The roles of feedback and prior information on the effectiveness of the base rate manipulation for response Bias

Pala, Cavit Deniz
Recognition memory is the ability to discriminate previously encountered items from new ones. Sensitivity is the degree to which participants discriminate between old and new items, whereas response bias indicates the tendency to classify an item as old. Response bias can be manipulated via methods, such as base rate manipulation, and strength manipulation, etc. The aim of the current study was to investigate the roles of response feedback and prior information in base rate manipulation for criterion shifts. Yes-no word recognition memory tasks were carried out in the study with this purpose. The base rates of test lists and type of information were manipulated in two experiments. The Base rates were 50%, 20% and 20% for three successive tests in Experiment 1A, while the base rates were 50%, 80% and 80% in Experiment 1B. The presence of feedback and prior information was also manipulated across four groups in both experiments. The results indicated that participants made adaptive shifts in their response bias in accordance with the base rates of test cycles when feedback or prior information were provided. However, the criterion did not differ across tests when no supportive cues were presented. Feedback and prior information together caused greater shifts in criteria compared with the groups with the feedback or the prior information alone. Sensitivity also decreased when test lists were comprised of mostly old or mostly new items. The findings were interpreted and compared with the literature.