'Non-Invasive Polygraph' Uses Infrared Light

opticsorg writes "Infrared laser pulses could soon be used to determine whether someone is telling the truth or is under stress. In patent application WO 03/057003, US firm Defense Group describes a non-invasive polygraph machine that fires infrared pulses at the subject. The reflected and scattered pulses are gathered and analysed by a receiver. 'The receiver is connected to an information processing device capable of determining various physiological characteristics exhibited by the human subject,' say the authors." Whether "various physiological characteristics" are reliable signs of truth-telling is another issue, though.

Comments

Since when were standard polygraphs invasive?

[HaloZero]

invasive ( P ) Pronunciation Key (n-vsv)

adj.

1. Of, engaging in, or given to armed aggression: an invasive military force.
2. Marked by the tendency to spread, especially into healthy tissue: an invasive carcinoma.
3. Of or relating to a medical procedure in which a part of the body is entered, as by puncture or incision.
4. Tending to intrude or encroach, as upon privacy.

Polygraphs have consisted of blood-pressure monitors, pulse/respiration monitors/graphing, temperature, relative humidity/condensation on the epidermis, and as of late, retinal imaging. These are usually accomplised by a series of patches attached to the EXTERIOR of the patient's skin. No where, no how, is anything poked, prodded, or inserted.

If my invasive, you mean, less cumbersome, then sure, maybe. The patient would still have to breathe normally, and hold perfectly still (as to not alter the readings taken by the IR), which is really the only cumbersome thing about it.

Re:Since when were standard polygraphs invasive?

[Anonymous Coward]

not quite.

the poly i was given (it was for a gov't security clearance, and part of a larger background investigation for that clearance) consisted of a pair of sensors on two of my fingers (IIRC, index and middle; detects sweating), a pair of cords across my chest and stomach (monitors breathing), and a blood pressure wrap reader on my upper arm (blood pressure (duh) and heart rate). and you get a nice leather reclining chair to sit in. no patches slapped to my skin anywhere.

not sure how much retinal imaging would do, i was allowed to close my eyes as long as i didnt fall asleep.

they say "breathe normal," knowing full well the subject being interviewed is going to be nervous as hell, even when they are telling the truth. my breathing was more of a forced deep rhythm.

Re:Still subjective measurements

[outlier]

All "lie detector" tests are bogus because the results are always "subjective" to the machine's operator.

Not quite. Polygraphs can be valid under the right circumstances. They are reasonably accurate when used to ask questions about specific instances. Less so when they are used in hiring decision contexts. See this recent report from the National Academy of Science. There are many effective countermeasures to "fool" a polygraph. I wouldn't want my future (guilt or innocence) to depend on one, but they are pretty good at recognizing when people have unusual reactions to stimuli. How they are interpreted (e.g., is that a 'lie' or just nervousness?) is another matter.

Anyone know when this concept was first used?

The use of the polygraph as lie detector was pioneered by psychologist Dr. William Moulton Marston. He may be more familiar to Slashdotters under his pseudonym Charles Moulton. That's the name he used when he created the comic book "Wonder Woman."

Seriously!