'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

Inadmissability of polygraph results

[Dancin_Santa]

Maybe if they'd require them, we'd have found the real killers by now.

Starburst: The Juice is Loose

another issue?

[Hubert_Shrump]

Whether "various physiological characteristics" are reliable signs of truth-telling is another issue, though.

You question our methods, terrorist?

Perhaps it is you that stole the stapler!

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:Since when were standard polygraphs invasive?

[HaloZero]

Alright, points made.

But did they stick you with anything, at any time? Skin penetration is the whole 'invasive' thing.

Re:Since when were standard polygraphs invasive?

[Anonymous Coward]

no they didnt. just strapped a whole bunch of things to me.

maybe they should s/Invasive/Contact/

Re:Since when were standard polygraphs invasive?

[Anonymous Coward]

They could also be talking about invasive as in penetrating your "personal space" when attaching various instruments to you. Invasive doesn't necessarily have to mean sticking through the skin, so lets not get overly anal and obtuse about definitions here. :)

Re:Since when were standard polygraphs invasive?

[nelsonal]

Sounds just like mine, was kinda fun all things considered, and the interviewer had a nice relaxing voice.

Re:Since when were standard polygraphs invasive?

[schlyne]

Supposedly, the retinal imaging section of the test is more reliable. If the pupil dilates suddenly, the person is lying.

Re:Since when were standard polygraphs invasive?

[LudditeMind]

I think what they're trying to say is that it could be used on you without your knowledge. Granted I would consider that more invasive, but it depends on your perspective.

Re:Since when were standard polygraphs invasive?

[Anonymous Coward]

I have to agree wholeheartedly with what the poster said about their experience with a polygraph test. My breathing was rhythmic. I wasn't sure how deeply I was allowed to breathe without being accused of trying to skew the results so I just my breathing rhythmically.

I had no fear the whole time my two tests (on back-to-back days) were given. Boredom was more the word. I almost feel asleep during the first-day test I was so bored!

I had to restrain myself from laughing when, during the second test, the interrogator came over and tried to readjust the blood pressure cuff on my arm. I don't have much upper body mass and could never get my arm muscles to develop no matter how many pushups, curls, etc I did. As a result, I'm sure he thought the cuff wasn't tight enough when in fact I was so relaxed during the testing that he probably thought something was wrong.

All in all it was an interesting experience but the testers were idiots.

Re:Since when were standard polygraphs invasive?

[Deflagro]

And that is exactly the problem with the accuracy behind that test. It's all subjective...one tester sees something the other does not. Just because your heart rate goes up, doesn't mean you lied, etc... I still think it's a silly way to look for the truth.

Re:Since when were standard polygraphs invasive?

[Anonymous Coward]

But did they stick you with anything, at any time?

Not really, unless anal probes are regarded as invasive these days...

Re:Since when were standard polygraphs invasive?

[argel]

4. Tending to intrude or encroach, as upon privacy

Duh!!!!

Re:Since when were standard polygraphs invasive?

[smithmc]

4. Tending to intrude or encroach, as upon privacy.

Yup, sounds like a polygraph to me...

Re:Since when were standard polygraphs invasive?

[HaloZero]

No, it really couldn't be used on someone without their knowledge, as the target would have to remain seated, very very still, and have regular breathing. I think it'd be quite obvious what you, the patient, could do about it.

Re:Since when were standard polygraphs invasive?

[LudditeMind]

Where in the article does it say that it is necessary for the person to be seated, very very still, and have regular breathing?

If you would like some actual information on the subject listen to this The Material World Program. They have an interview the people that are developing this.

This would make politics interesting

[Phillup]

Wouldn't it be cool to have one pointed at every politician, every time they made public statements?

Re:This would make politics interesting

[eglamkowski]

There'd be no point - it'd go off every time the politicians moved their lips.

Re:This would make politics interesting

[Anonymous Coward]

There'd be no point - it'd go off every time the politicians moved their lips.

