您能控制自己的身体反应骗过机器吗(下)

A common strategy examiners employ involvesasking a combination of both relevant (Did you rob the bank?) and irrelevantquestions (Have you ever taken anything that didn’t belong to you?). Since noone can reAlly answer ‘no’ to the irrelevant questions without lying somewhat,the theory is that the physiological response to the irrelevant questionsserves as a type of baseline. The idea is to get a decent profile of what itlooks like when you’re lying when unstressed – this helps the person readingthe machine to be more confident that they are observing a response to astressed lie than if they were only comparing with obvious truths (such as ‘are you aman?’).

测谎人员一个常见的策略是同时提出相关问题（你是否抢了银行？）和无关紧要的问题（你是否拿过不属于自己的东西？）。由于没有人能做到对无关紧要的问题不撒谎就回答“否”，理论上，将受试者对无关紧要问题的生理反应充当测试基准。这种思路是，得到受试者在无压力状态下撒谎的合理情况，与仅对照明显事实（如‘你是男性吗？’）相比，这样做这有助于测谎人员更相信自己对有压力状态下撒谎反应的判断。

George Maschke, who has since 2000, says the strategy for beating a polygraph is torecognise the control questions and augment your reactions to them.

乔治·马施克（George Maschke）自2000 年起经营一家网站，他表示，战胜测谎仪的策略是，承认对照问题，并放大自己对它们的反应。

“When you’re asked a control question, like ‘Did you ever lie to getout of trouble?’ you can try to solve a math problem as quickly as you can inyour head and that mental activity will tend to raise your sweating, yourbreathing, et cetera,” he says. “If you have a stronger reaction to the controlquestions than the relevant questions you will pass the test.”

他说，“在被问到像‘你是否曾为了摆脱困境而撒谎？’这样的对照问题时，你可以试着在大脑中尽快解答一个数学题，这种心理活动会促使你出汗增加、呼吸加速，还有其他一些指标也会提高。如果回答对照问题时你的反应要比回答相关问题时还要激烈，那么你就能通过测谎测试。”

Goodson says that although he cansuccessfully defeat a polygraph against novice students, defeating anexperienced examiner is harder. “Altering human physiology is not difficult,and there are many anti-polygraph websites that teach this. What these websitescan’t teach is how to alter one’s physiology that appears to a polygraphexaminer as a genuine or natural response to a polygraph exam question,” hesays. “When polygraph examinees try to alter or control their bodies’ normalreactions, it creates abnormal data that is easily recognisable by a polygraphexaminer trained to detect these unnatural physiological responses.”

古德森表示，尽管他面对新手能成功骗过测谎仪，但欺骗有经验的测谎人员却并不容易。“改变人的生理反应并不难，有许多对付测谎仪的网站教人怎样做。但这些网站却无法教给人怎样在回答测谎问题时改变生理反应的同时，面对测谎人员还能做出真实或自然的反应，”他这样表示。“当受试者试图改变或控制身体的正常反应时，会产生异常数据，训练有素的测谎人员很容易就能发现这种不自然的生理反应。”

Some researchers are also concerned thatwhen wrong, the tests produce more false positives (meaning innocent people whowrongly fail) than false negatives (meaning guilty people who wrongly pass), aphenomenon that can be seen in a 2004 report on the validity of polygraphs bythe British Psychological Society.

有些研究人员也会担心，测试有误时，测试生成的错误阳性结果（意思是，无辜者错误地未通过测谎）多于错误的阴性结果（意思是，有过错的人错误地通过测谎），这种现象在2004 年英国心理学学会验证测谎仪有效性的报告中就可以看到。

According to Goodson, some people who aretelling the truth can fail polygraph tests by trying too hard to control theirbody’s responses. “When truthful persons alter their physiology, thinking theywill help themselves pass the polygraph, polygraph literature suggests thatmany of these truthful examinees are classified as deceptive when they do so,”he says.

据古德森说，有些人说真话时过于努力控制自己的身体反应也通不过测谎测试。他说，“说真话的人也会改变自己的生理反应，以为这会有助于自己通过测谎，而测谎文献表明，许多这种说真话的受试者在试图这样做的时候也会被归入欺诈行列。”

Many scientists are concerned that thetheory behind lie detectors is faulty, since a physiological response is notnecessarily linked to lying. A 2011 meta-analysis by the American PolygraphAssociation found that polygraph tests using comparison questions had incorrectoutcomes about 15% of the time.

许多科学家担心，测谎仪背后的理论是错误的，因为生理反应与撒谎并不具有必然联系。美国测谎协会2011 元分析报告（A 2011 meta-analysis by the American Polygraph Association）发现，当时测谎测试使用的对照问题约15% 都会得到错误的结果。

The type of test I’m trying to pass howeveris sounder, and slightly more difficult to cheat. Since I’m doing this for astory, Mordi has devised a way for me to test the system that doesn’t requirecomparison questions. He asks me to write a number between one and seven on apiece of paper and will monitor my physical response as I try to lie my way througheach number, as if I didn’t write anything at all.

我试图通过的测试比较可靠，想骗过测谎器会更难。由于我是为了写报道才这样做的，所以穆尔迪为我设计了一种测试系统的方法，无需使用对照问题。他让我在纸上写出1 到7 之间的一个数字，然后在我试图隐瞒每个数字，好像我什么也没有写的时候，监控我的生理反应。

It’s a simplified version of the GuiltyKnowledge Test, which is used in investigations after a known crime. Anexaminer presents a potential suspect with specific information unrelated andrelated to a crime to test whether examinees have a response to the relevantitems. Take a bank robbery for instance. You could present the amount of moneythat was stolen from the bank among other figures, or a genuine ransom notethat was passed to the bank teller among other notes created by the police.

这是犯罪知识测试的简单版本，这种测试用于已知犯罪后进行的调查。测谎人员会给一名潜在疑犯出示与犯罪无关紧要的特定信息和有关联的特定信息，然后测试受试者对有关信息是否有反应。以抢劫银行为例。你可以给疑犯出示若干数字，其中有银行被盗的金额；或者出示若干交给银行柜员的勒索信，其中有真正的勒索信，也有警方制作的假勒索信。

Though Maschke says it’s still possible tocheat through it, the Guilty Knowledge Test is considered more theoreticallysound than the comparison strategy and less controversial by scientists,according to the report by the British Psychological Society. The 2011meta-analysis conducted by the American Polygraph Association found that GuiltyKnowledge type tests were incorrect closer to 10% of the time.

尽管马施克表示，还是有可能骗过犯罪知识测试，但根据英国心理学会的报告，在理论上，这种测试要比对照策略更为可靠，科学家对此的争议要少一些。美国测谎协会2011 元分析报告发现，当时，犯罪知识类测试的错误率接近10%。

Far from perfect –but still,it caught me out. I failed spectacularly. There is a screenshot of myphysiological reactions below. See if you can tell when I lied.

虽然这种测试离完美还相差甚远，但也足以抓住我这样的人了。我没有通过测试，结果还很糟。下面是显示我的生理反应的截图。试试看，您能否发现我在撒谎。

If you look at the thick black line inparticular, you can probably guess that I lied about the number six. And Mordispotted it too.

如果您仔细观察黑色粗线，可能就会发现我对数字6 撒了谎。这点穆尔迪也发现了。