polygraphs one

Polygraphs, one



detect reaction expertise
apart clear (2) goosebumps
pocket court (2) admissible
rather hook up investigate
chest breathe trigger (2)
either indicate hold your breath
belly stimulate blood pressure
react response deceptive
fold confirm heart rate
spread field (2) homeostasis
fear spike (2) determine
scary scream catch/caught
goose suspect adrenaline rush
flat (2)






Detective Harms: Basically a polygraph test is a lie detector test. That’s what everybody knows them as. It basically just measures the reactions in your body to questions.

Journalist: And for the Bloomington Police Department, this is Detective Harms’ field of expertise.

Detective: We use it for several different reasons: one would be to clear somebody of a crime. If they’re a suspect, it’s a good way to clear them of it. Or it’s a good way to confirm that it’s the person we are looking for.

A lot of times it helps us with interviewing people, that type of thing.

Polygraphs aren’t admissible in court. So we can’t bring the results in court and say here; he failed the test or he passed the test, that type of thing.

It’s more of an investigative aid.

Journalist: Rather than just explaining how a polygraph works, Detective Harms showed me. And that meant first getting hooked up to the machine.

Detective: There are two indicators we put on; one is for the upper chest and one for the belly. Males are typically belly breathers; females are typically chest breathers. We measure them both, to cover both areas.

And we look for slowing of the breathing, stopping breathing. People typically if they tell a lie, they either hold their breath or their breathing slows down. So we look for that.

The cardio, your blood pressure. In that we look for spikes in your blood pressure, heart rate, those types of things are indicators that someone is being deceptive.

Galvanic skin response is electrical conductivity in the skin when it’s reacting to stimulus such as fear that type of thing.

“So what I did is ask you to write a number down one to seven. Write it down on a piece of paper. Fold it up. Put it in your pocket. I didn’t see what number you wrote down.”

Journalist: I was instructed to hold still, keep my feet flat on the floor and fingers spread apart.

Detective: Is the number you wrote down number “2”?
Journalist: No.
Detective: Is the number you wrote down number “4”?
Journalist: No.
Detective: Is the number you wrote down number “7”?
Journalist: No.

Journalist: Once the test was finished, Detective Harms examined my reactions to each of the seven numbers to determine which I had written down.

Detective: So your breathing slows there. I’m going to go with…number six. Are you that good? There you go.

Alright. When a person tells a lie, they relive that event. And it’s the fear to be caught in a lie that triggers the autonomic nervous system, that’s what it’s called.

It’s broken down into the sympathetic and parasympathetic. And what that is…there’s the phrase, “fight or flight phase” the adrenaline rush, it’s the sympathetic portion of the autonomic nervous system that kicks in to protect the body.

The parasympathetic then tries to bring the body back down to homeostasis, normal everyday life type of thing.

When I’m explaining the polygraph test to someone, a person coming in to take the polygraph test, I basically ask them, have you watched a scary movie before.

They typically say “yes” I was watching a scary movie, the scary part comes, they start to get goosebumps, the adrenaline rush.

The scary part comes, you jump, scream, whatever it is you do.

Then you go back down to normal.

That’s the autonomic nervous system in the body. I can’t control that with the polygraph. They can’t control that; it’s a natural reaction. And that’s basically what it measures.

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1. The polygraph and polygraph expert were at a scientific laboratory. Is this true or false?

2. According to the detective, why are polygraph tests used?

3. Are lie detector tests admissible in courts?

4. Did the detective only explain how the polygraph works to the journalist?

5. The polygraph indicates directly if a person is lying. Is this correct or wrong?

6. What does the lie detector measure?

7. The polygraph examiner asked the journalist personal questions. Yes or no?

8. Describe what “typically” happens when someone tells a lie.
A. Are there polygraphs in your city or country? Are polygraph tests admissible in courts?

B. Have you or your friends or colleagues taken a polygraph test? If yes, what was it like?

C. Would you like to take a polygraph test “for fun”?

D. Do you agree or disagree with the legality and morality of lie detector tests used by the police, companies and marriage counselors?

E. Who should be required to take polygraph tests? Who would you like to see undergo a lie detector test?

F. What will happen in the future?


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