Detecting concealed familiarity using eye movements: the role of task demands

Abstract

Background What can theories regarding memory-related gaze preference contribute to the field of deception detection? While abundant research has examined the ability to detect concealed information through physiological responses, only recently has the scientific community started to explore how eye tracking can be utilized for that purpose. However, previous attempts to detect deception through eye movements have led to relatively low detection ability in comparison to physiological measures. In the current study, we demonstrate that the modulation of gaze behavior by familiarity, changes considerably when participants perform a visual detection task in comparison to a short-term memory task (that was used in a previous study). Thus, we highlight the importance of theory-based selection of task demands for improving the ability to detect concealed information using eye-movement measures. Results During visual exploration of four faces (some familiar and some unfamiliar) gaze was allocated preferably on familiar faces, manifested by more fixations. However, this preference tendency vanished once participants were instructed to convey countermeasures and conceal their familiarity by deploying gaze equally to all faces. This gaze behavior during the visual detection task differed significantly from the one observed during a short-term memory task used in a previous study in which a preference towards unfamiliar faces was evident even when countermeasures were applied. Conclusions Different tasks elicit different patterns of gaze behavior towards familiar and unfamiliar faces. Moreover, the ability to voluntarily control gaze behavior is tightly related to task demands. Adequate ability to control gaze was observed in the current visual detection task when memorizing the faces was not required for a successful accomplishment of the task. Thus, applied settings would benefit from a short-term memory task which is much more robust to countermeasure efforts. Beyond shedding light on theories of gaze preference, these findings provide a backbone for future research in the field of deception detection via eye movements. Electronic supplementary material The online version of this article (10.1186/s41235-019-0162-7) contains supplementary material, which is available to authorized users.

Eye spy a liar: assessing the utility of eye fixations and confidence judgments for detecting concealed recognition of faces, scenes and objects

“…Our findings are consistent with eye movement research underlining the crucial role of cognitive factors such as degree of familiarity, explicit task instructions and stimulus presentation on attention during visual processing tasks (e.g. Loftus & Mackworth, 1978;Nahari, Lancry-Dayan, Ben-Shakhar, & Pertzov, 2019;Yarbus, 1967). Markers of recognition for personally familiar non-face items in Experiment 2 were not as robust as those observed for faces in Experiment 1 (i.e.…”

“…Ben-Shakhar & Elaad, 2003 ; Meijer et al, 2014 ). However, few studies have assessed the robustness of fixation measures during informed countermeasures to conceal recognition (Millen & Hancock, 2019 ; Peth et al, 2016 ; Nahari et al, 2019 , this issue). Whereas Millen & Hancock ( 2019 , this issue) found that fixation durations were largely robust to intentional eye movement strategies to look at every face the same way, Nahari et al ( 2019 ) found that fixation duration as a marker of recognition in simultaneous displays of faces (one familiar face to many unfamiliar faces) vanished when participants were instructed to look at all faces equally.…”

“…However, few studies have assessed the robustness of fixation measures during informed countermeasures to conceal recognition (Millen & Hancock, 2019 ; Peth et al, 2016 ; Nahari et al, 2019 , this issue). Whereas Millen & Hancock ( 2019 , this issue) found that fixation durations were largely robust to intentional eye movement strategies to look at every face the same way, Nahari et al ( 2019 ) found that fixation duration as a marker of recognition in simultaneous displays of faces (one familiar face to many unfamiliar faces) vanished when participants were instructed to look at all faces equally. Alternatively, Peth and colleagues examined the effectiveness of physical and mental countermeasures (physical finger wiggling or mental imagining of emotional events) during recognition of incidentally encoded information, and found that fewer fixations were invulnerable to both countermeasures but that fixation durations were not.…”

Keep an eye on your belongings: Gaze dynamics toward familiar and unfamiliar objects.

“…The parallel display was divided to two periods of times (1000 ms and 4000 ms) based on our previous studies(Lancry-Dayan et al, 2018;Nahari et al, 2019).1894 LANCRY-DAYAN, NAHARI, BEN-SHAKHAR, AND PERTZOV This document is copyrighted by the American Psychological Association or one of its allied publishers.This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.…”

Concealed information revealed by involuntary eye movements on the fringe of awareness in a mock terror experiment

“…In addition to orienting, there is evidence of an arousal inhibition effect that is applied by the subjects to conceal their orienting activity, and its measure is used for detecting deception 22 . Typically, CIT measures physiological responses such as heart rate and skin conductance 19 , neural responses, primarily the P300 brain wave 23 , as well as eye movements, eye blinks, and pupil dilation 24 – 27 . These measures typically require a serial repetitive presentation for averaging; as a result, false positives could occur due to an arbitrary orienting and to the observer’s fatigue as well as biological noise, affecting the signal-to-noise ratio (SNR) as in the P300 BCI methods 28 .…”