[Paleopsych] BBC: The future of lying
checker at panix.com
Sun Jan 23 18:26:30 UTC 2005
The future of lying
By Chris Summers
As the British government unveils plans to make lie detector tests
mandatory for convicted paedophiles, some scientists in the US are
working on more advanced technology which might be better equipped at
Imagine the Pentagon equipped with a machine which can read minds.
Sound like the plot of a Hollywood thriller?
Well, it might not be that far away.
The US Department of Defense has given Dr Jennifer Vendemia a $5m
grant to work on her theory that by monitoring brainwaves she can
detect whether someone is lying.
She claims the system has an accuracy of between 94% and 100% and is
an improvement on the existing polygraph tests, which rely on heart
rate and blood pressure, respiratory rate and sweatiness.
Her system involves placing 128 electrodes on the face and scalp,
which translate brainwaves in under a second. Subjects only have to
hear interrogators' questions to give a response.
But the system has a long way to go before it replaces polygraphs,
which were invented almost a century ago and remain a tried and tested
system of deception detection.
On Thursday the UK government unveiled its Management of Offenders and
POLYGRAPH PILOT AREAS
Leicestershire and Rutland
Devon and Cornwall
Bedfordshire, Hertfordshire and Cambridgeshire
A key plank of the bill is increasing the use of polygraph tests for
convicted paedophiles who have been released on licence.
A voluntary scheme has been running in 10 pilot areas in England since
But under the new bill the tests will become compulsory for
paedophiles in the 10 pilot areas.
They are asked whether they have had contact with children, while
having their anxiety levels measured.
But some critics believe the polygraph is flawed.
"The idea with polygraphs is that there is a tell-tale physical
response associated with deception and I just don't accept that is
"Even if it were true for the normal person then I don't think it's
true for psychopaths, or others with mental abnormalities," says
Steven Aftergood, of the Federation American Sciences.
The mouth may lie, but the face it makes nonetheless tells the truth
Mr Aftergood says he doesn't know about Dr Vendemia's invention but
"if there was a machine which was able to read people's minds, it
would give greater urgency to questions of people's privacy.
"In the United States it could even be unconstitutional because, under
the Fifth Amendment, citizens have a right not to self-incriminate
In the US a specific piece of legislation, the Employee Polygraph
Protection Law, forbids firms from using lie detectors to vet workers.
The one exception is the intelligence community, where polygraphs are
a ubiquitous form of checking on existing and potential employees.
Dr Vendemia says her system would be an improvement on polygraphs.
"If you are examined by a good interrogator a polygraph will be 85 to
90% accurate," she says. "But others have less than 50% accuracy. My
technology has levels of accuracy around 94 to 100%."
Dr Vendemia says her research has found it takes longer for the brain
to process lies, than to process the truth and this, she says, can be
tested by monitoring the brainwaves.
Her work is funded by US government grants but she says there were
ethical questions which arose from it.
Could it be used, for example, to help in the interrogation of
innocent people accused of being al-Qaeda terrorists?
"Anything can be misused. As a researcher working with technology
which has huge implications you have a responsibility to make sure
that what you are doing is ethical and make sure there is someone more
objective than you looking at what you do," says Dr Vendemia.
Professor Paul Matthews, a neuroscientist at Oxford University, says a
mind-reading machine is pure science fiction. "There is no technology
which can tell somebody what you are thinking. But you can see what
sort of areas of the brain are active. It is the same sort of
technology which is used in hospitals with MRI and EEG scanners."
Tor Butler-Cole, a philosopher and ethicist from King's College,
London, thinks we should be wary of allowing this technology to be
used if it is not 100% accurate.
"The recent controversy with cot deaths has taught us that we should
be aware of relying on science which may turn out to be wrong," she
Ms Butler-Cole believes there is also the danger jurors would give it
a lot of credibility simply because it was "scientific evidence".
Dr Vendemia was one of a number of experts discussing the subject of
"Criminal Memories" in a special debate at the Dana Centre in London
on Thursday. The event will be shown on a webcast next week.
HOW A LIE DETECTOR WORKS
A polygraph works on principle that a person who is lying will show
signs of stress
Pneumographs (1) measure breathing rate
Galvanometers (2) test how much the subject is sweating by measuring
skin's electrical resistance
Cuff (3) measures heart rate and BP which increase under stress
The results from each instrument appear as wave patterns
By comparing the patterns with those when the subject was definitely
telling the truth, the examiner can spot a potential lie
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