Background. Recently, scientific and technological progress allows the widespread use of high-tech electronic means to create security systems. The advantages of identifying people who are high on drugs or alcohol with video surveillance systems on pupillograms are indisputable. However, those who bear aggressive intentions stay in the shade. The standard method of identifying emotions aimed at recording facial expressions is sufficient enough, but it is difficult to recognize negative intentions in a person if they keep control of themselves. To solve this problem, we propose to switch from passive safety systems to active ones. Therefore, studies of the pupillary response to the stimuli presented are relevant today.
The Objective of the research is to identify patterns of pupillograms that can be used to control pupillary reactions to the stimuli significant for an individual. Simultaneously, the following tasks were solved: checking the possibility of interpreting the pupillogram by synchronizing them with the tracks of the attention focus and searching for the sites of the pupillograms allegedly resulting from emotions in response to the presented stimuli.
Design. At the first stage, the images used as stimuli presented to the subjects of the research were selected. Incentives were thematic in nature and contributed to identifying the unstable psychophysical state of a person or their susceptibility to aggression. At the second stage, the calibration of the optoelectronic system used to record the pupillograms and oculograms, as well as stabilizing factors that affect the size of the pupils, was carried out. Pupilograms were obtained using groups of two age categories (16–25 years old and 45–50 years old) of 10 and 5 subjects accordingly (both males and females). The subjects selected for the research did not have any eye diseases; their eye sight was normal or adjusted.
Results.The interdependence of the size of the pupils and the displacement of the center of attention were identified. The verification of the pupillogram rank correlation was obtained when different subjects viewed identical sequences of visual stimuli showed that in general the p significance level did not exceed the critical value alpha = 0.05. The reliability of the correlation confirms the pupillograms depend on the shape of the objects viewed and the patterns that unite the pupillograms. The microsaccades in pupillograms are well explained by moving and focusing the gaze on the details of the image, which makes it possible to interpret them as waves of attention. Synchronizing the pupillograms and oculograms allows distinguishing areas that are presumably explained by the emotional reaction of the individual to a weak external stimulus. The Fourier analysis of the pupillograms revealed a change in the observed frequency spectrum, depending on the presence or absence of an emotional reaction, the speed of the shift in the focus of attention.
Findings.The observed set of frequencies suggests a connection between the diameters of the eye pupils and the brain potentials. The practical significance of the results is to expand the possibilities of using biometric security systems, including prevention of suicide in adolescents.