Interference resolution in retrieval-induced forgetting: Behavioral evidence for a nonmonotonic relationship between interference and forgetting

Retrieving memories renders related memories less accessible. This phenomenon, termed retrieval-induced forgetting (RIF), is thought to be the result of processes that resolve interference during competitive retrieval. In several studies, researchers have manipulated the level of interference to test different theoretical accounts of RIF (e.g., inhibitory vs. noninhibitory). However, the nature of how interference and RIF are related has not been systematically investigated. Here, we introduce a design that allows for assessing interference during competitive retrieval by measuring the recall RTs associated with target recall. Using such a design, we found that RIF occurred only when interference during competitive retrieval reached moderate levels, but not when it was too low or too high. This finding might indicate that low levels of interference do not trigger interference resolution, whereas interference resolution might fail when the interference reaches extremely high levels.