Why seemingly more difficult test conditions produce more accurate recognition of semantic prototype words: A recognition memory paradox?

•A semantic prototype lure (PL) has a very high false alarm rate (FAR).•Unrelated distractors at test produced a high PL FAR.•Related distractors produced a lower PL FAR.•More related test probes also lowered PL FAR.•Spreading activation cannot account for these results. Subjects studied Deese-Roediger-McDermott semantic-associate lists and took a recognition test. The makeup and number of test probes were manipulated. In Experiments 1 and 2A, one of three or all three distractors were semantically related to the list theme. In Experiment 2B, 6 or 30 related probes were used at test. Results showed that semantically related distractors and a longer list of test words both had a beneficial effect on the accurate discrimination of the prototype lures from the studied semantic associates and on the discrimination of studied from unstudied prototype words. These findings are inconsistent with predictions of memory interference and activation theories. We propose that the counterintuitive findings can be explained by the notion of old/new recognition as categorization learning and that relatedness and a larger number of test probes provide more accurate information about the prototype lure as a distractor, thereby improving its classification as a distractor.