‘Infidelity would definitely be the most popular reason somebody would do one of our lie detector tests’

From love cheats to family thefts, there are many reasons people turn to lie detector tests. Our reporter gets hooked up to a polygraph to see if she can keep calm under pressure

Unveiling the truth: How do polygraphs really work?

Kirsty Blake Knox

It’s a strange feeling getting hooked up to a lie detector test. There is a lot of paraphernalia. Two coiled wires are wrapped around your chest and your stomach to monitor your breathing rate and pattern, and a pressure cuff attached to your arm to take a constant reading of your heart rate. Two clips are fixed to your index and ring finger to monitor electrodermal activity, while a plethysmograph monitor looks at blood rate volume. Finally, you sit down on a sensor mat to track exactly how much you squirm and shift.

Examiners ask you a series of questions and, depending on the physiological changes recorded on the machinery, they assess whether you have passed or failed.