The effects of pre-viewing of mock crime scene on detection of deception using P300.

日本野外测谎术的独特之处在于依靠有罪知识测试（GKT）来确定有罪。现场gkt的一个特点是，与实验室gkt相比，犯罪和测试之间的间隔要长得多（通常至少一个月，而不是几分钟）。随着时间的推移，这种记忆的消退表明，相对于实验室的准确性，现场的准确性降低了。本研究以事件相关电位（P300）为因变量，旨在测试在使用GKT之前刷新实验室模拟犯罪细节的记忆是否会提高GKT的准确性。这个模拟犯罪包括进入一个房间，从五个抽屉中的一个抽屉里偷一件东西（戒指）。GKT是在模拟犯罪发生一个月后进行的。就在GKT之前，由10名受试者组成的恢复记忆组（RM）观看了一段视频，视频中描绘了一个月前他们模拟犯罪的房间，而其余10名无记忆组（NRM）的对照组观看了一段同样长度的视频，视频中描绘了学院其他地方的场景。两组的GKT准确度都很高，关键项目图片比非关键项目图片得到更高的P300 (p< 0.001)， P300测量正确识别20名受试者中的17人有罪。然而，GKT准确度在两组之间没有差异。未来的研究将验证这样一个假设，即为了在实验室中提高GKT的准确性，人们不仅要在认知上刷新被试的记忆，还要激励他们更多地关注他们模拟犯罪的细节。

Japanese field polygraphy is unique in relying on the Guilty Knowledge Test (GKT) for determining guilt. A feature of field GKTs is that the interval between the commission of the crime and the testing is much longer (usually at least a month vs.a few minutes) than in laboratory GKTs. This fading of memory through time suggests that field accuracy is reduced relative to lab accuracy. The present study, with event-related potential(P300) as the dependent variable, was designed to test whether refreshing the memory of laboratory mock crime details just before the administration of the GKT would enhance GKT accuracy. The mock crime involved entering a room, and stealing an item (ring) from one of five desk drawers. The GKT was administered about a month after the mock crime. Just before the GKT, the refresh-memory group (RM) of 10 subjects viewed a video which depicted the room in which they had committed the mock crime about a month ago, while the remaining 10 subjects in the no-RM (NRM) control group viewed a video of the same length that depicted scenes from other parts of the college. GKT accuracy in both groups was high, with the critical-item pictures eliciting greater P300s than the non-critical pictures (p<.001), and the P300 measure identifying 17 of the 20 subjects correctly as guilty. However, GKT accuracy did not differ between the two groups. Future studies will test the hypothesis that to enhance GKT accuracy in the lab, one must not only cognitively refresh subjects' memories, but also motivate them to pay more attention the details of their mock crime.