Eidetic memory

How it works

An eidetic image is a detailed mental picture that stays “in front of” a person for up to a few minutes after the real picture is removed. Children who have it can scan the image with their eyes and report details, such as how many stripes a cat has, as if they were still looking at it¹. This is different from an afterimage. An afterimage moves with the eyes and shows reversed colours. An eidetic image stays on the surface where the picture was and keeps its true colours¹.

The psychologist Ralph Haber tested hundreds of schoolchildren in the 1960s and 1970s and found the ability in a small minority. It is most common between the ages of 6 and 12 and fades with age¹. Almost no adults have it. One hypothesis is that as children learn to put what they see into words, the raw visual store is used less and weakens. This is not proven.

The popular idea of a photographic memory is different. It means an adult who can look at a page once and recall every word later, as if from a photograph. Nobody with this ability has passed a controlled test¹. People who do well in memory competitions use trained techniques, such as attaching items to places along an imaginary walk. The cognitive scientist Marvin Minsky called photographic memory an unfounded myth³.

How common it is

Between 2% and 10% of children aged 6 to 12 show eidetic imagery in tests¹. The rate in adults is close to zero.

History and culture

The strongest claim ever recorded was a Harvard student known as Elizabeth, tested in 1970. She reported fusing two random-dot patterns viewed a day apart into a single 3D image, which would require an exact memory of thousands of dots². She later married the researcher and declined every request for a repeat test¹. No other person has repeated the feat.