Adrenalin Kick

‘Honesty is the best policy’ Anon

I heard a story this week about a medical doctor who, out of curiosity, took a lie detector test and discovered when he looked at the printout that it had many unstable places with spiking that indicated he had lied.Puzzled, since he knew he had been totally truthful, he checked the oral recording of the questions and his answers against the results and realized that each time he had made a wisecrack he must have had an adrenalin rush to which the machine reacted.Since it was a lifelong habit of his to make witticisms at every opportunity, he realized he must be addicted to the adrenalin kicks he was getting every time.

Polygraphs or ‘lie detectors’ of one sort of another have been around since the turn of the 20^th century and are used in many countries as an aid to groups such as law enforcement agencies and employment organizations. To eliminate the problem posed by our doctor friend, only yes or no answers are demanded of the person being tested.

The test is based on the theory that when a person lies, they involuntarily release certain hormones like adrenaline from an area deep in their brain. These hormones cause the famous ‘fight or flight’ reaction that makes their heart beat faster, increases their blood pressure and breathing rate and causes them to sweat. Getting all hooked up to take the test, I think would tend to make anyone anxious and for that reason, the examiner usually poses innocuous test questions and the results are checked over with a person to be tested to create a relaxed atmosphere.  To further reassure them, the person taking the test is also made familiar ahead of time with all the questions to be asked.

I was surprised when I looked up polygraph testing on the Internet to find a number of prominent sites that can teach you how to cheat the machine and pass the tests even if you are guilty.  Since they are now no longer believed to be infallible, in most places lie detector test results are not permissible as evidence in courts. This is most unfortunate since innocent people are sometimes jailed and criminals freed because of the ease with which lies can be told in court.

Fortunately, it is possible that modern science could be coming to the rescue. As with the important forensic successes now possible using reliable DNA identification tests, 21^st century neuroscientist are working toward an infallible lie detection test. Apparently two companies are doing research using functional magnetic resonance imaging (fMRI) machines to do brain imaging to detect deception under controlled laboratory conditions.  The new ability that this machine provides to analyse what is happening inside someone’s head when they are actually telling a lie, presents serious ethical questions that will have to be sorted out in the courts before they could be used. Let us hope that in the future the threat of using these new methods will be enough to deter witnesses from lying when on the stand in court.   Rie