Associations supporting items gained and maintained across recall tests

When performing successive recall tests without restudy, subjects' recalls exhibit intriguing variability across tests, including gaining or losing items across tests. To examine the cognitive mechanisms underlying this variability, research has focused primarily on hypermnesia, the finding that recall performance increases across tests (Erdelyi & Becker, 1974). Hypermnesia studies commonly consider conditions that impact recall levels of items gained across tests versus items maintained across tests. By contrast, analyses of recall clustering in hypermnesia studies typically collapse across maintained items and item gains. Here, I examine associative processes separately for item gains and maintained items. Experiment 1 examines these effects in final free recall, a paradigm also used to examine changes in recall across tests but less commonly linked with hypermnesia, whereas Experiment 2 uses a classic hypermnesia design. In both experiments, subjects exhibited significant temporal and semantic clustering for maintained items, but there was less evidence of these associations supporting item gains. In Experiment 1, transitions to maintained items boasted a greater proportion of same-list transitions than item gains, and in Experiment 2, there were no significant clustering effects to item gains on a test producing hypermnesia. Further, in Experiment 1, subjects exhibiting greater list-level temporal clustering of maintained items also maintained more items across tests. The results highlight the importance of episodic and semantic associations to changes in recall across tests and have implications for current theories of hypermnesia. (PsycInfo Database Record (c) 2025 APA, all rights reserved).