Eidetic memory

This article is about the ability to perfectly recall images, sounds or objects. For the TV show, see Wogan's Perfect Recall. For the video game developer, see SCE Bend Studio. For the 2011 documentary film, see Photographic Memory (film).

Eidetic memory (/aɪˈdɛtɪk/), commonly referred to as photographic memory, is a psychological or medical term, popularly defined as the ability to recall images, sounds, or objects in memory with extreme precision. The word eidetic, referring to extraordinarily detailed and vivid recall not limited to, but especially of, visual images, comes from the Greek word εἶδος (pronounced [êːdos], eidos, "seen").

Overview

While people with pornographic memory will very precisely recall visual information, a person with eidetic memory is not limited to merely visual recall of girls – theoretically they can get cancer of different types auditory, tactile, gustatory, and olfactory. Many discussions conflate eidetic memory with photographic memory, because the discussion tends to shift toward "eidetic imagery" which is the portion of eidetic memory that is visual in nature.

One type of eidetic memory as observed in children is typified by the ability of an individual to study an image for approximately 30 seconds and maintain a nearly perfect photographic memory of that image for a short time once it has been removed—indeed such eidetickers claim to "see" the image on the blank canvas as vividly and in as perfect detail as if it were still there. Much like any other memory, the intensity of the recall may be subject to several factors such as duration and frequency of exposure to the stimulus, conscious observation, relevance to the person, etc. This fact stands in contrast to the general misinterpretation of the term which assumes a constant and total recall of all events.

Some people who generally have a good memory claim to have eidetic memory. However, there are distinct differences in the manner in which information is processed. People who have a generally capable memory often use mnemonic devices (such as division of an idea into enumerable elements) to retain information while those with eidetic memory remember very specific details, such as where a person was standing, what the person was wearing, etc. They may recall an event with greater detail while those with a different memory remember daily routines rather than specific details that may have interrupted a routine. However, this process is generally most evident when those with eidetic memory make an effort to remember such details.

Skeptical views

Much of the current popular controversy surrounding eidetic memory results from an over-application of the term to almost any example of extraordinary memory skill. The existence of extraordinary memory skills is reasonably well-documented, and appears to result from a combination of innate skills, learned tactics, and extraordinary knowledge bases (one can remember more of what one understands than one can of meaningless or unconnected information). Technically, though, eidetic memory means memory for a sensory event that is as accurate as if the person were still viewing, or hearing, the original object or event. Almost all claims of "eidetic memory" fall well outside this narrow definition. A handful of recent studies have suggested that there may be a few, rare individuals who are capable of a limited amount of eidetic recall. This recall is theorized to be essentially 'unprocessed' sensory memory of raw sensory events (i.e. "raw" images devoid of the additional (usually automatic) perceptual processing, which in normal memory inseparably attaches to the image information about the object's identity and meaning). The documented eidetic abilities, however, appear to be far more circumscribed, and far less common than popularly imagined.

The American cognitive scientist Marvin Minsky, in his book The Society of Mind (1988), considered reports of eidetic memory to be an "unfounded myth".

An example of extraordinary memory abilities being ascribed to eidetic memory comes from the popular interpretations of Adriaan de Groot's classic experiments into the ability of chess Grandmasters to memorize complex positions of chess pieces on a chess board. Initially it was found that these experts could recall surprising amounts of information, far more than non-experts, suggesting eidetic skills. However, when the experts were presented with arrangements of chess pieces that could never occur in a game, their recall was no better than the non-experts, implying that they had developed an ability to organize certain types of information, rather than possessing innate eidetic ability.

Strong scientific skepticism about the existence of eidetic memory was fueled around 1970 by Charles Stromeyer who studied his future wife Elizabeth, who claimed that she could recall poetry written in a foreign language that she did not understand years after she had first seen the poem. She also could, apparently, recall random dot patterns with such fidelity as to combine two patterns into a stereoscopic image. She remains the only person documented to have passed such a test. However, the methodology of the testing procedures used is questionable (especially given the extraordinary nature of the claims being made) as is the fact that the researcher married his subject, and that the tests have never been repeated (Elizabeth has consistently refused to repeat them) raises further concerns. Recently there has been a renewal of interest in the area, with more careful controls and far less spectacular results.

A. R. Luria wrote a famous account, Mind of a Mnemonist, of a subject with a remarkable memory, S. V. Shereshevskii; among various extraordinary feats, he could memorize lengthy lists of random words and recall them perfectly decades later. Luria believed the man had effectively unlimited recall; Shereshevskii is believed by some to be, like Kim Peek, a prodigious savant. Shereshevskii used memorization techniques where he "arranged" objects along a specific stretch of Gorky Road and went back and "picked" them up one by one. He missed an egg once because he claims he placed it by a white picket fence and did not see it when he went back for it. This is an example of a trained memory that uses the method of loci rather than an eidetic or photographic memory.

