Shown 10,000 photos once each, people still recognized most of them days later

In a 1973 experiment, participants viewed 10,000 photographs for a few seconds each, then were tested on recognizing them against new images days afterward, with accuracy staying above 80%. Pictures are consistently remembered far better than the equivalent words describing the same content, a gap known as the picture superiority effect. Researchers think images get encoded through both a verbal label and a visual trace, giving them two routes back to memory instead of one.

— Lionel Standing, Learning 10,000 pictures — Quarterly Journal of Experimental Psychology, 1973