Memory for license plates.
Andrew L. Cohen, Caren M. Rotello, Lisa M. Fiorenzo · Psychology Public Policy and Law · 2014
The ability of an eyewitness to recall a briefly viewed license plate is an understudied issue with great practical significance. Using large samples of adult participants (total N 1,859), we assessed the memory implications of a current proposal (EZ-ID, n.d.) to include a nameable symbol, such as a triangle or heart, on standard-issue license plates. In 2 experiments, no overall memory benefit was observed for license plates with symbols compared to standard designs. Although symbols conveyed no memory advantage, we show that, under certain conditions, including symbols can reduce the number of matching plates when a plate is partially remembered, enhancing the ability of investigators to identify the specific vehicle involved in a crime. We also assessed recall performance for license plates viewed under a range of conditions. Exposure time and the time delay to report have both real-world relevance and clearly predicted effects grounded in the basic memory literature. Memory increased with exposure time, but there was no effect of study-test delay. We also manipulated viewing orientation to allow comparison of memory given a standard view with the mirror-reversed view that a witness might experience while driving. Memory was significantly worse for mirror-reversed plates.