Brain scans used as Lie Detecters
Editor's
Note: A 2002 study by the National
Academy of Sciences concluded that the federal
government should not rely on polygraph examinations
for weeding out spies or other security risks
among current or prospective employees. In 2004,
LiveScience reported that brain scans might one
day replace polygraphs as the best lie detectors.
In this article, the reporter plays thief and
finds out whether brain scans can catch him.
CHARLESTON, S.C. (AP)-Picture
this: Your boss is threatening to fire you because
he thinks you stole company property. He doesn't
believe your denials. Your lawyer suggests you
deny it one more time-in a brain scanner that
will show you're telling the truth.
Wacky? Science fiction? It might happen this summer.
Just the other day I lay flat on my back as a
scanner probed the tiniest crevices of my brain
and a computer screen asked, "Did you take
the watch?''
The lab I was visiting recently reported catching
lies with 90 percent accuracy. And an entrepreneur
in Massachusetts is hoping to commercialize the
system in the coming months.
Related Links:
Your
Stomach Cannot Tell a Lie
Fingerprint
Technology Gets High-Tech Upgrade
The
Real Crime: 1,000 Errors in Fingerprint Matching
Every Year
Innocent
Suspects Confess Under Pressure
False
ID: Face Recognition on Trial
Brain
Scans Might Be Better Lie Detectors
"I'd use it tomorrow in virtually every criminal
and civil case on my desk'' to check up on the
truthfulness of clients, said attorney Robert
Shapiro, best known for defending O.J. Simpson
against murder charges.
Shapiro serves as an adviser to entrepreneur Steven
Laken and has a financial interest in Cephos Corp.,
which Laken founded to commercialize the brain-scanning
work being done at the Medical University of South
Carolina.
That's where I had my brain-scan interrogation.
But this lab isn't alone. Researchers at the University
of Pennsylvania have also reported impressive
accuracy through brain-scanning recently. California
entrepreneur Joel T. Huizenga plans to use that
work to start offering lie-detecting services
in Philadelphia this July.
His outfit, No Lie MRI Inc., will serve government
agencies and "anybody that wants to demonstrate
that they're telling the truth,'' he said.
Both labs use brain-scanning technology called
functional magnetic resonance imaging, or fMRI.
It's a standard tool for studying the brain, but
research into using it to detect lies is still
in early stages. Nobody really knows yet whether
it will prove more accurate than polygraphs, which
measure things like blood pressure and breathing
rate to look for emotional signals of lying.
But advocates for fMRI say it has the potential
to be more accurate, because it zeros in on the
source of lying, the brain, rather than using
indirect measures. So it may someday provide lawyers
with something polygraphs can't: legal evidence
of truth-telling that's widely admissible in court.
(Courts generally regard polygraph results as
unreliable, and either prohibit such evidence
or allow it only if both sides in a case agree
to let it in.)
Laken said he's aiming to offer the fMRI service
for use in situations like libel, slander and
fraud where it's one person's word against another,
and perhaps in employee screening by government
agencies. Attorneys suggest it would be more useful
in civil than most criminal cases, he said.
Of course, there's no telling where the general
approach might lead. A law review article has
discussed the legality of using fMRI to interrogate
foreigners in U.S. custody. Maybe police will
use it as an interrogation tool, too, or perhaps
major companies will find it a cheaper than litigation
or arbitration when an employee is accused of
stealing something important, other observers
say.
For his part, Shapiro says he'd switch to fMRI
from polygraph for screening certain clients because
he figures it would be more reliable and maybe
more credible to law enforcement agencies.
In any case, the idea of using fMRI to detect
lies has started a buzz among scientists, legal
experts and ethicists. Many worry about rushing
too quickly from the lab to real-world use. Some
caution that it may not work as well in the real
world as the early lab results suggest.
And others worry that it might.
Unlike perusing your mail or tapping your phone,
this is "looking inside your brain,'' Hank
Greely, a law professor who directs the Stanford
Center for Law and the Biosciences, told me a
few days before my scan.
It "does seem to me to be a significant change
in our ability ... to invade what has been the
last untouchable sanctuary, the contents of your
own mind,'' Greely said. "It should make
us stop and think to what extent we should allow
this to be done.''
But Dr. Mark George, the genial neurologist and
psychiatrist who let me lie in his scanner and
be grilled by his computer, said he doesn't see
a privacy problem with the technology.
That's because it's impossible to test people
without their consent, he said. Subjects have
to cooperate so fully-holding the head still,
and reading and responding to the questions, for
example-that they have to agree to the scan.
"It really doesn't read your mind if you
don't want your mind to be read,'' he said. "If
I were wrongly accused and this were available,
I'd want my defense lawyer to help me get this.''
So maybe the technology is better termed a "truth
confirmer'' than lie detector, he said.
Whatever you call it, the technology has produced
some eyebrow-raising results. George and his colleagues
recently reported that using fMRI data, a computer
was able to spot lies in 28 out of 31 volunteers.
I joined an extension of that study. That's why
I found myself lying on a narrow table in George's
lab while he and his assistants pulled a barrel-shaped
framework over my head like a rigid hood. As it
brushed the tip of my nose and blotted out the
light from the room, I looked straight ahead to
see a computer screen, which would be my interrogator.
Then the table eased into the tunnel of the fMRI
scanner, a machine the size of a small storage
shed. Only my legs stuck out.
As I focused on the questions popping up on the
computer screen, the scanner roared like a tractor
trying to uproot a tree stump.
It was bombarding me with radio waves and a powerful
magnetic field to create detailed images of my
brain and detect tiny changes in blood flow in
certain areas. Those changes would indicate those
areas were working a bit harder than usual, and
according to research by George and others, that
would in turn indicate I was lying.
