The Feedback Concealed Information Test:The Combination Of Recognition And Feedback ERPs

For centuries,many researcher have devoted great efforts to detecting deception by using an event-related potential(ERP)-based concealed information test(CIT).That is,P300,as a cortical signal of the recognition of meaningful information,can be employed to distinguish guilty and innocent.However,many researches found the P300-based CIT is so vulnerable to countermeasures and information encoding that new improved paradigm has been explored.Recent studies have showed that a novel variant of the concealed information test(CIT),called the feedback-related CIT(fCIT),is a scientifically validated paradigm which could be used in criminal investigation.This new paradigm would provide participants with immediate truthful/deceive feedback regarding their responses.Based on this paradigm,our study will further explore and systematically reveal the mechanism of the fCIT through two experiments to promote its application in real scenes.Experiment 1 examined whether the fCIT can be used to detect autobiographical information,which means the detection efficiency of feedback-ERPs underlying autobiographical memory concealment.Participants either played a role of spy or innocent during the fCIT.The probes(the spy name)and a series of irrelevents(others' name)were presented as the ratio of 1:4,following feedback regarding their deceptive/truthful responses.So for spy participants the probes actually were their own names.Experiment 2 examined whether feedback in the fCIT influences recognition-P300 and validated fCIT with crime-related information.Participants were randomly assigned to guilty or innocent by mock-crime task,then complete fCIT or CIT task.The same probe stimuli was used in both tasks,with the only difference is that subjects who performed the fCIT would receive immediate feedback of "honesty +4" or "lying-2" based on their responses.Our study have draw to the following conclusions:1.The fCIT can effectively detect autobiographical information.Results showed that spy name elicited larger recognition-P300 s than irrelevant name among spy participants;But in the innocent group,there was no significant difference inrecognition-P300 s.In the feedback stage,irrelevant name would elicit more negative FRN than spy name in spy group,but there was no significant difference in innocent group;Moreover,spy name elicited more positive feedback-P300 s than irrelevant name among spy participants,but there was no significant difference in innocent group.2.The fCIT can effectively detect crime-related information.Results showed that criminal information elicited larger recognition-P300 s than irrelevant information among guilty participants;But in the innocent group,there was no significant difference in recognition-P300 s.In the feedback stage,irrelevant information would elicit more negative FRN than criminal information in guilty group,but there was no significant difference in innocent group;Moreover,criminal information elicited more positive feedback-P300 s than irrelevant information among guilty participants,but there was no significant difference in innocent group.3.The trial-based feedback in the fCIT had no effect on the detection rate of recognition P300.With or without feedback stimulus,there was no significant difference in P300 amplitude between the probe and the irrelevant,and no significant difference in detection efficiency of P300 recognition.4.Both recognition-and feedback-ERPs were highly effective in distinguishing between guilty and innocent participants.