What is real: three kinds of exceptional memory

Exceptional memory is real, but each documented form works differently from a camera. Three are well described: trained memory, memory for one’s own life, and savant memory.

Memory athletes trained their way there

The people who win memory contests are the nearest thing to living proof of photographic memory, and they do not claim to have it. Wikipedia’s summary of the field notes that none of the world’s best competitive memorizers has claimed a photographic memory.² In a 2003 UK study, Eleanor Maguire’s team at University College London found that top competitors showed no exceptional intellect and no structural brain differences; what set them apart was a spatial learning strategy that engaged the hippocampus, a region critical for memory, especially memory for places.⁷

The usual strategy is a mental route, and it can be learned. In Martin Dresler’s 2017 study, run by teams in Germany, the Netherlands and the US, beginners who practiced a route for six weeks developed brain-network patterns closer to those of 23 champions, and the closer the match, the larger their memory gains up to four months later.⁸ How the route works and how to build one is covered in the beginner’s guide to mnemonics. A champion’s feat is a record of practice, so for a long list you need next week, building a route is the tested option.

HSAM: memory for your own life

Highly superior autobiographical memory (HSAM), also called hyperthymesia, is an unusual ability to recall the events of one’s own life, often with the date and day of the week. It was first described in 2006 by Elizabeth Parker, Larry Cahill and James McGaugh at UC Irvine in a woman called AJ whose remembering was “nonstop, uncontrollable, and automatic”.⁹ Unlike memory athletes, she used no practiced mnemonics.

In the group’s 2012 follow-up led by Aurora LePort, most adults who came forward believing they had the ability did not pass the two screening quizzes. Eleven who passed were studied in the lab: they recalled public and personal events and their dates far better than matched controls, yet scored about the same on most standard laboratory memory tests, and most reported obsessive-like tendencies.¹⁰ The authors conclude that the ability is specific to recalling autobiographical events rather than strong memory in general: it is memory for lived events, one branch on the map of the types of memory.

31 of 115adults who believed they had HSAM and passed both screening quizzes, US studySource: LePort et al., 2012

Even this memory seems to be reconstructed when it is recalled. A 2013 US study by the same group with Elizabeth Loftus found that people with HSAM formed false memories in standard tasks about as readily as controls, and in one task more often.¹¹

Savant memory is deep and narrow

Savant syndrome is a rare condition in which a person with a serious mental disability, including autism, has an island of exceptional skill. A 2009 review by Darold Treffert of the University of Wisconsin Medical School states that as many as one in 10 people with autistic disorder have such abilities to some degree, and that whatever the skill, it is always linked to massive memory.¹²

Even the famous cases fall short of a camera. Foer points out that the claim that Kim Peek, the inspiration for the film Rain Man, memorized thousands of books was never rigorously tested, and that the artist Stephen Wiltshire, who sketches scenes after looking at them for a few seconds, takes liberties with what he sees.⁶ Savant memory is real and remarkable; it is narrow, and the evidence for perfect copies is missing.

Set side by side, the common claims sort cleanly into what the evidence supports and what it does not.

Good recall without a special memory

None of the cases above involves a camera in the head, so the habits that help ordinary memory are open to anyone. Squire’s BrainFacts answer notes that how well people remember depends largely on how well they pay attention when the material is presented, and on how much they replay it and connect it to what they already know.¹

A manager who reads a report once and hopes to quote it in a meeting is relying on the snapshot that does not exist. The same manager who pauses after each section to say its point aloud, and links it to last quarter’s numbers, is doing what memory needs.

Claims of perfect memory also turn up in ads, course pitches and TV shows. The cases above suggest a short screen for them.

The bottom line

Photographic memory as a perfect mental snapshot has no support in adults, and the one famous case was never repeated. When you need to remember something precisely, treat your memory as a rebuilder: pay attention on the first pass, recall it once soon afterward, and learn one tested technique such as a memory route.