Question About Polygraph

[Chris T]

Question:  I have quickly read through "The Lie Behind The Lie Detector" and noticed that the sensors that are put on a persons fingers when they are being "tested" is not really mentioned, and I saw no countermeasures for this aspect of the polygraph mentioned at all.  Is the reason for this because the polygrapher relies little on these, or because it is difficult or impossible to use countermeasures for this aspect of the polygraph machine (or some other reason :-)

Thanks -- CT

[John D.]

Excellent question. The countermeasures listed in the book will effectively manipulate the polygraph. However, beating the two metal plates that record sweat glad activity, like the rest of the polygraph, is easily overcome. According to the Backster School of Lie Detection, if the impending polygraph victim simply and lightly pushes the metal plates into the armrest of the polygraph chair, it will void the ability of the plates to record activity. Backster, in an attempt to overcome this flaw, suggests to its examiners that they tell the impeding polygraph victim to extend their finger past the end of the armrest so as that the victim's wrist hangs over the end of the armrest. This way the examiner can visually monitor the metal plates so as to make sure this type of countermeasure is not being employed.

But, as the Backster School of Lie Detection teaches, all the impeding polygraph victim must do is put slight downward pressure on the wrist that hangs over the arm wrist and this will sufficiently defeat the skin moisture.

I wouldn't worry about the skin moisture monitoring because the other countermeasures effectively and sufficiently manipulate the examination. It is more important to concentrate on keeping a straight face and refrain from laughing as you beat the polygraph and you watch the examiner go through the monkey drill outlined in the book.

[Chris T]

Thank You for your reply to my question.  

[George Maschke (Guest)]

Chris,

While I am not familiar with the teachings of the Backster School of Lie Detection, John D.'s advice seems sound:

I wouldn't worry about the skin moisture monitoring because the other countermeasures effectively and sufficiently manipulate the examination. It is more important to concentrate on keeping a straight face and refrain from laughing as you beat the polygraph and you watch the examiner go through the monkey drill outlined in the book.

The anonymous psychophysiologist cited in Chapter 2 The Lie Behind the Lie Detector with regard to the Aldrich Ames espionage case wrote to me the following regarding the GSR channel:

On countermeasures: The "cardiac" countermeasures also work for the skin conductance response (SCR or GSR), the third response (in addition to cardiac and breathing) measured by the polygraph. (Many people believe that SCR, also known as GSR, is the most important of the three responses, and it weighs heavily in the computer scoring algorithms.) I have taught people to beat a polygraph by using a skin conductance meter and letting people practice countermeasures that produce an SCR response. This gives people feedback on which countermeasures work, and also builds confidence.  You might want to inform your readers that they can buy a GSR "biofeedback" monitor for as little as $60 (www.bio-medical.com, GSR biofeedback monitor, item T2001). (This is not an endorsement -- I haven't seen that monitor -- but anything will do for practice.  I bought one several years ago from Radio Shack for less than $60, but that item is discontinued.)  Both physiological and psychological countermeasures tend to produce parallel responses in SCR and cardiac measures, since the response elicited is an integrated "fight-or-flight" response.  (This is true even of constricting the anal sphincter, because in addition to affecting the cardiovascular system, this produces some discomfort, which produces an SCR response.)

Our failure to address this point in the book is my oversight.

You may have heard recommendations to rub antiperspirant or even nail polish on your fingertips to attenuate GSR response, but this is unsound advice. Pressing one's fingers down seems unwise, too: it's unnecessary and might be observed by the polygrapher. Remember, the key to "passing" a polygraph interrogation is to make no significant admissions and to produce stronger responses to the "control" questions than to the relevant questions.

George Maschke

[Shropshire Lad (Guest)]

Chris,

I agree with John regarding the merits of your question.  It is an excellent question and suggests that maybe the omission you cite might be as the result of some oversight on the part of the authors and perhaps accompanied by negative consequences for those who would apply countermeasures. I don't believe the initial assumption (oversight) to be true, and I am quite certain that the possibly-drawn conclusion (regarding negative consequences) is not true.

