The influence of proportion overlap of lists on a picture fragment completion task

The ratio of studied to non-studied words on a test list is called the proportion overlap. Fujita (1994) reported that the proportion overlap affected the availability of conceptually driven processing, but not data-driven processing, on a word fragment completion test. In this experiment, we sought to extend the finding of the proportion overlap effect to a non-verbal implicit memory test. Participants previously studied either a list of pictures or words and then were presented with a picture fragment completion task. The proportion of studied items on the test was 20% or 80%. In the picture-study condition, perceptual priming occurred, and the amount of priming was not different between the 20% and 80% conditions. In the word-study condition, however, cross-form priming occurred only in the 80% condition, but not in the 20% condition. These results are consistent with the findings from the word fragment completion test, and suggest the generality of the proportion overlap effect on the data-driven implicit memory test.