Developmental Changes in the Inhibition of Previously Relevant Information

This study examined whether developmental differences exist in the ability to suppress irrelevant information that has entered working memory. Second graders, sixth graders, and young adults (M ages = 7. 5, 11.7, and 22.4 years, respectively) were asked to provide the ending for a series of sentences that highly constrained a terminal noun (e.g., "He mailed the letters without any stamps."). Responses to filler sentences were confirmed with the anticipated ending, whereas responses to critical sentences were disconfirmed with an unexpected ending (e.g., help). In either case, participants were instructed to remember the terminal noun (target) that was presented to them. Using another sentence-completion task, memory for both disconfirmed and target nouns was measured implicitly in terms of priming effects. Children, particularly second graders, showed priming effects with disconfirmed nouns, whereas young adults exhibited priming effects only with the target nouns. These results are consistent with the view that there are developmental differences in the ability to inhibit irrelevant information (Bjorklund & Harnishfeger, 1990; Hasher & Zacks, 1988).