Dr. Larry Farwell - Brain Fingerprinting in the New
New York Times on
Farwell Brain Fingerprinting
and Justice, by the Blip of a
By BARNABY J. FEDER
Since the World
Trade Center bombing in 1993, Dr. Lawrence A.
Farwell has been arguing that terrorist
operations can be investigated through careful
monitoring of the brain waves emitted by
suspects during interrogation. The claim did
not get very far with the Federal Bureau of
Investigation or any other major law
enforcement agency then.
Now, since the Sept. 11 terrorist
attacks, Dr. Farwell and a number of
supporters are pressing for a much more
Their effort is another instance
of the typical innovator's natural impulse to
dress up old visions in front- page news. But
Dr. Farwell's investigative technique, which
he likes to call brain fingerprinting, may
also be seen as a typical story of conflict
over how to develop real-world applications
from promising bodies of research.
Dr. Farwell's concept is an
offspring of a vast body of research on the
electrical activity of the brain. Most of the
research has focused on easily observed
phenomena like alpha and beta waves, which
have been respectively linked to activities
including sleep and heightened alertness. But
one subset beginning in the mid-1960's homed
in on extremely brief electrical wave patterns
associated with recognition of familiar
sounds, smells and sights.
The most widely studied of such
event-related changes is a split-second bump
in electrical activity that starts anywhere
from 300 milliseconds to 800 milliseconds
after a recognized stimulus. Many researchers
have studied how the bump, called p300,
appears to be affected by various diseases of
the brain. Some have pondered how it may be
used to help severely disabled people control
computers. Starting in the 1980's, Dr. Farwell
and a few other neuroscientists began
exploring whether the phenomenon could be used
to detect concealed knowledge.
One reason for their interest is
that the most widely used lie detectors, known
as polygraphs, have long been considered an
embarrassment by many scientists. Polygraphy
measures a suite of physical reactions to
interrogation. The underlying premise is that
people being questioned about crimes in which
they were involved will involuntarily exhibit
telltale increases in their pulse, blood
pressure, breathing rate and sweat levels.
But polygraphy has been under fire
ever since it was invented in the 1920's.
Supporters say that experience in framing
questions and the constant improvement in the
monitoring equipment has made polygraphy
highly reliable. Critics say such testing is
flawed because it measures emotion rather than
knowledge. They say the guilty can train
themselves to respond in ways that deceive
their questioners while many easily flustered
people have been wrongly branded as guilty.
In 1988, Congress barred most
businesses from using polygraphy or any other
lie detection device to screen job applicants.
The law left businesses free to ask employees
to take such tests in connection with a
specific loss but companies cannot fire or
demote an employee who refuses.
"The diagnostic value of this type
of testing is no more than that of astrology
or tea-leaf reading," said Dr. Drew C.
Richardson, a psychologist who formerly headed
the F.B.I.'s research laboratory at Quantico,
Va., and its unit overseeing chemical and
biological warfare threats.
Dr. Richardson is among those who
has believed for many years that measuring
brain waves is a far better alternative. He
recently left the F.B.I. to join Human Brain
Science, a company in Fairfield, Iowa,
founded by Dr. Farwell, who began researching
p300 waves in the mid- 1980's as a graduate
student at the University of Illinois.
Dr. Farwell caught Dr.
Richardson's attention in 1993 with an
experiment that correctly identified 11 F.B.I.
agents and four impostors by measuring their
brains' responses to cues that would be
familiar only to someone who had been through
the F.B.I.'s training school. The cues
included short phrases, acronyms and images on
a computer screen.
Dr. Farwell's technique, like
other non-surgical probes of the brain's
electrical activity, relies on readings taken
by electrodes attached to the scalp.
Like many forms of polygraphy, Dr.
Farwell works with three classes of stimuli
known as targets, probes and irrelevants.
Targets are sights, sounds or
other stimuli the person being questioned
already knows or is taught to recognize before
the test. Any American, for example, could be
shown a picture of the White House. Probes are
stimuli only a guilty suspect would be likely
to know. In the case of the hijackers, a
detail from a Boeing 767 cockpit might be a
target. The third category, irrelevants, are
stimuli unlikely to be recognized.
Suspects are given a keyboard to
tap or some other way of indicating whether or
not they recognize a stimulus, but that
physical prop is just to keep them focused.
The real answer comes from their brain waves
long before they tap the keyboard, Dr. Farwell
In peer-reviewed research
published in 1991 in the journal
Psychophysiology, Dr. Farwell and his
collaborator, Dr. Emanuel Donchin, claimed 87
percent accuracy in early efforts at
recognizing concealed knowledge.
But Dr. Farwell refined his work.
He concluded that analysis of the dip in
electric activity that followed the p300
response, along with other measurements, could
add even more certainty to his conclusions. He
coined the acronym MERMER, for memory and
electroencephalographic response, to describe
the entire package and patented the concept.
He has claimed 100 percent success
rates in experiments using the technique for
tasks like singling out Central Intelligence
Agency agents who had been exposed to a mock
espionage situation and Navy officers with
In 1998, the brain-wave monitoring
provided Missouri police with evidence
supporting a confession by James B. Grinder,
who said he had participated in a 1984 rape
and murder. Over the years, he had given
conflicting accounts. Last year, Dr. Farwell
used the technology to support an attempt to
overturn a 1978 murder conviction in Iowa.
Dr. Farwell testified that his
test results showed that Terry Harrington, 17
at the time of the crime and had never stopped
proclaiming his innocence, did not recognize
details that would have been known to the
murderer and did recognize those consistent
with his alibi.
Judge Tim O'Grady of Pottawattamie
County District Court became the first judge
to consider brain- wave technology as
admissible evidence. Judge O'Grady did not
hold a separate hearing on the scientific
validity of the concept before listening to
the evidence because there was no jury in the
His written opinion suggested that
he asked himself the questions that would have
been explicitly addressed in such a hearing
under the widely followed Daubert standard
endorsed by the United States Supreme Court.
Daubert admits evidence based on science that
has been tested, peer-reviewed and published.
It also must be deemed accurate and widely
accepted in the scientific community.
But Judge O'Grady made it clear
that he was talking about the basic p300
theory, not Dr. Farwell's patented system. And
he refused to free Mr. Harrington, ruling that
it had not been proved that Dr. Farwell's
evidence would have led to a different result
in the original trial. (On February 26, 2003
the Iowa Supreme Court has reversed the
murder conviction of Terry Harrington and
ordered a new trial.
In October 2003, the State of Iowa elected not
to re-try Mr. Harrington.)