The contribution of recollection and familiarity to recognition and source-memory judgments: a formal dual-process model and an analysis of receiver operating characteristics.

A formal dual-process model that assumes that memory judgments can be based on a threshold recollection process and a signal-detection based familiarity process is proposed to account for both recognition and source-memory performance. The model was tested in 4 experiments by examining recognition and source-memory receiver operating characteristics (ROCs). In agreement with the predictions of the model, recognition and source memory dissociated in certain conditions. Recognition ROCs were curvilinear in probability space and relatively linear in z-space, as expected if recollection and familiarity contributed to performance. In contrast, source ROCs typically were linear and exhibited a pronounced U shape in z-space, as expected if performance primarily relied on recollection. However, in conditions in which familiarity was clearly indicative of an item's source, the source ROC became curvilinear, suggesting that participants could use familiarity as a basis for source judgments. Several alternative models, including the unequal-variance signal-detection model, were found to be inconsistent with the ROC data.