Eidetic Imagery and "Photographic Memory"

Most people have heard of photographic memory. People with photographic memories are called eidetikers (eye-DET-ik-ers). The image they preserve is called an eidetic image. The very concept of eidetic imagery is controversial because the phenomenon is so rare. One well-documented case was a young teacher at Harvard named Elizabeth (Strohmeyer, 1970).

What is eidetic imagery?

Elizabeth could project complete sensory images onto a visual scene. For example, she could imagine a beard on somebody's face, and when she did so, she actually saw it. The image was so vivid she could use it to obscure parts of her field of vision, if she wished. However, she never confused her memory images with real perception.

What "foolproof" test for eidetic imagery did Bela Julesz devise?

Strohmeyer tested Elizabeth with a pair of dot patterns developed by Bela Julesz. Julesz used a computer to design random-dot patterns that would reveal a hidden figure when superimposed (set over each other). Normally this would be done in a special instrument (a stereoscope) that revealed the hidden figure. But a person with truly photographic memory should be able to view the two images at different times and combine them to see the hidden figure.


Random dot patterns like those from Julesz, used to test Elizabeth the eidetiker

Elizabeth looked at the left panel with her left eye, then (after a delay) looked at the right panel with her right eye. She was able to combine the two from memory and "immediately" reported seeing the pattern hidden in the dots. Elizabeth was tested with patterns containing letters of the alphabet, which she readily discriminated by projecting one image upon another.

Elizabeth not only had an extraordinary ability to generate images; she also retained the images for years in memory. She could remember pages of a book written in a foreign language, reproducing it by memory years later, even though she did not understand the language. She said her photographic memory helped her get A's in school all the way through college, but she had to use other talents in graduate school, where creativity was emphasized more than reproduction of information.

How was Elizabeth unlike other people called eidetikers in the psychology literature?

Neisser (1982) notes that Elizabeth is unlike other people called eidetikers in the psychology literature. The term originally described children who claimed to be able to see images for 3 or 4 minutes after viewing them. However, these children were not much better than other children at describing details from the images. They were probably using ordinary visual memory. Elizabeth was clearly extraordinary.


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