ERP Components During Instructed Deception: A Case Study

Deception or lie is a cognitive process that involves the participation of different parts of the brain [1]. Liars have to inhibit truthful responses and generate a reliable false one [2]. The designed task in deception researches based on ERP components could be with or without crime content. In the present study, a task without crime content was designed.Method In this study, a simple classification task was designed based on [3]. The stimuli were 10 pictures (five animals and five plants). Before the test, the participant should select an envelope from two boxes, including 5 animals and 5 plant pictures, view the pictures and intentionally misclassify them during the experiment. The experiment comprised 3 main blocks, each containing 60 trials (48 non-target pictures and 12 target ones). 32 channel EEG signal was recorded with the sampling rate of 512 Hz. After preprocessing (1- 80 bandpass and notch filters, ICA- Correlation method for EOG reduction) the clean EEG signal was segmented into 2- seconds (-400, 1,600 ms) intervals, time-locked to stimulus onset and averaged for ERP calculation.Results The average of target and non-target epochs was calculated. Fig. 1 shows the ERP wave for both target and non- target stimulus in the Fz channels. P300 component is evident in about 500 msec after stimulus onset. It can be observed that the amplitude of P300 is larger for target stimuli rather than non-targets ones.Conclusions The present study investigates the ERP components of instructed deception. The larger P300 amplitude for target stimuli may be due to more attention on the target stimuli rather than non-target ones.