Feedback does not influence the recognition-related P300 in a novel concealed information test while feedback-evoked P300 shows promising diagnostic accuracy.

The feedback concealed information test (fCIT) is a novel variant of a CIT, which provides participants with feedback regarding their memory concealment performance during the CIT. Previous studies have found that feedback-related ERPs associated with feedback processing in the fCIT can accurately identify concealed information. However, it is still unknown whether the feedback influences the process and ERP signs of recognition during memory concealment, such as the recognition P300. To address this issue, the present study directly compared the recognition-based P300 in CITs with and without feedback. Results showed that the probe elicited a larger recognition P300 than irrelevants in both CITs with and without feedback, and there were no significant differences in recognition P300 between those two CITs. Moreover, the detection rate for recognition-based P300 in both CITs also had no significant difference. The feedback-related ERPs, especially feedback P300, continued to discriminate guilty and innocent subjects with AUCs well above the chance.