Eidetic memory, photographic memory, or total recall is the ability to recall images, sounds, or objects in memory with extreme accuracy and in abundant volume. The word eidetic means related to extraordinarily detailed and vivid recall of visual images, and comes from the Greek word είδος (eidos), which means "form." Eidetic memory can have a very different meaning for memory experts who use the picture elicitation method to detect it. 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 eidetikers claim to "see" the image on the blank canvas as vividly and in as perfect detail as if it were still there.

Although many adults demonstrate extraordinary memory abilities, it is unknown whether true eidetic memory can persist into adulthood. While many famous artists and composers (Claude Monet and Mozart) are frequently thought to have had eidetic memory, it is possible that their memories simply became highly trained in their respective fields of art, as they each devoted large portions of their waking hours towards the improvement of their abilities. Such a centre on their individual arts most likely improved the relevant parts of their memory, which may account for their surprising abilities.

People with eidetic memory

A number of people claim to have eidetic memory, but nearly no one has been tested and documented as having a memory that is truly photographic in a literal sense. Regardless, here are a number of individuals with extraordinary memory that have been labeled by some as eidetikers, such as:

Ampère, French physicist and mathematician.

Henri Poincaré

Stephen Wiltshire, MBE, is a prodigious savant, capable of drawing the entire skyline of a city after a helicopter ride.

Kim Peek "prodigious savant"

Tom Morton, a taxi driver, knew over 16,000 telephone numbers in Lancashire and beat the British Olympia Telephone Exchange computer with his recall while being interviewed by Esther Rantzen and Adrian Mills on the popular BBC magazine programme That's Life! in 1993.

Nikola Tesla

Sandra Schimmel Gold, a well known artist, was studied for years at the State University of New York in Oneonta by Dr. Michael Siegel. A paper about her abilities was presented at the national APA convention in 1976-77.

Rashida Jones, actress, daughter of Quincy Jones.

Memory records

Guinness World Records lists people with extraordinary memories. For example, on July 2, 2005, Akira Haraguchi managed to recite pi's first 83,431 decimal places from memory and more recently to 100,000 decimal places in 16 hours (October 4, 2006). The 2004 World Memory Champion Ben Pridmore memorized the order of cards in a randomly shuffled 52-card deck in 31.03 seconds. The authors of the Guinness Book of Records, Norris and Ross McWhirter, had extraordinary memory, in that they could recall any entry in the book on demand, and did so weekly in response to audience questions on the long-running television show Record Breakers. However, such results can be duplicated using mental images and the "method of loci".

Some autistic individuals display extraordinary memory, including those with related conditions such as Asperger's syndrome. Autistic savants are a rarity but they, in particular, show signs of spectacular memory. However, many autistic individuals do not possess eidetic memory.

Synesthesia has also been credited as an enhancement of auditory memory, but only for information that triggers a synesthetic reaction. However, some synesthetes have been found to have a more acute than normal "perfect color" sense with which they are able to match color shades nearly perfectly after extended periods of time, without the accompanying synesthetic reaction.

Many people who typically 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 typically capable memory often use mnemonic devices to retain information while those with eidetic memory remember very specific details, such as where a person was standing, etc. They may recall an event with great detail while those with a normal memory remember daily routines instead of specific details that may have interrupted a routine.

Also, it is not uncommon that some people may experience 'sporadic eidetic memory', where they may describe a rather limited number of memories in very close detail. These sporadic occurrences of eidetic memory are not triggered consciously in most cases.

Eidetic memory in chimpanzees

A recent study on chimpanzee cognition has shown that young chimps performed a visual memory task better than comparably trained adult humans. To explain these results, Researcher Tetsuro Matsuzawa has suggested that after diverging from an ancestor common to humans and chimps, humans may have "traded" eidetic memory for higher cognitive capacities like language, while chimps retained a strong capacity for visual memory.

Eidetic memory in fiction

Main article: List of People in fiction with claimed eidetic memory

Works of fiction often have characters with extraordinary memory. Characters with eidetic memory are found in written works, film, television, and games.

Controversy

Dr. Marvin Minsky, in his book The Society of Mind, was unable to verify claims of eidetic memory and considered reports of eidetic memory to be an "unfounded myth".

Support for the belief that eidetic memory could be a myth was supplied by the psychologist Adriaan de Groot, who conducted an experiment 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 organise certain types of information, instead of possessing innate eidetic ability.

Some people attribute exceptional powers of memory to enhanced memory techniques as opposed to any kind of innate difference in the brain. However, support for the belief that eidetic memory is a real phenomenon has been supplied by some studies. Charles Stromeyer studied his future wife Elizabeth who could recall poetry written in a foreign language that she did not understand years after she had first seen the poem. She also could recall random dot patterns with such fidelity as to unite two patterns into a stereoscopic image. She remains the only person to have passed such a test. It's possible to test yourself by examining the bottom pair of the exemplar Julesz random-dot stereograms in this Wiki without a stereoscope or without crossing your eyes to view them stereoscopically. There are more complex figures in

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 a prodigious savant like Peek. However, it is possible that he used memory techniques as well.