Bias Effects in a Two-Stage Recognition Paradigm: A Challenge for “Pure” Threshold and Signal Detection Models

We explored a two-stage recognition memory paradigm in which people first make single-item “studied”/ “not studied” decisions and then have a chance to correct their errors in forced-choice trials. Each forcedchoice trial included one studied word (“target”) and one nonstudied word (“lure”) that received the same previous single-item response. For example, a studied-studied trial would have a target that was correctly called “studied” and a lure that was incorrectly called “studied.” The two-high-threshold (2HT) model and the unequal-variance signal detection (UVSD) model predict opposite effects of biasing the initial singleitem responses on subsequent forced-choice accuracy. Results from two experiments showed that the bias effect is actually near zero and well out of the range of effects predicted by either model. Follow-up analyses suggested that the model failures were not a function of experiment artifacts like changing memory states between the two types of recognition trials. Follow-up analyses also showed that the dual process signal detection model made better predictions for the forced-choice data than 2HT and UVSD models.