SPACING EFFECTS ON IMPLICIT MEMORY TESTS

The spacing effect refers to the advantage in memory for information that is repeated at separated points of time over information repeated in massed fashion. Spacing effects have been demonstrated on numerous explicit measures of memory. A series of experiments reported here demonstrate spacing effects on three implicit memory measures: (a) spelling of homophonic words, (b) word-fragment completion, and (c) perceptual identification. The spacing effect in perceptual identification was not found when materials were studied incidentally or when spacing was manipulated between lists. Also, whereas recognition of synonyms decreased as a function of spacing between synonyms, perceptual identification was uninfluenced by the spacing between synonyms. The results are interpreted as evidence that spacing effects on cued memory tests (both explicit and implicit) reflect optional rehearsal strategies.