Inhibition of return following instructions to remember and forget

Inhibition of return (IOR) refers to slowed responding to a target that appears in the same rather than in a different location as a preceding peripheral onset cue. This study examined IOR as a function of whether the peripheral onset cue was a word that participants were directed to remember or forget. Using a modified item-method directed forgetting paradigm, words appeared one at a time to the left or right, followed by a remember or forget instruction. A target dot was then presented either in the same peripheral location as the preceding word or in a different location; participants made a speeded response to localize this target. Confirming compliance with the memory instructions, recall tests that alternated with blocks of IOR trials (Experiment 1) revealed few intrusions of to-be-forgotten words, and a final recognition test (Experiments 1 and 3) revealed more hits for to-be-remembered words than for to-be-forgotten words. Reaction times to the target dot revealed greater magnitude IOR following to-be-forgotten words than following to-be-remembered words (Experiments 1 and 3). Moreover, when compared to baseline IOR values (Experiment 2), it appeared that this difference resulted from a magnification of IOR following forget instructions and a reduction in IOR following remember instructions. These results demonstrate the usefulness of IOR as an index of memorial processes and suggest that attentional orienting may play a role in the remembering and forgetting of words presented in peripheral visual locations.