Polygraph Notes

Question 1

The polygraph instrument examination is applied in two different areas:

Answer 1

Criminal Matters -Specific Incident (Crime)

Employment Background Screening (pre-employment).

Question 2

The autonomic (self-regulating) nervous system has 2 part.

Answer 2

The parasympethetic system: (high stress situation) in this situation: heart-rate increases, respiration and perspiration increase.

The sympathetic nervous system: is active after the stress is over allowing the body to wind down & rest, ie. doing its “housekeeping” functions such as digestion, slowing heart rate & blood pressure.

Question 3

The Polygraph measures: 3 things

Answer 3

• heart rate, blood pressure- measured by a sphygmomanometer (B.P. Cuff)
• respiratory rate-pneumograph tubes fastened around abdomen & chest
• electro-dermal activity (sweatiness)- measures galvanic skin response by electrodes placed on fingertips

Question 4

Common Countermeasures:

Answer 4

o Sedatives, Antiperspirant on fingertips, Tacks placed in the shoe, & Biting tongue, lip or cheek.

Question 5

Admissibility

Answer 5

Given the controversy over the accuracy and assumptions of polygraph tests, the results from them are typically deemed inadmissible in most courts.