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.