Proceedings of the Annual Meeting of the Cognitive Science Society

The P300-based Complex Trial Protocol (CTP), developed by Rosenfeld et al. (2008), is known to compensate for accuracydegradation and countermeasure issues of the Concealed Information Test. Although a myriad of CTP studies usingelectroencephalogram has been investigated, the lack of crime-related details and the complexity of the previously usedcountermeasures have revealed the necessity of in-depth experiment. In the present study, fifty participants were dividedinto three groups: guilty, innocent, and guilty-countermeasure. Participants engaged in a mock-crime scenario and onlythe guilty-countermeasure group performed ecologically validated countermeasures during the CTP. Participants reactiontime and the amplitude of P300 components of event-related potential were analyzed and there was a significant difference(p¡0.05). Moreover, using the bootstrapping method, participants were correctly classified as guilty or innocent, regardlessof the use of countermeasure, with accuracy above 80%. The results support the possibility of the on-site usage of theCTP.