Effects of Successful Psychopathy on Reward-Based Decision-Making

Abstract

Previous research suggests that psychopathy may be correlated with decision-making impairments in reward processing. Explanations for such a relationship may be a result of enhanced reward sensitivity, or reduced sensitivity to losses. Striatal dopamine is critical for reward-based decision-making and may be a mechanism for differential sensitivity to gains versus losses in individuals high in psychopathy. This research addressed whether psychopathy is indeed associated with deficits in decision-making due to hypersensitivity to reward, or if, instead, such deficits result from hyposensitivity to losses, and whether dopamine influences this sensitivity. Participants completed the Iowa Gambling Task (IGT) and dopamine levels were measured indirectly using spontaneous eyeblink rate. Here we show that striatal dopamine moderates the effects psychopathy on decision-making. Individuals who had higher levels of dopamine, and also reported more antisocial behavior, chose more advantageous decks. Likewise, more manipulative individuals chose more advantageous decks than less manipulative individuals. However, more manipulative individuals with higher striatal dopamine levels chose less advantageous decks on the IGT. Striatal dopamine appears to function as a buffer among individuals who engage in antisocial behavior more often, resulting in better decision-making, but was associated with detrimental IGT performance among highly manipulative individuals. Our results highlight the importance of analysis at the facet level and examining physiological factors to better understand the mechanisms underlying decision-making of psychopathic individuals.