Blood preasure v. pulse rate

[nopolycop]

As I understand this discipline, if one lies their pulse rate increases and blood pressure rises.  Let's assume for a moment this is true.  My question, is this:  Does the increased pulse rate cause the blood pressure to rise, or are the two phenomenon independent of each other?  If they are, what causes the blood pressure to rise?

[Sergeant1107]

As I understand this discipline, if one lies their pulse rate increases and blood pressure rises.  Let's assume for a moment this is true.  My question, is this:  Does the increased pulse rate cause the blood pressure to rise, or are the two phenomenon independent of each other?  If they are, what causes the blood pressure to rise?

I think it would be more accurate to say that there have been people who, while their physiological reactions were being monitored, experienced increases in heart rate and blood pressure while while giving answers which were later proven (or already known) to be lies.

I do not believe that information can be extrapolated to mean that everyone who is polygraphed and reacts in a similar way is lying.  Polygraph examiners apparently feel comfortable making that assumption.

[1904]

Remember that p/g does not measure blood pressure per se, but the increase in blood volume.
But, you were going in the right direction anyway.

The greater the threat to the subject (like loss of liberty for SO's) the greater the pp response.
Unfortunately it is not only liars that experience that phenomenon, but certain truth-tellers also.

That is the fundamental problem with polygraph. Not that it does not catch liars, but that it incorrectly 'catches' truth-tellers as well. It also fails to catch a few baddies.

Yes it has a greater than chance efficacy, but what is 'CHANCE' ?
Chance is spitting against the wind. Maybe it'll hit you in the face. Maybe it wont.
Is chance 20 / 30 50 / 60 %.
There is no definitive scale for chance.
If 'chance' was 96% then the p/g is great.
If chance is 50% then the p/g, being significantly better than chance may not be so good.
How much is "significant" ? ....20 / 30 / 40 % ??

If a p/g examiner was falsely accused of raping and killing a woman, merely because eye
witnesses saw him asking her for directions, I wonder if the examiner would be willing to submit
to a p/g exam by lets say..... Ed Gelb ?

[nopolycop]

As I understand this discipline, if one lies their pulse rate increases and blood pressure rises.  Let's assume for a moment this is true.  My question, is this:  Does the increased pulse rate cause the blood pressure to rise, or are the two phenomenon independent of each other?  If they are, what causes the blood pressure to rise?

I think it would be more accurate to say that there have been people who, while their physiological reactions were being monitored, experienced increases in heart rate and blood pressure while while giving answers which were later proven (or already known) to be lies.

I do not believe that information can be extrapolated to mean that everyone who is polygraphed and reacts in a similar way is lying.  Polygraph examiners apparently feel comfortable making that assumption.

For the purposes of this question though, we are assuming that when one tells a lie, the pulse rate increases and the blood pressure increases.  Please understand there is a reason behind my question regarding any causal link between increased heart rate and increased blood pressure, (see below).

[raymond.nelson]

Sergeant1107:

I think it would be more accurate to say that there have been people who, while their physiological reactions were being monitored, experienced increases in heart rate and blood pressure while while giving answers which were later proven (or already known) to be lies.

Correct.

I do not believe that information can be extrapolated to mean that everyone who is polygraphed and reacts in a similar way is lying.  Polygraph examiners apparently feel comfortable making that assumption.

Not correct.

Mr. Sergeant1107,

Your syllogism and conclusion are in error here. Unless you have borrowed Mr. Maschke's magic mind-reading machine, I cannot see how you can allow yourself to speak for the feelings of polygraph examiners.

Mostly though, your argument is a reductionistic straw-man type of argument, and without substance. You should know very well by now that the polygraph employs more physiological data than simple blood pressure. Your form of argument is based on the false premise that a single index of any datastream is regarded as adequate and informative in isolation.

As I assume you be reasonably intelligent and somewhat knowledgeable about polygraph science already. I can only conclude that you are intentionally attempting to mislead people with this false information.

Please be more careful. Providing false and inaccurate information is a violation of the post policies.

Thank you.

r

[nopolycop]

Remember that p/g does not measure blood pressure per se, but the increase in blood volume.
But, you were going in the right direction anyway.

Okay guys, help me out here.  The APA web site states the following in their glossery of terms:

"Cardiograph: The sensor component in polygraph instruments that records blood pressure, blood volume, and heart rate. "

How does the "Cardiograph" accomplish this?

Also, If we can simply address my questions, I would greatly appreciate it.  There IS a reason to these specific issue questions, one which I am not at liberty to disclose at this time, but none-the-less, I can disclose that these questions or the answers I seek are NOT intended to be used to conceal ANY criminal activity.

When responding, please do so in terms a group of lay persons would understand.

[raymond.nelson]

nopoly4me:

Does the increased pulse rate cause the blood pressure to rise, or are the two phenomenon independent of each other?  If they are, what causes the blood pressure to rise?

