List-method directed forgetting after prolonged retention interval: Further challenges to contemporary accounts

Numerous studies on list-method directed forgetting (LMDF) have shown that people can voluntarily forget information when cued to do so. But the cognitive mechanism(s) behind this form of forgetting are still subject to debate. The present study focused on two explanations of LMDF: selective rehearsal and mental context change. Experiment 1 addressed the context-change account by comparing the persistence of LMDF with that of context-dependent forgetting. Results showed that LMDF, but not context-dependent forgetting, was lasting, which is inconsistent with the context-change account. Experiments 2 and 3 addressed the selective-rehearsal account by examining whether persistence of LMDF depends on the status of (intentionally vs. incidentally) encoded items and the type of distractor activity (demanding vs. undemanding) between study and test. Results showed that LMDF was lasting for both intentionally and incidentally studied items but was absent after an undemanding distractor task, which disagrees with the selective-rehearsal account. The present findings challenge both the context-change and the selective-rehearsal account as well as a dual-mechanisms view, which assumes a role of both types of mechanisms in LMDF.