Crime Memory strength in the Reaction Time Concealed Information Test

The Reaction-Time Concealed Information Test (RT-CIT) is a cognitive deception detection task used to determine whether a suspect recognizes crime information. Despite having clear theoretical and applied impact, there is a paucity of studies assessing the impact of crime memory strength on the RT-CIT. We tested the impact of memory strength in the RT-CIT by i) using crime items that are either well remembered or not (Strong or Weak memory; within-subjects) and ii) introducing a delay (1-day or 1-week; between-subjects) between encoding and testing. Participants (n = 100) encoded crime details from an online interactive heist video and after a delay completed a memory test of 18 crime details before undergoing an RT-CIT. As predicted at pre-registration, an interaction between delayed testing and memory strength was found for participants’ recognition confidence. But unexpectedly, this interaction was not mirrored in the RT-CIT effect. We only found evidence that the RT-CIT effect was larger for strongly remembered crime items than for weakly remembered items, with anecdotal evidence of a delay effect. This is the first study to indicate that the RT-CIT may be sensitive to memory strength.