The system spies on people through a camera, using powerful software that detects the changes in emotions on a person's face. The system bases its results on studies that associate lying to things like sudden eye movements, lip biting, heavy breathing, swallowing, and rapid blinking. Thermal imaging technology then determines rise in temperature brought about by an increase in blood flow, which is another telltale sign of lying. Professor Hassan Ugail (the head of the research) says, "When someone is making something up on the spot, brain activity usually changes and you can detect this through the thermal camera."
