Eye gaze fixations for critical targets with concealed knowledge

The present study explored the differences in eye movement fixations as a function of deceit as compared to conditions requiring either passive viewing or truth telling for real scene photographic images and collages. The task that the participants had to perform entailed nondisclosure of information pertaining to place of hiding of the concealed item (critical target), and later viewing the same on an eye-tracker. In deception condition, participants were motivated to lie, and in truth condition, they were expected to respond truthfully to the concealed item. Free viewing was the (first viewing) control task that did not require any response. Fixation patterns and temporal indicators of eye fixations showed significant difference between free viewing and deceit conditions, but not between deceit and truth. Greater number of participants decided to fixate on the critical target when presented in collage form compared to real scene photographs in all the three conditions. When lying, people tend to spend more time encoding information when viewing the target for the first time. Whereas for the overall dwell time, the findings show evidence of fewer eye movements or shorter fixation durations when respondents are lying as a result of increased cognitive load resulting from different executive processes and cognitive mechanisms. The findings are discussed in the light of dual process theory and gaze aversion.