4.1 Conflict-monitoring N200
Although some studies have found a more negative N200 for the probe compared to the irrelevant stimuli, some studies have reported null or opposite results (Gamer and Berti, 2010, 2012, Ganis et al., 2016,also see a review Sai et al. 2023). One possible reason for this discrepancy maybe due to N200 overlapping with neighboring components such as P200 and P300. In our current study, we used PCA to separate the N200 from other components and found that the probe indeed elicited a more negative N200 than the irrelevants in guilty group. This may be because guilty participants need to conceal their knowledge about the probe stimuli, which required more control monitoring compared to truth-telling about irrelevant stimuli. However, caution is advised when utilizing the N200 as an indicator to detect concealed information, as highlighted by Ganis et al. (2016). Their research suggests that the N200 elicited by probes larger than irrelevant stimuli might be attributed to differences in the stimuli, potentially leading to the absence of the CIT effect under controlled conditions (Gamer and Berti, 2010, Ganis et al., 2016). It’s worth noting that our experiment differed from theirs, as our stimuli exclusively consisted of traditional Chinese names with two or three words, ensuring uniformity in the stimulus presentation. In contrast to their study, where N200 yielded null results, our findings demonstrated a significant CIT effect for N200. This discrepancy might be attributed to our utilization of PCA, which effectively isolated the genuine N200 response from other components, such as P200 and P300, (Daffner et al., 2015; Kayser et al., 1998). Additionally, it should be noted that the stimuli used in this study were autobiographical information, further studies should use the PCA method to examine whether the effect of N200 can also be found in mock-crime situations.