Northwestern University researchers say they have developed a system that can pluck details of planned attacks from the minds of terrorists.
When researchers knew in advance specifics of planned attacks by the make-believe 'terrorists', they were able to correlate P300 brain waves in the cortex to guilty knowledge with 100 percent accuracy, said psychology professor J Peter Rosenfeld.
The technique could potentially allow law enforcement officials to confirm details about an attack such as date, location and weapon, he says.
Rosenfield's team used a mock terrorism scenario in which the subjects were planning, rather than perpetrating, a crime. The brain waves were measured by electrodes attached to the scalp of the 'suspects'.
The most intriguing part of the study, Rosenfeld said, was that even when the Northwestern researchers had no advance details about mock terrorism plans, the technology was still accurate in identifying critical concealed information.
"Without any prior knowledge of the planned crime in our mock terrorism scenarios, we were able to identify 10 out of 12 terrorists and, among them, 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."
The 29 study participants planned a mock attack based on information they were given about bombs and other deadly weapons. Next, they had to write a letter detailing the rationale of their plan, in order to fix the information in their 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.
"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, 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. Real terrorists would presumably rehearse details central to a planned attack repeatedly, leading to deeper encoding of related emories, Rosenfield 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," he said.