Barnaby J. Feder reports for the New York Times about Dr. Lawrence A. Farwell’s brain fingerprinting technique. Excerpt:
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 thorough consideration.
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.