单选题
For decades, researchers have grappled with the problem of creating a machine that can tell, definitively, whether a person is lying. Until recently, their work has been far from successful. The past generation of lie-detection technologies has been put under scientific scrutiny and found
wanting
. But science, ever resourceful, is coming up with new ideas.
The problem with past lie detectors is that it relies on second-hand signs of lying, such as a person"s breathing rate, pulse, blood pressure which a good actor can suppress. Furthermore, someone who is telling the truth might exhibit just these signals, because the very act of being questioned by the authorities is stressful. Instead, current research is looking directly at the source of lies, the brain itself.
Daniel Langleben uses a brain-scanning technique called functional magnetic-resonance imaging to probe his subjects" honesty. The lie which those subjects are asked to tell is a small one: they have to persuade Dr. Langleben that they are holding a particular playing card when often they are actually holding a different one. Each successful deception earns a subject $20. The researchers have not had to hand out much cash, though. The brains of lying subjects light up in particular places in ways that they do not in the honest.
Another brain-probing lie-detection technique, based on electroencephalography (EEG), has actually made it out of the laboratory and into the courtroom. Lawrence Farwell calls it MERMER (memory and encoding related multifaceted electroencephalographic response). MERMER works by hooking someone up to an EEG machine and asking him about specific details of, for example, a crime scene. Lack of a brainwave called P300 denotes lack of familiarity with the details in question, suggesting any denial should he taken at face value. The technique has already stood up to legal scrutiny twice. It will soon be used again, in the appeal by Jimmy Slaughter against his conviction for murdering his ex-girlfriend, Melody Wuertz. MERMER suggests that Mr. Slaughter had no recollection of important facts about the murder, such as which rooms the victim" body was located in.
Although not yet foolproof, these methods do offer possible alternatives to the antiquated techniques of the polygraph. The truth is out there. It is just a question of finding it.
单选题
"Wanting" in paragraph 1 is closest in meaning to ______.