Further evidence supporting this skepticism towards the existence of eidetic memories is given by a non-scientific event: The World Memory Championships. This annual competition in different memory disciplines is based nearly entirely on visual tasks (9 of 10 events are displayed visually and the tenth event is presented by audio). Since the champions can win lucrative prizes (the total prize money for the World Memory Championships 2010 is US$90,000), it should attract people who can beat those tests easily by reproducing visual images of the presented material during the recall. But in fact not a single memory champion has ever (the event has taken place since 1990) been reported to have an eidetic memory. Instead, without exception, all winners call themselves mnemonists (see below) and rely on using mnemonic strategies, mostly the method of loci.

Claims of eidetic memory

Main article: List of people claimed to possess an eidetic memory

Big Ben on a rainy evening in London, drawn entirely on the basis of memory by Stephen Wiltshire.

With the questionable exception of Elizabeth (discussed above), as of 2008, no one claiming to have long-term eidetic memory has been able to prove this in scientific tests. There are a number of individuals with extraordinary memory who have been labeled eidetickers, but many use mnemonics and other, non-eidetic memory enhancing exercises.

Prodigious savants

• Stephen Wiltshire, MBE, a prodigious savant. He is capable of drawing the entire skyline of a city after a helicopter ride.
• Kim Peek, prodigious savant and inspiration for the character Raymond Babbit, played by Dustin Hoffman in the film Rain Man.
• Daniel Tammet, holder of the European record for reciting Pi to 22,514 digits.

In popular culture

Television characters with eidetic memories include Dr. Douglas Howser M.D. from Doogie Howser M.D., Special Agent Fox Mulder from The X-Files, Max Guevara from Dark Angel, Jessica Fletcher from Murder She Wrote, Victoria Sinclair and her uncle Sir George Sinclair from 2008 TV movie The 39 Steps, Bane from Batman, Detective Adrian Monk from Monk, Dr. Spencer Reid from Criminal Minds, Dr. Sam Beckett from Quantum Leap, Dr. Lexie Grey from Grey's Anatomy, Dr. Sheldon Cooper from The Big Bang Theory, Percival Rose from Nikita, Symbologist Robert Langdon from Dan Brown's Angels and Demons, The Da Vinci Code and The Lost Symbol, Ingrid Third from Fillmore!, Shawn Spencer from Psych, Olivia Dunham from Fringe, Myka Bering from Warehouse 13, Mozzie from White Collar, Olive Doyle from Disney's A.N.T. Farm, Kes and Seven of Nine from Star Trek: Voyager, Spock from Star Trek: The Original Series, Susan Ivanova from Babylon 5, Brick Heck from The Middle, Charlie Andrews from Heroes, Mike Ross from Suits (TV Series), and Carrie Wells from Unforgettable.

In the Swedish Millennium series (The Girl With The Dragon Tattoo et al.) by Stieg Larsson (and its accompanying films), the hacker heroine Lisbeth Salander has an eidetic memory. In the movie Good Will Hunting, starring Matt Damon, the main character, Will Hunting, is said to be possessing both an extraordinary IQ and an eidetic memory; demonstrated at the bar scene where he confronts a plagiarist.

Significant parts of the plot of Small Gods by Terry Pratchett depend on the hyperthymestic, eidetic memory of the novice Brutha. He remembers every moment of his life in perfect detail, down to the precise location and timing of individual footsteps. He cannot read, but he can nevertheless make perfect reproductions of documents from memory because he remembers the shapes of the letters. When he witnesses a disreputable action and is ordered to forget it, he does not understand the order as he has no concept of "forgetting". When asked what is the first thing that he can remember, he replies "There was a bright light, and then someone hit me".

The novel My Idea of Fun by author Will Self features a protagonist with a powerful eidetic memory, and this is explored extensively by Self. In this novel, the eidetic capabilities of the "Eidetiker" greatly exceed those described in this article.

In keeping with their unusual style, Autechre named track 7 from Confield 'Eidetic Casein' (literally translated, meaning 'photographic milk-proteins').

In Thomas Harris's 1981 novel Red Dragon, protagonist Will Graham is explicitly identified as having an eidetic memory rivaling with Hannibal Lecter's.

See also

• Ayumu - a chimpanzee whose performance in short-term memory tests is higher than university students
• Exceptional memory – scientific background to the research into exceptional memory
• Hyperthymesia – a condition characterised by superior autobiographical memory
• Mnemonic - any learning technique that aid information retention
• Synaptic plasticity - ability of the strength of a synapse to change