understanding the role of inhibition in cognition. Research on a wide variety of psychological processes, including attention, perception, learning and memory, psycholinguistics, cognitive development, aging, learning disabilities, and neuropsychology, suggests that resistance to interference (which implies capacity for inhibition) is an important part of cognition. More recently, researchers suggest that the hippocampus plays a role in the regulation of disliked and competing memories, and fMRI studies have shown hippocampus activity during inhibition processes. Empirical research Part-set cuing effect The "part-set cuing effect" was initially discovered by Slamecka (1968), who found that providing a portion of to-be-remembered items as test cues often impairs retrieval of the remaining un-cued items compared with performance in a no-cue (free-recall) control condition. Such an effect is intriguing because normally cues are expected to aid recall (e.g., Tulving & Pearlstone, 1966). A prominent figure in retrieval-based inhibition research, Henry L. Roediger III was another one of the first psychologists to propose the idea that retrieving an item reduces the subsequent accessibility of other stored items. Becoming aware of the part-set cueing effect reduces the effect, such that relearning part of a set of previously learned associations can improve recall of the non-relearned associations. Hasher and Zacks' inhibition account of aging Using inhibition to explain memory processes began with the work of Hasher and Zacks (1988), which focused on the cognitive costs associated with aging and bridging the attention-memory gap. Hasher and Zacks found that older adults show impairments on tasks that require inhibiting irrelevant information in working memory, and these impairments may lead to problems in a variety of contexts. Retrieval-induced forgetting Anderson and Spellman's model of retrieval-induced forgetting suggests that when items compete during retrieval, an inhibitory process will serve to suppress those competitors. For instance, retrieval of one meaning for a word (e.g. the verb meaning of the word sock) will tend to inhibit the dominant meaning of that word (e.g. the noun meaning of sock). In 1995, Anderson and Spellman conducted a three-phase study using their retrieval-induced forgetting model to demonstrate unlearning as inhibition. Study phase: Participants study a list of category-exemplar pairings where some exemplars semantically similar in that they belong to another category besides the one they are explicitly paired with (e.g. Food-Cracker, Food-Strawberry, Red-Tomato, Red-Blood). Retrieval-practice phase: Participants are cued to practice remembering some of the exemplars given the category cue (e.g. Red-Bl__). Test phase: Given each category as a