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.”…

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.