Educing Information: Interrogation - National Intelligence University

esponded to questions as to whether the viewed cards matched any of those
in their set of cards. Subjects were instructed to lie only if one of the viewed
cards matched one of the cards in their hand. Subjects were offered $20 for lying
successfully. The result showed that both lying and truth-telling affected cardiac
symptoms; however, only lying was associated with gastric symptoms. The EGG
showed a significant decrease in the percentage of normal gastric slow waves when
the subject was lying that corresponded to a significant increase in the average
heart rate.
Potential
EGG is a non-invasive procedure that usually takes approximately three
hours in a clinical, diagnostic setting. As with the polygraph, EGG recordings
would be subject to artifacts from anxiety and stress that may not result from
intentional deception. EGG measurements are also subject to motion artifacts
(such as respiration, cardiac signals, and possible myoelectrical activity from
other organs) that can spoil the results (Liang et al., 1997). These artifacts can be
removed manually with much subjectivity, or via commercially available signal
processing software run on a personal computer.
The results of the EGG are analyzed by waveform and spectral analysis
methods, thereby requiring a powerful personal computer. It is likely that this
technique would have to be combined with another to increase its accuracy and
reliability in detecting deception. Given that only one study has been conducted
to date using this technique in a deception detection task, more research is needed
to determine the accuracy and reliability of this method.
Radar Vital Signs Monitor
The radar vital signs monitor (RVSM) remotely measures psychophysiological
motion processes such as heartbeat, respiration, and eye blinks using
electromagnetic waves in the gigahertz frequency range. For example, the RSVM
does not sense the actual heartbeat but the motion of the chest and body during
cardiac and respiration cycles (Geisheimer and Greneker, 2000; Geisheimer and
Greneker, 2001).
This technology is the product of several research projects conducted over
the past ten years at the Georgia Tech Research Institute (GTRI). Experiments
conducted at GTRI have shown that respiration and heartbeat data can be sensed
from nearly any portion or orientation of the thorax. The RVSM had to be slightly
modified to detect eye blinks. Although the researchers believe other eye motions
may be present in the signals, they produce smaller amplitudes than the eye blinks
(Geisheimer and Greneker, 2000; Geisheimer and Greneker, 2001).
Potential
RVSM technology is non-invasive, portable, and remote. RVSM can
be placed out of the subject’s sight; such covert use of this technology could
diminish the use of countermeasures. However, because of RVSM’s sensitivity in
detecting motion, any stray motions within the sensor’s beam will be measured
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