Department of Psychology, Normal College, Hubei University, Wuhan, China.
Department of Psychology, Institute for Neuroscience, Northwestern University, Evanston, Illinois, USA.
Psychophysiology. 2022 Aug;59(8):e14033. doi: 10.1111/psyp.14033. Epub 2022 Mar 1.
Innocent subjects who are knowledgeable of crime-related information will often be misclassified as "guilty" in P300-based complex trial protocol (CTP). Therefore, it is necessary to develop a more rigorous CTP that can effectively discriminate the guilty from both the knowledgeable and the unknowledgeable innocents. Sometimes the guilty and the knowledgeable innocents possess the same item memories but different source memories. The present study designed a novel item-source complex trial protocol based on the differences of source memory among the three kinds of individuals. Either the crime-related probe (e.g., the stolen ring) or one of the crime-unrelated stimuli (e.g., watch, earring, bracelet, or bangle) (item memory) was presented in the first part of each trail, and either a stealing-source word (e.g., stole) or other-source word (e.g., fetched) (source memory) was presented in the second part of each trail. The results showed that: (1) the P300 evoked by item memory could effectively discriminated the guilty from the unknowledgeable innocent (AUC = 0.76) but failed to effectively discriminate the guilty from the knowledgeable innocent (AUC = 0.60); (2) the late positive component evoked by source memory could effectively discriminated the guilty from both the knowledgeable innocent (AUC = 0.94) and the unknowledgeable innocent (AUC = 0.84) in one test.
在基于 P300 的复杂审判协议（CTP）中，对犯罪相关信息有一定了解的无辜受试者往往会被错误地归类为“有罪”。因此，有必要开发一种更严格的 CTP，能够有效地将有罪者与知情和不知情的无辜者区分开来。有时，有罪者和知情的无辜者拥有相同的项目记忆，但来源记忆不同。本研究基于三种个体之间来源记忆的差异，设计了一种新的项目-来源复杂审判协议。在每个试验的第一部分，呈现与犯罪相关的探针（例如，被盗戒指）或与犯罪无关的刺激之一（例如，手表、耳环、手镯或手链）（项目记忆），在每个试验的第二部分呈现盗窃来源词（例如，偷）或其他来源词（例如，取）（来源记忆）。结果表明：（1）项目记忆诱发的 P300 可以有效地将有罪者与不知情的无辜者区分开来（AUC=0.76），但无法有效地将有罪者与知情的无辜者区分开来（AUC=0.60）；（2）来源记忆诱发的晚期正成分可以在一次测试中有效地将有罪者与知情的无辜者（AUC=0.94）和不知情的无辜者（AUC=0.84）区分开来。
