What eidetic imagery is
Eidetic imagery is the experience of continuing to see an image for a short while after it has been removed. The person reports that the picture still seems to be in front of them for a moment, and then it fades.
It has been reported in a small minority of children. In adults it is very rare.
How it differs from photographic memory
The two terms are often used as if they mean the same thing. They do not.
| Question | Eidetic imagery | Photographic memory, the popular idea |
|---|---|---|
| What is it? | Briefly still seeing an image after it is gone | Storing an exact picture you can read back at will |
| How long does it last? | A short time | Permanently |
| What is the evidence? | Reported in a small minority of children, very rare in adults | Never convincingly demonstrated in adults |
The photographic memory test page looks at the popular idea on its own.
What this test shows
The game on this page flashes a set of squares on a grid for about a second. When the board goes blank, you tap the squares that were lit, in any order. It starts with 3 squares on a 3 by 3 board, adds one square per level, and the board grows as far as 7 by 7. Three wrong taps on a level costs one of your three lives. Your score is the highest level cleared, and 7 to 9 is typical.
That tells you how large a pattern you can hold for a few seconds. It cannot tell you how you held it. Someone who groups the squares into shapes taps the same answer as someone who feels they can still see the board, so no score here proves eidetic memory.
Notice how you remember
Right after the board clears, ask yourself whether you are looking at a lingering image or rebuilding the pattern from a description, such as an L in the corner plus a row along the top. For most adults it is the second, and that strategy is what raises scores.
One of the researchers behind the Kyoto chimpanzee study suggested that young chimps may have something like a snapshot memory for a scene. The chimpanzee test page has that task.
This is a game for curiosity. If you are worried about your memory, see a doctor.