Thermal imaging may help catch terrorists

A revolutionary new lie detector, incorporating a high definition thermal imaging camera that can detect thermal pattern changes around the eyes, has been developed (Nature 2002;415:35).

To test the camera 20 volunteers were asked to commit a mock crime--to stab a mannequin and grab $20 from its hand--and then to proclaim their innocence. The camera imaged their faces while they were questioned (figure). Volunteers in a control group were not aware of the crime. The camera correctly categorised 83% of the volunteers (75% of the test group were correctly found guilty and 90% of the control group were correctly found innocent).

Thermal imaging cameras enable rapid analysis of changes in blood flow around the eyes. Auditory startling can, however, produce similar blood flow changes to lying (Lancet 2001;357:1757). If thermal changes occur independently of auditory startling then the camera can be used as a lie detector. The near instantaneous rush