Do polygraphs work? Not really, experts say. Use these tips instead.

测谎器有用么？并非如此，专家们说。不如使用以下秘诀。

You can guess, of course, whether the man was answering truthfully - but today's polygraphs cannot.

当然，你可能猜想这家伙在说假话，但今天所用的测谎仪却不能。

Law enforcement officials try to tap into that effort, for example with polygraphs, to find out if a suspect is telling the truth.

法律执行者们试图利用大脑的这种活动来确认嫌犯是否在说谎，他们所用的仪器是测谎仪。

The investigators say they need to validate this initial result and compare the technique with polygraphs and other lie detection tools.

研究者们说，他们需要进一步确认这些初始的研究结果，并把该项技术与测谎仪以及其它的测谎工具进行比较。