a H.Mehmam - M.S student of Biomedical Engineering in Shahed University
A Motei Nasabadi - Biomedical Engineering Department, Shahed University, Tehran, Iran
A Mohammadian - PhD candidate of Biomedical Engineering in Amirkabir University of Technology. Member of Research Center ofIntelligent Signal Processing
SH Torabi - member of Research Center of Intelligent Signal Processing

In this study we have used Recurrence Plots (RPs) in order to discriminate between guilty and innocentsubjects, using their single-trial ERPs. Data were recorded during the Guilty Knowledge Test (GKT). The results from 49 subjects who participated in concealed face recognition test indicate that amplitude of some RQA variables in guilty subjects are significantly higher than innocent ones, around 300ms (P<0.05). Increment of these RQA variables are relating to complexity reduction of brain’s system, during familiar face recognition. Also, results show that appearance of the P300 component can increase determinism and synchronization, in brains’ signals.