That would be the baseline right? I bet if you used any lie detector on a politician who wasn't trained in gaming them they would actually register stress whenever they told the truth, or gave a lie that wasn't prescripted with their political advisers. But only if they planned to run for another office... I doubt one would ever go off.

Re:This would make politics interesting

[Anonymous Coward]

In all seriousness, many politicians are so used to lying that they'd probably be able to pass any lie detector test. If lying doesn't cause any stress, the lie detector can't detect it. But then, lie detection is a sham, anyway.

Re:This would make politics interesting

[Stonent1]

As senate majority leader, *BUZZZ* As senate minority leader, *BUZZZ* Damn, who can you trust?

Re:This would make politics interesting

[MrLint]

hey there's an interesting idea you can mount one to the top of the TV camera and report the result on an infowindow in real time along with the propaganda:)

Still subjective measurements

[neitzsche]

All "lie detector" tests are bogus because the results are always "subjective" to the machine's operator. This one is no improvement on the old [also invalid] concept.

Anyone know when this concept was first used? Sending someone to stand in front of a mystic or seer so as to evoke a confession?

Re:Still subjective measurements

[tanguyr]

Sir Bedevere: There are ways of telling whether she is a witch.
Peasant 1: Are there? Oh well, tell us!
Sir Bedevere: Tell me. What do you do with witches?
Peasant 1: Burn them!
Sir Bedevere: And what do you burn, apart from witches?
Peasant 1: More witches!
Peasant 2: Wood!
Sir Bedevere: Correct. Now, why do witches burn?
Peasant 3: ...because they're made of... wood?
Sir Bedevere: Good. So how do you tell whether she is made of wood?
Peasant 1: Build a bridge out of her!
Sir Bedevere: But don't we also build bridges out of stone?
Peasant 1: Oh yeah.
Sir Bedevere: Now, does wood float in water?
Peasant 1: No, no... Throw her into the pond!
Sir Bedevere: No, no. What else floats in water?
Peasant 1: Bread!
Peasant 2: Apples!
Peasant 3: Very small rocks!
Peasant 2: Cherries! Great lumpy gravy!
Peasant 3: Crutches!
King Arthur: A Duck!
Sir Bedevere: Exactly!

Re:Still subjective measurements

[Jonsey]

So... 'f she weighs the same as a duck.

Does that mean she's lying, or telling the truth?

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!

Re:Still subjective measurements

[ClosedSource]

My brief look at the report you cite suggests that the researchers didn't do any experiments on their own but rather relied on a number of older experiments performed by a variety of organizations (correct me if I'm wrong).

Here's my first crack at how such an experiment should be handled:

Subjects should be representative of the population at large.

The questions should be chosen such that the truthful answer is "yes" about 1/2 the time across the subject population.

The technician hooking up the subject, the questioner and the one retrieving the data are different people who never meet for the life of the study.

Those trying to "read" the result should have no information on the questions or any information about the subject the data comes from. Again, they are isolated from other team members. Multiple individuals perform the analysis.

The coorelation between the questions and analysis is performed by another group who are also isolated from the others.

I'm sure this isn't a complete list, but you get the idea. If they followed rules like these and got a mean accuracy > 90% I would be impressed. I think anything short of that would keep it in the novelty category.

Re:Still subjective measurements

[outlier]

Two points:

First, you are on the right track in pushing for a double-blind, methodologically sound study. However, the value of analyzing "a number of older experiments performed by a variety of organizations" should not be underestimated. In many ways a meta-analysis (evaluation of existing analyses) is actually more reliable than a single well designed study. No matter how well it is designed, any single study will have weaknesses -- they have a small number of subjects, the truths/lies are limited to a single domain, the time and location of the study has some unexpected influence on the results, etc.

By combining these studies, organizing them by potentially meaningful variables (question type, subject pool, etc.), and weighting their influence by the number of subjects (bigger studies are more important than small ones), you essentially cancel out a lot of the noise (e.g., experimenter bias, weird questions or instructions, etc.)

