How to Catch a Terrorist: Read His Brainwaves

It's been a dream of scientists, interrogators and law enforcement professionals for years: Strap a terrorist suspect to a couple of electrodes, start asking him questions, and watch his brainwaves rat him out.

In a recent paper, a Northwestern University professor uses some of his recent fieldwork to urge the intelligence community to give the science another shot. Just one problem: His self-described "Oddball Approach" to exposing terrorists probably won't work in the real world.

Psychologist J. Peter Rosenfeld writes in the journal Psychophysiology that he can predict and prevent terrorist attacks, all after running a clinical trial in which his students had to plan a mock assault. The idea was to create a test that would allow interrogators a foolproof way of extracting information about planned attacks from resistant suspects using just two wires connected to the forehead. "They could either send him to Egypt for the waterboard," Rosenfeld tells Danger Room, "or give him a scientifically based test."

Rosenfeld's students received a briefing on a series of options that they could employ: four potential locations in Houston, four types of bombs, and four dates in July. Individually, they wrote letters to their "superiors" in their imaginary terror cells outlining their intended acts.

Enter the probe. Psychologists established decades ago that people will involuntarily activate a certain brainwave when they encounter a familiar stimulus, known as a P300. In theory, it's better than a lie detector: you don't have to worry about the brain letting out a P300 out of nervousness, the way a panicked heart can create false positives for polygraphs. As Wired.com reported shortly after the September 11 attacks, that's why every couple of years someone proposes using electroencephalography - EEG, to you and me - as a reliable (and, potentially, legally admissible) alternative to the old lie detector.

During a 25-minute test, Rosenfeld's students were shown a screen that flashed hundreds of names of random cities, dates and bomb methods. Sure enough, the students' P300s told Rosenfeld when and where the hypothetical attacks would take place. Even if someone tries hard not to remember his intended terrorist act, "we still catch them eight out of nine or 10 times," Rosenfeld says. "It's pretty damn good."

Now to convince someone in the intelligence community. And that may be more difficult than the respected psychologist figures. Anyone familiar with interrogations of real-life terrorist suspects will immediately spot a problem with Rosenfeld's test: it presumes way too much knowledge on the part of both the interrogator and the interrogated.

The typical terrorist who finds himself in front of FBI or CIA agents won't necessarily know everything about a particular plot. The 9/11 hijackers, for instance, were kept deliberately in the dark about everything besides their specific piece of the operation. And that's on the off chance that someone that spies or G-men round up have even made it into the active stage of terror-plotting, a pretty elite group.

Alternatively, someone who finds himself in an interrogation chair might have been caught red-handed - think underpants bomber Umar Farouk Abdulmutallab - rendering Rosenfeld's test moot. It then falls to interrogators to figure out a suspect's place in the conspiracy, something that's a lot harder to determine than with a simple synaptic firing. Anyone might recognize Osama bin Laden and let out some P300s, but that doesn't mean that he's collaborated with him.

Most often, interrogators don't have any idea whether the guy in the chair opposite them is a bit player or a terror master. That's why real-life interrogator tools for unraveling terror webs are far more simplistic, in order to draw out broad information and then whittle it down.

Ali Soufan, for instance, a retired FBI counterterrorist, got the first-ever al-Qaeda confirmation of the terrorist group's culpability for 9/11. His secret weapon? Sugarless cookies, fed to a hungry al-Qaeda affiliate named Abu Jandal.

Rosenfeld concedes that his test depends on both terrorist and interrogator having a great deal of knowledge about a given plot. (Self-deprecatingly, he refers to his P300 test as his "Oddball Approach.")

He says he's had just one interaction with an American spook since his paper came out earlier this summer, a Defense Intelligence Agency official named Donald Krapohl, who was skeptical that the P300 test would be useful to interrogators for precisely that reason. (In an email, Krapohl confirmed corresponding with Rosenfeld, but did not receive permission from his bosses to speak with me for this story.)

Aside from a guy who works with the Transportation Security Administration at Midway Airport in Chicago, Rosenfeld says, "We haven't had any [other] bites in the counterterrorism community."

That points to a fundamental clinical disconnect. Rosenfeld wants to help U.S. counterterrorists. But he doesn't know any. So it's hard for him to design a test that's relevant to actual interrogators.

"It's like I tell everybody," he says. "We've done a lot of work in the lab now for a long time, and we'd really like to see it out in the real world." Anyone from Langley wants to give Rosenfeld a shout, he's ready to put some electrodes together in the hope that he can help stop the next attack.

Photo: Brown University