Reward anticipation and punishment anticipation are instantiated in the brain via opponent mechanisms.

fMRI investigations have examined the extent to which reward and punishment motivation are associated with common or opponent neural systems, but such investigations have been limited by confounding variables and methodological constraints. The present study aimed to address limitations of earlier approaches and more comprehensively evaluate the extent to which neural activation associated with reward and punishment motivation reflects opponent or shared systems. Participants completed a modified monetary incentive delay task, which involved the presentation of a cue followed by a target to which participants were required to make a speeded button press. Using a factorial design, cues indicated whether monetary reward and/or loss (i.e., cues signaled probability of reward, punishment, both, or neither) could be expected depending upon response speed. Neural analyses evaluated evidence of (a) directionally opposing effects by testing for regions of differential activation for reward and punishment anticipation, (b) mutual inhibition by testing for interactive effects of reward and punishment anticipation within a factorial design, and (c) opposing effects on shared outputs via a psychophysiological interaction analysis. Evidence supporting all three criteria for opponent systems was obtained. Collectively, present findings support conceptualizing reward and punishment motivation as opponent forces influencing brain and behavior and indicate that shared activation does not suggest the operation of a common neural mechanism instantiating reward and punishment motivation.