The anger incentive delay task: A novel method for studying anger in neuroscience research.

Unlike other basic emotions, anger is relatively difficult to produce in the lab, with the most reliable methods involving elaborate and time-consuming manipulations. These factors preclude the possibility of using them for studying short-lived changes in neural activity associated with the subjective experience of anger. In this paper, we present a novel task that allows for the trial-by-trial manipulation of anger and the examination of associated ERPs. Participants completed an incentive delay task, in which accurate responses were rewarded with monetary gains (or breaking even, in a neutral condition), and inaccurate responses were punished with monetary losses. After participants received accuracy feedback, they received information that indicated the amount of money they won or lost on that trial. On a majority of trials, this amount was consistent with the feedback stimuli, while on a minority of trials this amount was inconsistent. Results indicated that participants reported the most anger after trials where goal pursuit was frustrated by monetary losses despite accurate responses. P3b amplitudes were greater for inconsistent outcomes than consistent outcomes, regardless of whether these resulted in unexpected gains or frustrating losses. On frustrating trials, P3b amplitudes were positively correlated with self-reported anger. The same correlation was not observed for trials with stimuli that signaled surprise gains. Discussion focuses on the implications of these results.