Mediofrontal negativities to averted gains and losses in the slot-machine task - A further investigation

In a previous study we addressed the question whether a feedback-related negativity (FRN) can be elicited by outcomes that are not contingent on any preceding choice or action (Donkers, Nieuwenhuis, & Van Boxtel, 2005). Participants took part in a simple slot-machine task in which they experienced monetary gains and losses in the absence of responses. In addition, they performed a time estimation task often used to study the FRN, and a flanker task known to elicit the error-related negativity (Ne/ERN). Outcomes in the slot-machine task elicited a medioftontal negativity whose amplitude correlated with the amplitude of the FRN associated with negative feedback in the time estimation task. However, the mediofrontal negativity was observed both for (unfavorable) outcomes that averted a gain and for (favorable) outcomes that averted a loss of money, a finding that is inconsistent with previous FRN research. In the present study we examined the similarity between the medioftontal negativity observed in the slot-machine task and the frequency-sensitive N2. We manipulated the overall frequency of obtaining gains and losses in the slot-machine task and compared the negativities on averted gains and losses across the different trial probabilities. The results showed that larger feedback-related negativities were elicited by unexpected unfavorable outcomes than by expected unfavorable outcomes.