Knowing Lies Detection Devices: How To Work, Function, And Accuracy In A Case

Illustration of lying (Toa Heftiba on Unsplash)

YOGYAKARTA The lie detector is one of the methods used by the National Police in uncovering a case. One example of the case that used this tool was the alleged premeditated murder of Brigadier J alias Nopriansyah Yoshua Hutabarat.

There are various names for lie detectors, namelylie detectors to polygraphs. Although different, the results obtained are both used for the investigation of a case. For more details, here is information about thelie detector.

The lie detector is a machine used to detect human lies called a polygraph.

Quoted by the American Psychological Association (APA) this polegraph tool is used to monitor significant changes in the body. Polygraphs will collect and analyze the human physiological response through sensors connected from machines to the human body.

The use of this tool has apparently been carried out since 1924, but the first finding occurred around 1902. Although it has been found for a long time, the polygraph continues to undergo adjustments, especially in its increasingly sophisticated use of technology.

The Criminal Investigation Unit of the National Police itself has a lie detector produced by Canada in 2019. The tool has been recognized by the American polygraphy association and is claimed to have an accuracy rate of up to 93% according to ISO (The International Organization for Standardization) or IEC 17025 standards.

In using the polygraph, Puslabfor uses three techniques, namely heart sensors, sweat glands, and respiratory sensors. All three have become the standard of American polygraphy associations.

The way this lie detector works is actually simple, namely monitoring changes that occur in a person's body when he provides information related to the case involving himself.

The tool is assumed to detect lies or, fears, emotional changes, and physiological changes that then have an impact on body changes.

The changes themselves are driven by an autonomous nervous system that plays a role in regulating the body's internal and other things beyond their control. This frequency cannot be consciously regulated by humans. That is, no matter how close the person lies, physiological changes such as respiratory frequency, blood pressure, and even sweat productivity will occur.

When this test is carried out, according to the How Stuff Works website, the subject will be asked to sit quietly in a polygraphic inspection chair. On his body has been connected to tubes and cables that are useful for monitoring physiological activity.

When the subject issued a statement that was not in accordance with what he believed to have happened, physiological changes occurred and were read by the polygraph. In addition, the test was also accompanied by forensic psychophysiologists.

In general, lying detectors have several functions, namely as follows.

However, there are still pros and cons related to this tool. Some experts reveal doubts about the results of this tool. Then, how big is the accuracy level?

Quoted from detikcom, researchers detected lies, Prof. Aldert Vrij explained that basically the accuracy of the polygraph has been a question since 1921.

"This tool does not measure lies, which should be the core of its function. The concept, lies will show an increase in the body's response when answering key questions, while people who answer honestly do not. But there is no strong theory to support this concept," said Vrij.

Sedangkan pelatih penguji poligrafi Prof. Don Grubin, menjelaskan sejumlah alasan tes poligraph bisa jadi tidak akurat, yakni perumusan pertanyaan yang buruk, pembawan salah membaca hasil, hingga sulitnya membawancar korban.

In addition, there is a possibility that the test results found the subject lying because his emotional condition during an interview was traumatic.

"Testing the victim is a very different thing because the nature of the question of the lie detector is to trigger an increase in the body's response," he said.

That's a glimpse of the lie detector. To get other interesting information, visit VOI.ID.