The scientific widespread search for deception detection, in the sense of detecting deliberate attempts to mislead others, has long been and still is a present struggle of everyday life. It has been found that lying is an extremely complex social behaviour that does involve several cognitive processes. The right indicators of deception can be revealed with specific verbal and nonverbal behaviour, or more specific, with the help of physiological signals that can be measured with a vast variety of technologies. In our study, we were investigating deception detection while placing more emphasis on psychophysiological measures with the use of a non-invasive thermal imaging technology, which can be used in stress level detection based on facial thermal readings. In the empirical part of the laboratory study, our goal was to evaluate the accuracy of the recognition of psychophysiological responses during the narration of true and untrue stories. The research protocol began and ended with the conduct of a semi-structured interview which should made participants more comfortable with the environment. Before measurement, the participants filled out the STAI-X1 (State-Trait Anxiety Inventory) questionnaire about the level of anxiety, followed by the central part of the survey. In the first part, there was a control measurement, where participants answered a set of neutral and comparative questions. The second part followed the narration of a true and an untrue story where we used the technique of a stimulated cognitive load, as participants had a maximum of two minutes for preparation. First, we assumed that between a true and a false story there is a noticeable temperature difference on the narrator’s face with regard to the selected regions of interest (ROI), and second that heart rate (HR) and electrodermal activity (EDA) will increase, while temperature of hands will decrease when telling the false story. The results did not show statistically significant differences between true and lied story for any measurement compared between measured participants and within each participant individually, but slight differences still appeared. I conclude my master thesis as a review in the field of psychophysiological detection of deception with a critical approach to the use of the measuring instruments, focusing on important limitations that may have led to the inability to recognize the deception and by proposing suggestions for future research.
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