Concealed identity information detection with pupillometry in rapid serial visual presentation

Abstract

The concealed information test (CIT) relies on bodily reactions to stimuli that are hidden in mind. However, people can use countermeasures, such as purposely focusing on irrelevant things, to confound the CIT. A new method designed to prevent countermeasures uses rapid serial visual presentation (RSVP) to present stimuli on the fringe of awareness. Previous studies that used RSVP in combination with electroencephalography (EEG) showed that participants exhibit a clear reaction to their real first name, even when they try to prevent such a reaction (i.e., when their name is concealed information). Since EEG is not easily applicable outside the laboratory, we investigated here whether pupil size, which is easier to measure, can also be used to detect concealed identity information. In our first study, participants adopted a fake name, and searched for this name in an RSVP task, while their pupil sizes were recorded. Apart from this fake name, their real name and a control name also appeared in the task. We found pupil dilation in response to the task-irrelevant real name, as compared to control names. However, while most participants showed this effect qualitatively, it was not statistically significant for most participants individually. In a second study, we preregistered the proof-of-concept methodology and replicated the original findings. Taken together, our results show that the current RSVP task with pupillometry can detect concealed identity information at a group level. Further development of the method is needed to create a valid and reliable concealed identity information detector at the individual level.

ERP and Pupillometry Synchronization Analysis on Rapid Serial Visual Presentation of Words, Numbers, Pictures

“…In the early five time windows of 500-600 ms, 500-700 ms, 500-800 ms, 500-900 ms and 500-1000 ms, the average amplitudes of pupil dilation at 200 ms presentation rate was significantly higher than those at 100 ms presentation rate. The possible explanation was that, pupil dilation was induced by inhibition of the parasympathetic nervous system and Edinger-Westphal nucleus, and the inhibition was controlled by the LC-NE system [8,10,11]. At the early stage within 1000 ms, the activation intensity of the LC-NE system at 200 ms presentation rate might be greater than that at 100 ms presentation rate, thus the size of pupil dilation at 200 ms presentation rate was higher than that at 100 ms presentation rate.…”

“…Previous studies demonstrated that pupil dilation was related to target recognition. When subjects focused on targets, the pupils dilated [8][9][10]. Pupil dilation is induced by the inhibition of the parasympathetic nervous system and Edinger-Westphal nucleus, and the locus coeruleus-norepinephrine system (LC-NE) controls these inhibitory processes, which dominates the regulation of attention [8,10,11].…”

“…When subjects focused on targets, the pupils dilated [8][9][10]. Pupil dilation is induced by the inhibition of the parasympathetic nervous system and Edinger-Westphal nucleus, and the locus coeruleus-norepinephrine system (LC-NE) controls these inhibitory processes, which dominates the regulation of attention [8,10,11]. Previous studies demonstrated that pupil dilation was related to cognitive processing of visual information, such as memory, attention and cognitive load [12][13][14].…”

“…Moreover, they also found that the lower the target probability, the larger the pupil size. For information complexity, Ivory et al [10] used pupil size to detect concealed identity information in the RSVP tasks. The results demonstrated that the pupil size of concealed identity information was significantly higher than that of control information.…”

Intelligent Eye-Tracker-Based Methods for Detection of Deception: A Survey

“…We also focused on research that introduces more accurate countermeasure resistant paradigms or applies the instruction for guilty participants to look at every familiar and unfamiliar face in the same way [27,28,35,38]. The results of the countermeasure instruction studies point out that this task attenuated the initial orienting response to the familiar face but still concealed that recognition was detected by overt avoidance of the familiar face.…”