Combining the P300-complex trial-based Concealed Information Test and the reaction time-based autobiographical Implicit Association Test in concealed memory detection


  • This research was supported by the Graduate Research Grant of Northwestern University awarded to Xiaoqing Hu.

Address correspondence to: Xiaoqing Hu, Department of Psychology, Northwestern University, 2029 Sheridan Rd., Evanston, IL, 60208. E-mail:


Despite the P300-Concealed Information Test's validity in detecting concealed memory when it is conducted immediately after the mock crime, whether the P300-CIT's detection efficiency is moderated by time delay remains unknown. Here, we conducted a mock crime study in which guilty participants were tested immediately after the mock crime or 1 month later. An innocent group was also tested. Assuming that the autobiographical Implicit Association Test (aIAT) and the P300-CIT rely on nonoverlapping mechanisms for memory detection, participants were tested using both the P300-CIT and the reaction time (RT)–based aIAT. Results suggested that the sensitivity of both tests remains even after the 1-month delay. The indicators from the RT-aIAT and P300-CIT were uncorrelated, thus combining P300-CIT and aIAT data further increased the efficiency of memory detection.