Item repetition and retrieval processes in cued recall: Analysis of recall-latency distributions

The SAM (search of associative memory) model provides a unified account of accuracy effects, assuming that retrieval is a cue-dependent two-stage process of sampling and recovery, which depends on the strength of items relative to all others and on that item associated with the sampling trace, respectively. On the other hand, the relative strength model uniquely provides latency predictions, assuming that recall latency is determined solely by relative strength (similar to the sampling rule in SAM): Latency should remain unchanged for strong and weak items in pure lists, but will be shorter for strong items than for weak items in mixed lists. To test the predictions, the present study examined accuracy and latency distributions, which were fit with the ex-Gaussian, using item repetition as a means of strengthening. Massed versus spaced repetitions were used where repetitions were either cue-target pairs or cue alone. When repetitions were spaced in mixed lists, accuracy and latency both increased with cue-target repetitions, relative to cue-only repetitions, and slow recall for cue-target repetitions was due to initially nonretrievable items. However, even after successful recall on a pretest, cue-target repetitions led to an increase in latency in pure lists. These findings are difficult to reconcile with relative-strength explanations of latency. They indeed suggest that (1) separate traces are created for each repetition, (2) memory traces are updated if the item is retrieved (otherwise, new traces are stored), and (3) recovery plays a role in latency, which are discussed with the distinction between sampling and recovery of SAM.