Second point: The polygraph is reasonably valid as a lie detector. I'd characterize their accuracy as "better than most people, but not good enough to execute someone." Unaided humans in studies similar to the one you outline above perform in the 55-65% range. Significantly better than chance, but not particularly awe inspiring. Moreover, police officers, judges, customs agents, FBI agents, and college students all tend to perform about the same. Some Prisoners, Secret Service Agents, Psychologists interested in deception, and some people who have grown up in abusive environments have been shown to perform even better. But accuracy tends to be pretty domain specific.

The polygraph can arguably be characterized as having an accuracy as a lie detector in the 60-80% range. There are people (and organizations) that will claim accuracies in the 95-100% ranges, as well as those who would argue that the accuracy of the polygraph is 55% or lower. In both cases, you're probably dealing with people who have hidden (or not so hidden) agendas.

Again, the polygraph is a decent tool to determine if someone reacts unusually to some stimulus. Any assumptions beyond that may be unfounded.

Re:Still subjective measurements

[ClosedSource]

"In many ways a meta-analysis (evaluation of existing analyses) is actually more reliable than a single well designed study. No matter how well it is designed, any single study will have weaknesses -- they have a small number of subjects, the truths/lies are limited to a single domain, the time and location of the study has some unexpected influence on the results, etc."

Well that makes sense if each of the original studies is well designed, but if some of those studies are flawed then it's quite likely that the meta-analysis will be flawed as well. A better approach might be to evaluate each of the prior studies, determining their weaknesses and then design an experiment that avoids them.

"Again, the polygraph is a decent tool to determine if someone reacts unusually to some stimulus. Any assumptions beyond that may be unfounded."

Well, it's only advertised value is for detecting lies, so that's the only valid standard it should be evaluated on. If law enforcement wants to drop it because it's just a tool to "determine if someone reacts unusually to some stimulus" then other criteria could be applied.

Re:Still subjective measurements

[Alsee]

So... 'f she weighs the same as a duck.
Does that mean she's lying, or telling the truth?

Yes.

-

If it really worked

[ClosedSource]

the medical applications would be far more important and profitable then the "lie detecting" application. The fact that it wasn't a patent for a medical device suggests that it doesn't really measure anything meaningful.

Since there is no scientific standard for lie detectors (and the current ones are obviously a scam), you can use any kind of dubious technology you like. A medical device, however, has to demonstrate efficacy which is a much higher standard.

Re:If it really worked

[jdiggans]

Near-infrared neural imaging is already a very useful technique.

This is a new application whether or not you approve.
-j

Re:If it really worked

[ClosedSource]

I know I get a diffuse optical tomography check-up every year from my doctor. Seriously, does this really have anything to do with the lie detector patent?

According to the story:

"The receiver is connected to an information processing device capable of determining various physiological characteristics exhibited by the human subject"

If those "physiological characteristics" included blood pressure, for example, it would be a major breakthrough since it could lead the way to frequent non-invasive PB measurements. I suspect, however, that the characteristics referred to can not acurately measure any medically useful parameters, thus my original point.

Re:If it really worked

[ClosedSource]

Make that "BP" instead of "PB".

Re:If it really worked

[jdiggans]

From a cog. neuro friend of mine, the argument is that when a person lies, there's a characteristic increase in bloodflow to a particular area of the brain. The IR system discussed in the story is used to measure this increase in bloodflow (which is the same thing that makes it useful in many other aspects of functional cognitive neuroscience; it's much cheaper than an fMRI). The real question here isn't really the machine or even the patent (God knows we get enough stupid patents around here). The real question is whether or not this increase in bloodflow is 100% always indicative of lying and nothing BUT lying.

There's another variation on this theme that I find much more fascinating. Using the same technique (or fMRI for increased resolution and depth) one can screen a subject for a particular type of lie -- by showing the subject a picture of a crime scene and testing for neural recognition (and nothing but) you have a sort of 'lie detector' that relies on a lot more heavily proven science.

