Author: Polygraph Examiner Maryna Surkis,

a graduate of the VAP Polygraph Examiner Courses in the Fall of 2024.

Japan is a land of precision, observation, and discipline. Everything the Japanese touch undergoes multi-level scrutiny, is polished to perfection, and only then is implemented into practice. It is no coincidence that this nation, which blends high technology with a philosophy of attentive contemplation, became one of the first in the world where polygraph research acquired systemic national importance. While other countries debated whether the polygraph could be trusted, Japan asked a different question: how to make it as accurate and scientifically sound as possible.

The history of polygraphy in Japan is not a tale of sensational confessions but a consistent path of scientific evolution. Starting in the 1950s and 60s, local forensic scientists—notably Naoya Osugi, Issei Matsuda, Tatsuya Ogawa, and others—focused not on “the lie” itself, but on how memory preserves traces of an event. They focused on a fundamental psychophysiological mechanism: the orienting reflex.
Scientists realized that when the brain recognizes significant information (such as a weapon used in a crime), the body reacts automatically, regardless of the person’s desire to hide it. This research laid the foundation for the Guilty Knowledge Test (GKT) — a tool that analyzes physiological reactions to familiar images and facts rather than mere words.

The decision to adopt the GKT was not accidental. Japanese specialists sought a method that reduces the risk of false accusations and minimizes expert subjectivity. The Control Question Technique (CQT), popular in the U.S., involves a direct confrontation between “lies” and “truth” and depends heavily on how the respondent perceives comparative questions. In contrast, the GKT works more subtly: it does not accuse; it observes whether the person’s memory contains specific details that only someone involved in the crime could know. While CQT often relies on emotional tension and the fear of detection, the GKT approach relies on cognitive processes of recognition and attention.

Over decades, Japanese researchers (Osugi, 2010, 2013; Matsuda, 2018, 2019; Ogawa, 2023) developed an exceptionally precise model where every detail—from the interval between stimuli to the number of repetitions—is empirically justified. By the 1970s, Japanese polygraphers had completely moved away from CQT, making the GKT the official national standard. Researchers concluded that CQT was too dependent on the polygrapher’s interpretation and the respondent’s emotional state. Their legal system required a clear, controlled model: мeasurable physiological reactions instead of psychological assumptions; quantitative interpretation of results; statistical verification and a minimal risk of false positives.

Since then, the polygraph in Japan has become a scientific memory test. Accuracy rates reach 86–94%, while false-positive reactions are as low as 4%. This is the lowest error rate among all known polygraph methods.

Today, the GKT operates as a standardized state tool. Approximately 100 polygraphers conduct about 5,000 examinations annually within police forensic units. In 1968, the Supreme Court of Japan recognized the admissibility of these findings as evidence, provided the examination is conducted according to strict protocols.

The Japanese experience shows how national culture shapes methodology. For Ukraine, this is particularly valuable as we are currently forming our own school based on these principles: professional standards, systemic training, and an ethical approach. Our path is a conscious reimagining of these best practices through the lens of our own experience.

The Japanese and Ukrainian approaches to the GKT are two related branches of the same scientific tree. They develop in different cultures but with the same goal: to make polygraphy more accurate, honest, and humane. We look forward to future cooperation between our specialists to combine the precision of the East with the humanism of the Ukrainian school. In this quest, we follow the ancient wisdom: “Reason triumphs over falsehood.”

References:
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Matsuda, I. (2019). The current status of the polygraph examination in Japan. Forensic Science International: Synergy, 1, 261–266. https://doi.org/10.1016/j.fsisyn.2019.09.004
Matsuda, I., Nittono, H., & Allen, J. J. B. (2012). The current and future status of the Concealed Information Test for field use. Frontiers in Psychology, 3, Article 532. https://doi.org/10.3389/fpsyg.2012.00532
Matsuda, I., Nittono, H., & Ogawa, T. (2013). The orienting response as a tool for memory detection. Japanese Psychological Research, 55(2), 158–168.
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https://www.jstage.jst.go.jp/article/jjcp/41/1/41_29/_pdf
Ogawa, T., & Matsuda, I. (2023). Advancements in physiological data analysis for the Guilty Knowledge Test. Journal of Forensic Sciences.
Osugi, A. (2011). Daily application of the GKT in Japan. In B. Verschuere, G. Ben-Shakhar, & E. Meijer (Eds.), Memory detection: Theory and application of the Concealed Information Test (pp. 253–275). Cambridge University Press.
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Verschuere, B., Ben-Shakhar, G., & Meijer, E. (2012).
Memory detection: Theory and application of the Concealed Information Test. Frontiers in Psychology, 3, Article 532.
https://www.frontiersin.org/articles/10.3389/fpsyg.2012.00532/full