Abstract
The contemporary situation regarding polygraph tests in Japan, which has changed in the 21 century, was outlined. Physiological recording systems used in present-day field tests have been upgraded to digital polygraphs. Moreover, additional indices such as skin conductance level (SCL), heart rate (HR) and normalized pulse volume (NPV) have been introduced. Furthermore, the concealed information test (CIT) is always used to test an examinee's knowledge about a crime. We analyzed respiratory speed (RS), skin conductance response (SCR), SCL, HR and NPV in 113 CITs of 38 examinees in whom knowledge was confirmed in subsequent investigations. The results of these physiological responses corroborated prior laboratory studies. Moreover, the results indicated that the detection rates of the indices were highest for HR, followed by SCR, RS, NPV and SCL in that order.
