[Paleopsych] Boston Globe: "Brain Fingerprints" May Offer Better Way to Detect Lying
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Tue Feb 8 22:00:31 UTC 2005
"Brain Fingerprints" May Offer Better Way to Detect Lying
The Boston Globe
July 5, 2001
[Note date. What's the current situation?]
Former CIA agent Aldrich Ames easily fooled lie-detector tests,
concealing his work as a Russian spy. But could he have duped a "brain
fingerprinting'' exam, which probes what people know by checking their
electrical brain waves?
Nanny Louise Woodward passed a polygraph, denying that she killed a
Newton baby in her charge, though she was later convicted of the
crime. Suppose she had put her head in a brain-scanning machine that
measures deceit in blood flow patterns?
Then there's John and Patsy Ramsey, who insist lie-detector tests
clear them of any role in the death of their 6-year-old girl. But what
would happen if a computerized video machine taped their facial
expressions for signs of dishonesty?
As polygraphs become increasingly controversial, sparking a cottage
industry on how to "beat" the test, scientists are hunting for new
high-tech ways of solving the most ancient of human dilemmas: How do
you tell if someone is lying?
"I believe it's only a matter of time before we have much better
lie-detectors," said Stephen Kosslyn, a Harvard University psychology
professor who is studying the brain scans of liars. "The science of
this is only going to get better."
Rather than measure signs of stress, such as blood pressure and heart
rate, as polygraphs do, many of the new techniques try to get inside
the brain itself.
They measure things such as brain waves and cerebral blood flow, which
people cannot control--at least not yet. And they're making headway: A
judge even admitted some brain-testing results as evidence in an Iowa
murder case last March while polygraph evidence is still inadmissible.
Beyond the courtroom, intelligence agencies have been quick to
recognize the value of a better truth-detector.
The CIA, scandalized by discoveries of double-crossers within its
ranks, is funding much of the lab work, along with science
The FBI and other law-enforcement groups are hiring some of these
scientists as consultants, and asking them to train staff in new
Although these researchers are confident their technology may prove
more accurate than today's polygraphs, they are quick to point out
there will never be a magic box that discerns truth with 100 percent
accuracy, and all these devices should be seen as supplements to
old-fashioned gumshoe work.
"There's no such thing as 100 percent certainty," said Paul Ekman, a
psychology professor from the University of California who pioneered
the study of deceit-detection through fleeting facial expressions.
"That's why I'm not eager to see my work be used in criminal court
Advanced Lie-Detectors Within a Decade?
Kosslyn of Harvard shares these concerns. "More advanced lie-detectors
could be out within the next decade, but the big question is, how will
they be used?" he said.
Iowa-based neuroscientist Lawrence Farwell, however, is eager to see
his "brain fingerprinting" work get into more courtrooms, convinced as
he is that it has a near-perfect accuracy rate.
His method focuses on a specific electrical brain wave, called a P300,
which activates when a person sees a familiar object. The subject
wears a headband of electrodes and faces a computer screen, which
This technique provides a potential window into someone's past visual
experience. If a person looks at random pictures of weapons, without
activating a P300 wave, these objects are presumably unknown to him.
But if the murder weapon is shown, and a P300 wave activates, then the
person clearly has some experience with that weapon.
"This technique is used to see if they have the information stored in
their brain or not," said Farwell, a Harvard graduate who now runs
Brain Wave Science in Fairfield, Iowa. "All of this relates indirectly
to lie detection."
Of course, for the P300 to be truly incriminating, the prosecutor
would have to show that the tested person didn't see that murder
weapon in some other innocent way, such as in media accounts or by
being a bystander.
His "brain fingerprinting" helmet of electrodes is currently available
within the CIA, Farwell said, though he doesn't know if or how often
However, Farwell knows some strategies for using P300 to detect moles.
A US agent suspected of being a spy for Cuba, for instance, could be
shown objects known only to Cuban undercover agents, something as
simple as a job-related paper form or the "contact" person.
Farwell's lie-detection technique won a modest legal victory this past
March, when an Iowa judge ruled there was enough scientific basis to
admit "brain fingerprinting" results as evidence in the case of Terry
Harrington, a convicted murderer trying to win a new trial.
Farwell showed that Harrington did not have a P300 wave when showed
key parts of the crime scene, but did emit the P300 wave when shown
scenes from his alibi, suggesting he was unfamiliar with the crime.
After reviewing evidence from all sides, however, the judge did not
grant a new trial, though Harrington is appealing.
Harvard psychology professor Kosslyn also focuses on the brain in his
study of deception, but he uses brain-scanning equipment to see what
areas receive intense blood flow during questioning.
While his work has not yet been completed, preliminary results show
that different regions of the brain light up when people tell the
truth or lie. Further, he believes different regions are activated
depending on the type of lie.
His data so far, he said, show the anterior cingulate, located near
the front of the brain and associated with conflict resolution, is
often activated during lies.
When lies are spontaneous--making it up on the spot, as opposed to a
fiction created over a period of time--the back part of the brain
associated with visualization is also lit up.
Kosslyn said he believes that is related to the fact that the
spontaneous liar has to visualize whether quick fibs make sense or
Focus on Smirks and Eye Flutters
Beyond the brain, tiny alterations in facial expressions, from smirks
to eye flutters, are the focus of work at the Salk Institute for
Biological Studies in La Jolla, California.
Piggy-backing on the work of psychologist Eckman, neuroscientist Terry
Sejnowski is convinced that specific expressions suggest deception,
though they are often imperceptible to the untrained eye. He is trying
to link computers with video cameras, which would be able to record
someone's face during testimony and see if it's truthful.
Not everyone is thrilled about this new generation of lie-detectors.
Mark Zaid is a Washington attorney representing 11 people who say they
were unfairly rejected for federal law-enforcement jobs when they
failed a mandatory polygraph.
While some polygraph advocates put its accuracy rate at 90 percent,
Zaid is among those who say the polygraph, in use since the 1920s, is
hardly better than a coin-toss. He says future lie-detectors may be no
different. "It's possible that new brainwave machines will say if
someone is lying or not, but now, I don't buy it," he said.
Yet, even a Massachusetts plaintiff in Zaid's case, who works in local
law-enforcement, said he keeps an open mind that someday a better
lie-detector will come along.
This man, who asked to remain anonymous, said he feels today's
polygraph is faulty and gave him a "false positive" when asked about
past drug use. But he knows from his own job that the mere presence of
a polygraph can be useful in questioning.
Back in 1995, for instance, police had no evidence linking Susan Smith
to the drowning of her two young sons. While she claimed the boys were
abducted by a carjacker, she had three polygraphs showing signs of
deception. Police kept the focus on her. Later, she admitted she let
the car roll into a South Carolina pond, and the bodies of her two
boys were found in the water.
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