Remembering what one intended to forget: the lack of directed forgetting effects in implicit memory

The results of previous studies on directed forgetting effects in implicit memory have led to the conclusion that the underlying mechanism for such effects is an inhibition of retrieval or an encoding difficulty. Differences in procedure and stimuli may contribute to these different conclusions. In 2 studies we standardized the procedure while varying the stimuli. As in previous research, directed forgetting results were obtained for direct memory tasks. However, the magnitude of the directed forgetting effect varied with the stimuli. In Experiments 1 and 2, medium- and low-frequency to-be-remembered (R) and to-be-forgotten (F) words appeared to be equally accessible using the indirect task. In Experiment 3, we devised a procedure in which a single stem could lead to an R-word or F-word, but space was provided for only one word. In that way, we could examine the relative accessibility of R- and F-words. Results are discussed in light of Mandler's (1980) conceptualization of the contributions of identification and familiarity to memory retrieval processes.