The polygraph instrument explained

Polygraph. Deception, lies, make part of our society and the quest to detect this behavior is also part of human nature. An apparatus that can help detect deceptive behavior is the holy grail to a fairer society.
The polygraph became a famous instrument due to it’s use in the entertainment industry. Different movies, tv shows have used this apparatus for the entertainment of a broad public.
The idea that a device can help discover the hidden actions, behavior of somebody is definitely interesting for science fiction or entertainment.
That is why the polygraph, also known as lie detector, is an instrument that is so fascinating to the public.
However, is the polygraph really a lie detector and is it really reliable? Can we really connect somebody to a device and trust the outcome of the analysis?
All questions that are valid and also important to explain so that the public understands the possibilities but also the limitations of the instrument and psychophysiology.
In this section you can find a little introduction to the history of polygraphy as well as a technical explanation of the instrument.
Also, we will try to explain the concept of reliability and validity of lie detection tests.