False memories for compound words: role of working memory

Subjects studied pairs of compound words; pair members were presented simultaneously (one above the other) for 2 sec or sequentially (one immediately following the other) for 1 sec each, and 6-sec interstimulus intervals separated the end of presentation of one pair and the start of that of another. A subsequent recognition test included within-pair and between-pair conjunction foils (recombinations of stimulus parts from the same study pair and from separate pairs, respectively). Previous experiments using faces as stimuli have demonstrated that when faces are presented simultaneously there are many more false alarms to within-pair than to between-pair conjunction items, and when faces are presented sequentially there is an equal number of false alarms in those two conditions. However, Experiment 1 showed that for compound word stimuli there were equally high false alarm rates toboth types of foils in both study conditions relative to completely new test items. Experiment 2 showed that when rehearsal of compound words was prevented, the pattern of conjunction errors was very similar to the one typically obtained for faces. In Experiment 3, subjects falsely recalled conjunctions of within-pair compound words but not conjunctions of between-pair words in the simultaneous-study condition; no conjunctions were recalled in the sequential-study condition. The results support the idea that working memory processing is necessary for binding stimulus parts together in episodic memory.