Science Buddies: "Ask an Expert"

Hi guys,
Im doing my project on lying detector test and i just wanted to know if knowing that people lie because the machine detect a specific nerve or is it because the heart rate increases during testing.

Hi,

The method in this project is different from lie detector machines. The machines often work by detecting a change in the behavior or heart rate of the subject while questions are being answered. If you can do a web search using the words "how does a polygraph work?", you will find alot of background information.

The method used in the Pinocchio's Arm project is based on the idea it takes effort to lie, so while lying the effort is placed on the lie and not on holding the arm still - so it is easier to move the arm while someone is lying.

Tonya