A simple slide show could be the next weapon against terrorists. Using a brain-electrode cap and imagery, scientists at Northwestern University can pick the date, location and means of a future terrorist attack from the minds of America's enemies.
The new research could not only stop terrorist attacks before they happen, but could also be used to help prevent other capers, or convict criminals after they break the law.
"We presented [the mock terrorists] with stimuli that are rational choices of what they might do, said J. Peter Rosenfeld, a scientist at Northwestern University and coauthor of a new study in the journal Psychophysiology.
"They sit in a chair, we put brain wave recording electrodes on their scalp and they look at the screen."
The electrodes measure the P300 brain wave, an involuntary response to stimuli that starts in the temporoparietal junction and spreads across the rest of the brain. When the wave hits the surface of the brain, the electrodes detect the signal. The stronger the reaction of the subject to a particularly stimuli, the stronger the P300 brain wave.
Rosenfeld and his co-author, graduate student John Meixner, divided 29 Northwestern University students into two groups. One group planned a vacation while the other group planned a terrorist attack. The students then had electrodes placed on their scalp, and were shown a series of images of various cities, such as Boston and Houston, and various means of attack, along with other related, but irrelevant, images as controls.
As the slide show advanced, the electrodes recorded the P300 waves. When, for instance, the mock terrorists saw an image of the city they planned to attack, the electrodes recorded strong P300 brain waves. The Northwestern scientist then compared the strength of all the brain waves to find out who was planning at attack on which city, when they were planning it and how they meant to carry out the attack.
The Northwestern scientists correlated the strongest brain waves with "guilty knowledge" every time. Weaker P300 waves were seen when subjects saw images not associated with their planned attack. Scientists also examined P300 waves from the students in the group that was planning vacations, and did not falsely identify any of them as terrorists.
The P300 waves could be even more pronounced in real terrorists, said Rosenfeld. The college students spent a mere 30 minutes planning out their attack. Real terrorists would likely spend days, weeks or months planning an attack, which should mean even stronger P300 waves.
While the terrorists plan their attack, they could also plan their defense. That's because P300 brain waves can, or at least could, be defeated. By artificially creating a strong response to an image that is unrelated to their attack, terrorists could have a countermeasure against the electrodes.
"The subject just has to be on the alert for any other stimulus, and when they see an irrelevant stimulus, they secretly make a response," said Rosenfeld. "That response could be anything from thinking about their girlfriend or wiggling a toe."
The new research can identify, and counter, the countermeasures up to 83 percent of the time, according to the Psychophysiology article. In his as yet unpublished work, Rosenfeld says that he can defeat nearly 100 percent of countermeasures.
"This new research is very impressive," said Gershon Ben-Shakhar, a scientist who also studies brain waves and deception at the Hebrew University of Jerusalem. Not only did Rosenfeld show that it's possible to find the location and means of a terrorist attack, "but he also invented and demonstrated a technique to detect and prevent countermeasures."
The new Northwestern research won't put police officers or soldiers out of work anytime soon though, said Ben-Shakhar.
It's still very difficult to detect someone who has actually committed a crime, let alone someone who is only planning a crime. The chances that this technology will be used anytime soon to prevent terrorist attacks is low, for now at least, but it offers intriguing possibilities for the future of law enforcement.