The use of polygraph tests and related evidentiary aspects in labour disputes name: daniel francisco calaca



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These two systems work against each other according to the Polygraph Institute of South Africa and the example that they use to explain it is as follows The emergency system becomes dominant only when there is some threat to an individual and he or she becomes apprehensive. For example, if you are walking down the street and a man suddenly approaches you and pulls out a knife, you will be alarmed. That message will register in the brain, and the brain in turn will send a message back to the autonomic nervous system to put the emergency system in control. When that happens, a series of physiological changes takes place that helps you cope with that situation. Your heart, for instance, contracts more quickly and strongly, which sends more blood throughout the body and provides it with nourishment in order to function more effectively. The Polygraph Institute of South Africa, records the responses on paper for permanent record keeping. As referred to in chapter 1 20
the polygraph machine firstly measures the rate and depth of respiration byway of pneumographs that are strapped around the chest and the abdomen, secondly the cardiovascular activity is measured by a blood pressure cuff and the last being the test for perspiration byway of electrodes that are attached to the fingertips. As referred to above, the first testis to measure the rate and depth of respiration. This is done by measuring the responses that are occurring from chest inhalations and exhalations, this is measured by two tubes around the upper and lower chest of a person. Inmost scenarios the responses are recorded from outside the body. This is done not to cause any harm to the person being tested. The second test involves the testing of the person’s cardiovascular responses by using a standard blood pressure cuff. The test records pulse rates, strengths of heartbeats and the increase and decrease of blood pressure as well as the functioning of heart valves. The galvanic or perspiration testis conducted by electrodes that are attached to the fingertips of the person. This test will measure the electrical conductivity of the skin.
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Chapter B, p.


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