Repetition effects in associative false recognition: Theme-based criterion shifts are the exception, not the rule

Previous reports have demonstrated that false memory for the critical items of associative lists decreases when lists are studied multiple times (Benjamin, 2001). In three experiments, we explored two hypotheses that might account for false memory reductions with repetition. Under an identification hypothesis, repetition decreases false memory because participants realise that critical items are absent from the list at encoding and thus reject them at test. Under a criterion shift hypothesis, repetition decreases false memory because it increases the discriminability of studied words from lures, causing participants to set a higher response criterion for positive recognition responses. Results uniquely supported the criterion shift hypothesis. Furthermore, results showed that participants only changed their criterion on separate recognition tests, not on an item-by-item basis within a single recognition test. The failure to establish separate criteria within a test increased false memory for repeated lists.