Combination of Event Related Potentials and Peripheral Signals in order to Improve the Accuracy of the Lie Detection Systems

Since it was being predicted that combination of psychophysiological and ERP signals, during the detection of a guilty person's knowledge can increase the performance of integrative lie detection system toward using the separate procedures; Using the knowledge of both aspects, in this study it has been tried to determine the proper Inter-Stimulus Intervals (ISI) together with suitable sequence of stimulations in order to simultaneous recording of P300 component of brain Event Related Potentials and peripheral signals. Also a proper mock crime scenario has been designed; it has the capability of exciting the cognitive aspect of mock crime and also was capable of provoking the subject’s concerns, based on telling lie about the crime.At the next stage, after recording data from 32 participants, features from their ERP and SCR (as one of the most important peripheral signals) signals have been extracted. Then, an LDA classifier was applied on selected features which were selected by Genetic algorithm and these accuracies: 76.67%, 73.33% & 80% have been obtained for EEG, SCR and Combined data respectively.The resulted accuracies at the first show the proper quality of scenario and protocol, in synchronous stimulation and recording of both signal categories, also the improvements which have been resulted by integrated data in compare with separate ones are observable.