The Ultimate Body Language Book

commands. As our brains work, it requires blood to operate and the greater the work done, the more
blood is required. What gives lies away is that certain areas of the brain “light” up through increased
blood flow when lying take place. The job of the fMRI machine is to read this flow and decipher
patterns. Regions of the brain that are used in lying include the anterior (front) cingulated which
functions in process goals and intensions, the right orbital interior frontal which processes reward, and
the right middle frontal that helps govern tasks that require more than just ordinary thought. It is these
three brain centers working in concert that produce and also mask lies.
The fMRI measures blood flow and hence measures which areas of the brain are using up oxygen faster
and are working harder. Proponents of fMRI machines in lie detection claim that if you can get hits in
all three zones of the brain at the same time you can catch liars. In some studies lying has been detected
in upwards of ninety-three percent success rate with the help of fMRI machines. However, the current
methodologies of the study present some very big hurdlers before the machines can use the technology
in lie detection. For example, small movements in the head or speaking aloud can disrupt the scan and
produce unreadable information. The test also requires baseline procedures that compare deceptive
thought patterns and honest thought patterns, both of which can be made troublesome by an
uncooperative participant. The units are also expensive, bulky and require immersion into the unit
which proves to be impractical under most circumstances.
A second more portable device is in creation that uses processes similar to fMRI except that it uses
near-infrared light that pass through the forehead and skull but penetrates only the first few centimeters
of cortical tissue. This also uses blood flow similar to the fMRI. Once it passes through it is captured
by optical sensors and filtered. The unit is formed with a headband studded with LEDs and silicon
diode sensors. Researchers were able to detect lying in a card game ninety-five percent of the time
using these machines.
While blood flow to certain parts of the brain can be excellent predictors of lying, it does no help for us
as human lie detectors since there are no direct body language cues as yet discovered that are tied
directly to brain activity.
Chapter 16 - Deception and Lie Detection
Some Other Lie Machines – Thermal Scanners,
Eye Trackers, Pupillometers And Stress Sniffers
Other machines that could potentially find their way into law enforcement and homeland security
include thermal scanners, eye trackers and pupillometers. Scientists at Dodpi or the Department of
defense polygraph institute have created a machine that measures the body’s emissions of heat, light,
vibration and other minute changes that happen during lying. One of the tools measures the amount of
heat that is released just inside each eye. The theory is that heat increase with lying and stress and this
should increase during lying. From this chapter, we know that this machine has severe limitations since
not all liars experience stress and fear, and not all honest people lack it. Another machine tracks
people’s gaze patterns to determine if they’re looking at something they recognize or something novel.
This would be useful in criminal investigations where the murder weapon was kept hidden from the
public. If a suspect was read to recognize the item, he could be linked to the crime. Other machines
measure pupils sizes to determine arousal which as we have been discussing can signal stress, fear, but
also interest. A sniffer machine is also being tested which looks for an increase in stress hormones on
the breath.