Memory Conformity for New and Old Items with Immediate and Delayed Testing

Memory conformity for images was examined using a mixed factorial design. Participants were presented with 50 images then later completed an old/new recognition test on these plus 50 fillers. Some received post‐event information (PEI) attributed to a co‐witness that was introduced either soon after the original 50 images were presented or 2 days later. The memory test was either soon after the co‐witness PEI was shown or 2 days later. When the memory test was 2 days after receiving PEI, the PEI had no effect. PEI had a large effect when presented just before testing. The memory conformity effect was largest when PEI was presented, and the when memory test was completed 2 days after the initial presentation. Memory conformity effects were larger for new items than for old when PEI immediately preceded the test. Thus, the PEI affected the false alarm rate more than the hit rate. Copyright © 2012 John Wiley & Sons, Ltd.