-j

Re:If it really worked

[ClosedSource]

"The real question is whether or not this increase in bloodflow is 100% always indicative of lying and nothing BUT lying."

Well, unless one believes God is responsible the answer to that question is very likely to be no. What is the survival value of such a feature and how did it evolve?

I have to say I'm a bit sketical of the neural recognition argument as well. Exactly how close can two images be to be considered different by the brain? Obviously most visual information from a crime scene has nothing to do with the crime.

It's very similar to the problems encountered with supervised learning in neural nets. You never know exactly what the net "thinks" is significant.

Re:If it really worked

[jstott]

Near-infrared neural imaging is already a very useful technique.

This is a new application whether or not you approve.

I work with some of the authors you cited and I personally know most of the others. Near infrar-red spectroscopy and diffuse optical tomography are very good for measuring localized changes in blood oxygenation and volume (and, by inference, brain activation), but going from "you show activation in your right frontal cortex" to "you're lying" is a huge leap and way beyond the limits of any neuroscience research I've ever run across.

This is a submarine patent-they've got an idea, but I assure you they don't know how to make it work yet. First, collecting the signals will be extremely difficult since you have to get past all the light reflected off the skin. The changes in signal level you're looking for are easily at the PPB (yes, 1e-9) level compared with the light you're putting in, so this is decidedly non-trivial. Second, this "information processing device capable of determining various physiological characteristics" is going to be real interesting to build since no one knows what those characteristics are and (as with conventional polygraph) there are innocent explanations for most everything you can measure. Finally, NIRS doesn't penetrate very far through the brain, so you're limited to areas near the skull. Deep structures (eg, the hippocampus) aren't probed at all. If the brain doesn't do any work in these superficial regions (which may or may not be the case), there's nothing to be measured.

In short, you have nothing to worry about from this patent. Worry instead why the government is so interested all of a sudden in an undetectable remotely operated lie detector. We've had visitors from NIMA in our lab, and various three-letter agencies have sent letters to several of my cognitive science colleagues offering to fund research along these lines as well.

-JS

Polygraph story

[Laplace]

So I knew this woman, a world class athlete, who also worked for the Department of Defense. For her Top Secret clearance she had to submit to a polygraph test every six months. On the day of one of her tests she arrived at the testing center having just worked out. Her pulse, respiration, and skin moisture were all a bit elevated, and the tester noted these abmornal readings to her. Now, one of her training techniques involved meditation, and she became adept at both mentally and physically relaxing in a very short amount of time. She went into her meditation routine and almost instantly her pulse and breathing rate dropped. The tester became angry with her, and told her to come back the next day. Now how hard can it be to learn to game the whole polygraph system?

Re:Polygraph story

[Anonymous Coward]

six months? nah. I have a TS clearance from DOD, and it's five years between retesting at the polygraph. but with backlogs, it often comes out to six or seven before someone actually gets to the front of the queue.

Re:Polygraph story

[Anonymous Coward]

Report to my office -- you're overdue.

Re:Polygraph story

[Anonymous Coward]

That's a crock of shit.

Here's how a polygraph works. You measure certain things--not one thing, but many--and watch them over time. You look for deviations, not from some presupposed idea of "normal" but rather from the subject's baseline at that given instant.

Now, we're not talking about things like heart rate and respiration here, although those are observed. We're talking about things like galvanic skin response, which basically measures how sweaty you are at a very fine level of detail. These are not things you can change with rhythmic breathing or whatever. They are beyond your conscious and autonomic nervous systems and into the realm of physiological response.

That's why a polygraph session starts with as much as a half an hour of fairly inane questions: to relax the subject and let the operator establish a baseline.

So if your world-class athlete woman came in all sweaty, nobody would care. If she took deep breaths to lower her heart rate, nobody would care.

This anecdote is, in other words, a crock of shit.

Re:Polygraph story

[Anonymous Coward]

This just shows how little you know...

