The effects of a brief motivation manipulation on reward responsiveness: A multi-method study with implications for depression.

Individual differences in reward responsiveness can be reliably measured at the neurophysiological level using the reward positivity (RewP) event-related potential (ERP). Alterations in reward responsiveness impact physical and psychological health. In particular, prior research indicates that a reduced RewP prospectively predicts depressive symptoms. However, it remains unclear whether RewP can be modified through intervention or prevention. The present study examined the effects of a brief motivation manipulation on behavioral, neural, and self-report indicators of reward responsiveness in an unselected sample of young adults (N = 98). Participants completed a monetary incentive delay task twice while ERPs to monetary reward and loss feedback were recorded. Before the first round, all participants were read standard instructions. For the second round, participants were randomized to either a motivation manipulation, in which the experimenter prompted the participant to focus on the positive outcomes of winning, or to a neutral condition. Participants completed a self-report questionnaire assessing motivation to win/not lose money following both rounds. Reaction time for incentive trials decreased, while RewP to wins and self-reported motivation increased, from the first to the second round only in the motivation group. These results provide the first evidence that a brief motivation manipulation can enhance multiple indicators of reward responsiveness, including RewP. Longitudinal research is needed to test whether effects persist across time and generalize to clinically depressed samples and those at high risk for depression.