Positive and negative remember judgments and ROCs in the plurals paradigm: evidence for alternative decision strategies.

Using old-new ratings and remember-know judgments we explored the plurals paradigm, in which studied words must be distinguished from plurality-changed lures. The paradigm allowed us to investigate negative remembering--that is, the remembering of a plural-altered study item; capacity for this judgment was found to be poorer than or equivalent to the conventional positive remembering. A response-bias manipulation affected positive but not negative remembering. The ratings were used to construct ROC curves and test the prediction of the most common dual-process theory of recognition memory (Yonelinas, 2001) that the amount of recollection can be independently estimated from ROC curves and from remember judgments. By fitting the individual data with pure signal detection theory (SDT) models and dual-process models that combined SDT and high-threshold components (HTSDT), we identified two types of subjects. For those who were better described by HTSDT, the predicted convergence of remember-know and ROC measures was observed. For those who were better described by SDT, the ROC intercept could not predict the remember rate. The data are consistent with the idea that all subjects rely on the same representation but base their decisions on different partitions of a decision space.