There is no reliable baseline while people are coming down off a workout, for a period of more than an hour in cases of intense exercise...

Re:Polygraph story

[Sylver Dragon]

That's a crock of shit.

Stop right there. You have just described the whole "science" of polography. The only reason it sticks around is there is enough money being pumped into it, that the purveyors of this snake oil can keep lots of people convinced that it works. The only thing it is useful for is convincing weak minded idiots that you actually have a way to see inside their heads, and get them to confess. Other than that, it is total bunk.

Re:Polygraph story

[Anonymous Coward]

You have just described the whole "science" of polography.

And if we were talking about the science of "polography," that might mean something. (What is "polography," anyway? The act of making maps of polo grounds?)

Polygraphs, on the other hand, work very well.

Re:Polygraph story

[jazman_777]

The only thing it is useful for is convincing weak minded idiots that you actually have a way to see inside their heads, and get them to confess.

So it does have its use. But then, so does torture.

Re:Polygraph story

[Sylver Dragon]

Sorry, bit of a typo there. Though I still stand by my assertion polygraph tests are junk science. If you haven't done so, I would recommend reading The Lie Behind the Lie Detector (PDF), its a good read and very informative about polygraph tests and the like. Polygraphs are just the moden day version of a mystic. They don't do anything in and of themselves, they only convince people to confess, and are great for destroying someone's credibility because the media believes in them.

Re:Polygraph story

[Incongruity]

"Now, we're not talking about things like heart rate and respiration here, although those are observed. We're talking about things like galvanic skin response, which basically measures how sweaty you are at a very fine level of detail. These are not things you can change with rhythmic breathing or whatever. They are beyond your conscious and autonomic nervous systems and into the realm of physiological response."

How about you stop right there and go and read up a bit more. Galvanic skin responses can be ellicited by *a lot* of conciously controlled actions. If you take a sudden, strong sniff of air, for example, you'll see a really big GSR. That's an easy one. Also, btw, GSR *is* an autonomic response. If you doubt me on either of these two points, go ahead and read the recently published report on the scientific basis for the polygraphby the National Academies of Science. You can find it online and read it for free.

Re:Polygraph story

[Anonymous Coward]

Bingo. The polygraph is a form of interrogation, just as torture is. The veracity of the information obtained in both situations is, of course, highly suspect. Their real point is just to spread fear. On a side note, it's rather sad that this story was listed under *science* here on Slashdot.

Re:Polygraph story

[alecto]

The only reason it sticks around is there is enough money being pumped into it, that the purveyors of this snake oil can keep lots of people convinced that it works.

Kind of like DRM, in that respect.

Re:Polygraph story

[ThereIsNoSporkNeo]

They couldn't come up with a color for "Modern day torture"... or, more accurately, it was already taken by the "Games" section.

Re:Polygraph story

[Anonymous Coward]

I don't know how to respond to this, but I've been involved in situations with a government subcontractor which required me to submit to a polygraph.

Ok, I arrive. By nature, I am a bit high-strung. Always been that way. Even at radio shack. I put my hands on a glass counter, and there's a puddle of water left from condensation.

They hook me up, and seem quite frustrated. They keep asking me questions, I try to answer them, they keep trying to tell me to relax. How can I? I am being interrogated! I have no idea what they want. The nature of the questions they ask would put anybody on edge. The ones that got the best of me was those loyalty questions reminiscent of the movie "Crimson Tide" ( Morgan Freeman ) . They are playing all this secret hush-hush need-to-know basis stuff with me, and I feel just as helpless as when I'm trying to get a Microsoft system to work in the way the customer tells me he wants it to work. ( By revealing my sentiments toward proprietary authorization based systems, I've told you I have a strong need to know how and why things are the way they are, because, as an Engineer, I feel its my responsibility to make sure things do what they are designed to do, no matter what happens. )

I was terminated from my job about two weeks later, from what I still feel was a "rigged" termination to make it look as if I were incompetent. ( They told me I was required to use a new CAD system which I was totally unfamiliar with, then compared me against guys who had used it for years.)

