End to water-boarding: Using brain waves to reading terrorists minds about imminent attacks
to the research, when meaningful information is presented to a person with “guilty knowledge.”
Research on the P300 testing emerged in the 1980s as a handful of scientists looked for an alternative to polygraph tests for lie detection. Since it was invented in the 1920s, polygraphy has been under fire, especially by academics, with critics insisting that such testing measures emotion rather than knowledge.
Rosenfeld and Northwestern graduate student John B. Meixner are co-investigators of the study, outlined in a paper titled “A Mock Terrorism Application of the P300-based Concealed Information Test,” published recently in the journal Psychophysiology.
Study participants (twenty-nine Northwestern students) planned a mock attack based on information they were given about bombs and other deadly weapons. They then had to write a letter detailing the rationale of their plan to encode the information in memory.
Then, with electrodes attached to their scalps, they looked at a computer display monitor that presented names of stimuli. The names of Boston, Houston, New York, Chicago, and Phoenix, for example, were shuffled and presented at random. The city that study participants chose for the major terrorist attack evoked the largest P300 brainwave responses.
The test includes four classes of stimuli known as targets, non-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. Probes are stimuli only a guilty suspect would be likely to know. Irrelevants are stimuli unlikely to be recognized.
“Since 9/11 preventing terrorism is a priority,” Rosenfeld said. “Sometimes you catch suspicious people entering a building. You suspect that they’re terrorists, and you have some leads from the chatter. You’ve heard they’re going to attack one city or another in one fashion or another on one date or another. Our hope is that our new complex protocol — different from the first P300 technology developed in the 1980s — will one day confirm such chatter in the real world.”
In the laboratory setting, study participants only had about thirty minutes to learn about the attack and to detail their plans. Thus, Rosenfeld said, encoding of guilty knowledge was relatively shallow. It is assumed that real terrorists rehearse details central to a planned attack repeatedly, leading to deeper encoding of related memories, he said. “We suspect if our test was employed in the real world the deeper encoding of planned crime-related knowledge could further boost detection of terrorist intentions.”
—Read more in John B. Meixner and J. Peter Rosenfeld, “A mock terrorism application of the P300-based concealed information test,” Psychophysiology (30 January 2010) ((DOI:
10.1111/j.1469-8986.2010.01050) (sub. req.)
