This section has been designed to explain to the layman in relatively non-scientific terms how the polygraph works so they will get an easier understanding of it.

The polygraph instrument measures respiration, cardiovascular activity, and autonomic nervous system response. It has been determined by looking for deviations in stress levels at a mean average that an examiner can ascertain whether that deviation from the stress level average is indicative of deception or nondeception.

By attaching a device that measures the respiration, a device that wraps around the upper chest and lower chest around the lower stomach, a recording can be made of respiration without removing any clothing from the polygraph subject. This is done outside of the clothing in a very comfortable manner.

There are attachments to two fingers of either hand which measure skin conductivity, which is actually indicative of autonomic nervous system responses to the examiner’s questions. Again, there is no electricity or anything that is input into the subject. This is just measuring biofeedback from the polygraph subject. This is a non-intrusive attachment velcroed to two fingers of the test subject, as explained earlier.

Lastly, there is a cardio stigma graph that is attached to the subject’s bicep, which is nothing more than a blood pressure device that all subjects are monitored with at their doctor’s office during any physical check-up.

These three components are effectively all that are attached to the subject during the course of the polygraph examination, none of which are giving any input into a polygraph subject. All the data is biofeedback that is coming from the subject. This information is transferred by a polygraph instrument to a polygraph chart, whether it is a computer chart or an ink and paper chart that is coming out of the old analog polygraph instrument.

The benefit of the computerized polygraph is that the data stored in the polygraph can be printed out later, can be faxed or sent via Internet, or can be put on disk for other examiners to grade the same charts more easily. Plus, the computer itself can compare these charts and readings for a database that literally has tens of thousands of confirmed deceptive and truthful charts so that the exampled chart can be compared more objectively to truthful and deceptive individuals. This aids the examiner in a more objective decision as to whether the subject is being truthful or not.