Educing Information: Interrogation - National Intelligence University

and the subject has indicated readiness for the next question, and before the next
question appears on screen. The authors hypothesized that during the ITI, subjects
may be reviewing their answers. Based on their results, the authors rejected this
hypothesis and concluded that the effects of a trial ended with the subject’s
indication of readiness for the next trial.
Potential
Eye blink measurements can be recorded non-intrusively and without the
subject’s awareness, provided there is direct line of sight. The measurements
can then be automatically post-processed, with some minimal amount of manual
preprocessing required. Although this processing (both pre and post) cannot be
conducted in real time, the technology (a video camera and computer system
capable of high-speed image processing) is portable. To date, no research results
suggest any characteristic pattern(s) of eye blinks, saccades, or fixations that
correlate with deceptive behavior. Much more research must be conducted to
determine, first, whether eye behavior is indicative of underlying deception, and
second, the accuracy of systems measuring this behavior in real-world situations
with ethnically diverse individuals.
Voice Stress Analysis
Voice stress analysis (VSA), sometimes called psychological stress
evaluation (PSE), is based on the use of a machine developed in 1964 by Charles
R. McQuiston. Presumably, this machine detects laryngeal micro-tremors in the
voice. When people speak, air is pushed upward from the lungs to the vocal cords.
This causes the vocal cords to vibrate as the air continues to flow upward to the
mouth, through the tongue, teeth, and lips to form speech. According to McQuiston,
the amount of blood in the vocal cords drops as a result of stress and the microtremors
disappear. The voice stress analyzer searches for the disappearance of
this normal tremor when the individual speaks (Van Damme, 2001).
VSA was developed because the U.S. Army wanted “a remote lie detector”
as an alternative to the polygraph (i.e., one that did not require physical contact
with the subject’s body). Given that the transmission of these micro-tremors
and the stress occur simultaneously, VSA could be used to analyze a narrative
conversation, not just “yes” or “no” responses (this was considered an additional
advantage over the polygraph). The first VSAs appeared on the market in 1970,
a product of Dektor Counterintelligence and Security, Inc. (McQuiston was one
of its founders). Approximately twelve years later, the Verimetrics system (also
invented by McQuiston) appeared. This system allowed personal computers to
produce charts. The Computer Voice Stress Analyzer (CVSA) appeared on the
market shortly thereafter. The CVSA allowed real-time analysis by eliminating
the need to record on magnetic tape. There have been additional adaptations of
the VSA, such as the Diogenes Voice Stress Analysis System in 1996, Truster in
1997, and Truster Pro/Vericator in 1998.
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