Using P300 brain-wave testing in a mock terrorism scenario in which make-believe “persons of interest” were planning a crime, Northwestern University researchers were able to detect guilty knowledge with 100 percent accuracy with no false positives, J. Peter Rosenfeld, Northwestern professor of psychology reports. “Even when the researchers had no advance details about mock terrorism plans, the technology was still accurate in identifying 10 out of 12 terrorists and 20 out of 30 crime-related details,” Rosenfeld said. “The test was 83 percent accurate in predicting concealed knowledge, suggesting that our complex protocol could identify future terrorist activity.”

This means law enforcement officials may ultimately be able to confirm details about an attack (such as date, location, and weapon) that emerge from terrorist chatter by using P300 brain-wave testing with suspects.

Study participants (29 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, connected to an EEG machine, 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. And 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.”

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Zeroing in on dates and locations: the ultimate Homeland Security tool?

Our results suggest that one might be able to identify locations or times of terrorist attacks if the location or time is restricted to a small enough set to perform a test similar to that of the current experiment. In the field, generating such a small set may be simple for the month of the attack, as there are only 12 possible months, whereas determining the city and type of attack would be considerably more difficult because of the multitude of possibilities. In determining the city where the attack is planned to occur, one could attempt a type of partition test, where the subject is presented several potential large locations (such as theNortheast, Midwest, etc.). Using the blind analysis method demonstrated here, it should be possible to determine which of these larger areas is the planned location of attack and subsequently separate that area into smaller and smaller partitions until the location is discovered. — John B. Meixner and J. Peter Rosenfeld, A Mock Terrorism Application of the P300-based Concealed Information Test, June 22, 2010, in the journal Psychophysiology

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In the laboratory setting, study participants only had about 30 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.”

More info: Northwestern University news