Effect of a countermeasure which reduce physiological responeses in the detection of deception

测谎仪测试中的依赖性测量是自主活动，例如分别是皮肤电反应和心血管反应。近年来，事件相关电位（ERP）被认为是检测欺骗行为的重要指标，而反欺骗手段是被欺骗者有意采用的改变其生理反应的技术。许多实验已经表明，有可能，事实上很容易，训练有罪的受试者，让他们为测谎仪测试做好准备，这样他们就有很高的概率被发现是诚实的。本研究旨在探讨一种基于事件相关电位（ERPs）的心理对策对内疚知识测验（GKT）的影响。这项研究表明... 1.心理对抗抑制P3波幅。2.以被试姓名为相关刺激时，基于ERP的GKT在对策条件下的正确率为81%，在非对策条件下的正确率为94%。3.以模拟犯罪中被盗的珠宝为相关刺激，对策条件下的GKT正确率为50%，非对策条件下的GKT正确率为79%。结果表明，以ERP为基础的GKT对心理对策具有保护作用。

The dependent measures in a polygraph test are autonomic activities such as respectively, electrodermal, and cardiovascular responses. Recently, however, event-related potentials (ERPs) are expected as the index for detection of deception.Countermeasures are deliberate techniques that might be used by the suspects to alter their physiological reaction. A number of experiments have indicated that it is possible, indeed quite easy, to train guilty examinees and prepare them for a polygraph examination in such a way that they will be found truthful with a high probability. A possible approach for dealing with countermeasure manipulation is use of guilty knowledge test (GKT) that are based on ERPs instead of autonomic measures.In this research, we examined effects of a mental countermeasure on the GKT based on P300 (one of the ERPs). This research demonstrated that...1.A mental countermeasure inhibited the P3 amplitude. But there was a significant difference between amplitudes to relevant stimulus and to irrelevant stimulus because countermeasure inhibited the P3 amplitude not only to the relevant stimuli but also irrelevant stimulus.2.When subjects name were presented as relevant stimulus, the accuracy of GKT based on ERP in countermeasure condition was 81% and in non-countermeasure condition was 94%. There was no significant difference between accuracy of those GKTs.3.When jewels which subjects were stole in mock crime were presented as relevant stimulus, the accuracy rate of GKT based on ERP in countermeasure condition was 50% and in non-countermeasure condition was 79%. There was no significant difference between accuracy of those GKTs.It is concluded that GKT based on ERP is protected against a mental countermeasure.