I agree with two things that John has said: (1) "The countermeasures listed in the book will effectively manipulate the polygraph." And  (2) in part with "I wouldn't worry about the skin moisture monitoring because the other countermeasures effectively and sufficiently manipulate the examination."  I say in part with the second statement for the following reason.  It would appear that he believes that the examination can be successfully manipulated (true) but independent of EDRs (sweating responses) (false).  The methods he discusses (focusing on the level of the finger plates) and other similar ones are poor and clearly should be avoided.   EDA, however, is a critical and heavily weighted (subjective as well as objective) component of a polygraph examiner's chart scoring (and therefore can not be ignored).   The GOOD NEWS is that there is a correct approach and logic for affecting this polygraph channel, and it is largely covered, albeit implicitly, in the text you reference.  It is unclear whether John would recommend either of the methods he discusses.  His failure to condemn and suggest alternatives though allows for the possibility of confusion about whether sweating responses are important in chart evaluation and what represent good and bad choices for affecting this important physiological channel.  

With regard to electrodermal activity (EDA) (emotional sweating), EDRs (electrodermal responses)(the sweating responses recorded by a polygraph in a "lie detection" exam) and countermeasures and counter-countermeasures affecting this channel specifically and thus in turn affecting the probability of success in manipulating the overall exam outcome, I submit the following:

(1) The type of countermeasure (finger or wrist pressing associated with the finger plates used to record EDA) as described by John is ineffective, counterproductive, and risky.  (explanation forthcoming)

(2) Polygraph countermeasures are generally of two types:  (a) those which seek to affect examiner opinions through examinee behavior and conversation (Aldrich Ames type) and those directed at affecting polygraph chart recordings.   It is this latter type which your question/John's answer refer to and which I seek to address.

(3)   The latter type (chart manipulation) type of countermeasure can be subdivided: (a) those which seek to directly manipulate recording devices/sensors of a specific channel(s) and (b) those which seek to manipulate chart recordings indirectly by manipulating physiology which in turn will affect the chart recordings.

(4) The type of countermeasure described by John is the first type discussed in #3 (directly manipulating recordings independent of physiology recorded).  John's discussed method depends upon applying pressure (finger/wrists in association with finger plate obtained recordings) thereby affecting electrolyte concentrations at the finger plates and in turn affecting the polygraph tracing for the electrodermal (sweating) channel.  

(5) As previously mentioned, I believe this latter type of countermeasure is dangerous/risky (subject to detection through counter-countermeasures).  I believe this to be the case for the following reasons: (a) It involves physical movement lateral to body midline.  This type of movement is much more readily detected by a movement bar (actually weight shift detection bar) than a physical countermeasure applied along the body's midline (e.g., tongue biting and anal sphincter contraction); (b) Because it is an artificial manipulation (not truly involving physiological manipulation) it produces an artificial response which can be different in morphology (shape) and timing from a true physiologically manipulated response; and (c) it is not accompanied by the expected parallel responses in the other monitored autonomic channels (more in next point)

NOTE: YOU DO NOT HAVE TO UNDERSTAND WHAT I AM ABOUT TO SAY IN POINT #6 TO TAKE FULL ADVANTAGE OF WHAT I WILL SUGGEST IN POINT #7, BUT FOR SAKE OF COMPLETENESS...

