International Journal of Comparative Psychology

One of the most familiar children’s games (marketed under many names including the memory game, Concentration, and Husker Du also would seem to provide an excellent test of visuospatial memory. A computerized version of this game was written in which human adults or rhesus monkeys were required to find matching pairs of pictures by “flipping over” computer-generated images of cards. Finding one of the 2 to 6 pairs of images (color patches, line drawings, letters, etc.) caused the pictures to remain visible, but errors (mismatches) caused the images to be concealed again and thus required the participants to remember which images had been seen and where each was hidden. In a series of experiments, all participants were able to locate the pairs of stimuli, but monkeys were consistently and significantly worse than the human adults. Indeed, the monkeys frequently perseverated on errors, causing them to be worse than chance in many conditions, even after training. In the present manuscript, data are presented to suggest that this species difference does not simply reflect a limitation on the monkeys’ knowledge of the “rules of the game.”