Norman, K. A. (2002). Differential effects of list strength on recollection and familiarity. Journal of Experimental Psychology: Learning, Memory, & Cognition, 28(6), 1083-1094.

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Numerous studies have found a null list strength effect (LSE) for recognition sensitivity: Strengthening memory traces associated with some, but not all, studied items does not impair recognition of non-strengthened studied items. In Experiment 1, we set out to test the generality of this result; contrary to prior research, we found a LSE using ROC-based measures of recognition sensitivity (Az and da). To account for the discrepancy between our result and prior results, we argue that a LSE is present for recollection but not for discrimination based on familiarity. Thus, the size of the LSE will depend on the extent to which recollection is driving recognition. In Experiment 1, we obtained suggestive evidence in favor of this hypothesis using self-report measures of recollection.

In Experiment 2, we set out to increase the contribution of recollection by using switched plurality (SP) lures that were highly similar to studied items. As predicted, there was a significant LSE for comparisons involving SP lures. In contrast, the LSE for discrimination of studied items and nominally unrelated lures was not significant.