George W. Maschke wrote on Jun 8^th, 2015 at 8:30pm:

The mental activity the original poster described cannot credibly be characterized as a polygraph countermeasure

Characterized by you, perhaps.  To us, attempting to control one's physiology between questions is typical for someone employing mental CMs.  The poster's remark that it was done to calm himself down and not to influence the outcome of the exam is typical rationalization.  "Yes, I did it, but my intent was pure";  right;  then he confessed why?