Eidetic memory (//), commonly referred to as photographic memory or total recall, is the ability to recall images, sounds or objects in memory with great precision, and is not acquired through mnemonics. The word eidetic comes from the Greek word εἶδος (pronounced [êːdos], eidos, "seen").
The ability to recall images in great detail for several minutes is found in early childhood (between 2% and 10% of that age group) and is unconnected with the person's intelligence level. Like other memories, they are often subject to unintended alterations. The ability usually begins to fade after the age of six years, perhaps as growing vocal skills alter the memory process. A few adults have had phenomenal memories (not necessarily of images), but their abilities are also unconnected with their intelligence levels and tend to be highly specialized. In extreme cases, like those of Solomon Shereshevsky and Kim Peek, memory skills can actually hinder social skills.
Persons identified as having a related condition known as Highly Superior Autobiographical Memory (HSAM) are able to remember very intricate details of their own personal life, but this ability seems not to extend to other, non-autobiographical information. People with HSAM have vivid recollections of such minutiae as what shoes a stranger wore or what they ate and how they felt on a specific date many years in the past. In cases where HSAM has been identified and studied, patients under study may show significantly different patterns of MRI brain activity from other individuals, or even have differences in physical brain structure. Possibly because of these extraordinary abilities, certain individuals have difficulties in social interactions with others who have normative memories (only 2 of 55 in the US have successful marriages), and may additionally suffer from depression stemming from the inability to forget unpleasant memories and experiences from the past.
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, suggesting that they had developed an ability to organize certain types of information, rather than possessing innate eidetic ability.
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.
Claims of eidetic memory
With the questionable exception of Elizabeth (discussed above), as of 2008, an article claims that of the people rigorously scientifically tested, no one claiming to have long-term eidetic memory has proven this ability. There are a number of individuals with extraordinary memory who have been labeled eidetic, but many use mnemonics and other, non-eidetic memory enhancing exercises. Others have not been thoroughly tested.
- Stephen Wiltshire, MBE, a prodigious savant. He is capable of drawing the entire skyline of a city after a helicopter ride.
- Daniel Tammet, holder of the European record for reciting Pi to 22,514 digits.
- 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
- Synaptic plasticity - ability of the strength of a synapse to change
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- Adams, William (1 March 2006). "The Truth About Photographic Memory". Psychology Today (Sussex Publishers). Retrieved 10 July 2013.
- Searleman, Alan (12 March 2007). "Is there such a thing as a photographic memory? And if so, can it be learned?". Scientific American (Nature America). Retrieved 10 July 2013.
- Barber, Nigel (December 22, 2010). "Remembering everything? Memory searchers suffer from amnesia!". Psychology Today (Sussex). Retrieved July 10, 2013.
- Minsky, Marvin (1998). Society of Mind. Simon & Schuster. p. 153. ISBN 978-0-671-65713-0. "...we often hear about people with 'photographic memories' that enable them to quickly memorize all the fine details of a complicated picture or a page of text in a few seconds. So far as I can tell, all of these tales are unfounded myths, and only professional magicians or charlatans can produce such demonstrations."
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- Martin, David. Savants: Charting "islands of genius", CNN broadcast September 14, 2006
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