It is an instrument to measure and record many physiological responses from respiration and skin conductivity's to blood pressure, pulse. This takes place while the subject is asked a series of questions and answers. False answers will produce distinctive measurements in the reading and the physiological changes caused by the nervous system during questioning. Many kinds of technologies are used, but the polygraph is the most famous.

From 1945 to this day, at least 6 Americans had been committing espionage while they successfully passed the polygraph tests. Larry Wu Tai Chin and Aldrich Ames were the only most notable cases of two men who created false negative results.

A Functional magnetic resonance imaging (FMRI) can be used to compare brain activity differences..Electroencephalography is used to detect changes in brain waves and is one of the most recently developed forms of neuroimaging.

Lie detecting principles have been around for many, many years. In West Africa anyone suspected of a crime was made to hand a bird's egg to another person. Anyone who broke the egg would be considered guilty, based on their nervousness.

In ancient China suspects were told to hold a handful of rice in their mouths during a prosecutor's argument. The suspect was considered guilty if, by the end of that argument, the rice stayed dry -- because salivation was believed to cease in times of anxiety.

In today's world many people lie to get insurance, jobs or other services, and with security and business issues to think about it is very important to determine whether someone is telling the truth. Lie detecting is big business as companies are resorting to using assistance in gaining the truth regarding issues within a business.

It's very common among cheating partners to seek proof that they were cheated by obtaining the help of a private investigator. Private detectives are used on The game show "The Moment of Truth." Maury Povich and Jeremy Kyle frequently use lie detectors on their shows in order to determine whether someone is cheating on their partners.

Sex offenders are now routinely polygraphed in many states of the U.S., and it is often a mandatory condition of probation or parole. The UK will soon follow.

A London council has been using voice analysis technology to obtain the changes in voice patterns. When the department is contacted all calls are analysed and the technology is used in real time. You can refuse to take the test, which would result in a delay in your claim until further evidence is obtained. Insurance claimants who fail the test will be classified as "high risk."

The future of the Lie Detector ... It is a fact that lying produces physical and neurological side effects. Yet, could certain medical conditions or other unknown reasons cause a truthful person to fail a polygraph test?

Machines are used to read DWI's breath to convict, so why should it be so hard to have machines to read the body and mind?

What if someone decides not to take part in a test or decides not to talk? Do you tie them down and attach probes to them, knowing that this technology is so sophisticated that -- with such as the (FMRI) and Electroencephalography as well as future scientific improvements -- you only need to "ask" questions to "read" the truth?

Imagine, no more trials, no more jurors, many innocently convicted criminals would be released and the real criminals imprisoned. Borders would be properly controlled, too.

What if every business started to use voice analysis software? Millions of dollars would surely be saved. What would the repercussions be from this, considering the many privacy and human rights laws?

There are gadgets available to buy, all based on the voice pattern principles. Imagine, when this voice technology becomes so common and so good that software will be pre-bundled in every mobile phone! If this were the case, people may well be doing more texting than talking in the future!

If lie detecting techniques can be improved and offer proof beyond a reasonable doubt, I believe polygraph screening and lie detecting techniques certainly have a future role in making this a safer and more honest society -- and that's the truth!