Educing Information: Interrogation - National Intelligence University

fixates when it pauses in a particular position. The resulting series of fixations and
saccades is called a scanpath.
The literature has explored eye blinks and their relationship to cognitive
processes, particularly attention and vigilance; however, only one study of their
relationship to deception has been found. Fukuda (2001) measured subject eye
blinks while performing a guilty knowledge card test using an automatic eye
blink analysis system developed by Matsuo and Fukuda (1996). With this headmounted
video recording system, it is possible to identify blinks and their timing
with respect to stimuli, and to analyze the eye blink waveform. Ten subjects were
presented with eight sets of five playing cards, and instructed to select one of the
five cards in each of the eight sets to be the “lie” card. Subjects were then serially
presented with the five cards on a computer display, and pressed a “no” key to
indicate that none of the five cards presented was the card they had selected. The
results showed that subject blink rate pattern discriminated between relevant and
irrelevant stimuli.
The CMU/Pitt team (Cohn et al., 2001; Moriyama et al., 2002) measured and
classified eye blinks with their automated facial expression analysis system. Their
system achieved an overall accuracy of 98%, with 100% accuracy between blinks
and non-blinks, in an analysis of 335 single and multiple blinks and non-blinks.
These accuracies were based on agreement with human coders. The UCSD/Salk
team (see the previous section, “Facial Expressions”) also achieved an overall
accuracy of 98% for detecting blinks (Bartlett et al., 2001). Both of these studies
used spontaneous facial behavior video recorded from a prior study of deception
(Frank and Ekman, 1997) for testing. However, no analysis was made of eye
blinks based on deception/truth-telling conditions.
The literature on saccadic eye movement is similar to the eye blink literature
in that much attention is paid to inferences about cognitive activity, but only
one study of saccadic eye movement and deception has been found. Baker et
al. (1992) studied the horizontal eye movements of ten subjects responding to
autobiographical questions presented via a computer display. The subjects
initially answered all questions truthfully, then were told to lie in response to a
subset of the questions. The authors partitioned subject reaction time into three
components. The first was the time spent reading the questions. This component
did not distinguish between the deception and truth conditions. The second was
the time spent thinking of an answer (i.e., think time). This component identified
lying in five of the ten subjects. The third was the time spent fixating during think
time. The measure of this component was significantly longer for nine subjects
in the deception condition. These results suggest that saccadic eye movements
during response generation are irrelevant to deception. Instead, the amount of
fixation time during think time, when it is assumed that subjects are generating
responses, is more indicative of deception.
Baker and others (Baker et al., 1992) also studied saccadic and fixation
activity during the five-second inter-trial interval (ITI); that is, during the period
of time after which one question has been removed from the computer screen
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