Abstract: The present invention comprises methods and apparatus for assessment of the effects mental stress involving the measurement of periodic changes in skin perfusion. Using a remotely mounted infrared camera, dynamic area telethermometry (DAT) measures the autonomic nervous activity by monitoring and quantitatively analyzing the modulation of cutaneous perfusion. When people gets "nervous" their sympathetics "act up" and they blush (vasodilates) or becomes pale (vasoconstricts). A DAT test of the face proves to be a superior "lie detector" test since emotional stress is reflected in an autonomic nervous response that can be measured remotely. DAT is much more sensitive than any visual assessment of skin color or than instrumental measurement of diaphoresis. Not only is it more reliable than currently used polygraph tests, but its non-contact administration is so simple and innocuous that it could be done without the subject's awareness.