由於我們的認知資源是有限的，增加認知負荷可以增強說謊和說實話認知過程的差異，從而提高鑑識測謊測試的準確性。本研究旨在探討在P300的隱匿犯罪相關知識（CIT）測謊測試中，增加認知負荷是否會提高區分每位受測者準確性。在實驗1中，我們進行了模擬犯罪CIT事件相關電位（ERP）實驗，並以P300振幅作為區分有犯罪相關知識刺激和無犯罪相關知識敇激的指標。在實驗2中，我們在CIT測謊測試中增加了空間提示任務作業，透過實驗操弄受測者的注意力增加認知負荷，加大犯罪相關知識敇激和無犯罪相關知識刺激之間在CIT測謊測試的P300振幅差異，進一步提高區分的準確性。結果顯示，納入空間提示作業表現出顯著的三因子變異數分析交互作用（群組x空間提示任務作業x犯罪相關知識刺激，p < .05, ηP2 = .39），並提高了區分每位受測者的準確性。因此，加入認知負荷的空間提示任務作業P300 CIT測謊測試（實驗2）證明比典型的P300 CIT 測謊測試（實驗1）更有效。;Since our cognitive resources are limited, increasing cognitive load can augment the differences in the cognitive processes of deception or telling a truth and, in turn, increase the accuracy of detection of deception. This study aimed to explore whether increasing cognitive load enhances the accuracy in classifying the participants into the group with or without knowledge about a mock crime in a P300-based concealed information test (CIT). Two experiments were conducted in this study: In Experiment 1, we conducted a mock crime CIT event-related potential (ERP) experiment and computed the P300 amplitudes as an index for differentiating knowledgeable and unknowledgeable participants. In Experiment 2, spatial cueing was blended with the traditional P300-based CIT task to increase the cognitive load by manipulating participants’ attention and, in turn, maximize the P300 amplitude differences between probe and irrelevant conditions in a CIT to further improve the accuracy of the differentiation. Results indicated that incorporating spatial cueing exhibited a significant three-way interaction effect (group x cueing x stimulus, p < .05, ηP2 = .39) and improved the accuracy of differentiating the knowledgeable participants from the unknowledgeable ones. The CIT with spatial cueing (Experiment 2) was thus proved more effective than the typical P300-based CIT examination (Experiment 1).
