4.3 Feedback ERPs
Unexpectedly, the feedback-related negativity (FRN) triggered by feedback following probes and irrelevants did not exhibit a significant difference in either the guilty or innocent groups. This outcome diverged from some prior studies (Sai et al., 2016; Zheng et al., 2022), yet it aligned with the findings of Sai et al. (2020). One plausible explanation for this discrepancy lies in the fact that FRN might be associated with rapid outcome evaluation in the fCIT. As a result, the level of participant engagement within the fCIT could potentially influence FRN outcomes. Instances of low engagement (e.g. participants not attending to feedback, lacking belief in or indifference toward the feedback) might account for the observed null effect of FRN. This matter merits further exploration and discussion in subsequent fCIT studies.
Furthermore, consistent with previous fCIT studies (Sai et al., 2016, 2020; Zheng et al., 2022), feedback following the probe elicited greater feedback P300 than that which followed irrelevants only in the guilty group, not in the innocent group. Previous studies suggest that participants’ motivational state modulates the feedback P300 (Hajcak, Holroyd, Moser, & Simons, 2005; Luo et al., 2011). Particularly, outcomes could elicit a larger feedback P300 when participants were motivated to deceive (Luo et al., 2011). In the fCIT, guilty participants are strongly motivated to conceal the probe (e.g. their own names), so that feedback following the probe elicited a larger feedback P300 than feedback following irrelevants. However, with respect to innocent participants, like other irrelevant items the probe (e.g. the guilty name) was meaningless to them; hence there was no significant difference in the feedback P300 between the probe and irrelevants.