Lie Detectors

[WhiteBears]

hmm i just wonder how acurate these are, heres an scenario (apologies if my spellings/grammer are poor)

say for instant you were asked if you did certain thing, and you are so sure you didnt do it. and the lie detectors detects this and results shows you're telling the truth.

later reviews that on cctv shows you Actually did it... but you say you do not remember doing such thing, the lie detector also confirms this?

so, what would be the out come of this scenario ? the lie detector confirms this person did tell the truth that he/she did no such thing, however this person did actually did it, but could not remember doing it?? can lie detector detect this??

or am i going mad? do u get what i mean??

[bednobs]

i think if you believe the lie to be true then it would not show up on a lie detector

[society]

I believe a mentally stable person with a strong mind could fool / control it.

[WhiteBears]

but bednob, its not a lie!

i guess the police, crime squad etc dont use it as its an unrealiable source to find the truth? cos you could be really nervous about answering a certain question, although you're telling the truth but the detector says youre lying.

or like society says, you could fool the machine!

[askyourgran]

As far as I know, all a lie detector does is record every movement however slight when you are asked a leading questions. Any change in breathing/movement can effect the machine making peaks and troughs which match with the questions asked. I do not know this from personal experience but the machine is sensitive just that, You are nervous your breath quickens your hands sweat and shake when asked the question you have been dreading. Bingo you've lied you are guilty. But if you honestly believe you didn't do anything wrong, it would not record the peaks they are looking for.

[Buenchico]

Lie detectors don't work anyway:
http://www.ukskeptics.com/polygraph.php

But, if you're looking for a method which might work . . .

http://www.youtube.com/watch?v=3qsJsGX9CRM

[123everton]

I've often wondered whether lie detectors detect truth or guilt, there's a difference.
You might not have committed an act, but feel (perhaps wrongly) that it was your fault....