Re:Polygraph story

[Alsee]

They are beyond your conscious and autonomic nervous systems and into the realm of physiological response.

Wrong. Ordinary meditation will lower every single thing that the polygraph records. Breathing, heart rate, and yes, even galvanic skin response.

Anyone who hooks themselves up to a polygraph and invests the time to practice bio-feedback can learn to manipulate those autonomic physiological responses and make them dance under concious control.

-

Lie detectors are not subjective in that way.

[Anonymous Coward]

"All "lie detector" tests are bogus because the results are always "subjective" to the machine's operator. This one is no improvement on the old [also invalid] concept."

That is not the problem: the electricity flows the same regardless of the operator. The problem is false positives from things that are not lies but show up on the machine as such.

Re:Lie detectors are not subjective in that way.

[ClosedSource]

No. The problem is that the operator doesn't solely rely on what "shows up" on the machine. If they did, they could have a technician hook you up, turn the machine on, ask the questions and then submit the recorded info to an "expert" reader with just question numbers and time stamps. That won't work, however, because the reader won't be able to tell which questions you are supposed to be lying on and he won't be able to bluff you into revealing something. The machine is just a prop.

Clinton detector

[Anonymous Coward]

It would be a hand-held Clinton-detector.

(Clinton already had his own hand-held Monica detector)

Politicians would learn to carry blocking devices, made by the company that makes the Fuzzbuster.

Re:Clinton detector

[Anonymous Coward]

Boy, how dated. Try a Bush/Blair detector.

WMD a "clear and imminent threat." Now that would have sent the detector into overload!

Since they started using the 4th definition

[morcheeba]

4. Tending to intrude or encroach, as upon privacy.

If there is anything that should be private, it should be one's own thoughts. Attempting to read these is invasive.

Polygraphs are a Fraud

[jazman_777]

Read about it here. Looks like polygraphs are biased against honest people.

Great

[joelt49]

Great, another machine to do the impossible. I mean, really, how is this different than just looking someone in the eye when you ask them a question? Some people can lie convincingly and others can't. That's all there is to this system. Once you have a system, you CAN beat it, and some people do. Why don't we just accept that fact and get rid of polygraph machines? Either that, or have an experienced poker player read the results, as they have TONS of experience with poker-faces.

Re:Great

[nomel]

I can't not lie unconvincingly. I was arrested last year for being under the influence. I kept telling the guy that my heart rate was up cause I had walked about a half a mile, my mouth was dry because I had walked about half a mile, I was having "uncrontrollable muscle spasms" because I had walked a half a mile in shorts and a t-shirt in 40 to 50 degree F weather. I got very nervous after two more cop cars pulled up, one of them a drug specialist, which added to all the other symptoms. etc. etc. It all lead to me being arrested and pissing the cop off cause I didn't care that I had been arrested. It was funny, but sucked.

An alternative to classic lie detector

[FrankoBoy]

is found in new techniques involving brain scans. A brain wave pattern called P300 ( "positive wave" 300 ms after onset ) has been discovered to be activated when a person looks at a familiar object ( the P300 hypothesis has gained very solid evidence since a few years ). So you can display some pictures to the accused person and embed in these actual crime scenes pictures, and then tell if the accusee is familiar with crime scene pictures ( like what the place looked like, weapons involved, etc. ). Of course, you have to display pictures that has not been released to the media and whatnot, but the uniqueness of the combinations needed to figure out that someone is involved in the crime is pretty high. Links here, here and here.

This polygraph stuff got to be thrown away at some point anyway, since it's based on reaction patterns that many people just don't have so its accuracy isn't high enough for the important task it has to do.

Re:An alternative to classic lie detector

[Anonymous Coward]

Well, this would only mean that the person is familiar with said object, it doesn't mean the person is guilty of commiting a crime.

