Why do Socratic stimuli produce hypermnesia?

Summary

Socratic stimuli, giving a description of a word without presenting the word itself, increase recall as a function of retention interval (see the studies on hypermnesia in Erdelyi, Buschke, & Finkelstein, 1977). In the present study, one lengthy recall task (20 min) or four consecutive recall trials of 5 min followed the presentation of either Socratic descriptions of words or words themselves, which were either of high or low imagery value (Experiment 1). The recall task used the impaired feedback technique (Gardiner, Passmore, Herriot, & Klee, 1977) leaving the already retrieved items unavailable during the remaining time of the recall trial or trials. The nature of the recall task did not affect recall performance, and only Socratic descriptions of high imagery words produced a recall increase. In Experiment 2, two possible sources of hypermnesia with Socratic stimuli were further explored: imagery and the generation effect. Generation failed to produce hypermnesia, while Socratic descriptions of high and low imagery words produced significant effects. Moreover, high imagery words without Socratic descriptions also led to hypermnesia. An encoding context that improves a unique semantic processing is likely to be critical for obtaining hypermnesia.