The claims made differ somewhat, but stress the recall of visual information. Examples of the information include: pages from books, magazines, and license plate numbers. It is claimed that those with a photographic memory tend to have higher IQs than those without it. A person with this ability does not use mnemonics.
The ability is said to occur in the early childhood of a small number of children (between 2 percent and 10 percent) and generally is not found in adults.
Adriaan de Groot studied the ability of chess grandmasters to memorize the positions of chess pieces on a chess board. At first, people thought they had photographic memory because they could memorize far more information than nonexperts. However, arrangements of pieces that could never occur in a game, their recall was no better than nonexperts. This suggests that they only have an ability to remember certain types of information, rather than photographic memory.
Around 1970, Charles Stromeyer studied his future wife, Elizabeth. He claimed that she could recall poetry written in a foreign language which she did not understand. She could remember the poetry years after she had first seen the poem. She also could, apparently, recall random dot patterns so as to combine two patterns into a stereoscopic image. She is the only person who is known to have passed such a test. The methods used in the testing procedures were not clear. Additionally, the tests have never been repeated (Elizabeth has consistently refused to repeat them). This raised further concerns, and increased skepticism about whether photographic memories were real.
- The word eidetic comes from the Greek word εἶδος eidos, "seen". "Eidetic". American Heritage Dictionary, 4th ed. 2000. Retrieved 2007-12-12.
- "Eidetic image", Encyclopaedia Britannica
- Haber R.N. 1979. Twenty years of haunting eidetic imagery: where's the ghost? Behavioral and Brain Sciences. 2 (4) 583- 594. 
- 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 memorise 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.
- de Groot A. 1946. Het denken van den schaker. Amsterdam: Noord-Hollandsche Uitgevers Maatschappij; and 1965. Thought and choice in chess. The Hague: Mouton.
- Stromeyer C.F. & Psotka J. (1970). "The detailed texture of eidetic images". Nature. 225 (5230): 346–349. doi:10.1038/225346a0. PMID 5411116.
- Thomas N.J.T. 2010. Other quasi-perceptual phenomena. In The Stanford Encyclopedia of Philosophy.
- Blakemore C; Braddick O. & Gregory R.L. 1970. Detailed texture of eidetic images: a discussion. Nature. 226, 1267–1268.
- Foer, Joshua 2006. Kaavya Syndrome: The accused Harvard plagiarist doesn't have a photographic memory. No one does. Slate.