Title: Assessment of Neurophysiological variables in terms of Event Related Potentials for Intention to Masquerade Truth
Authors: Umesh Gupta, Abhishek Saini, Amitabh Dube
DOI: https://dx.doi.org/10.18535/jmscr/v6i5.47
Abstract
Background: The aim of the present study was to investigate whether Event Related Potentials (ERPs) can reveal a veiled and covert psychological process and /or inscription, an observation that underscores masquerading of an identified fact.
Objectives: To assess and compare P300 amplitude among two groups namely, deception (wherein the subjects were concealing the information) and control group (wherein the subjects were not concealing), in response towards performance of a tailor-made task that required selection of a playing card among five other cards.
Material and Methods: A total of 30 subjects in the age group of 18 – 25 years participated in the present study, taking part in the formation of both groups which differed only with respect to the task requirements. The candidates were asked to select one playing card (probe) among five playing cards, which were then presented to the subject one by one in a pseudo-randomised sequence on a computer monitor, in a dimly lit, sound attenuated room. While performing under the deception group, the participants were asked to conceal the selected card from the knowledge of the examiner and to respond equivocally/uniformly towards the selected card (probe) as well towards the non-selected cards. A playing card with an image of joker served as target which required a specific response in form of pressing YES on a keyboard in order to ascertain attention. Electroencephalogram (EEG) was recorded simultaneously along with the performance of these tasks using 10-20 international system of electrode placement. The data so obtained was selectively averaged for Pz electrode site and P300 ERP component was evaluated in terms of amplitude in µV. The obtained parameters were compared between both groups and a p-value of < 0.05 was accepted as a marker of significance.
Result: The results of the present study indicated that the amplitude of P300 component of ERP came out to be higher under the circumstances wherein the participants were performing the task under Deception group as compared to their performance as controls.
Conclusion: The P300 component of the Event Related Potentials (ERPs) can serve as a proxy marker to reveal a hidden psychological process like concealment.
Keywords: P300, Event related potentials (ERP), Electroencephalography (EEG), Deception and Concealment.