Analysis of pupil fluctuations for detection of deception

The relation between pupil fluctuation and deception is considered. The response of pupil to light or noise stimuli has been extensively studied, together with the relation between anomalous fluctuations and drug or alcohol abduction. Moreover it is known that cognitive process, fatigue and emotions have influence in pupil fluctuation and in its reaction to stimuli. Since 1940 the idea of studying the pupil movement and fluctuations as index of deception has been considered; nevertheless, since many different cognitive processes can influence pupillary dilatation, it is necessary to improve the technique and to assess the accuracy of pupil movement as such a possible parameter. The present paper analyses the pupil fluctuation, the movements of its center and the increase of the number of eye blinking in order to propose possible indicators of deception. The first results proposed appear to be encouraging; of course in all laboratory studies of deception the simulation context is different from real-life investigations; this limitation will require further development.