Direct evidence for the role of inhibition in resolving interference in memory

Interference from competing material at retrieval is a major cause of memory failure. We tested the hypothesis that such interference can be overcome by suppressing competing responses. In a three-phase task, participants in the critical interference condition first performed a vowel-counting task (Phase 1) that included pairs of orthographically similar words (e.g., allergy and analogy). After a delay, participants were asked to solve word fragments (e.g., a _ l _ _ gy) that resembled both words in a pair they had seen, but could be completed only by one of these words (Phase 2). We then measured the consequence of having successfully resolved interference in Phase 2 by asking participants to read a list of words, including rejected competitor words (i.e., the word in each pair that could not be used to solve the word fragments), as quickly as possible (Phase 3). Participants in the interference condition were slower to name the competitor words than participants in conditions that did not require interference resolution. These results constitute direct evidence for the role of active suppression in resolving interference during memory retrieval.