Some questions that popped up on that screen were
easy: Am I awake, is it 2004, do I like movies.
Others were a little more challenging: Have I
ever cheated on taxes, or gossiped, or deceived
a loved one. As instructed, I answered them all
truthfully, pushing the "Yes'' button with
my thumb or the "No'' button with my index
finger.
Then, there it was: "Did you remove a watch
from the drawer?''
Just a half-hour or so before, in an adjacent
room, I'd been told to remove either a watch or
a ring from a drawer and slip it into a locker
with my briefcase. This was the mock crime that
volunteers lied about in George's study. So I
took the watch. As I lay in the scanner I remembered
seizing its gold metal band and nestling it into
the locker.
So, the computer was asking, did I take the watch?
No, I replied with a jab of my finger. I didn't
steal nuthin.'
I lied again and again. Other questions about
the watch popped up seemingly at random during
the interrogation. Is the watch in my locker?
Is it in the drawer? Did I steal it from the drawer?
The same questions came up about the ring, and
I told the truth about those.
It would be a different computer's job to figure
out which I was lying about, the watch or the
ring. It would compare the way my brain acted
when I responded to those questions versus what
my brain did when I responded truthfully to the
other questions. Whichever looked more different
from the "truthful'' brain activity would
be considered the signature of deceit.
Finally, after answering 160 questions over the
course of 16 minutes-actually, it was 80 questions
two times apiece-I was done. The machine returned
me to the bright light of the scanning room.
The computer's verdict? That would take a few
days to produce, since it required a lot of data
analysis. I didn't mind waiting. It's not like
the result would help get me fired, or lose a
lawsuit, or send me to jail.
Nobody in George's studies faced consequences
like that, which is one reason the lab results
may not apply to real-world situations. George
has already begun another study in which volunteers
face "a little more jeopardy'' from the mock
crime. He declined to describe it because he didn't
want prospective volunteers to hear about it ahead
of time. That work is funded by the Department
of Defense Polygraph Institute.
Other questions remain. How would this work on
people with brain diseases? Or people taking medications?
How would this work on people outside the 18-to-50
age range included in George's recent work?
How about experienced liars? George hopes eventually
to study volunteers from prisons.
And then there's the matter of the three people
who got away with lying in his recent study. For
some reason, the computer failed to identify the
object they'd stolen. George says he doesn't know
what went wrong.
But in a real-world situation, he said, the person
being questioned would go through an exercise
like the ring-or-watch task as well as being quizzed
about the topic at hand. That way, if the computer
failed in the experimental task, it would be obvious
that it couldn't judge the person's truthfulness.
Because of that, George said, he's comfortable
with entrepreneur Laken's plans to introduce the
scanning service to lawyers, though just on a
limited basis, by the middle of this year. Lab
studies are obviously necessary, he said, but
"at a certain point you really have to start
applying and see how it works. And I think we're
getting close.''
But Jennifer Vendemia, a University of South Carolina
researcher who studies deception and the brain,
said she finds Laken's timetable premature. So
little research has been done on using fMRI for
this purpose that it's too soon to make any judgment
about how useful it could be, she said.
Without studies to see how well the technique
works in other labs-a standard procedure in the
scientific world-its reliability might be an issue,
said Dr. Sean Spence of the University of Sheffield
in England, who also studies fMRI for detecting
deception.
Speaking more generally, ethical and legal experts
said they were wary of quickly using fMRI for
spotting lies.
"What's really scary is if we start implementing
this before we know how accurate it really is,''
Greely said. "People could be sent to jail,
people could be sent to the death penalty, people
could lose their jobs.''
Greely recently called for pre-marketing approval
of lie-detection devices in general, like the
federal government carries out for medications.
Judy Illes, director of Stanford's program in
neuroethics, also has concerns: Could people,
including victims of crimes, be coerced into taking
an fMRI test? Could it distinguish accurate memories
from muddled ones? Could it detect a person who's
being misleading without actually lying?
Her worries multiply if fMRI evidence starts showing
up in the courtroom. For one thing, unlike the
technical data from a polygraph, it can be used
to make brain images that look simple and convincing,
belying the complexity of the data behind them,
she said.
"You show a jury a picture with a nice red
spot, that can have a very strong impact in a
very rapid way.... We need to understand how juries
are going to respond to that information. Will
they be open to complex explanations of what the
images do and do not mean?''
There's also a philosophical argument in case
fMRI works all too well. Greely notes that four
Supreme Court justices wrote in 1998 that if polygraphs
were reliable enough to use as evidence, they
shouldn't be admitted because they would usurp
the jury's role of determining the truth. With
only four votes, that position doesn't stand as
legal precedent, but it's "an interesting
straw in the wind'' for how fMRI might be received
someday, he said.
It didn't take any jury to find the truth in my
case.
"We nabbed ya,'' George said after sending
me the results of my scan. "It wasn't a close
call.''
I was ratted out by the three parts of my brain
the technique targets. They'd become more active
when I lied about taking the watch than when I
truthfully denied taking the ring.
Those areas are involved in juggling the demands
of doing several things at once, in thinking about
oneself, and in stopping oneself from making a
natural response-all things the brain apparently
does when it pulls back from blurting the truth
and works up a whopper instead, George said.
Of course, nobody is going to make me or anybody
else climb into an fMRI scanner every time they
want a statement verified. The procedure is too
cumbersome to be used so casually, George says.
But he figures that if a perfect lie detector
were developed, that practical consideration might
not matter. The mere knowledge that one is available,
he said, might provoke people to clean up their
acts.
"My hope,'' George said, "would be that
it might make the world operate a little bit more
openly and honestly.''