My specialty is the academic field of psychophysiology. When people think of psychology, they generally think of counseling, but in psychophysiology, we measure physiological responses such as brain waves and heart rate to capture the movements of people's hearts that are not expressed in words and actions and are closer to their true feelings.
Before coming to this university, I was involved in research on polygraph tests, or "lie detectors," at the National Research Institute of Police Science. When people lie, they control themselves so that their words and behavior do not show it, but unconscious mental movements are expressed as physiological reactions. Polygraph tests are a practical application of psychological techniques, in which subjects are presented with both items related to the case and similar items that are unrelated to the case, and the difference in physiological reactions to each is measured. Careful preparation is essential for the test, and after understanding the details of the case from the investigative materials, questions are created based on psychological knowledge to determine whether the person knows things that only the perpetrator would know. Due to the meticulous temperament of the Japanese, polygraph tests have evolved in a unique way in Japan. While the mainstream method overseas is to interrogate with more direct questions, in recent years I have had the opportunity to be contacted by overseas researchers and investigators who are interested in Japan's unique approach. In fact, there are even foreign researchers who have deepened their knowledge of polygraph tests in my laboratory and are aiming to popularize and use them in their own countries.
So far, we have been working on research into polygraph testing from two perspectives: "Why physiological reactions occur when you have something to hide" and "Improving the accuracy of judgments based on the results of physiological reactions." In the former research, we found that there is a two-stage process when a person tries to hide something. First, an unconscious and automatic reaction occurs about 0.2 seconds after the question is asked, and then the prefrontal cortex of the brain (the area involved in thinking, decision-making, reaction control, etc.) becomes active in an attempt to hide the reaction, causing changes in breathing. In the latter effort, we combined peripheral reactions such as heart rate, breathing, and sweat with central reactions such as electroencephalograms to improve the accuracy of judgments with a unique approach. Polygraph testing is a test that scientifically examines memory, and is also useful in investigating cases with little physical evidence. Since it can objectively show whether or not the subject knows the facts of the case, it can be said that this research field can contribute to the realization of a fair and just society.
I encountered polygraph testing as part of my police duties, and discovered how fascinating it was to be able to objectively grasp, even if only in part, the human mind. I have been researching this topic passionately for 17 years. During that time, I began to think that I wanted to explore the physiological aspects of the human mind more broadly, and so I moved to a university to pursue this field.
Measurement data of biological reactions
