Psychology researchers from the University of Granada in Spain used thermography to study the temperature of people's faces in experiments. They said they found a jump in the temperature around the nose and in the orbital muscle in the inner corner of the eye during lying. They also found that face temperature drops for people performing a difficult mental task and rises for people experiencing high anxiety.
The researchers said these effects could have something to do with the insula, a region of the brain involved in consciousness as well as the detection and regulation of body temperature. Lying boosted activity in this region, the team said.
Thermography could be used to study emotional or physiological states that become manifest through body temperature, such as sexual excitement, which heats up the chest and genitals, and even empathy. The researchers said that when highly empathic people see a person getting an electric shock in the forearm, they experience an increase in the temperature in their forearm as if feeling the other person's pain.
The work on the so-called "Pinocchio effect" was part of a doctoral thesis and has yet to be published in a scientific peer-reviewed journal.