head nod?

[flight815]

took another poly, which i passed.

this examiner did something interesting and for my last two "blocks" of questions, he told me instead of answering verbally, to just nod my head very slightly yes / no to answer.

is this normal? was it to mess with me? did they suspect CM or something? was there interference or some other reason?

i was pretty nervous and my hands/legs were shaking a little, so i didnt know if there was extensive artifact and they had me answer silently to reduce that?

[Knightshaiid]

It says in The Lie Behind The Lie Detector that the 'silent answer test' is supposedly a countermeasure, but the book goes on to say that this particular anti-CM's only purpose is to catch the examinee off guard. (Other anti-CM techniques are designed to get the examinee to answer differently, thus 'catching' you.)

In my opinion, your polygrapher either suspected counter-measures or was just doing it to throw you off. If he said he was doing it to reduce 'extensive artifacts' or anything else he was (again in my opinion) probably lying.

[flight815]

I totally believe him on the artifact, I was shaking like a leaf.

Shame they do this to you to get a job...