Implicit Memory Effects When Using Pictures with Children and Adults: Hypermnesia Too?

Pictorial stimuli were used to investigate implicit- and explicit-memory phenomena in 3 experiments. The general procedure involved the presentation of a series of pictures during a study phase, followed by an implicit-memory test and an explicit-memory test. In the implicit-memory test, participants were presented with picture fragments and were instructed to write down what the fragment looked like. In the explicit-memory test, participants were asked to make a yes/no recognition decision regarding each picture. For children, implicit memory for pictures was robust when they were tested after a 48-hr interval, but that effect declined after 1 week; a similar implicit-memory effect for pictures was seen with college students; and the time course of the implicit-memory effect for pictures among college students (all short intervals of less than 1 week—1, 2, 3, 4, and 5 days) produced a more elevated implicit-memory performance than during the immediate testing condition. Hypermnesia may have been the cause of the increase in memory performance over the short intervals.