Lots of people have visions/dreams of things that happen in the real world. A lot of people are also spazzy, meaning that a picture of a cat might remind them of their child hood pet which would certainly trigger a similiar reaction.

The only way we'll ever have a technology that can provide a lie or not is to monitor the person's brain activity for long periods of time. In other words, double up every human with another and make the watcher see all that the subject does, thinks, and feels (feels being a question of motive more than anything else).

If only we could use it on the Terrorists and the Politicians. The terrorists, to find out what they're problem is so that we can right wrongs, and the politicans so we can stop wrongs from happening.

Re:An alternative to classic lie detector

[jstott]

A brain wave pattern called P300 ( "positive wave" 300 ms after onset ) has been discovered to be activated when a person looks at a familiar object ( the P300 hypothesis has gained very solid evidence since a few years).

These are extremely controversial findings. I've had discussions with cognitive neuroscience researchers I work with and not one of them is totally convinced this is real yet.

-JS

Consumer Grade Unit

[4of12]

Infrared laser pulses

(Wife points TV remote at hubby.)

"Now tell me again where you were until 2:30 last night! And don't think you can get away with lying - I've got my IR polygraph aimed right at your forehead!"

#4 smarty

[Anonymous Coward]

It encroaches on the privacy of the person being questioned. It also can cause false positives.

Response time is a factor, so please pay attention

[brianjcain]

Anyone else think of Voight-Kampf?

Right

[FrankoBoy]

Well since you would have to be familiar to MANY ( think tens ) distinct pictures at the same time to get caught by P300 scanners, I guess this probability is pretty small, but there are chances it still might happen indeed so in essence, you are quite correct. Particularly in your conclusion, as you may expect I would by my sig ;) In fact I wouldn't be surprised at all if such scanners were used as we're talking in Guantanamo. But not in Washington though... yet.

Last time I checked

[phorm]

Women didn't need any special tools to know when a man is guilty... they all seem to have built-in polygraphs. Not to mention super detective skills, eagle-eyes, and sharp noses.

They know when you're lying, they can smell that faint whiff of perfume clinging to you, and they can spot that small piece of blonde hair on your light-coloured sweater...

Re:Response time is a factor, so please pay attent

[Anonymous Coward]

No.

By non invassive

[Morgahastu]

they mean: can be used secretely/without the persons consent.

This is bad news.

Right #2

[FrankoBoy]

I know they are, that's why I said it was an hypothesis. Having gained very solid evidence in the past years doesn't mean that a concept is beyond doubt, though it seems like new theories are always very controversial before they are widely accepted. Anyway, we'll see, and I'm sorry if my post left a "sure shot" kind of impression even if it seems to work according to what I know right now. Please link some pages about this controversy if you have some, I'd be pretty interested about that.

Great!

[nusuth]

Infrared laser pulses could soon be used to determine whether someone is telling the truth or is under stress.

Now please invent a device that can tell whether someone is overweight or anorexic.

Isn't IR hot???

[Sanga]

Tell us where those WMD are or we will sear your flesh !!!!

Just as effective as sharks with frikking lasers on their heads.

(Yeah: I did not read the article)

Better idea for learning the truth

[Stonent1]

http://answers.google.com/answers/main?cmd=threadv iew&id=156832

Pro...

[da5idnetlimit.com]

Being a "pro" salesman (think car dealer) I can lie to you all day long and not even break a sweat.

I'm so deep into the art of seceiving that it comes to me naturally, with no bio feedback for you to play with.

And you just lost the only "Truth" test you had against me...

JOIN TODAY THE MOVEMENT FOR THE ERADICATION OF CAR DEALERS !!!

Different path

[Armbrust84]

I just wonder if there is anyone out there who is combining the new insights we gain each week into the workings of th emind with the newest theories and practices of forensic investigation. Seems to me that we cannot rely on only one method. Although, ever more frequently, the police require less evidence to arrest, and judges/juries even less to convict. Oh well, I pity my great-grandchildren.