Sweat Ducts May Act As Antenna For Lie Detection

Reservoir Hill writes "Researchers have discovered that human skin may contain millions of tiny "antennas" in the form of microscopic sweat ducts that may reveal a person's physical and emotional state. This discovery might eventually result in lie detectors that operate at a distance. In experiments, the team beamed electromagnetic waves with a frequency range of about 100 gigahertz at the hands of test subjects and measured the frequency of the electromagnetic waves reflecting off the subjects' skin. Initially, the experiments were carried out in contact with the subjects' hands, but even at a distance of 22 cm, researchers found a strong correlation between subjects' blood pressure and pulse rate, and the frequency response of their skin."

Is someone telling the truth?

[BadAnalogyGuy]

I knew a guy who claimed he was abducted and sodomized with various probes then dumped in a field in the middle of nowhere. Is he lying? He believes it.

Whether you know if someone is lying or not does not necessarily bring you closer to the truth.

Re:tinfoil hat

[aleph42]

Just a quick reminder of the facts:

Brain scanner can tell if you are going to buy a product or not:
http://www.boingboing.net/2007/01/11/brain-scans-predict-.html [boingboing.net]

Brain scaner can tell what you are looking at:
http://science.slashdot.org/article.pl?sid=08/03/06/0435226 [slashdot.org]

Brain scanners are so easy to do that now they are in game controllers:
http://hardware.slashdot.org/article.pl?sid=08/02/20/1314254 [slashdot.org]

And better than a tinfoil hat, we will need something able to filter what you let or do not let through, as was done with the rfid firewall:
http://www.rfidguardian.org/index.php/Main_Page [rfidguardian.org]

Re:At a distance?

[Anonymous Coward]

Not if you want to monitor large groups of people... like in a shopping mall or ($next_wild_idea_to_improve_security && $think_of_the_children); Combine this with CCTV, face recognition and you can detect who goes where and if they're 'suspiciously nervous' without having to tell the person(s) in question. Being someone who has panic attacks and periods of agoraphobia, I do not like this at all..

It's even crappier

[Moraelin]

It's even crappier. We already know know about the normal polygraphs that they don't really work. They just mention someone's reaction to stress, and from there it's a leap of faith that "lying emotional stress". The latter just isn't so.

1. As you mention, what do you do about people who genuinely believe something bogus?

As a milder example, human memory isn't photographic, ever. It seems to store more like the description of a scene, and just ad-lib the details that it forgot. Over time you'd forget that, say, the guy was wearing a blue shirt, or maybe that detail never even made it into permanent memory in the first place. But if you try too hard to remember it, it will just give you some best guess. Like that he was wearing a black shirt.

2. We know that people can train to not feel much emotion about lying, and to psychopaths it even comes naturally. So even measuring their pulse and blood pressure and everything directly, you just can't tell that they're lying.

Basically we're relying there on the false idea that everyone was educated that it's not nice to lie, and everyone therefore has a hard time telling one and is feeling severely guilty about it. Which is false from start to finish. E.g., speaking of education, we know that some people's upbringing just taught them that it's perfectly _normal_ and indeed _logical_ to tell a lie, if the alternative is a savage beating by your father. They won't feel any guilt extrapolating from there to lying to save their arse from jail.

3. That emotional stress someone is feeling, can be for a bazillion other causes.

E.g., because the topic is painful to them for other reasons. A rape victim being the witness in someone else's rape trial might experience severe stress just thinking about it, whether they tell the truth or not. A PTSD [wikipedia.org] sufferer will be in a disproportionate amount of stress when recounting the event that caused it, or anything that reminds them of it. So, you know, some grandpa who fought in Vietnam and still wakes up in cold sweat after dreaming of it, would register as shamelessly lying when they tell you about the atrocities of war. Etc.

E.g., particularly bad cases of repressed memories and/or the results of some particularly hard to justify cognitive dissonance, can cause a disproportionate emotional responses when you're forced to think or talk about something which challenges them. You see that not only in polygraph tests. A lot of people who are rabidly against something are really just against you challenging their already decided model of the world. The less of an actual justification they have to support that position, other than "but my daddy said so", actually the harder it can be to get them to think logically about it.

Etc.

Basically let's just say there are good reasons why that test can't be demanded in court.

So now we have something that promises to test one parameter from a distance, instead of several measured directly, and which must correlate in certain ways to be considered a "yep, he's lying" proof. It's basically adding one more indirection step to that already weak inference chain. But even if the correlation between skin pores and all those parameters were that infallible, you're back to "stress he's lying", which is already known to be false even measured up close with electrodes.

Re:It's even crappier

[gnick]

Hypnosis can be used to remember e.g. a phone number you saw when you were 6 months old and couldn't read yet...

According to some sources [wikipedia.org] roughly as reliable as most hypnosis publications, people can pull up memories dating all the way back to conception. The fact that somebody recovers a repressed memory and strongly believes its accuracy doesn't make it true...

Personnal experience

[courteaudotbiz]

I personnaly had a pre-employment polygraph test, and I can assure you that, remotely or directly, a polygraph is no more than a more or less sophisticated vital signs recorder.

The test was 10 questions long, repeated 3 times in a different order each time, and out of those 10 questions, I intentionnaly lied to 4 of them. Strangely, the guy told me "this particular question about computer crimes, I think you lied to this one". In fact, when I was asked this question, I could feel my eart beating a little faster, and my skin got a little sweating. But I know I was telling the truth about this one. It's just that since it's my domain of expertise, I was a little more stressed about the question, but I am so straight when it comes to licenses and copyrights that I even personnaly bought a retail version of Microsoft Office, and all the games I have are boxed originals...

Strangely, when I was asked questions about other stuff for which I lied deliberately, I had no reaction at all, and the guy thought I was truthful about them.

Ok, I prepared myself for the polygraph, and I read an EBook on antipolygraph.org [antipolygraph.org] . I guess the results are a little more biased than with someone who really believes the polygraph is a precision instrument to discover the truth, but maybe this is the reason NO FURTHER RESEARCH should be made about lie detection, except maybe with celebral flux, where I guess a different part of the brain creates lies than the part which effectively remembers the facts you actually lived.