國家地理:Lie Detector 測謊儀的奧秘

It might be the cheeks flushing with embarrassment or a voice choking with emotion. Our physical reactions can reveal what we truly feel. And some think they can show when someone's lying.
Typically when a person tells a lie, they begin to sweat. I'm sure we've all seen the 1940s and 50s interrogation movies where the person in the hot seat has a sweaty brow or a sweaty upper lip or perhaps sweat dripping down from their sideburns.
"All right, if you lean forward in the chair, put your arms up (in) front of you, like you're gonna dive into a swimming pool. Put this around your stomach. "
Jack Trimarco uses physical sensations to probe for truth. His primary tool? The lie detector, or polygraph.
"This cuff is just like the one of the doctor."
Polygraph, its work's very similar to any other biofeedback instrument. It simply records deviations from a person's physiological norm, such as someone's blood pressure going up and then coming back down, or perhaps a decrease or an increase in pulse rate, or sweat pore activity.
"Are you sometimes known as Bobbie?"
"Yes."
A polygraph examiner knows what to look for when questioning someone.
"D o you intend to be completely truthful with me?"
"Yes."
Any deviation from normal could signal deception. Our body can give us away.
"And are you sure that I won't try to trick you on this test?"
"Yes."
We may think we're being cool, but when we're stressed, our network of nerves starts to prepare our body for action as if it's under attack. It's a response that harks back to our ancient ancestors -- fight or flight.
It starts by triggering your stress hormone -- adrenalin. Your heart rate increases to pump more blood to your muscles as if you were about to go into battle. Your breathing deepens as vital oxygen reaches your muscles. And you begin to sweat -- the body cools so that you won't overheat when rushed into action. The brain won't let us stop the survival strategy. These basic nervous functions are automatic. That's why a polygraph can often uncover a liar.
1. hot seat: (n., slang) 1. The electric chair used to cause death by electrocution in legal executions.
(informal ) 2.A position in which you can easily get into trouble.
e.g. A judge in a beauty contest is on the hot seat.
2. sideburns: pl.n.(復(fù)數(shù)名詞)Growths of hair down the sides of a man's face in front of the ears, especially when worn with the rest of the beard shaved off. 連鬢胡子：在耳朵前面沿著臉側(cè)部向下生長的毛發(fā)，尤指胡子刮去之后留下的殘茬
3. hark back: To return to a previous point, as in a narrative.
e.g. he keeps harking back to his music-hall days
4. adrenalin: [生化]腎上腺素
5. rush sb into sth
參考中文翻譯：
可能由于尷尬臉會(huì)變紅，或者由于情緒激動(dòng)聲音會(huì)顫抖。我們的身體反應(yīng)會(huì)揭示出我們的真實(shí)感受。有人說當(dāng)有人撒謊時(shí)也可以體現(xiàn)出來。
特別是當(dāng)一個(gè)人說謊時(shí)，就會(huì)開始流汗。我確定我們都看過四五十年代的電影，當(dāng)犯人坐在電椅上接受審訊時(shí)，總是會(huì)額頭冒汗，或者上唇出汗，或者，汗珠從胡子上滴下來。
“對(duì)，像坐在椅子上一樣身體前傾，胳膊放在身前，就好像準(zhǔn)備跳入游泳池中的動(dòng)作。把這個(gè)放在胃部周圍。”
Jack Trimarco 利用身體的反應(yīng)來探尋真相。他的主要工具是什么?測謊儀。
“這就像是醫(yī)生的探測儀一樣的。”
測謊儀的工作原理像其他的身體反饋儀器一樣。它簡單的記錄某項(xiàng)身體指標(biāo)的偏差，比如某人的血壓突然升高然后回落，或者脈搏加快或者降低，或者汗腺活動(dòng)。
“你有時(shí)候是不是會(huì)被認(rèn)作Bobbie?”
“是的。”
測謊儀檢測者知道問某人問題時(shí)應(yīng)該注意哪些方面。
“你打算對(duì)我講真話嗎?”
“是的。”
身體反應(yīng)的任何偏差都會(huì)發(fā)出欺騙信號(hào)。我們的身體會(huì)出賣我們。
“你是否確信在這場測試中我不會(huì)戲弄你?”
“是的。”
或許我們認(rèn)為自己很平靜。但是當(dāng)我們遇到壓力時(shí)，我們的神經(jīng)系統(tǒng)使你的身體處于準(zhǔn)備好接受襲擊的狀態(tài)。這是可以追溯到我們的祖先的原始反應(yīng)——還擊或逃跑。
它從觸發(fā)你的壓力荷爾蒙——腎上腺素開始。心率增加，向肌肉中泵入更多血液，就好象時(shí)刻準(zhǔn)備戰(zhàn)斗一樣。呼吸加重，更多的氧氣進(jìn)入血液中。你開始流汗——體溫下降，因此當(dāng)你倉促行動(dòng)的時(shí)候不會(huì)流汗過多。大腦不會(huì)讓我們停止生存策略。這些基本的神經(jīng)功能是無意識(shí)的。這就是測謊儀能找出說謊者的原因。