(6) The discussed countermeasures are inefficient (do not take advantage of the parallel processing and power of the autonomic nervous system).  The polygraph chart recordings (4 commonly recorded channels) are largely a function of the output of the autonomic nervous system (ANS)(breathing also involves a somatic voluntary component as well).  The complete picture of an ANS response recorded on a polygraph (whether response to examiner-posed question or to properly applied countermeasure) involves a reflex action.  This may involve sensory or pain afferent (input) tracts to the central nervous system (CNS) (or simply cognitive processing within the CNS) which then (stemming from either sensory or cognitive) is reflected by a global efferent motor response to the host of end organs innervated by the ANS including all four channels recorded in a polygraph exam.  The reason that this is so powerful is because of the divergent/convergent nature of the body's response.  Examining it from the CNS (brain/spinal cord) to the periphery, it is divergent, i.e., pyramidal with the brain sitting at the pinnacle of the pyramid and the various end-organ effector sites at the base of the platform.  Again, efferent motor output from the brain, brain stem, and spinal cord through the ANS will simultaneously affect the whole host of these end organs, including the ones whose physiology are measured by the polygraph.  This is where reflex physiology is so powerful, e.g., anal sphincter contraction produces pressure which is sensed by a particular receptor which relays information to the brain through a particular afferent nerve tract in the periphery synapsing and travelling through a specific column with the spinal chord, and ultimately reaching the brain.  Efferent output through the ANS beginning largely in various nuclei in a brain structure know as the hypothalamus ultimately affects all the end-organs innervated by this involuntary visceral efferent system.  Aside from the risks previously discussed relating to manipulating finger plates, the initial direct (there will actually be a secondary reflex response similar to what was just described but out of sync with the first response) response will be void of the multi end-organ response characteristic of an autonomic response.  Even if the artificial electrodermal response looks right it will certainly not contain properly timed responses within the cardio channel and probably not in the respiratory as well. As an aside, it should be mentioned that because the respiratory and electrodermal motor nuclei in the brainstem (medulla) are adjacent, there are strong interactions between these two channels that can not be taken advantage of and would be absent with finger plate manipulations.

(7) The preceding points ending with an admittedly somewhat arcane discussion of physiology leads us to the following conclusions:   (1) Electrodermal Activity (EDA, emotional sweating activity) is a critical component of the polygraph process and chart evaluation procedure,  (2) Manipulation of end-organ sensors (finger plates in the case of EDA) is inappropriate and risky, and (3) Manipulations of physiology (particular involving cognitive and mid-line physical countermeasures) such as described in "The Lie Behind the Lie Detector" and which produce general activation of the ANS and its effector organs will likely be the most efficient and least risky methods of applying countermeasures.  I refer you to that text for a discussion of when to apply these countermeasures.

Shropshire Lad

[Chris (Guest)]

Thank you for your replies George and Shropshire Lad.  George, I don't really feel that it was an oversight to not mention more thoroughly the subject of the GSR, because, as I have learned from your reply and Shropshire Lad's alike, the other countermeasures effectively manipulate the overall psysiological responses which are being monitored and recorded.  I feel that it may have been more of an oversight of my own not to realize this (I blazed through The Lie Behind The Lie Detector, quite honestly, whereas I should read it more carefully). Anyhow, Thanks again.  P.S. I have another question:  what exactly (or commonly) do polygraphers watch for in the examinee as far as body language and overall demeanor is concerned?  Thanks in advance for any responses............Chris

[George Maschke (Guest)]

Chris wrote:

P.S. I have another question:  what exactly (or commonly) do polygraphers watch for in the examinee as far as body language and overall demeanor is concerned?

See the DoDPI Interview and Interrogation handbook, recently added to the AntiPolygraph.org Reading Room.

George Maschke

[John D.]

Chris, George, and Shropshire Lad,

Please let me clarify my response regarding the GSR.  I do not advocate the counter measures of the GSR insofar as pressing against the plates or pressing your wrist of the hand attached to the plates against the arm rest of the polygraph chair.  It is very risky and simply not worth it as the countermeasures outlined in this book are more than sufficient to manipulate the test. I apologize if I inferred in anyway as an advocate of this method. I was simply passing on my knowledge of the GSR as taught by Backster.  Undoubtedly, Backster is teaching his examiners to watch out for this type of countermeasure.

[Chris (Guest)]

John D, Surely you leave me feeling that using the GSR countermeasures was unessary.  Thank you for the clarrification though.

[John D.]

Chris,

My personal opinion is the GSR countermeasure is unnecessary. The techniques in this book are sufficient. In my own experience, the anal sphincter was sufficient and the breathing was too complicated (for me). Good luck!