Evidence for Multiple Mechanisms Underlying List-Method Directed Forgetting

Directed forgetting (DF) studies demonstrate that humans can intentionally forget item information. In the presented study, participants learned three lists of words. After studying the first two lists (L0+L1), we cued half of the participants to forget these lists before learning a new list (L2), the other half remembered all three lists. Typically, such a forget instruction impedes recall of previously-studied to-be-forgotten words but enhances memory for subsequent to-be-remembered items. Instead of recalling the words, we asked participants to select the list a word was studied in, assessing how DF affected both item- and list-memory. In line with the context-change hypothesis, list-memory for L1 did not differ between the two groups suggesting that even if recall of to-be-forgotten words is typically impaired, list-memory is still intact. Furthermore, after the forget instruction, participants’ list-memory was enhanced particularly for early L2 words, providing evidence for a reset of encoding or rehearsal processes.