The average person will be nervous during the administration of a polygraph test. In fact, a certain level of nervousness is expected by the Examiner. Although the increase in physiological activity will be recorded and clearly visible during chart collection, (increased heart rate, etc.) this will not affect the test itself, its accuracy or the scoring process. Simply put, you cannot fail a polygraph test due to nervousness. The mental effort taken to lie is much greater than that used to tell the truth (cognitive load) and this, together with associated changes in the nervous system relative to increased risk whilst lying, not nervousness, is effectively what is being measured.