Effect of delay on recognition decisions: evidence for a criterion shift

Recent evidence indicates that in intermixed recognition testing of different stimulus classes, people can apply different decision criteria (a criterion shift) to stimulus classes distinguished by the study-test delay (Singer, Gagnon, & Richards, 2002), but not by a conspicuous strength manipulation (Stretch & Wixted, 1998b). In an attempt to reconcile these differences, we applied Singer et al.'s text retrieval method to word recognition. People first studied blocked items from each of five categories. After a delay, five new category lists were presented. After each one, the participants recognized intermixed targets and distractors from the current category and one of the earlier ones. At delays of up to 40 min, the answering criteria for immediate and delayed categories were indistinguishable. At delays of 2 days, in contrast, however, both yes-no and confidence-rating data indicated that more lenient criteria were applied to delayed than to immediate test items. This suggests that people can use the delay between study and test to flexibly adjust the decision criteria of word recognition.