Your question seems rather obvious.

Blood pressure is mediated by pulse rate, cardiovascular contractility, and vascular tension.

This is, of course, the bare-bones physiological explanation for the lay person.

More information about your actual concern might help elicit more useful information. Unless, perhaps you are baiting an argument.

r

[nopolycop]

nopoly4me:

Does the increased pulse rate cause the blood pressure to rise, or are the two phenomenon independent of each other?  If they are, what causes the blood pressure to rise?

Your question seems rather obvious.

Blood pressure is mediated by pulse rate, cardiovascular contractility, and vascular tension.

This is, of course, the bare-bones physiological explanation for the lay person.

More information about your actual concern might help elicit more useful information. Unless, perhaps you are baiting an argument.

r

Thank-you Mr. Nelson:

I needed to get the above question answered before asking the more specific one, which is follows.

If a person can artifically raise or lower his heart rate based on mental imagery only, can he defeat the cardiograph of a polygraph by simply controlling his heart rate?

[EJohnson]

a rerun post from policehopeful's post;

Your question brings to mind the potential for a person to endure open heart surgery without anesthetic---by virtue of yogi-like self control. Perhaps it is possible, but such power over the mind and corresponding body is extroadinary---a word that is used too frequently and has lost it's meaning. A target-guilty examinee would have to be deluded, and completely detached from the oft times very intense experience of the test. Such detachment is nick-named "probably on mind altering drugs" and will merit such remarks on the report. Like getting caught attempting----or even mere suspicion of intentional countermeasures, and such a label wraps the neck with a skunk's tail.

[nopolycop]

Mr. Johnson:

I appreciate your comments, but please understand this questioning has no causal link to policehopeful's obvious attempt to fool a polygrapher.

Can you answer me this hypothetical.  Suppose a subject pulse rate was 80 BPM on the control questions.  What increase in BPM would result in a "deception indicated" result?

(I hope I got the terminology correct).

Thank-you in advance for your thoughtful response.

[raymond.nelson]

nopoly4me:

"Cardiograph: The sensor component in polygraph instruments that records blood pressure, blood volume, and heart rate. "

How does the "Cardiograph" accomplish this?

Also, If we can simply address my questions, I would greatly appreciate it.  There IS a reason to these specific issue questions, one which I am not at liberty to disclose at this time, but none-the-less, I can disclose that these questions or the answers I seek are NOT intended to be used to conceal ANY criminal activity.

When responding, please do so in terms a group of lay persons would understand.

Through the use of a standard issue blood pressure cuff and sphygmomanometer (that's a pump-bulb and dial, to you and me).

r

[nopolycop]

nopoly4me:

"Cardiograph: The sensor component in polygraph instruments that records blood pressure, blood volume, and heart rate. "

How does the "Cardiograph" accomplish this?

Also, If we can simply address my questions, I would greatly appreciate it.  There IS a reason to these specific issue questions, one which I am not at liberty to disclose at this time, but none-the-less, I can disclose that these questions or the answers I seek are NOT intended to be used to conceal ANY criminal activity.

When responding, please do so in terms a group of lay persons would understand.

Through the use of a standard issue blood pressure cuff and sphygmomanometer (that's a pump-bulb and dial, to you and me).

r

Thank-you.  With that in mind, my experience with a blood pressure cuff and sphygmomanometer stems from being an EMT, and of course whenever going to the doc.  But, I never understood that procedure to measure the volume of blood, just the pressure for systolic and diastolic readings.  How is blood flow measured then?

Secondly, at what pressure is the cuff typtically inflated to?  Sometimes when an overly aggressive health care worker pumps that sucker up, it is really quite painful.  I cannot fathom sitting for an hour or two with that level of pressure on my arm.  

[raymond.nelson]

nope,

You'll have to try to refrain from engaging all the anti-drama at this site. Unless that is what your here for.

The cuff is not inflated for an hour at a time. It is not even inflated with enough pressure to occlude circulation. Nobody's arm has ever fallen off during a polygraph test.


r

[nopolycop]

How does it measure blood flow then?

[Barry_C]

Can you answer me this hypothetical.  Suppose a subject pulse rate was 80 BPM on the control questions.  What increase in BPM would result in a "deception indicated" result?

We don't score pulse rate alone, so your question doesn't make a whole lot of sense.  (There is a correlation between a HR of 100BPM or greater and deception to the relevant questions, but that's more trivia than anything.)  DACA is now looking at rate if, and only if, there is no phasic response in either channel being compared, but I can't say I've ever seen that one, and most of the research on rate changes (and it's not as simple as increasing or decreasing) use a computer to "see" such changes.

The bottom line in scoring any feature is simply asking which reaction is greater.  The bigger reaction gets the score.  That's oversimplified, I know, but it's easy.