Quote:There is a difference between ANS reaction and CNS thought.
The autonomic nervous system has a "sympathetic response" and a "para-sympathetic" response.
SR is evidenced by increase in BP, sweating, faster heart beat, more rapid and breathing.
Which is pretty much what the polygraph measures.
The SR can be thought of as a "continuum" from mild arousal to a panic response (full kick in of the "fight, flight or freeze" response).
This is indeed affected by conscious thought. The unconscious in fact takes many of it's cues from the conscious mind.
I know all of this because I suffer from an anxiety disorder. I know from experience that a pattern of negative thought (say thinking about my polygraph experience) causes a pattern of negative emotions (hate, anger, fear...etc), which manifests in ANS arousal (increase BP, heart rate, breathing, sweating) though not necessarily into a FFF response!
Quote:Why would someone react with ANS activity to any queston if no immediate threat existed?
That still doesn't explain why that reaction necessarily equates to "lie" or "deception".
There are other possible reasons for people to have a "visceral reaction" to a question other than deception.
Ever hear of Dr. Phil Zimbardo at Stanford University. I distinctly remember watching an educational tape from him talking about the polygraph. His conclusion:
"There is no direct and UNEQUIVOCAL relationship between ANS and telling a lie."
I believe the NAS came to the same general conclusion.