The Exploratory Study on Brain Fingerprinting in Application to Polygraph in Taiwan

• Main Author: 鄧皓允
• Other Authors: 施志鴻、林進燈
• Format: Others
• Language: zh-TW
• Published: 1060
• Online Access: http://ndltd.ncl.edu.tw/handle/39211365559694043299

碩士 === 中央警察大學 === 刑事警察研究所 === 105 === 　　The application of polygraph has been widely used in the criminal investigation of our country. In many cases where critical evidence is missing, polygraph is used as an investigation method to target or to rule out suspects and is also used as an evidence present in courts. However, it has been doubtful of polygraph being used as evidence in the recent years. The Control Yuan of Taiwan also issued a report in this year indicating numerous deficiencies and criticisms. Among all the techniques of polygraph, Control Question Test (“CQT”) is majorly used in the general practice of criminal investigation in our country. CQT is a kind of “Deception Test” which determines the dishonest reactions by the differences of physical reactions of the subjects, such as heartbeat, GSR (Galvanic skin response), breath, etc., under different designs of questions. But CQT is easily affected by emotion of the subjects and countermeasures, which attributes to distortion and reproducibility of the results. On the other hand, “Recognition Test” is a method less impacted by the environment factors and more reproducible in comparison to the Deception Test. In addition, multiple countries over the world have adapted Concealed Information Test (“CIT”), which induces physical reactions through cognitions, as the major technique of polygraph and have been pursuing to enforce its accuracy and reproducibility by involving more physical factors. Among which, Brainwave-P300 had been verified of its high correlation to human memories. An US scholar Dr. Lawrence A. Farwell combined Brainwave-P300 with CIT and developed a new polygraph technique based on cognition- Brain Fingerprinting. In the case studies conducted in both FBI and CIA, the accuracy of 100% was reached and no misjudgment was found. 　　This study is based on Brain Fingerprinting to analyze the issues occurred during the operation of technique and also to determine its reproducibility through designation and imitation of specific situations. Eighteen subjects were equally divided into two groups to imitate a robbery: the control group (9 subjects) is innocent which does not contact with the robbed jewelry; the experiment group (9 subjects) is guilty which contacts the robbed jewelry. The results show that the brainwave of the control group is conforming to the prediction, meaning the brain does not exist cognition of the robbed jewelry; and the brainwave of the experiment group is also conforming to the prediction, meaning the brain does exist cognition of the robbed jewelry. However, multiple peaks were observed in the result of the experiment group which do not conform to the prediction. This observation will need further research and discussion. In conclusion of the experiment, P300 can be used to determine if the brain has cognition to a specific object so as to differentiate the control group (innocent) and the experiment group (guilty). This technique should be able to determine if a suspect has cognition to the key evidence in a real crime scene if further improvement and application would be made in the future.