Respectfully, I've also taken a handful of polygraph's over the years (Illinois Dept. of Corrections required another one of me just last month for a change in my status, was so annoyed at first but hey, at least now I can throw in my two cents here):
I was asked something like 'Are there any questions right now you are afraid I'm going to ask you?' and 'Are you scared/afraid (can't remember what word he used) of any of the questions I"m about to ask?' - somethin along those lines. I do NOT recall that question the first time I took the test for the IDOC which was about ten years ago (hence my 'renewal and reclassification' test, luck me).
Not sure if the reason I was asked this question was because I had already had a poly on file, and they wanted to check my 'updates' or, conversely, if it's because I have been reclassified and my new position - although basically the same as prior - requires that question, whereas the first poly didn't? I don't think that this was because there was any deception indicated, because it was the second or third question I was asked after the base questions - also, two of my friend's have taken poly's there recently (one new hire and one transfer) and they both were asked this, or a variation thereof.
Maybe it's asked when you are looking hard at that person for deception, and want to see their reaction...I don't know. I do know that the questions immediately following the 'scared' question involved matters VERY serious and important (#1, I'd say) for someone in my place - whether I have/had any drug history, have brought in contraband, have seen someone bring it in, etc., et.al -- don't want to go into too much detail but basically the MOST important questions relative to me, were asked immediately following that question.
FWIW and all that.